What are some positive and negative impacts of agriculture?
Over irrigation and salt buildup in soils, over fertilization and groundwater pollution, monoculture (biocide use) and loss of biodiversity are major issues.
Agriculture is number 1 water consumer (others are houses (residential areas) and industry). If farmers use excessive water for irrigation of their plants in summer days, salt buildup occurs in soil. If soil is polluted with any type of biocide (pesticide, herbicide, fungicide, etc.), groundwater resources (aquifers) as well as surface water bodies are subject to pollution. Excessive nitrogen and phosphorus application to agricultural fields causes eutrophication of surface water.
Therefore, optimum level of biocide application and optimum level of fertilizer (nitrogen and phosphorus) use should be monitored.
Monoculture is another problem because farmers tend to eradicate all other creatures when they want to harvest their products in good quantity (without any loss). Therefore, biodiversity is lost in some places where monoculture type agriculture is an issue.
People tend to cut down trees to have agricultural fields and to have palm trees instead of native trees. This is also a problem. Ecosystem functions are lost in this case.
Agriculture is beneficial when you obey the rules of nature. Organic type, subsidence agriculture and policulture agriculture are some examples of beneficial agriculture. Using drip irrigation instead of canal irrigation saves water. Best Management Practices (BMPs) should be developed and applied. Agricultural activities provide money to many people (farmers, dealers, food companies, etc.).