impact of urban areas on farming

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IMPACT OF URBAN AREAS ON FARMING Dr. N. Sai Bhaskar Reddy [email protected] Urbanisation is possible only with the surplus production by the farmers. The global urban population is already more than 50% and in some of the states in India, the urban population soon exceeds the rural population. The rivers flowing out of urban areas loaded with domestic sewage and industrial pollutants are the source of water for irrigation by farmers. If crops are irrigated by polluted water the crops cultivated are also polluted. Especially the periurban areas and areas close to urban areas are high intensive agriculture areas, especially farmers cultivating perishable crops and diary. The crops include mainly leafy vegetables, vegetables, grass as fodder for milch animals, etc. In the recent years the small rivers or they could be best called sewerages have become perennial and the total flows have tremendously increased. The farmers in the periurban areas are cultivating throughout the year i.e., harvesting 3 to 4 crops in a year. The heavy metal contaminants from the polluted waters are reaching the consumers through the food chain. Especially in the leafy vegetables the heavy metal contaminants and biological pathogens are finding their way. As the domestic sewage systems has heavy loads of phosphates and nitrogen apart from other nutrients the farmers need to invest very little on the fertilizer inputs. The overall yield of some of the crops grown is very high. Some grasses are highly adapted to these polluted waters, but loaded with pollutants affecting the quality of milk and other products. The rainfall in the perurban areas is sometimes higher, due to air pollutants (particulate matter), acting as nuclei for the cloud seeding. But the acid rains are very common in the perurban areas as there are many acidic polluted air (such as sulphur, CO2, NOx, et.). The acidic rains and the pollutants affect the crops. The natural drainage systems are affected due to the urban infrastructure and construction activities. The outer ring roads which are elevated has impacted the natural drainage systems, especially the every years recharging and filling of the tanks. Most of the tanks in the per-urban areas are not being filled. If “the tank bunds are roads – why not roads as tank bunds”, say around Hyderabad there are two ring roads, Outer ring road 158 kms (almost completed) and 290 kms (proposed regional ring road), the same elevated ring roads could be used for creating at last 100 tanks which could harvest all the waters from the urban areas and useful to the farmers in the per- urban areas for irrigation. The urban areas could also use for urban greenery, recharge and reuse of the waters. The overall ground water in the peri-urban areas is highly depleted due to urbanisation. The demand for water in the urban areas is very high. The farmers dependent on the groundwater are having great difficulty in having water. The ground water as they go deeper is saline, the saline waters when applied to the fields over a period increase the alkalinity of the soils.

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Page 1: Impact of urban areas on farming

IMPACT OF URBAN AREAS ON FARMING

Dr. N. Sai Bhaskar Reddy

[email protected]

Urbanisation is possible only with the surplus production by the farmers. The global urban

population is already more than 50% and in some of the states in India, the urban population soon

exceeds the rural population. The rivers flowing out of urban areas loaded with domestic sewage

and industrial pollutants are the source of water for irrigation by farmers. If crops are irrigated by

polluted water the crops cultivated are also polluted. Especially the periurban areas and areas close

to urban areas are high intensive agriculture areas, especially farmers cultivating perishable crops

and diary. The crops include mainly leafy vegetables, vegetables, grass as fodder for milch animals,

etc. In the recent years the small rivers or they could be best called sewerages have become

perennial and the total flows have tremendously increased. The farmers in the periurban areas are

cultivating throughout the year i.e., harvesting 3 to 4 crops in a year. The heavy metal contaminants

from the polluted waters are reaching the consumers through the food chain. Especially in the leafy

vegetables the heavy metal contaminants and biological pathogens are finding their way. As the

domestic sewage systems has heavy loads of phosphates and nitrogen apart from other nutrients

the farmers need to invest very little on the fertilizer inputs. The overall yield of some of the crops

grown is very high. Some grasses are highly adapted to these polluted waters, but loaded with pollutants affecting the quality of milk and other products.

The rainfall in the perurban areas is sometimes higher, due to air pollutants (particulate matter),

acting as nuclei for the cloud seeding. But the acid rains are very common in the perurban areas as

there are many acidic polluted air (such as sulphur, CO2, NOx, et.). The acidic rains and the

pollutants affect the crops.

The natural drainage systems are affected due to the urban infrastructure and construction

activities. The outer ring roads which are elevated has impacted the natural drainage systems,

especially the every years recharging and filling of the tanks. Most of the tanks in the per-urban

areas are not being filled. If “the tank bunds are roads – why not roads as tank bunds”, say around

Hyderabad there are two ring roads, Outer ring road 158 kms (almost completed) and 290 kms

(proposed regional ring road), the same elevated ring roads could be used for creating at last 100

tanks which could harvest all the waters from the urban areas and useful to the farmers in the per-

urban areas for irrigation. The urban areas could also use for urban greenery, recharge and reuse of the waters.

The overall ground water in the peri-urban areas is highly depleted due to urbanisation. The demand

for water in the urban areas is very high. The farmers dependent on the groundwater are having

great difficulty in having water. The ground water as they go deeper is saline, the saline waters when applied to the fields over a period increase the alkalinity of the soils.

Page 2: Impact of urban areas on farming

The leachates from the solid waste dump yard sites are polluting the ground water. In the recent

past people are producing compost from the city waste. The city waste compost has highest number

of the pollutants including the plastics which cause cancer. Some farmers buy these materials for

soil amendment / grown regulator for very high yield of the crops. But these pollutants find their

way into the food chain and finally in the products consumed by people. There are no regulatory

mechanisms.

Sewagigation and floatigation are the two methods for urban greenery are partially meeting the food security needs from less polluted water sources.

At least 20% of the urban green spaces should be used for growing plants whose products could be

consumed by the people. Urban greenery is a waste of resources and funds, incase of a calamity

none of the plants in urban areas could be consumed. Many plants are poisonous and exotic. If they don’t even support the local life like animals, birds and insects.

Instead of seeing the urban areas affecting the agriculture, there is a need to explore the possibilities of how urban areas could also support the farmers.