palouse and nezperce prairies soil quality card guide

Palouse and Nezperce PrairiesSoil Quality Card Guide

Accompanies the Palouse and Nezperce PrairiesSoil Quality Indicator Card

Palouse and Nezperce Soil Quality Indicator Card 2004 1

January 2004

Contents

Introduction 3Assessment Calendar 4Infiltration 5Compaction 7Tilth and Structure 9Organic Matter 11Plant Residue 13Worms 15Erosion 17Plant Growth 19Seedling Emergence 21Rooting Systems 23Example of Complete Indicator Card 25

Credits:Edited by Neil Peterson, Natural Resources Conservation Service (NRCS);Dennis Roe, NRCS; Cinda Williams, University of Idaho; Bob Mahler, Univer-sity of Idaho; Lynn Rasmussen, Nez Perce Soil and Water Conservation Dis-trict; Diana Smith, Pacific Northwest Direct Seed Association; Jeff Becker,McGregor Company; and Northern Idaho and Eastern Washington growers.

Adapted with permission from the Oregon State University Extension ServicePublication EM8710, Willamette Valley Soil Quality Card Guide and WillametteValley Soil Quality Card (Oregon State University, Corvallis, Oregon, June1998, reprinted April 1999), 28 pages, $3.00.

Funding for this project was provided by Sustainable Agriculture and Re-search Education (SARE).

Additional Copies:Additional copies of The Palouse and Nezperce Prairies Soil Quality IndicatorCard and Guide can be obtained from the Nez Perce Soil and Water Conserva-tion District at 1630 23rd Ave., Suite #501, Lewiston, Idaho 83501.


The Palouse and Nezperce Prairies

Soil Quality Card Guide

Agricultural producers, conservationists, and other land managers need reliable

methods to assess soil quality to make man-agement decisions that maintain long-termsoil productivity. A group of North Idaho andEastern Washington growers identified 10 soilquality indicators for the Palouse and NezPerce Prairies, which will assist in assessingthe impacts of agricultural activities on soilmanagement.

This guide is designed to supplement thePalouse and Nezperce Prairies Soil Quality Cardby providing information on the role of man-agement, explaining why the soil qualityindicators are important, and giving detailedmethods for evaluating them.

Each field and soil that is assessed will startfrom a unique baseline or reference point, andthe changes in indicators from year to yearwill show how management is affecting soilquality. An important point to remember isthat soil characteristics, such as clay content,are not affected by management.

Soil-quality indicators are highly interrelated.For example, conditions of soil structure suchas aggregate stability, compaction, and poresize influence and are influenced by, theactivities of earthworms and other soil organ-isms. Water infiltration and availability,which are controlled by surface and subsur-face soil structure, affect plant root growthand plant root health. Organic residue androot biomass from crop plants feed soil organ-isms and contribute to soil organic matter,which in turn enhances soil structure. Theseinterrelationships begin to show the complex-ity of soil systems.

Using this Guide For each indicator, this Guide con- tains:

• A description of the indicator• An explanation of why the indicator

is important for judging soil quality• A discussion of how management

affects the indicator• Suggestions for when to assess the

indicator• Instructions for performing an

accurate assessment

The assessment calendar on Page 4 showsthe times of the year that are best suited forassessment of each soil indicator. Timesvary according to the crop grown, but it isimportant to maintain as much consistencyas possible from year to year in the assess-ment of each field. Assessment of some orall of the indicators more than once a yearalso provide a clearer picture of potentialchanges in soil quality.

Several indicators include instructions forperforming both a basic and a more rigor-ous assessment. The rigorous assessmentsgive more precide information, but requiremore time and equipment than the basicassessments.

Regardless of method used, accuracy in-creases if the same test or observation isdone in several representative locationswithin a field to get an average rating forthe indicator. Assessments performedconsistently and carefully each year yieldthe most reliable information on soil quality.


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Management, crop and climatic factors determine the optimum time of soil quality assessment.The assessment times in this calendar are appropriate for the Palouse and Nezperce Prairies inNorthern Idaho and Eastern Washington.


