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LI NI U
Tun th php lut v bo v mi trng, hot ng bo v mi trng ni chung v nh gi tc ng mi trng ni ring c trin khai rng khp trn ton quc. T nm 1994 n nay, hng nghn cc d n pht trin tin hnh nh gi tc ng mi trng (TM), bo co TM ca cc d n ny c thm nh v ph duyt bi cc B Trung ng v cc a phng cp tnh.
Thi gian qua, vi s tr gip ti chnh t Hp phn Kim sot nhim cc vng ng dn ngho thuc Chng trnh hp tc Vit Nam an Mch v mi trng giai on 2005-2010, Cc Thm nh v nh gi tc ng mi trng, Tng cc Mi trng, B Ti nguyn v Mi trng (trc y l V Thm nh v nh gi tc ng mi trng trc thuc B Ti nguyn v Mi trng) phi hp cng cc chuyn gia xy dng v ban hnh hng dn k thut lp bo co TM cho mt s loi hnh d n pht trin:
- H thng h tng k thut khu/cm cng nghip; - Bi chn lp cht thi rn sinh hot; - Trm x l nc thi th; - Nh my sn xut xi mng; - Nh my nhit in; - Nh my sn xut thp; - Nh my sn xut giy v bt giy Tuy nhin, theo Ph lc ban hnh km theo s 21/2008/N-CP ngy 28 thng 02 nm
2008 ca Chnh ph v sa i, b sung mt s iu ca Ngh nh s 80/2006/N-CP ngy 09 thng 8 nm 2006 ca Chnh ph v vic quy nh chi tit v hng dn thi hnh mt s iu ca Lut Bo v mi trng, s lng cc loi hnh d n thuc i tng phi lp bo co TM l rt ln, khong 162 loi.
S tay TM, c bin dch t cc ngun ti liu quc t v chnh l cho ph hp vi iu kin ca Vit Nam, gii thiu v nh gi tc ng mi trng cho cc d n pht trin theo cc nhm ngnh, lnh vc. S tay TM, bao gm 02 (hai) tp, cung cp cho cc nh qun l, cc chuyn gia, cc nh khoa hc hot ng trong lnh vc bo v mi trng cch nhn bit cc tc ng mi trng chnh; cc gii php, bin php gim thiu cc tc ng tiu cc ca cc nhm loi hnh d n km theo danh mc cc ti liu tham kho.
Cc Thm nh v nh gi tc ng mi trng xin c gii thiu S tay TM cho nhiu i tng khc nhau s dng trong qu trnh nh gi tc ng mi trng ca cc hot ng pht trin. Trong qu trnh p dng vo thc t, nu c kh khn, vng mt xin kp thi phn nh v Cc Thm nh v nh gi tc ng mi trng theo a ch:
Cc Thm nh v nh gi tc ng mi trng 83 Nguyn Ch Thanh, H Ni in thoi: 844-37734246
Fax: 844-37734916
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Tp II: NNG NGHIP, KHAI THC M/NNG LNG,
THNG MI/CNG NGHIP
Hng dn xy dng nghin cu ton din v cc kha cnh mi trng ca d n
MC LC
LI NI U ................................................................................................................................. i
I. NNG NGHIP ........................................................................................................................ 18
1. Canh tc nng nghip ................................................................................................................ 18
1.1. Phm vi ............................................................................................................................... 18
1.2. Tc ng mi trng v cc phng php bo v ............................................................. 18
1.2.1. Cc tc ng mi trng ............................................................................................. 19
1.2.1.1. t ............................................................................................................................ 19
1.2.1.2. Nc. ........................................................................................................................ 20
1.2.1.3. Khng kh ................................................................................................................. 20
1.2.1.4. Sinh quyn ................................................................................................................ 20
1.2.2. Phng php bo v .................................................................................................... 21
1.2.2.1. iu kin chung ....................................................................................................... 21
1.2.2.2. Sinh thi nng tri .................................................................................................... 22
1.3. Nhng lu trong phn tch v nh gi ca cc tc ng mi trng ............................ 24
1.4. S tng tc vi cc khu vc khc .................................................................................... 26
1.5. Tm lc nh gi mi trng lin quan. .......................................................................... 26
1.6. Ti liu tham kho .............................................................................................................. 27
2. Bo v thc vt .......................................................................................................................... 31
2.1. Phm vi ............................................................................................................................... 31
2.2. Cc tc ng mi trng v bin php bo v ................................................................... 33
2.2.1. Tng quan v bo v thc vt ..................................................................................... 33
2.2.2. Cc phng php bo v thc vt c trng ............................................................... 34
2.2.2.1. Cc phng php vt l ............................................................................................ 34
2.2.2.2. Cc phng php ho hc ........................................................................................ 35
2.2.2.3. Cc phng php cng ngh sinh hc ...................................................................... 38
2.2.2.4. Cc bin php sinh hc ............................................................................................. 39
2.2.2.5. Cc phng php tng hp ...................................................................................... 39
2.3. Cc lu trong phn tch v nh gi tc ng mi trng .............................................. 40
2.4. S tng tc vi cc khu vc/lnh vc khc ...................................................................... 40
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2.5. Tm lc nh gi tc ng mi trng lin quan ............................................................ 41
2.6. Ti liu tham kho .............................................................................................................. 41
3. Lm nghip ................................................................................................................................ 46
3.1. Phm vi ............................................................................................................................... 46
3.1.1. Tng quan .................................................................................................................... 46
3.1.2. Cc lnh vc ................................................................................................................ 46
3.1.2.1. Qui hoch/sn xut sinh hc ..................................................................................... 46
3.1.2.2. Xc lp loi cy trng ............................................................................................... 47
3.1.2.3. S dng cy ci ........................................................................................................ 48
3.1.2.4. Cc k thut thu hoch ............................................................................................. 50
3.2. Cc tc ng mi trng v bin php bo v ................................................................... 53
3.2.1. Cc tc ng c th ca tng lnh vc n mi trng ............................................. 53
3.2.2. Cc chin lc bo v c th theo lnh vc ............................................................... 53
3.3. Cc lu trong phn tch v nh gi tc ng mi trng .............................................. 54
3.4. S tng tc vi cc khu vc/lnh vc khc ...................................................................... 56
3.4.1. Cc b sung ................................................................................................................. 56
3.4.2. Mi trng x hi ........................................................................................................ 57
3.5. Tm lc nh gi tc ng mi trng lin quan ............................................................ 57
3.6. Ti liu tham kho .............................................................................................................. 57
Ph lc: Gii thch mt s thut ng ......................................................................................... 61
4. Chn nui .................................................................................................................................. 63
4.1. Phm vi ............................................................................................................................... 63
4.2. Cc tc ng mi trng v bin php bo v ................................................................... 63
4.2.1. Cc dng qun l chn nui ........................................................................................ 63
4.2.1.1. Ch s dng ng c ................................................................................................. 63
4.2.1.2. S dng ng c v c b sung thm thc n .......................................................... 65
4.2.1.3. Sn xut c kh ........................................................................................................ 65
4.2.1.4. Chung, tri .............................................................................................................. 66
4.2.2. Cc h thng chn nui ............................................................................................... 66
4.2.2.1. Tri nui sc vt (Ranches- M, Canada) ............................................................. 66
4.2.2.2. H thng ng c ..................................................................................................... 67
4.2.2.3. Chn nui qui m nh ........................................................................................... 69
4.2.4. Cc trang tri ln vi qu trnh chn nui thm canh (chn nui thng mi) .......... 71
4.3. Cc lu trong phn tch v nh gi tc ng mi trng .............................................. 72
4.4. S tng tc vi cc khu vc/lnh vc khc ...................................................................... 72
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4.5. Tm lc nh gi tc ng mi trng lin quan ............................................................ 73
4.6. Ti liu tham kho .................................................................................................................. 73
5. Dch v th y ............................................................................................................................. 75
5.1. Phm vi ............................................................................................................................... 75
5.2. Cc tc ng mi trng v bin php bo v ................................................................... 75
5.2.1. Kim sot dch bnh .................................................................................................... 76
5.2.1.1. Khm v cha bnh .................................................................................................. 76
5.2.1.2. Phng bnh (prophylaxis) ........................................................................................ 76
5.2.1.3. Kim sot sinh vt trung gian (Vector control) ........................................................ 77
5.2.1.4. Kim sot dch bnh ................................................................................................. 79
5.2.1.5. Kim sot cc bnh c th ly lan sang ngi ......................................................... 79
5.2.2. Cc hot ng ti phng th nghim ............................................................................ 79
5.2.2.1. Chun on ti phng th nghim ............................................................................ 79
5.2.2.2. Sn xut vaccine ....................................................................................................... 80
5.2.2.3. Phn tch cht thi .................................................................................................... 80
5.2.3. Th tinh nhn to v cy phi ..................................................................................... 80
5.2.4. Kim tra thc phm ..................................................................................................... 80
