IMPACT OF AGRICULTURAL ACTIVITIES ON ENVIRONMENT

The initiatives, led by Norman Borlaug, the "Father of the Green Revolution" in 1960 s saved over a billion people from starvation, by development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers. This affected the environment in different ways.

Climate change

Land use change such as deforestation and desertification, together with use of fossil fuels, are the major anthropogenic sources of carbon dioxide; agriculture itself is the major contributor to increasing methane and nitrous oxide concentrations in earth's atmosphere.

Deforestation

One of the causes of deforestation is to clear land for pasture or crops  (5%),  heavy logging (19%),  due to the growing sector of palm oil plantations (22%), due to slash-and-burn farming (54%).

Resistance to pest and diseases : Use of synthetic pyretheroids created the problem of pesticide resistance and resurgence

Creation of super weed: Spread of genes from genetically modified plants to unmodified relatives, which might produce species of weeds resistant to herbicides. In some areas of the world "superweeds" have evolved naturally, these weeds are resistant to herbicides and have forced farmers to return to traditional crop management practices.

Loss of biodiversity:- The spread of Green Revolution agriculture affected both agricultural biodiversity and wild biodiversity. Growing of high-yield varieties of each crop led to susceptibility of a food supply to pathogens that cannot be controlled by agrochemicals. Monoculture Limits or destroys the natural habitat of most wildlife and resources. Mono culture of crops/crop varieties led to permanent loss of many valuable traditional genetic traits.  Bt-corn pollen might affect the monarch butterfly.

 Soil salinity, water logging:- Under irrigation gives poor soil salinity control which leads to increased soil salinity with consequent build up of toxic salts on soil surface in areas with high evaporation. This requires either leaching to remove these salts and a method of drainage to carry the salts away. Deep drainage (from over-irrigation) may result in rising water tables which in some instances will lead to problems of irrigation salinity requiring water table control by some form of subsurface land drainage.

Depletion of underground water:- Depletion of underground aquifers through overdrafting. Irrigation can also be done extracting groundwater by (tube)wells. As a hydrological result it is found that the level of the water descends. The effects may be water mining, land/soil subsidence, and, along the coast, saltwater intrusion.

When more groundwater is pumped from wells than replenished, storage of water in the aquifer is being mined. Irrigation from groundwater is no longer sustainable then. The result can be abandoning of irrigated agriculture.

Alter the biology of rivers and lakes:- Use of fertilizers can alter the biology of rivers and lakes (Eutrophication). Use of chemicals on fields creates run-off, excess runs off into rivers and lakes causing pollution. reduced downstream flooding. Reduced downstream river water quality

Owing to drainage of surface and groundwater in the area, which waters may be salinized and polluted by agricultural chemicals like biocides and fertilizers, the quality of the river water below the project area can deteriorate, which makes it less fit for industrial, municipal and household use. It may lead to reduced public health. Polluted river water entering the sea may adversely affect the ecology along the sea shore (Ex. Aswan dam).

Desertification: Intensive farming generally not sustainable - often results in desertification or, in a worst case scenario, land that is so poisonous and eroded that nothing else will grow . Bioretention is  an ecological restoration, mitigation, and remediation technique

Requires large amounts of energy:- Requires large amounts of energy input to produce, transport, and apply chemical fertilizers/pesticides.

Pesticide pollution: Use of pesticides have numerous negative health effects in workers who apply them, people that live nearby the area of application or downstream/downwind from it, and consumers who eat the pesticides which remain on their food. Pesticides generally kill useful insects as well as those that destroy crops.

Water pollution:- Runoff causing surface water and groundwater-aquifer hydrologic cycle water pollution. Stagnant water tables at the soil surface are known to increase the incidence of water borne diseases like malaria, filariasis, yellow fever, dengue, and schistosomiasis (Bilharzia) in many areas.

Formation of sodic soil :- Irrigation with saline or high-sodium water may damage soil structure owing to the formation of alkaline soil

Soil pollution :Agricultural waste disposal by incineration, use of fertilizers like Diammonium phosphate, Super phosphate accumulated heavy metals like cadmium lead to the soil

CASE STUDY

The Indian state of Punjab pioneered green revolution among the other states transforming India into a food-surplus country. The state is witnessing serious consequences of intensive farming using chemicals and pesticide. Indiscriminate use of chemicals increased incidence of cancer in this region.

In 2009, A study in 50 villages in Muktsar, Bathinda and Ludhiana districts revealed chemical, radiation and biological toxicity rampant in Punjab. Twenty percent of the sampled wells showed nitrate levels above the safety limit of 50 mg/l, established by WHO, the study connected it with high use of synthetic nitrogen fertilizers. With increasing poisoning of the soil, the region once hailed as the home to the Green Revolution, now due to excessive use of chemical fertilizer, is being termed by one columnist as the "Other Bhopal".