1 InfiltrationWhat is water infiltration?Infiltration is the process of water entering thesoil. When the soil is in good health or goodcondition, it has stable structure and continu-ous pores to the surface. Soil porosity is veryimportant to infiltration. The number, lengthand size of pores determines water movementand retention. Large pores (1/16th to 1/4thinch in diameter) are responsible for themajority of water flowing through a soil.

Water infiltration is also affected by other soilfactors such as texture, slope, compaction, soilaggregation and structure. Sandy soils gener-ally have higher infiltration rates than silty orclayey soils. Water tends to drain morequickly from positions higher on the land-scape.

Soil structure can control water infiltration.Unstable soil aggregates disintegrate whenwet, and release small clay particles that clogpores. Compacted soils restrict water move-ment into deeper subsoil layers where wateris stored for plant use.

Why is water infiltration important?nf• Soil with good infiltration has little sur-

face runoff and resists erosion. Goodinfiltration means the soil dries out andwarms up quickly after heavy rains.

• When there is good infiltration of waterinto the soil due to proper management,the soil can capture as much as allowedby the specific soil type. This will, inturn, increase the water holding capac-ity of the soil, which allows for adequatemoisture for plant use longer into andduring the growing season.

• Increased surface runoff can carry soilparticles, surface applied fertilizers andpesticides off the field.

iltrati impornt?

How does land management affectthis indicator?Management that promotes topsoil with aloose granular or crumb structure composedof aggregates that maintain their integritywhen wet, will be conducive to good waterinfiltration.

Tillage operations that preserve soil structurepromote good water infiltration. The additionof organic matter from organic residues willgreatly improve the soil aggregate stabilityand hence, increase water infiltration.

Decreasing the formation of crust by main-taining plant cover or by practicing residuemanagement will decrease the impact ofraindrops on the soil to improve infiltration.

Infiltration is best assessed after a heavyrainfall when you know the soil is completelysaturated. Observe and record the durationof any ponding on the soil surface.


How is the indicator assessed?

If you use the open cylinder method (shownat right) to determine water infiltration, youcan perform the test at any time of year. Thisassessment method is more quantitative andmay be performed at more than one locationin the same field

Cylinder TestMaterials needed: • Notebook • Open metal cylinder about 6” in diameter & about 6” long, that is sturdy enough to be driven into the soil. • Container with several gallons of waterWhat to do:1. Push the cylinder into the soil so that

about 3 inches extend above the top ofthe soil to allow water to be “ponded”there.

2. Place a cloth, burlap bag or plastic wrapon the soil surface to absorb the energyof the water as it is poured.

3. Gently fill the top of the cylinder withwater and keep it full by adding wateras it percolates down. Note that pour-ing water too vigorously on the soilsurface may disrupt infiltration. Con-tinue adding water and refilling thecylinder for about one-half hour oruntil you are sure the soil within thecylinder is completely saturated.

4. Observe the amount of time a knownamount of water (e.g., 1 gallon, 1 quart,etc.) remains on the surface within thecylinder after the soil within the cylin-der is saturated.

5. It is important to note whether thecylinder has been placed in a tractorwheel track, because these areas usu-ally allow slower infiltration than non-track areas.

Rating the indicator Least desirable=1 Moderate=5 Preferred=10

Water ponds or runs Water drains slowly Soil drains well after off field following most with some ponding. rain; Little or no ponding rains. Long wait to get Soil surface may be or runoff following rain. on the field following partially crusted. Can move equipment rain; Soil surface is into field immediately crusted. following a rain event.


Basic Test

Materials needed:

Palouse and Nezperce Prairies Soil Qual-ity Indicator Card

What to do:

To assess this indicator, observe the fieldafter a saturating rain or irrigation, andrecord how long water stands in the field

2 CompactionWhat is compacted soil?Soil compaction occurs when soil particles arepressed together, reducing the pore spacebetween them. Compaction occurs whenfarm machinery repeatedly passes over thesame area of soil. The weight of the equip-ment, the number of trips across the field, andthe type of soil determine the degree of com-paction.