5.2.4.1. Kim tra tht ............................................................................................................. 80
5.2.4.2. V sinh thc phm .................................................................................................... 80
5.3. Cc lu trong phn tch v nh gi tc ng mi trng .............................................. 81
5.4. S tng tc vi cc khu vc/lnh vc khc ...................................................................... 81
5.6. Ti liu tham kho .............................................................................................................. 82
6. nh bt v nui trng thu sn ................................................................................................ 83
6.1. Phm vi ............................................................................................................................... 83
6.2. Cc tc ng mi trng v bin php bo v ................................................................... 84
6.2.1. Cc tri nui c th cng qui m nh .......................................................................... 84
6.2.2. Nui trng thu sn qui m nh .................................................................................. 85
6.2.3. S dng cc h nhn to nui c v nui trng thu sn ....................................... 86
6.2.4. Ngh c trong khu vc 200 dm c quyn kinh t .................................................... 87
6.2.5. S dng rng ngp mn nui c v nui trng thu sn ........................................ 88
6.3. Cc lu trong phn tch v nh gi tc ng mi trng .............................................. 88
6.4. S tng tc vi cc khu vc/lnh vc khc ...................................................................... 89
6.5. Tm lc nh gi tc ng mi trng lin quan ............................................................ 90
6.6. Ti liu tham kho .............................................................................................................. 91
7. Cng ngh/k thut nng nghip .............................................................................................. 93
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7.1. Phm vi ............................................................................................................................... 93
7.2. Cc tc ng mi trng v bin php bo v ................................................................... 93
7.2.1. Con ngi, h sinh thi v k thut nng nghip ........................................................ 93
7.2.1.1. Con ngi v k thut nng nghip ......................................................................... 93
7.2.1.2. H sinh thi v k thut nng nghip ...................................................................... 94
7.2.2. Tng quan v k thut nng nghip ............................................................................ 94
7.2.2.1. Cc ngun nng lng, h thng ng lc, nhin liu v cht bi trn ................... 94
7.2.2.2. Sn xut cc k thut ph tr ................................................................................... 95
7.2.3. Cc c th ca sn xut cy trng ............................................................................. 95
7.2.3.1. Cy cy ..................................................................................................................... 95
7.2.3.2. Gieo ht/trng cy,chm sc v bn phn ................................................................ 96
7.2.3.3. Thu hoch, p la, ch bin, bo qun v lu tr ................................................... 97
7.2.3.4. Cung cp v phn phi nc .................................................................................... 97
7.2.4. Cc c trng ca ngnh chn nui ............................................................................ 98
7.3. Cc lu trong phn tch v nh gi tc ng mi trng .............................................. 98
7.4. S tng tc vi cc khu vc/lnh vc khc ...................................................................... 99
7.5. Tm lc nh gi tc ng mi trng lin quan ............................................................ 99
7.6. Ti liu tham kho .............................................................................................................. 99
8. Thu li ................................................................................................................................... 101
8.1. Phm vi ............................................................................................................................. 101
8.2. Cc tc ng mi trng v bin php bo v ................................................................. 101
8.2.1. Tc ng n cc thnh phn ca mi trng t nhin ............................................ 102
8.2.1.1. Cung cp, vn chuyn v phn phi nc .............................................................. 102
8.2.1.2. S dng v tiu thot nc ..................................................................................... 103
8.2.2. Cc tc ng kinh t-x hi gy bi qu trnh cp, vn chuyn, phn phi, s dng v tiu thot nc ..................................................................................................................... 104
8.2.2.1. Cc yu cu, nhn lc, thu nhp v phn phi ....................................................... 104
8.2.2.2. Sc kho ................................................................................................................. 105
8.2.2.3. Sinh k, nh v gii tr ......................................................................................... 105
8.2.2.4. Tp hun v cc quan h x hi ............................................................................ 106
8.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 106
8.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 107
8.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 107
8.6. Ti liu tham kho ............................................................................................................ 108
II. M V NNG LNG ....................................................................................................... 111
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1. Thm d, kho st v khai thc cc ngun ti nguyn thin nhin ......................................... 111
1.1. Phm vi ............................................................................................................................. 111
1.2. Cc tc ng mi trng v bin php bo v ................................................................. 112
1.2.1. Tip cn khu vc lm vic ........................................................................................ 112
1.2.1.1. Cc tuyn ng tip cn ....................................................................................... 112
1.2.1.2. Cc tuyn dng cp ................................................................................................ 112
1.2.2. Lp bn a hnh v a cht ................................................................................. 113
1.2.3. Tri v cc h thng h tr ........................................................................................ 113
1.2.4. a vt l ................................................................................................................... 113
1.2.4.1. K thut hng khng .............................................................................................. 113
1.2.4.2. Kho st a chn ................................................................................................... 113
1.2.4.3. Kho st a vt l khng dng a chn ............................................................... 113
1.2.4.4. Bn ph ging khoan .............................................................................................. 113
1.2.5. Kho st a cht thu vn ........................................................................................ 114
1.2.5.1. Bm th nghim di hn ......................................................................................... 114
1.2.5.2. Th nghim phun .................................................................................................... 114
1.2.5.3. Th nghim nh du .............................................................................................. 114
1.2.6. Cng tc thm d ....................................................................................................... 114
1.2.6.1. Cc h th nghim ................................................................................................. 114
1.2.6.2. Hm, ng l ........................................................................................................ 114
1.2.6.3. Khoan ..................................................................................................................... 115
1.2.6.4. Cht thi rn/qu trnh b .................................................................................. 115
1.2.7. Thu mu ..................................................................................................................... 116
1.2.7.1. Ly mu b mt ...................................................................................................... 116
1.2.7.2. Ly mu hi dng hc .......................................................................................... 116
1.2.8. Th nghim/phng th nghim ................................................................................... 116
1.2.8.1. Phn tch phng th nghim .................................................................................... 116
1.2.8.2. Th nghim tuyn, lm giu qung ......................................................................... 117
1.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 117
1.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 117
1.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 118
1.6. Ti liu tham kho ............................................................................................................ 118
2. Khai thc m l thin .......................................................................................................... 120
2.1. Phm vi ............................................................................................................................. 120
2.2. Cc tc ng mi trng v bin php bo v ................................................................. 121
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2.2.1. Cc h qu mi trng tim tng ca qu trnh khai thc l thin ............................ 121
2.2.1.1. Khai thc kh ......................................................................................................... 122
2.2.1.2. Khai thc t .......................................................................................................... 125
3. Khai thc ngm ........................................................................................................................ 127
3.1. Phm vi ............................................................................................................................. 127
3.2. Cc tc ng mi trng v bin php bo v ................................................................. 127
3.2.1. Tc ng mi trng n tr lng v cc vng nguyn liu ln cn ...................... 128
3.2.1.1. Khai thc cc ngun ti nguyn ............................................................................. 128
3.2.1.2 S ph v cc kt cu .............................................................................................. 128
3.2.1.3. S ph v/chia r dng chy ca nc ngm ......................................................... 128
3.2.1.4. Thay i cht lng nc ngm ............................................................................. 128
3.2.2. Cc tc ng mi trng ca khai thc ngm ........................................................... 128
3.2.2.1. Khng kh/kh hu .................................................................................................. 128
3.2.2.2. Ting n .................................................................................................................. 129
3.2.2.3. Bi .......................................................................................................................... 130
3.2.2.4. Nc m ................................................................................................................. 130
3.2.3. Cc tc ng pha trn b mt ................................................................................... 130
