Environmental impact of modern agriculture
• The environmental impact of modern agriculture is the effect that different farming practices have on the ecosystems around them, and how those effects can be traced back to those practices.
• The environmental impact depends on the production practices of the system used by farmers.
• The connection between emissions into the environment and the farming system is indirect, as it also depends on other climate variables such as rainfall and temperature.
• There are two types of indicators of environmental impact:
"Means-based", which is based on the farmer's production methods. For ex: the quality of groundwater, that is effected by the amount of nitrogen applied to the soil, and
"effect-based", which is the impact that farming methods have on the farming system or on emissions to the environment. For ex: An indicator reflecting the loss of nitrate to groundwater.
Issues related to Agriculture
• Assessment of the effects of global climate changes on agriculture might help to properly anticipate and adapt farming to maximize agricultural production.
• Agriculture has been shown to produce significant effects on climate change, primarily through the production and release of greenhouse gases such as carbon dioxide, methane, and nitrous oxide that affect air, water, and soil quality, as well as biodiversity.
• Agriculture also alters the Earth's land cover, which can change its ability to absorb or reflect heat and light, thus contributing to radiative forcing.
• Deforestation is clearing a wide area of trees. One of the causes of deforestation is to clear land for pasture or crops.
• Trees act as a carbon sink: that is, they absorb carbon dioxide, an unwanted greenhouse gas, out of the atmosphere.
• Removing trees releases carbon dioxide into the atmosphere and leaves behind fewer trees to absorb the increasing amount of carbon dioxide.
• It worsens climate change and causes extreme fluctuations in temperature.
• Genetically engineered crops are herbicide-tolerant, and their overuse has created herbicide resistant "super weeds", which may ultimately increase the use of herbicides.
• Seed contamination is another problem of genetic engineering; it can occur from wind or bee pollination that is blown from genetically-engineered crops to normal crops.
• Among some of these problems is the depletion of underground aquifers through over-drafting.
• Soil can be over-irrigated because of poor water distribution and poor management of waste water, chemicals, leads to water pollution.
• Over-irrigation can cause deep drainage from rising water tables that can lead to problems of irrigation salinity requiring water table control by some form of subsurface land drainage.
• A wide range of agricultural chemicals are used in farming. some of them become pollutants through use, misuse, or ignorance.
• Pesticides can leach through the soil and enter the groundwater, as well as linger in food products and result in death in humans.
• The erosion of topsoil, which contains chemicals such as herbicides and pesticides, can be carried away from farms to other places.
• Additional and specific problems that may arise with the release of pollutants from agriculture are Pesticide drift, soil contamination, air pollution spray drift, Pesticides, especially those based on organochloride, Pesticide residue in foods, Pesticide toxicity to bees, Bioremediation.
• Soil degradation is the decline in soil quality that can be a result of many factors, especially from agriculture.
• Soils hold the majority of the world's biodiversity, and healthy soils are essential for food production and an adequate water supply.
• Common attributes of soil degradation can be Soil erosion, salting, waterlogging, pesticide contamination, decline in soil structure quality, loss of fertility, changes in soil acidity, alkalinity, and salinity.
• Plasticulture is the use of plastic mulch in agriculture. Farmers use plastic sheets as mulch to cover 50-70% of the soil and allows them to use drip irrigation systems to have better control over soil nutrients and moisture.
• Rain is not required in this system, and farms that use Plasticulture are built to encourage the fastest runoff of rain.
• The incineration and recycling options are complicated by the variety of the types of plastics that are used and by the geographic dispersal of the plastics.
• While there has been minor success with this, there is also the problem of how long the plastic takes to degrade, as many biodegradable products take a long time to break down.