Why is compaction important?• Compaction restricts rooting depth, de-

creases pore size, and affects the activ-ity of soil organisms by decreasing therate of decomposition of soil organicmatter and subsequent release of nut-rients.

• Soil compaction greatly decreases infil-tration and thus increases runoff andthe hazard of water erosion.

• The reduced pore space that resultsfrom compaction limits the ability ofearthworms and other organisms to livein the soil.

How does management impact com-paction?The more intensely a soil is tilled, the morelikely it is to be compacted. Fewer trips acrossthe field can reduce compaction. Machinerythat has axle loads of more than 10 tons maycause compaction below 12 inches.

Compaction can be prevented or reduced bynot working the soils when they are satu-rated. Often, compacted soils are found justbelow the till zone. This depth is the down-ward limit of stirring and loosening actionperformed by implements. Physically break-ing through a deep compacted layer withsubsoiling equipment when the soil is dry cancounteract deep compaction.

Increasing organic matter in soils by additionof cover crops and organic residues willcontribute to biological activity and aggregatestability. This will greatly enhance the soil’sability to resist compaction.



Assess soil compaction both before springtillage and during the crop growing season.

Soil moisture content greatly affects penetra-tion into the soil. Perform this assessmentwhen there is adequate moisture in the soil forcrop growth.

Basic Test

Materials needed:

Wire flag or metal rod about 1/8inch in diameter

What to do:

Hold the wire flag or rod and pushit vertically into the soil at severaldifferent locations in the field.Record the depth at which itbends due to resistance in thesoil.

Rating the indicator

Least desirable=1 Moderate=5 Preferred=10

High resistance to pene-trations by soil probe,shovel, wire flag, tillageimplement, etc. Tillagepan present. The flagbends readily. Plant rootsthat turn horizontallyindicate a hardpan.

Some resistance topenetration by soilprobe, wire flag, tillageimplement, etc. Somerestrictions to a pen-etrating wire flag, someroot growth restrictions.

Little resistance topenetration by soil probe,shovel, wire flag, tillageimplement, etc. No tillagepan present. The wire flagcan penetrate all the wayinto the topsoil beyond thetillage layer and into thesubsoil without bending.


3 Tilth and Structure

What is soil structure and tilth?Soil structure is the way the solid particles in asoil are held together. It is the naturally occur-ring arrangement of soil particles into second-ary units or peds. Soil porosity is maintained,in part, by soils having a good granular orcrumb structure. Granular and/or crumb struc-ture allows the free movement of air, water,plant roots, and organisms throughout the soil.Soils that lack this kind of structure often lackgood porosity.

If the individual soil crumbs break into powdereasily, the soil is said to have poor aggregatestability. If the crumbs do not break apart, theyare too hard, or cemented. The formation ofstable soil aggregates results from the grindingaction of humus and other soil organic mattercomponents, the activities of soil organismsand the growth of plant roots. When the soilhas good granular structure, infiltration ofwater into the soil is increased and erosionreduced.

Good soil tilth means the soil works easily.Individual crumbs retain their shape under thestresses of tillage, yet the soil is still friable.Also related to tilth is bulk density, which is theweight per unit volume of dry soil. A lowerbulk density means a higher soil porposity andbetter soil tilth.

Why is soil structure important?• Soils with ample pore space and an even distribution of large and small pores are well aerated, have good water-holding capacity and infiltration rates, and are easy for roots to grow through.• Stable crumb aggregates preserve pore space in soils by preventing the clogging of pores with loose particles.

How does management impact soilstructure and tilth?Soil management directly affects soil struc-ture and tilth. A seasonal or yearly assess-ment of this indicator may show whethercurrent management practices are helping orhindering the free movement of air andwater through the soil.

Management of plant residue that encour-ages biological activity and residue decom-position creates soil organic matter andimproves structure.

Operations that allow erosion and compac-tion of the soil, such as leaving a field bareover winter or working a soil high in claywhen it is too wet, result in poor soil struc-ture.