3.2.3.1. Khng kh/kh hu .................................................................................................. 130
3.2.3.2. Nc ....................................................................................................................... 131
3.2.3.3. St ln .................................................................................................................... 131
3.2.3.4. X thi cht thi, nhu cu s dng t, cnh quan ................................................. 131
3.2.4. Cc h qu khc ca qu trnh khai thc ngm ......................................................... 132
3.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 132
3.3.1. Khng kh/kh hu ..................................................................................................... 132
3.3.2. Ting n ..................................................................................................................... 133
3.3.3. Bi ............................................................................................................................. 133
3.3.4. Nc .......................................................................................................................... 133
3.3.5. t ............................................................................................................................. 134
3.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 134
3.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 135
3.6. Ti liu tham kho ............................................................................................................ 135
4. X l v ch bin khong sn ................................................................................................. 139
4.1. Phm vi ............................................................................................................................. 139
4.2. Cc tc ng mi trng v bin php bo v ................................................................. 139
4.2.1. X l .......................................................................................................................... 139
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4.2.2. Tn vn, sng, nghin v phn loi ........................................................................... 140
4.2.3. Tch, tuyn ni .......................................................................................................... 140
4.2.4. Nung .......................................................................................................................... 143
4.2.5 X l, bo qun cc cht lm giu, ti trng trt................................................... 143
4.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 144
4.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 145
4.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 146
4.6. Ti liu tham kho ............................................................................................................ 146
5. Du m v kh thin nhin Khai thc, sn xut, x l, lu tr ............................................ 149
5.1. Phm vi ............................................................................................................................. 149
5.2. Cc tc ng mi trng v bin php bo v ................................................................. 149
5.2.1. Khai thc ................................................................................................................... 149
5.2.1.1. Mi trng t nhin v sinh thi ............................................................................ 149
5.2.1.2. Mi trng x hi ................................................................................................... 151
5.2.1.3. Sc kho v an ton ............................................................................................... 151
5.2.2. Sn xut ..................................................................................................................... 151
5.2.2.1 Mi trng t nhin v sinh thi ............................................................................. 152
5.2.2.2. Kinh t, x hi ........................................................................................................ 152
5.2.2.3. Sc kho v an ton ............................................................................................... 152
5.2.3. X l v lu tr ......................................................................................................... 153
5.2.3.1. Mi trng t nhin ............................................................................................... 153
5.2.3.2. Sc kho v an ton ............................................................................................... 153
5.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 153
5.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 153
5.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 154
5.6. Ti liu tham kho ............................................................................................................ 154
6. Sn xut than cc (coke), kh ho than, sn xut v phn phi kh ..................................... 156
6.1. Phm vi ............................................................................................................................. 156
6.2. Cc tc ng mi trng v bin php bo v ................................................................. 158
6.2.1 Cc tc ng mi trng ............................................................................................ 158
6.2.2. Cc bin php bo v ................................................................................................ 159
6.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 162
6.3.1. Tng quan .................................................................................................................. 162
6.3.2. Tm lc cc gi tr gii hn v tiu chun .............................................................. 162
6.3.3. nh gi tc ng mi trng ................................................................................... 166
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6.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 167
6.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 167
6.6. Ti liu tham kho ............................................................................................................ 167
7. Cc trm nhit in ................................................................................................................. 169
7.1. Phm vi ............................................................................................................................. 169
7.2. Cc tc ng mi trng v bin php bo v ................................................................. 169
7.2.1. Khng kh .................................................................................................................. 172
7.2.1.1. Kim sot bi ........................................................................................................ 173
7.2.1.2. Kh lu hunh...................................................................................................... 173
7.2.1.3. Kh NOx ............................................................................................................... 175
7.2.1.4. Hiu ng nh knh ................................................................................................ 175
7.2.1.5.Cc ngun pht thi dng din ............................................................................ 175
7.2.2.Nc ........................................................................................................................... 176
7.2.3.t v nc ngm ...................................................................................................... 177
7.2.4.Sc kho cng ng ................................................................................................... 179
7.2.5. Cnh quan .................................................................................................................. 179
7.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 180
7.3.1. Cc gii hn pht thi ................................................................................................ 180
7.3.2. Cc gii hn pht thi vo khng kh ........................................................................ 181
7.3.3. Quan trc/gim st mc nhim .......................................................................... 182
7.3.4. Gii hn x thi nc thi ......................................................................................... 183
7.3.5. Ting n ..................................................................................................................... 184
7.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 184
7.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 185
7.6. Ti liu tham kho ............................................................................................................ 186
7.7. Ph lc .............................................................................................................................. 190
8. Truyn ti v phn phi in ................................................................................................... 195
8.1. Phm vi ............................................................................................................................. 195
8.2. Cc tc ng mi trng v bin php bo v ................................................................. 195
8.2.1. Cc h qu i vi mi trng .................................................................................. 195
8.2.2. Sc kho cng ng, an ton lao ng v ngn nga tai nn ................................... 197
8.2.3. Lm suy thoi cnh quan ........................................................................................... 198
8.2.4. Cc tc ng kinh t-x hi v vn ho-x hi ......................................................... 199
8.3. Cc lu trong phn tch v nh gi tc ng mi trng v tiu chun an ton ngh nghip ...................................................................................................................................... 199
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8.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 199
8.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 200
8.6. Ti liu tham kho ............................................................................................................ 200
9. Cc ngun ti nguyn ti to nng lng ................................................................................ 203
9.1. Phm vi ............................................................................................................................. 203
9.2. Cc tc ng mi trng v bin php bo v ................................................................. 204
9.2.1. Nng lng mt tri .................................................................................................. 204
9.2.2. Nng lng sinh khi ................................................................................................ 205
9.2.2.1. t .......................................................................................................................... 205
9.2.2.2. Kh ho .................................................................................................................. 206
9.2.2.3. Biogas ..................................................................................................................... 207
9.2.2.4. Nhin liu sinh hc ............................................................................................... 207
9.2.3. Nng lng gi .......................................................................................................... 208
9.2.4. Thu in ................................................................................................................... 209
9.2.5. Nng lng a nhit ................................................................................................. 209
9.3. Cc lu trong phn tch v nh gi tc ng mi trng ........................................ 210
9.4. S tng tc vi cc khu vc/lnh vc khc ................................................................ 210
9.6. Ti liu tham kho ........................................................................................................ 212