How is the indicator assessed?Assess soil structure and tilth when the soil isnot extremely wet or dry. Do not assessfrozen soils. When you make these assess-ments, be sure to note how much time haspassed since the last tillage operation.

Kitchen Scale TestMaterials Needed

ShovelSquirt bottle with waterSmall kitchen scale

What to do:Complete steps 1-2 of the basic test. Thensubstitute the following for steps 3 & 4.1. Place a soil crumb that is about 1

cubic inch in volume on the tray ofthe scale (1 inch by 1 inch by 1inch). Press down with your forefin-ger on the top of the crumb until itbreaks. Record the weight at thetime when the crumb broke apart.

2. Repeat this procedure using themoistened soil crumb.

3. Record how many pounds of pres-sure are needed to break the crumb.

4. Compare the two resistance differ-ences between the crumbs beforeand after wetting.



Soil has a cloddy,powdery, massive,or flaky structurewith no visiblecrumbs.

Soil has some crumb struc-ture. Individual crumbsbreak under only slightpressure and are muchmore fragile after wetting.

Soil is crumbly with adefinite crumb struc-ture. Aggregatesmaintain shape withpressure.

Note: Aggregates that cannot be broken withpressure between the thumb and forefinger wheneither wet or dry and that maintain their shapeunder at least 15 lbs. of force or greater, are consid-ered too hard and should be rated as least desirable.


Basic TestMaterials needed:

ShovelSquirt bottle with water

What to do:1. In one or more respective areas of

the field, dig out a section of soil6-10 inches deep.

2. Take an intact portion of soil aboutthe size and volume of a 15-ouncesoup can from the shovel.

3. With your finger, lightly break apartthis piece of soil. Look for individualgranular crumbs. If crumbs are pres-ent, squeeze a few of them betweenyour thumb and forefinger and notethe amount of pressure required tocollapse them.

4. Use the squirt bottle to gently wetsome of the remaining intact crumbs.Now see how much pressure isneeded to break them, comparingthis effort to the pressure used whenthe crumbs were not wetted. Notethe resistance difference between thewetted and unwetted crumb aggre-gates.

4 Organic MatterWhat is organic matter?Organic matter impacts water infiltration, tilthand nutrient cycling. Presence of a variety oftypes of residue from the previous seasonindicates that the soil is alive. For example,partially decomposed residue suggests thatorganic matter has been returned to the soiland nutrients recycled, while larger intactpieces are valued for their ability to providestructure and tilth to the soil.

Organic matter is formed when plant residuefrom a previous crop or added organic mate-rials, such as manure or straw, decomposesover time. When decomposition is active, soilorganic matter will be in all stages of break-down, from recognizable plant parts, toindividual plant fibers, to dark staining hu-mus. Soil organisms decompose plant residueand recycle it into many different forms thatbenefit the soil. Most of the decompositionthat takes place in soils is due to microbialactivity. As larger soil organisms consumeorganic residue, they break it down intosmaller pieces which allow bacteria and fungito work more efficiently. Active decomposi-tion of plant residues is a good indicator thatthe biological community is thriving in thesoil. No visible residue suggests that insuffi-cient organisms are available to decomposethe materials.

Residues in various stages of decompositionare most favorable since the larger pieces helpprovide tilth and structure to the soil, whilesmall pieces are used as food for soil microor-ganisms.

Why is organic matter important?• Increases the soil cation exchange ca-

pacity (its ability to hold essential plant nutrients)

• Provides decomposition products which glue soil particles into aggregates im- proving soil structure, water infiltration and tilth

• Provides a food source for a diverse population of soil organisms that promote nutrient recycling, aeration and water movement within the soil

• Represents the principle sources of N and S (and much of the P) for crops.

How does management impact or-ganic matter?Management systems that include cover cropsand the addition of organic residues to fields,supply the raw materials for organic matterformation.

Management that allows plant residue to bedistributed within the topsoil helps create soilorganic matter in all stages of decomposition.




Least desirable=1 Moderate=5 Preferred=10Light colored surfacesoil. Surface soil issimilar to subsoil color.No visible organic ma-terial in soil. No smell.Soil test shows loworganic matter.

Surface color closer tosubsoil color. Soil testshows medium organicmatter levels.

Dark colored soil surface.Visible organic material.Earthy smell. Soil testshows high organic mat-ter. Topsoil is defined andis definitely darker thansubsoil.


Advanced Test

Obtain a recent copy of a soil test anddetermine if the organic matter contentis low, medium or high for your soiltype.

Organic matter content can be evaluated bythe way the soil smells and by its color. Forexample, soils that are darker in color gener-ally indicate a higher organic matter content.A darker surface color than that of the subsoilcolor indicates a higher organic matter con-tent in the surface layer.

Basic Test

Materials needed:Shovel

What to do:1. Collect a surface soil sample.2. Collect a sample from 4-6 inches

deep.3. Compare the soil color from the

two depths. (Note: samples needto be compared when they are atthe same moisture level.)

4. Note the color differences. Is thesurface color similar to the subsoilcolor?

5. Smell the soil sample. A sweet,earthy smell indicates a soil high inorganic matter.

5 Plant Residue

What is plant residue?Plant residues protect the soil surface fromerosion as well as providing organic materialsto the soil. Plant residues located at the soilsurface break up the energy of raindrops andprevent the washing of surface soil particles.Plant residue from a previous crop, or addedorganic material such as manure or straw,decomposes over time and becomes soilorganic matter.

Soil organisms break down plant residue andrecycle it into many different forms thatbenefit the soil. Most of the decompositionthat takes place in soils is due to microbialactivity. As larger soil organisms consumeorganic residue, they reduce it to smallerpieces, thus allowing bacteria and fungi towork more efficiently.

When the soil has enough air, decompositionoccurs at an ideal rate and the soil has a fresh,earthy smell. Poorly aerated soil decomposesits organic matter more slowly and has a souror pungent smell.

Why is plant residue important?• Residue decomposition must take place

for the soil to maintain its organic mat-ter content. Organic matter is impor-tant to soil quality because it increasesthe soil’s ability to supply essential plantnutrients.

• Soil organic matter helps maintain goodsoil structure. The activities of soil or-ganisms create air and water passageways that improve soil structure.

• Rapid organic residue decompositionshows that a thriving biological com-munity lives in the soil.

• When organic residue is present, it in-creases infiltration and water storage.In this way, the potential for erosion bywater runoff is reduced.

How does management impact plantresidues?Management systems that include a majorityof high residue producing crops provide thelargest amount of available plant residues.

Residue management systems that are consid-ered no-till or direct seed systems leave themost plant residues on the soil surface. Mini-mum tillage, inversion tillage, and conven-tional tillage systems leave the least amountsof plant residues on the soil surface.



A good time to assess plant residue decompo-sition is during the growing season or in thefall, perhaps at the same time that soil struc-ture is assessed.

Wait at least one month after incorporating acover crop or other residue before assessingthis indicator.

Be sure to do this assessment at the same stateof soil moisture and temperature each timebecause these conditions affect the smell ofthe soil.



No visible residue onsoil surface. Residuedoes not decompose.

Some plant residuevisible on soil sur-face. Residue isslowly decomposing.

Noticeable residue on soilsurface. Residue is in allstages of decompositionand has an earthy, sweetsmell.


Materials needed:ShovelSquirt bottle with water

What to do: 1. Dig down at least 6 inches and

examine the soil for organic residueby breaking the soil apart with yourfinger. Look for evidence of organicresidue in various stages of decom-position.

2. Smell the soil particle after break-ing it apart and note the smell.

3. Lightly moisten some soil with asquirt bottle. Rub this soil betweenyour fingers and see if it leaves adark stain that is difficult to remove.

Basic Test

6 EarthwormsWhat are earthworms?There are thousands of species of earthwormsin the world. The two major behavioralclasses of earthworms that dwell in agricul-tural soils are the shallow soil species and thedeep burrowing species.