III. CNG NGHIP V THNG MI .................................................................................. 214
1. Phn bn ni-t (sn xut nguyn liu, amoni v ur - urea) ................................................... 214
1.1. Phm vi ............................................................................................................................. 214
1.2. Cc tc ng mi trng v bin php bo v ................................................................. 215
1.2.1. Sn xut kh ammoniac tng hp (ASGP) ................................................................ 215
1.2.1.1. ASGP t cc thnh phn hydrocarbons nh ........................................................... 215
1.2.1.2. ASGP t du cn .................................................................................................... 216
1.2.1.3. ASGP t nhin liu rn .......................................................................................... 217
1.2.1.4. in phn nc v tch kh .................................................................................... 218
1.2.2. Lu tr ammoniac tng hp ...................................................................................... 218
1.2.3. Tng hp v to ht ur ............................................................................................. 219
1.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 219
1.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 220
1.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 220
1.6. Ti liu tham kho ............................................................................................................ 221
2. Cc loi phn bn ni-t (nguyn liu ban u v sn phm cui) .......................................... 223
2.1. Phm vi ............................................................................................................................. 223
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2.2. Cc tc ng mi trng v bin php bo v ................................................................. 223
2.2.1. Sn xut a-xt ni-t-ric .............................................................................................. 223
2.2.2. Sn xut a-xt sun-phua-rc ....................................................................................... 224
2.2.3. Sn xut amoni ni-t-rat ............................................................................................ 225
2.2.4. Sn xut ni-t-rat can-xi amoni .............................................................................. 225
2.2.5. Sun-pht amoni ........................................................................................................ 225
2.2.5.1. Sn phm t cc l luyn coke hoc kh ho than ................................................. 226
2.2.5.2. Sn xut t amoni v a-xt sun-phua-rc ................................................................ 226
2.2.5.3. Phn bn nit nh l sn phm ph ....................................................................... 226
2.2.5.4. Sn xut t thch cao, amoni v CO2 ..................................................................... 226
2.2.6 Sn xut ni-t-rt can-xi ............................................................................................. 227
2.2.7 Sn xut cc dung dch ni-t ...................................................................................... 227
2.2.8. Sn xut clo-rua amoni .............................................................................................. 227
2.2.9. Bi-cc-bo-nat amoni .................................................................................................. 228
2.2.10. Vn chuyn, lu tr v ng gi cc phn bn dng rn ........................................ 228
2.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 228
2.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 229
2.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 229
2.6. Ti liu tham kho ............................................................................................................ 230
3. Xi-mng, vi, thch cao .......................................................................................................... 232
3.1. Phm vi ............................................................................................................................. 232
3.2. Cc tc ng mi trng v bin php bo v ................................................................. 233
3.2.1. Khng kh .................................................................................................................. 233
3.2.1.1. Kh thi ................................................................................................................... 233
3.2.1.2. Bi .......................................................................................................................... 234
3.2.2. Ting n ..................................................................................................................... 234
3.2.3. Nc .......................................................................................................................... 235
3.2.4. t ............................................................................................................................. 235
3.2.5. Mi trng lao ng .................................................................................................. 235
3.2.6. Cc h sinh thi ......................................................................................................... 236
3.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 236
3.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 237
3.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 237
3.6. Ti liu tham kho ............................................................................................................ 238
4. Gm s k ngh, dn dng v cng nghip ......................................................................... 240
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4.1. Phm vi ............................................................................................................................. 240
4.2. Cc tc ng mi trng v bin php bo v ................................................................. 241
4.2.1. Khng kh .................................................................................................................. 241
4.2.1.1. Kh thi ................................................................................................................... 241
4.2.1.2. Bi .......................................................................................................................... 242
4.2.2. Ting n ..................................................................................................................... 242
4.2.3. Nc .......................................................................................................................... 243
4.2.4. t ............................................................................................................................. 243
4.2.5. Ni lm vic .............................................................................................................. 244
4.2.6. Cc h sinh thi ......................................................................................................... 244
4.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 245
4.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 247
4.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 247
4.6. Ti liu tham kho ............................................................................................................ 248
5. Thy tinh ................................................................................................................................. 250
5.1. Phm vi ............................................................................................................................. 250
5.2. Cc tc ng mi trng v bin php bo v ................................................................. 251
5.2.1. Khng kh .................................................................................................................. 251
5.2.2.1. Kh thi ................................................................................................................... 251
5.2.1.2. Bi .......................................................................................................................... 252
5.2.2. Ting n ..................................................................................................................... 253
5.2.3. Nc .......................................................................................................................... 253
5.2.4. t ............................................................................................................................. 254
5.2.5. Mi trng lao ng .................................................................................................. 254
5.2.6. Cc h sinh thi ......................................................................................................... 254
5.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 255
5.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 257
5.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 258
5.6. Ti liu tham kho ............................................................................................................ 259
6. Gang, thp ............................................................................................................................... 261
6.1. Phm vi ............................................................................................................................. 261
6.2. Cc tc ng mi trng v bin php bo v ................................................................. 262
6.2.1. Nh my nung kt/to ht .......................................................................................... 262
6.2.2. L cao ........................................................................................................................ 263
6.2.3. Cc nh my kh trc tip ....................................................................................... 265
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6.2.4. Sn xut thp th ...................................................................................................... 265
6.2.5. Sn xut thp hnh ..................................................................................................... 267
6.2.6. Cc hot ng c v rn .......................................................................................... 269
6.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 270
6.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 271
6.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 272
6.6. Ti liu tham kho ............................................................................................................ 273
7. Kim loi mu ........................................................................................................................... 278
7.1. Phm vi ............................................................................................................................. 278
7.2. Cc tc ng mi trng v bin php bo v ................................................................. 278
7.2.1. Tch Aluminium ....................................................................................................... 278
7.2.2. Nu chy qung kim loi nng .................................................................................. 280
7.2.3. Cc nh my luyn th cp ....................................................................................... 283
7.2.4. Sn xut bn thnh phm ca kim loi mu .............................................................. 284
7.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 284
7.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 285
7.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 286
7.6. Ti liu tham kho ............................................................................................................ 287
8. C kh ch to v ng tu ...................................................................................................... 291
8.1. Phm vi ............................................................................................................................. 291
8.2. Cc tc ng mi trng v bin php bo v ................................................................. 292
8.2.1. Cc dng nguy hi tim tang ca mt s hot ng .................................................. 292
8.2.1.1. Ct kim loi ............................................................................................................ 292
8.2.1.2. Lm sch v ty m bn thnh phm ..................................................................... 293
8.2.1.3. Sn .......................................................................................................................... 295
8.2.1.4. Xi m in .............................................................................................................. 296
8.2.1.5. Hn ......................................................................................................................... 296
8.2.1.6. Hn nhit cao ..................................................................................................... 298
8.2.1.7. Mi ......................................................................................................................... 298
8.2.2. Qu trnh cng ngh c kh v vn hnh ca cc xng c kh v xng ng tu (shipyards) ........................................................................................................................... 299
8.2.2.1. Kh thi ................................................................................................................... 300
8.2.2.2. Nc thi ................................................................................................................ 301
8.2.2.3. Cht thi rn ........................................................................................................... 303
8.2.2.4. t .......................................................................................................................... 303
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8.2.2.5. Ting n .................................................................................................................. 304
8.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 306
8.3.1 Khng kh ................................................................................................................... 306
8.3.2 Nc thi .................................................................................................................... 306
8.3.3 Cht thi rn ............................................................................................................... 306
8.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 306
8.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 307
8.6. Ti liu tham kho ............................................................................................................ 307
9. Nng cng nghip ................................................................................................................ 310
9.1. Phm vi ............................................................................................................................. 310
9.2. Cc tc ng mi trng v bin php bo v ................................................................. 310
9.2.1. Tng quan v nng-cng nghip ............................................................................... 310
9.2.2. Mt s lnh vc chnh ................................................................................................ 311
9.2.2.1. Xay bt ng cc ...................................................................................................... 311
9.2.2.2. Ch bin tinh bt .................................................................................................... 311
9.2.2.3. Ch bin ht c du v tri cy .............................................................................. 311
9.2.2.4. Ch bin c ci ng v ma ng ..................................................................... 311
9.2.2.5. Ch bin rau qu ..................................................................................................... 312
9.2.2.6. B sa ..................................................................................................................... 312
9.2.2..7 Ch bin cc mt hng trung-cao cp v gia v ...................................................... 312
9.2.2.8 Chit/tch cht x t thc vt ................................................................................. 312
9.2.2.9. Thuc da ................................................................................................................. 313
9.2.3. Cc tc ng kinh t-x hi ....................................................................................... 313
9.3. Cc lu trong phn tch v nh gi tc ng mi trng ............................................ 313
9.4. S tng tc vi cc khu vc/lnh vc khc .................................................................... 314
9.5. Tm lc nh gi tc ng mi trng lin quan .......................................................... 314
9.6. Ti liu tham kho ............................................................................................................ 314
10. L sc sn v ch bin tht .................................................................................................... 315
10.1. Phm vi ........................................................................................................................... 315
10.2. Cc tc ng mi trng v bin php bo v ............................................................... 316
10.2.1. nhim nc .......................................................................................................... 316
10.2.2. nhim khng kh .................................................................................................. 318
10.2.3. Ting n ................................................................................................................... 320
10.2.4. Cht thi rn v cn ................................................................................................. 320
10.2.5. Nhit d ................................................................................................................... 320
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10.2.6. An ton cng nghip ............................................................................................... 321
10.2.7. Qui hoch v tr ........................................................................................................ 321
10.3. Cc lu trong phn tch v nh gi tc ng mi trng .......................................... 321
10.4. S tng tc vi cc khu vc/lnh vc khc .................................................................. 322
10.5. Tm lc nh gi tc ng mi trng lin quan ........................................................ 323
10.6. Ti liu tham kho .......................................................................................................... 323
11. Xay bt ng cc ..................................................................................................................... 325
11.1. Phm vi ........................................................................................................................... 325
11.2. Cc tc ng mi trng v bin php bo v ............................................................... 325
11.2.1.Lu tr v x l ng cc .......................................................................................... 326
11.2.1.1. Cc silo ti cng khi vn chuyn v ni xay/nghin ............................................ 326
11.2.1.2. Nh kho ca cc hp tc x .................................................................................. 328
11.2.1.3. Lm sch ht ......................................................................................................... 329
11.2.1.4. Sy kh ................................................................................................................. 329
11.2.2. Xay bt (xay bt la m ) ........................................................................................ 330
11.2.3. Xay ht c v ........................................................................................................... 330
11.2.3.1. Xay la ................................................................................................................. 330
11.2.3.2. Tch v v ch bin la min (sorghum) v k (millet) ....................................... 331
11.2.3.3. Xay (u) ......................................................................................................... 332
11.2.4. Qui hoch v tr ........................................................................................................ 332
11.2.5. Nng lng t v (tru) thi .................................................................................... 332
11.2.6. Cc qu trnh ch bin cht thi c lm sch v sn phm sau khi xay ......... 333
11.2.7. X l bi .................................................................................................................. 333
11.3. Cc lu trong phn tch v nh gi tc ng mi trng .......................................... 333
11.4. S tng tc vi cc khu vc/lnh vc khc .................................................................. 334
11.5. Tm lc nh gi tc ng mi trng lin quan ........................................................ 334
11.6. Ti liu tham kho .......................................................................................................... 335
12. Cht bo v du thc vt ....................................................................................................... 337
12.1. Phm vi ........................................................................................................................... 337
12.2. Cc tc ng mi trng v bin php bo v ............................................................... 338
12.2.1 Tim nng nguy hi ca cc cng on ch bin ..................................................... 338
12.2.2. Ch bin tri cy (qu c v -lu) ......................................................................... 339
12.2.3. Ch bin cc qu v ht c du ............................................................................... 340
12.2.3.1. Bo qun ............................................................................................................... 340
12.2.3.2. Lm sch v nghin .............................................................................................. 340
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12.2.3.3. n nh nguyn liu th ....................................................................................... 340
12.2.3.4. Qu trnh p .......................................................................................................... 341
12.2.3.5. Chit bng dung mi ............................................................................................ 341
12.2.3.6. Tinh luyn ............................................................................................................ 342
12.3. Cc lu trong phn tch v nh gi tc ng mi trng .......................................... 344
12.3.1. Khng kh ................................................................................................................ 344
12.3.2. Ting n ................................................................................................................... 344
12.3.3. Nc thi ................................................................................................................. 345
12.3.4. Cht thi .................................................................................................................. 347
12.3.5. t ........................................................................................................................... 347
12.3.6. La chn v tr ......................................................................................................... 347
12.3.7. Vn chuyn .............................................................................................................. 348
12.4. S tng tc vi cc khu vc/lnh vc khc .................................................................. 348