The shallow soil dwelling species are about 3to 5 inches long. These species dwell in thetop 12 inches of the soil, and burrow ran-domly through the soil, consuming plantresidues and mineral soil. This worm speciesis more active in the spring and fall.

The deep burrowing earthworm species areabout 4-8 inches long. These species constructlarge vertical permanent burrows that can beup to 6 feet deep. Deep burrowing earth-worms pull plant residues from the soil sur-face down into their burrows. This residue isdigested as it becomes softer and more de-composed. These earthworms are only foundin fields where permanent surface residueexists.

Why are earthworms important? • Earthworms have long been recog-

nized as an important part of goodagricultural soils. Burrowing typesingest large amounts of organic ma-terials and mineral soil and excretethem as casts at the soil surface.Earthworm casts contain more en-zymes, bacteria, organic matter, andavailable plant nutrients than the sur-rounding soil.

• Earthworms mix the soil and breakup raw plant material. Some bringorganic residue from the surface downinto their burrows and, in turn, de-posit minerals from deep soil layersat the surface with their casts.

• The movement of earthwormsthrough the soil creates passagewaysthat increase aeration and water in-filtration. Their lubricating secretionsbind soil particles together and in-crease aggregate stability.

How does management impact earth-worms?Management can directly affect earthwormpopulations. Addition of organic residues andcover crops provides food sources and can in-crease the diversity and abundance of earth-worms.

Management practices that leave permanentsurface cover, such as direct seeding or mini-mum tillage, support a larger more diversifiedearthworm population. This type of manage-ment supplies a larger food source and mulchprotection.



This indicator is assessed by digging into thesoil at about 12 inches and counting howmany earthworms are present, along with thesize of each worm.

• Earthworms are very sensitive tosoil moisture and temperature. Ifthe topsoil is too dry or saturated, orif the soil temperature is too hot ortoo cold, you won’t see them.

• Assess earthworm abundance in thelate spring and late fall when the soilis moist, but not saturated, and rela-tively warm.

• Time of day and weather should beconsistent among assessments sincethese factors also affect earthwormactivities.



0-1 worms in shovelfulof top foot of soil. Noworm casts or holes.Few insects or fungi.

2-10 worms in shovel-ful. Few casts, holesor worms. Some in-sects and fungi.

10+ worms in top footof soil. Lots of castsand holes in tilledclods. Birds behindtillage. Many insectsand fungi.


Basic Test

Materials needed:Shovel

What to do:1. Excavate a 12”x12”x12” hole,

using the shovel.2. Count the number of earth-

worms found in the excavatedsoil.

3. Note any earthworm castings or holes.

7 Erosion

What is soil erosion?Soil erosion is the physical wearing of theearth’s surface caused by wind, water orgravity. Soil erosion is a serious form of soildegradation.

Soil erosion may be a slow process that con-tinues relatively unnoticed, or it may occur atan alarming rate causing serious loss of top-soil.

Why is soil erosion important? • Soil erosion is important because ero-

sion removes the topsoil, the most pro-ductive layer in the soil profile. Soilerosion also reduces levels of soil or-ganic matter and contributes to thebreakdown of soil structure.

• Erosion removes the surface soil or top-soil, which often has the highest bio-logical activity and the greatest amountof soil organic matter. This causes aloss of nutrients and often creates aless favorable environment for plantgrowth and biological activity.

• Nutrients removed by erosion are nolonger available to support plantgrowth onsite, but can accumulate inwater where such problems as algaeblooms and eutrophication may occur.

• Deposition of eroded material can ob-struct roadways and fill drainage chan-nels. Sediment can damage fish habi-tat and degrade water quality instreams, rivers and lakes.

• Wind erosion can affect human healthand create public safety hazards.

What does management have to dowith soil erosion?Soil erosion can be prevented by reducing theamount of tillage on a field. Reduced tillageresults in more soil organic matter and plantresidues which aid in restricting the impact ofrain drops and prevent soil erosion.

No till and direct seed systems greatly reduceerosion by leaving residue on the soil surfaceand by not inverting the soil.

The physical characteristics of a field cancontribute to soil erosion. Factors such asslope gradient and length of field can affectthe speed of water flowing over the field.Splitting a field into different sections, such asin strip cropping, can reduce the soil erosion.



Soil erosion is assessed in the spring of theyear, after snow melts and more runoff oc-curs.

An advanced method (shown at right) maybe used for a quantitative measurement.

Basic Test

Materials Needed:Ruler or tape measure

What to do:1. Walk the field and observe the soil

surface for rill or gully erosion.2. Measure the rill or gully depth.3. Select appropriate rating on

indicator card.



Large gullies over 2”deep, joined to oth-ers. Thin or no top-soil, rapid runoffwith dark coloredwater.

Few rills or gullies;gullies up to 2”deep. Some swiftrunoff, light browncolored water.

No gullies or rills.Clear water or norunoff from soilsurface.


Advanced Test

The Alutin Rill Erosion Method was devel-oped by USDA/NRCS. Losses greater than100 tons per acre are considered ephemeralor concentrated flow erosion and shouldnot be measured using this method.

Materials Needed:Rule and tape measureNotebook for data recording

What to do:1. Using a tape measure , measure a

lineal distance of 37.5 or 75 feetacross a slope.

2. Using a ruler, measure (in inches)the width (W) and depth (D) of eachrill along the chosen distance.Record in the notebook.

3. Multiply each width and depthreading to obtain a product insquare inches (W x D = squareinches).

4. Add all products of readings alongthe chosen distance (sum of squareinches calculations).

5. Divide this sum by 3 if a 37.5 footdistance was selected, or divide by 6if the 75 foot distance was chosen.The result is ton(s) of soil loss peracre from rill erosion.

8 Seedling EmergenceWhat is seedling emergence?Seedling emergence is the emergence of theseed through the soil surface. Efficient man-agement is key for good crop emergence.This is the critical stage for achieving evencrop stands for good quality and yields. Inthe Palouse and Nezperce Prairies, this typi-cally occurs during the fall and spring of theyear.

Why is seedling emergence impor-tant? • This is the critical stage for good crop stand development. Better seedling emergence creates a higher yielding crop.

What does management have to dowith seedling emergence?Using Direct Seed technologies under ad-equate growing conditions, planted seed canreadily absorb more water and emergehealthier due to more nutrients from in-creased organic matter concentrations andmore stored water.

Managing for the seedling emergence stage ofcrop development can be economically effi-cient with management of crop residues.Crop residues increase storage of moisture inthe soil, decrease soil erosion and protect theseed beds for emerging seeds.

Erosion is not as frequent compared to fieldswhere excess tillage was used for preparingseed beds. Surface crusting is also decreasedwith management of crop residues, makingseedling emergence easier.

Using multiple crop rotations is important forisuring each crop has successful seedlingemergence. Planting winter wheat, followedby spring wheat or barley, peas, lentils orchickpeas, subsequently followed again bywinter wheat in the higher precipitation areas,can be beneficial to building soil health toproduce better seedling emergence. Alternat-ing crop rotations can also break disease andweed cycles and improve nutrient availabilityover time.

Consistent seed drilling depths are importantfor successful seedling emergence. Usingdepth bands for the desired depths is recom-mended. Types of drills used with seedlingsare also important. This should be deter-mined depending on moisture zone and soiltexture.





Slow and unevenemergence.

Some variabilityin emergence.

Rapid and evenemergence.

Always observe at same interval after seeding,generally 7-10 days, depending on the cropplanted.

Determine whether the planted rows can bereadily observed.

Use a ruler or tape measure to observe theheight of seedlings and the approximatenumber of seedlings that have emerged perfoot. Emergence is uniform if all seedlings areapproximately the same height and occur inthe same numbers per unit measured.