12.5. Tm lc nh gi tc ng mi trng lin quan ........................................................ 348
12.5.1. Tch du th ............................................................................................................ 348
12.5.2. Tinh luyn du ......................................................................................................... 349
12.6. Ti liu tham kho .......................................................................................................... 349
13. ng .................................................................................................................................... 352
13.1. Phm vi ........................................................................................................................... 352
13.2. Cc tc ng mi trng v bin php bo v ............................................................... 354
13.2.1. Trng, thu hoch, bo qun v lm sch nguyn liu ............................................. 354
13.2.2. Ct, nghin nguyn liu th v chit ....................................................................... 355
13.2.3. Lm sch dung dch sau khi chit ........................................................................... 356
13.2.4. Bay hi, kt tinh v lm kh ng ........................................................................ 357
13.2.5. Ch bin cc sn phm ph ..................................................................................... 357
13.2.6. Nhu cu nng lng ................................................................................................ 358
13.2.7. Qun l nc ........................................................................................................... 358
13.3. Cc lu trong phn tch v nh gi tc ng mi trng .......................................... 360
13.3.1. Cc yu cu v gii hn pht thi ............................................................................ 360
13.3.2. Cng ngh gim thiu pht thi v quan trc pht thi ........................................... 362
13.3.3. Cc gi tr gii hn lin quan n bo v sc kho ................................................. 363
13.4. S tng tc vi cc khu vc/lnh vc khc .................................................................. 364
13.5. Tm lc nh gi tc ng mi trng lin quan ........................................................ 364
13.6. Ti liu tham kho .......................................................................................................... 365
14. n g, ca, ch bin g v cc sn phm t g .................................................................. 367
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14.1. Phm vi ........................................................................................................................... 367
14.2. Cc tc ng mi trng v bin php bo v ............................................................... 367
14.2.1. Ch bin g bng c kh .......................................................................................... 367
14.2.2. Sn xut cc sn phm t g ................................................................................... 370
14.3. Cc lu trong phn tch v nh gi tc ng mi trng .......................................... 371
14.4. S tng tc vi cc khu vc/lnh vc khc .................................................................. 371
14.5. Tm lc nh gi tc ng mi trng lin quan ........................................................ 373
14.6. Ti liu tham kho .......................................................................................................... 373
15. Giy v bt giy .................................................................................................................... 377
15.1. Phm vi ........................................................................................................................... 377
15.1.1. Gii thiu/Thng tin chung/thut ng ..................................................................... 377
15.1.2. Sn xut bt giy ..................................................................................................... 377
15.1.2.1. Cc nguyn liu th .............................................................................................. 378
15.1.2.2. Cc sn phm v qu trnh sn xut ..................................................................... 378
15.1.3. Sn xut giy v ba ................................................................................................ 380
15.1.3.1. Cc vt liu dng si c bn, bt giy (nguyn liu th cho qu trnh sn xut giy v ba) .................................................................................................................................. 380
15.1.3.2. Cc sn phm v qu trnh sn xut ..................................................................... 380
15.1.4. Cc h thng my mc ph v ph tr .................................................................... 381
15.2. Cc tc ng mi trng v bin php bo v ............................................................... 381
15.2.1. Phm vi: Nguyn liu th v ph tr ...................................................................... 381
15.2.1.1. Nguyn liu th dng si ...................................................................................... 381
15.2.1.2. Nc ..................................................................................................................... 382
15.2.1.3. Nng lng ........................................................................................................... 382
15.2.1.4. Ho cht v cc cht ph tr khc ........................................................................ 383
15.2.2. Cc dng thi t qu trnh sn xut giy v bt giy .............................................. 383
15.2.2.1. Cc dng thi lng ................................................................................................ 383
15.2.2.2. Cc dng thi vo khng kh ................................................................................ 384
15.2.2.3. Cht thi rn ......................................................................................................... 384
15.2.2.4. Ting n ................................................................................................................ 384
15.3. Cc lu trong phn tch v nh gi tc ng mi trng .......................................... 385
15.3.1. Cc dng thi lng ................................................................................................... 385
15.3.2. Cc dng thi vo khng kh ................................................................................... 385
15.3.3. Cht thi rn ............................................................................................................ 386
15.3.4. Ting n ................................................................................................................... 386
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15.4. S tng tc vi cc khu vc/lnh vc khc .................................................................. 386
15.4.1. Cc phm vi c trng ............................................................................................ 386
15.4.1.1. Nguyn liu th .................................................................................................... 386
15.4.1.2. Cc cht ph tr v ph gia .................................................................................. 388
15.4.2. Cc phm vi khng c trng ................................................................................. 389
16. Dt ......................................................................................................................................... 402
16.1. Phm vi ........................................................................................................................... 402
16.1.1. Thut ng ................................................................................................................ 402
16.1.2. Nguyn liu ............................................................................................................. 402
16.1.3. Cc qu trnh sn xut ............................................................................................. 402
16.1.3.1. n nh si (Fibre conditioning) .......................................................................... 402
16.1.3.2. Xe si (sn xut si) ............................................................................................. 402
16.1.3.3. Dt v dt kim ...................................................................................................... 403
16.1.3.4. Hon tt sn phm ................................................................................................ 403
16.1.4. Kch thc ca dt nhum ...................................................................................... 403
16.1.4.1. Ko si ................................................................................................................. 403
16.1.4.2. Dt thoi v dt kim ............................................................................................... 403
16.1.4.3. Hon tt sn phm ................................................................................................ 403
16.1.5. Cc vn lin quan n v tr ................................................................................ 403
16.2.1. n nh si .............................................................................................................. 404
16.2.2. Xe si v nh ng .................................................................................................. 404
16.2.3. Dt thoi v dt kim .................................................................................................. 404
16.2.4. Hon tt sn phm ................................................................................................... 405
16.2.4.1. nhim nc thi ................................................................................................ 405
16.2.4.2. Cc dng kh v hi thi ....................................................................................... 407
16.2.4.3. Ting n ................................................................................................................ 408
16.2.5. Cc tc ng mi trng chung .............................................................................. 408
16.3.1. Kim sot nhim khng kh ................................................................................. 409
16.3.2. Kim sot ting n ................................................................................................... 410
16.3.3. Kim sot nhim nc ......................................................................................... 410
16.4. S tng tc vi cc khu vc/lnh vc khc .................................................................. 412
16.5. Tm lc nh gi tc ng mi trng lin quan ........................................................ 412
16.6. Ti liu tham kho .......................................................................................................... 413
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I. NNG NGHIP
1. Canh tc nng nghip
1.1. Phm vi
Cc thut ng sau thng c s dng v nh ngha ca chng nh sau:
- n canh (Single cropping) l ch canh tc mt loi cy trn mt mnh t c th, v d la. Nu trn mt mnh t m cc loi cy khc nhau c canh tc k tip nhau th cn c gi l lun canh (crop rotation).
- Xen (a) canh (Intercropping) l h thng c nhiu loi cy khc nhau c canh tc trn cng mt mnh t, v d nh kt hp trng sn (khoai m) vi ht k c (cowpeas).
- Cy thng nin (Annual crops) l thc vt c vng i trong mt nm, v d ng cc, cy h u, cc loi rau v thuc l.
- Cy lu nin (Perennial crops) l loi cy c vng i nhiu hn mt nm v thng ch trng hoc gieo ht mt ln, v d nh cy n tri, c ph, cacao, ch
- c canh (Monoculture) l ch trng mt loi cy c th trn mt vng t c th trong mt s chu k nht nh v d nh cy ma.
Trong trng hp sn xut g, nguyn liu th, thc n gia sc hoc thc vt dng sn xut cc vt dng xa x, canh tc nng nghip trn quan im khu vc - th hin mt dng tc ng ca con ngi n cn bng t t nhin.
Cc h thng canh tc truyn thng thng da trn a canh v nh hng tn ti. Cc dng vo bao gm phn bn v thuc bo v thc vt thng khng ph bin v s dng phm vi nh.
Ngc li, cc nng tri vi quy m ln thng dng c canh (ma, bng) hoc cy lu nin (c ph, ch, c ca). cc dng canh tc thng nh hng th trng v ph thuc vo cc dng ngoi vi.