Basic TestMaterials needed:

Ruler or tape measureWhat to do:

1. Measure several 100’ sections ofseeded rows.

2. Count the number of plantsemerging in the 100’ section.

3. Randomly measure the height ofseveral plants within the row.Plants with the same heightindicate even emergence.

9 Plant Growth and Vigor

What is plant vigor?Plant vigor is indicated by the health of indi-vidual plants in the field. Uniform growth ofall crop plants in a field is also a factor inplant vigor. Crop plants within a field thatreach maturity at the same time are alsoanother sign of good plant vigor.

Plant vigor is, in some ways, difficult to judgebecause plants respond to fertilizer inputs,pest problems and other factors not directlyrelated to soil quality.

The growth of all plants growing in the field,including weeds, can be used to assess thisindicator.

Why is plant vigor important?• Good plant growth requires a soil

with good structure, water regulation,nutrient cycling ability, and a diver-sity of soil organisms. Good plantvigor is an indication that these con-ditions are present.

What does management have to dowith plant vigor?With this indicator, it is especially importantto determine whether the crop was underoptimal management. If management wasless than optimal (e.g., late planting, insuffi-cient irrigation or rainfall, etc.), then plantvigor may not be a good soil-quality indicator.

Examine the crop for pest or disease damage.It is important to determine whether thedisease problem is related to soil quality. Forexample, root-borne diseases may be caused,in part, by compacted soil that remains satu-rated with water for long periods.



Assess plant vigor during the active growthphase of the plant, before flowering.

The light conditions during the assessmentmust be the same each time; for example, ashade of green looks different in full sunlightat midday than it would under a cloudy skyor later in the day.



Uneven color, variableheight and population,poor growth, visibleevidence of plantstress.

Some variation incolor, height, andpopulation; moder-ate growth; mildstress.

Uniform deep-greencolor, rapid growth,even stand (height andpopulation), no visiblesigns of stress.


Basic Test:

Materials needed:None

What to do:1. Walk a section of the field.2. Note color of plants, height of plants,

number of plants, and evidence ofplant stress.

10 Rooting SystemsWhat is healthy root growth?Root growth often is as extensive as above-ground plant growth. Soil with good struc-ture encourages a strong root system thatsends out many fine roots to explore as muchof the soil as possible.

Why is root growth important?• Roots are in direct contact with soil

constituents such as air, water, organ-isms, and soil aggregates. If these fac-tors are suboptimal, then plant rootsshow less than ideal characteristics.

• Plant roots supply the rest of the plantwith nutrients and water. A strong rootsystem anchors the plant and supportsits upright growth.

• Good root growth may indicate a di-verse population of soil organisms sup-ported by abundant organic matterthat inhibits the spread of certain rootdiseases caused by detrimental fungi,bacteria or nematodes.

Root growth can be restricted by coompactedlayers in the soil and by soil that is saturatedwith water for days at a time. Poor rootgrowth can be an indication of these condi-tions.

Management that encourages good soil struc-ture also promotes root growth. Cultivationand compaction can inhibit root growth.

Factors that contribute to good plant vigor arereflected in healthy roots as well.


How does management impact rootgrowth?

How is the indicator assessed?Assess root growth at the same time thatplant vigor is assessed -- during the growingseason of the plant.

Moisture conditions in the soil should besimilar for each assessment because thewetness of the soil may change the ease withwhich finer roots can be observed.

Basic Test

Materials needed:ShovelHand Trowel

What to do:1. Dig around a crop plant as extensively as

possible to get an idea of how deep theroots extend into the soil.

2. Examine the root system by separat-ing the soil from the roots.

3. Look for:• Extent of root system development• Number of fine roots• Color of new roots

Note: Weeds or annual crop plants can be re-moved completely from the soil for assessment.Examine perennial crop root systems in place bydigging soil away from beside the plant andremoving soil from around the roots with atrowel.



Few or no rootspresent; roots short,coarse, not uniformlydistributed; rootsgrowing sideways;obvious restrictions.

Roots present inprofile; somemisshaped roots;some restrictionto root growth.

Robust, large, deep,well-dispersed rootsystem; no obviousrestriction to rootgrowth; many fineroots.


palouse and nezperce prairies soil quality card guide

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