Sn phm nng nghip thng c cc hot ng sau:
- Bo v cy trng. - K thut nng nghip v sc ko ng vt. - Thy li. - Chn v nhn ging. - Ci to t v bn phn. - Chm sc cy v dit c, thu hoch, x l sau thu hoch. - Chng v kim sot xi mn. Cy trng pht trin p ng cc nhu cu sn xut v kinh doanh. Chng cng c mt
vai tr trong vic bo v t, khng kh v nc.
Sn xut nng nghip l c thc hin trn cc nng tri, hu ht s sng lao ng l cc thnh vin trong gia nh, m bo s tn ti v thu nhp.
1.2. Tc ng mi trng v cc phng php bo v
Trong h sinh thi nng nghip, con ngi s tr thnh cc yu t chi phi h sinh thi (h sinh thi nh hng nhn to). cc h sinh thi nng nghip khc vi h sinh thi t nhin ch cc qu trnh iu tit t nhin c xp hng hai sau qu trnh kim sot ca con ngi.
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Trong mi trng t nhin th thc vt l mt phn ca h sinh thi v ng vai tr quan trng trong vic bo v chng. Ty thuc vo phng thc canh tc, mt cch hin nhin, cng sut v tc ng qua li ca cc bin php canh tc s lm tng cc tc ng mi trng c th. Cc tc ng ny c th lm gim tnh a dng sinh hc, lm thay i cu trc t v gy nhim t, nc v khng kh (thuc bo v thc vt, cc loi mui l kt qu ca qu trnh ti v bn phn, Nitorat). Cc h sinh thi t nhin cng cng vi cc chc nng khc nhau c thay th bi s dng t nhn to km a dng hn.
Vic gia tng s dng cc sn phm cng nghip (phn bn, thuc bo v thc vt, nng lng) v cc k thut canh tc khng ph hp dn ti s nhim nc sinh hot bi phn bn v thuc bo v thc vt cng nh xi mn t, sa mc ha v thoi ha gen.
1.2.1. Cc tc ng mi trng
1.2.1.1. t
t l nn tng cho canh tc nng nghip v chc nng quan trng trong vic m bo s tn ti ca loi ngi.
Bo v t l yu t cn thit nu mi trng sng ca con ngi c duy tr bn vng kh nng cung cp thc phm cht lng cao cho con ngi.
Cc c hi thay i cc iu kin ch o ti mt v tr c th l c gii hn. Cc gii php canh tc do vy phi c iu tit bi cc iu kin t nhin ti khu vc .
Xi mn hay cn c gi l s dch chuyn t bi gi v nc l hu qu ln nht ca vic canh tc nng nghip c bit l vng nhit i.
Mc xi mn ph thuc vo loi cy trng v phng thc canh tc. gim thiu xi mn cn m vo mt t c che ph quanh nm. Trong trng hp c canh v n canh th ri ro xi mn s ln hn trong thi k u ca thc vt (v d ng, cy h u), khi mt cy thp v cc bin php tr c th ang mnh. i vi cy thng nin nh cy ng cc, thn c v ly ht i hi cy t thng xuyn v gy nn cc tc ng xu ti cu trc t dn n xi mn.
Cc cy lu nin nh cy n qu thng ngn cn qu trnh xi mn t khi tn, n cung cp lp che ph bn v c tc ng tch cc n cu trc t.
Tnh xi mn ca t cn ph thuc vo c trng vt l ca n. Ct mn v cc ht bo mn d b di chuyn trong khi d cc thnh phn v st th c tnh chng xi mn cao. Cc thng phn mn lm tng tnh n nh ca cu trc t cng nh kh nng gi nc c tc dng ngn cn kh nng xi mn.
Cc bin php quan trng chng xi mn gm:
- m bo che ph t tt (a canh, gieo chm). - "storeyed" canh tc kt hp vi cy c tn v cc cy bi. - Chia vng t canh tc thnh cc mnh nh v to cc vng ph gi i vi hng gi
ch o.
- Trnh tp trung gia sc hoc c cc bin php ngn cn sinh n ca gia sc ti cc vng mi gieo ht (xem tm tt mi trng v nui gia cm).
p dng cc bin php c gii nng trong bin php cy t v thu hoch s lm cho t b nn, cc rnh v cc vng ly, c bit trong trng hp t trong vng nhit i c cu trc yu. iu ny c th c nhng hiu qu bt li ca vic cho gim dng nc r qua v s cp kh
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cho h thc vt v ng vt trong t cng nh i vi cy trng. c gii ha cng c th dn ti s thay i ca vic phn chia lao ng gia nam gii v n gii.
Mc du thng xuyn cy cy trng trt s c tc dng kch thch hiu qu hot ng ca cc vi sinh vt v v vy cng b sung thm cht dinh dng, n gy ra cc iu khng thun li trong vng nhit i:
- Cht mn b thi ra s lm tng nhit . - H ng vt t b nh hng bi s hnh thnh cc cht mn mi. y mnh sn xut n canh s lm h hi mt phm vi rng ln v vic chm sc cn
thit phi s dng thuc tr su hi. a thuc tr su hi vo t s gy ra nhng tc ng ti h ng vt v thc vt t.
Cht hu c c mt vai tr ln trong ng thi ca t trong vng nhit i. N d tr nc, cung cp mi trng sng cho sinh vt t, tng cng cu trc bn vng ca t, v l ni cung cp v lu tr cht dinh dng. Ngoi cc chc nng cha ng cc cht dinh dng l cc cht hu c thc hin chc nng sng quan trng, th t trong vng nhit i t khi cha ng cht dinh dng cht lng cao v gn cc khong cht trong t. S dng cc khong cht lm mu m t v vy ph thuc vo s cn i v n nh cc cht hu c trong t. Nu s lng cc cht lm mu m t c s dng khng cn i vi cc cht hu c trong t, th n gy ra mt mi nguy him cho nc ngm khi thm vo lp t su hn. S dng qu nhiu cc cht lm mu m t th l nguyn nhn h hi h sinh thi v thit hi v kinh t.
Ri ro ca vic mt dinh dng khng cn bng l rt ln trong trng hp n canh v c canh. V d nh trong trng hp trng ng, c ca, cy ly c, cy ly thn. Ni m mt s loi thc vt pht trin a canh hoc h thng cy trng lun phin th r ro tr nn nh hn, nh l s p ng i hi nhu cu cht dinh dng khc nhau. Nh vy, dng trng cy kt hp vi s khc nhau v n su ca r cy (nng, cn) v nhu cu cht dinh dng khc nhau (cao, thp), s cnh tranh cc cht dinh dng, nc v nh sng gim i ng k.
1.2.1.2. Nc.
Xi mn nh cp trn c th dn ti ph dng ha cc ngun nc tip nhn cc cht dinh dng t qu trnh xi mn, v d nh phn lng, nitrat, v c th b nhim bi d lng thuc bo v thc vt
1.2.1.3. Khng kh
Kh hu nhng vng a canh v cc loi cy c nhiu tng th tt hn, ni mt cch khc cn bng hn so vi vng trng cy thng nin, n canh hay c canh. Tc gi thp hn, do vy s tt hn cho cc loi thc vt nhy cm vi gi (v d nh chui).
nhim khng kh cng c th gy ra do vic s dng ha cht bo v thc vt. S bay hi ammonia trong qu trnh s dng phn bn rn v lng l khng ng k. Di iu kin nhit i (nhit cao, kh nng hp ph trn b mt ca t thp), c th ln n 80% tng lng nit b bay hi.
nhim khng kh v bu kh quyn l kt qu ca s thi kh t qu trnh s dng cc my mc, trong k thut ct v t, v vic t cc sn phm thc vt d tha, nh vy vic thi cc kh nh CH4 v NOx t qu trnh chn nui cc by n gia sc ln v canh tc la nc. Cc yu t trn ng mt phn trong hu qu gy nn hiu ng nh knh.
1.2.1.4. Sinh quyn
Ri ro ca s mt cc loi v thay i mt cn bng trong cc loi th tng t l vi cng canh tc. Kim sot du canh quan st cc giai on khng canh tc cn thit s xm ln t
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nht trong iu kin mi trng t nhin ca vng khng ch mt cp vng b xa sch trn c s chn la. iu ny khng ch l bo tn cc khu rng, c bit l rng ma nhit i v cc ngun ti nguyn t chng, m cn bo v ngi dn rng, h thng c nhng hiu bit v s dng nhng th cy c kh nng cha bnh v mi tng quan sinh thi trong mi trng sng ca h.
Phng php canh tc cc v ma, mi lin h vi cc my mc, cc dng ha cht v phng php kim sot c di l nguyn nhn lm cho cc cy hoang d pht trin chim ch, dn n gim s lng cc loi.
Trong cc vng ty thuc vo cc thi k hn hn, vi quy m trng trt ln loi cy rng trong mt s h thng c canh th thng tng nguy c chy rng. Ngoi ra cc cht dinh dng v nc b mt, nhng iu ny cng c th l kt qu ca s tiu dit khng mong mun ca cc loi c v cc loi cy khng khng c c s chy.
Thay th v ph hy cc loi thc vt s dn ti s lm gim tnh a dng sinh hc. M rng phm vi s dng ca rng nhit i cng l nguyn nhn lm gim tnh a dng loi ng vt. V d trong trng hp ca cc loi linh trng v cc loi chim.
H sinh thi t nhin c nhng nh hng bt li khng nhng bi nhu cu t bt u cho sn phm nng nghip m cn bt u b phn chia ra (v d nh cc tuyn ng giao thng), cng vi kh nng c th mt tnh n nh ca t.
S dng t cho sn xut nng nghip thng dn ti lm gim din tch rng, h sinh thi kh, h sinh thi nc v l nguyn nhn lm cho phong cnh n iu, v d nh hu qu ca s gii phng mt bng, tiu nc, san mt bng v thy li.
Bng cch so snh vi h thc vt t nhin, sn xut nng nghip ph hy mi trng sng v lm gim tnh a dng trong vng. Tiu chun ha cc sn phm cho th trng v duy tr ni ging c cc im ring bit (v d nh l sn lng, hnh dng, mu sc) gp phn lm gim tnh a dng a phng (suy thi gen).
1.2.2. Phng php bo v
1.2.2.1. iu kin chung
Trong phm tr rng sn xut nng nghip b nh hng bi cc yu t c bn; n khng ch lin quan ti kh hu m c yu t quc gia (v d nh l phng php s hu t) hoc yu t quc t (quan h kinh t).
C rt nhiu vng kh hu v thc vt mang tnh nhy cm cao vi s can thip ca con ngi, cc hot ng ny tng ph hoi thm thc vt sau:
- Ph rng ma nhit i chu th Amazon ly g cht lng cao. - Ct v t gii phng mt bng bi cc vng t nng nghip Nigeria, ni chuyn
i sang trng trt c nh khng cn cho php t c c hi c ti sinh.
- Pht trin n gia sc qu mc trong vng Sahel l kt qu tp trung mt lng ln gia cm v chng n ht thm thc vt vn tha tht ti y.
Cc hu qu l thm ha, khng nhng ch xy ra vng nhit i m t m c i vi vng c lng ma t hn. Hu nh khng c thm thc vt no c th che ph,v vy thnh phn ca t s b thay i sau t nm; vai tr quan trng y l s tng kh nng phn hy cc cht hu c trong t v vi vic th vic b sung cc cht hu c mi l gim n mc ti thiu.
Trong phm vi nn kinh t th gii, gi tr thng mi cho cc quc gia quan tm l tnh trng n nh. l cc quc gia trn c gia tng chi ph nng lng v thng phm.
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Chnh sch nng nghip quc t hin nay khng c g m bo cn i pht trin sn xut nng nghip.
Tc gia tng dn s nhanh chng ng ngha vi din tch t nng nghip s gim xung v nh vy t ai li tr nn b s dng mnh m hn. Cc trang tri M La tinh ngy nay c kch thc trung bnh ch khong 2,7ha; v Chu phi trung bnh khong 1,3 ha, trong khi tng ng vi hnh thi ca chu th t hn 1ha. Nh vy, 10% s ngi sng nh vo nng nghip v Chu Phi, 25% Trung ng v 30% M La tinh khng c g. Hai phn ba trong s h c din tch t rt nh khng th vn v k thut u t nh thc tr su bnh, thuc dit c v khong cht lm mu m t.
Nh trn, t ai ngy cng thiu, h thng nng nghip chuyn i t du canh du c sang bn du canh v cui cng lp nng tri c nh. Qu trnh ny c hnh thnh chu , trong khi phn ln chu Phi v M Latinh vn ang ang c thc hin. Thay i thnh cc nng tri c nh c ngha l khng c cc vng t b hoang nh cc giai on trc (rng, bi cy, ng c) m cho php ci to t; vng t mu m b suy gim v cui cng cn li mt mc thp ch cho mt sn lng nh. S thiu ht t ai nn bt buc s dng cc vng t nghing, dc nn c nguy c xi mn v v vy gp phn lm suy gim mi trng.
Tnh quan trng ca cy trng cng c nhng thay i. Trong cc vng m t v cn nhit i trng khoai m, cy la min, v ng b st gim nng sut, trong khi cc v ma nh sn v khoai lang tr nn quan trng hn. Hai loi cy cp trn th cho sn phm ma v tng i tt ngay c trn cc vng t ngho, nhng trng n chnh l nguyn nhn t tr nn b bc mu mt cch nhanh chng.
Trong rt nhiu quc gia, va tng cng cng tc nng nghip v va qu trnh cng nghip ha th c nhiu tc ng xu ln mi trng. S ng nc, mn ha v bi p l nguyn nhn t qu trnh ct xn cc cng trnh thy li - thng th to ra mt chi ph ln mt kh nng mu m ca t sau mt vi nm, dn ti lm gim sn lng ng k. Du vt tn ti bn ca cc loi thuc tr su ngy cng tng trong ngun nc mt v nc ngm. Mt thp k va qua s lng ngi b nhim thuc tr su tng cao, trong khong thi gian cng tng ng k s lng loi khng thuc tr su bnh do s dng chng qu thng xuyn.
Cc yu t miu t y c thng tm thy khi c s n lc ang c thc hin nng cao sn lng, qu trnh hin i ha sn xut nng nghip mt cch thng thng. Tuy nhin, cc vn khng ch l hu qu ca cc d n sn xut quy m ln m n cn c gy ra bi qu trnh tch ly ca hng lot cc hot ng ca cc d n quy m nh.
Hin nay, cc chi ph mi trng thc t khng hoc c tc ng rt t t cc quan im qun l trn cc trang tri, ni m khng khuyn khch bo tn cc ngun ti nguyn thin nhin hay nng cao hiu qu mt cch bn vng.