Irrigation supports the large harvest yields that such a large population demands. Researchers and farmers alike are becoming increasingly aware of the consequences of this large-scale diversion of freshwater. One of the most obvious consequences is the depletion of aquifers, river systems, and downstream ground water.
However, there are a number of other negative effects related to irrigation. Areas drenched by irrigation can become waterlogged , creating soil conditions that poison plant roots through anaerobic decomposition. Where water has been diverted, soils can accrue too much salt, also harming plant growth. Irrigation causes increases in water evaporation, impacting both surface air temperature and pressure as well as atmospheric moisture conditions. Recent studies have confirmed that cropland irrigation can influence rainfall patterns not only over the irrigated area but even thousands of miles away.
Irrigation has also been connected to the erosion of coastlines and other kinds of long-term ecological and habitat destruction. Livestock Grazing A huge amount of agricultural territory is used primarily as pasture for cattle and other livestock. In the western United States, counting both federally managed and privately owned grazing lands, hundreds of millions of acres are set aside for this purpose—more than for any other type of land use.
Agricultural livestock are responsible for a large proportion of global greenhouse gas emissions, most notably methane. In addition, overgrazing is a major problem regarding environmental sustainability. In some places, stretches of forage land are consumed so extensively that grasses are unable to regenerate. The root systems of native vegetation can be damaged so much that the species die off. Near streambeds and in other riparian areas where cattle concentrate, the combination of overgrazing and fecal wastes can contaminate or compromise water sources.
Cattle and other large grazing animals can even damage soil by trampling on it. Bare, compacted land can bring about soil erosion and destruction of topsoil quality due to the runoff of nutrients. These and other impacts can destabilize a variety of fragile ecosystems and wildlife habitats.
Chemical Fertilizer Synthetic fertilizers containing nitrogen and phosphorus have been at the heart of the intensified farming from World War II to the present day. They are particularly effective in the growing of corn, wheat, and rice, and are largely responsible for the explosive growth of cereal cultivation in recent decades. While these chemicals have helped double the rate of food production, they have also helped bring about a gigantic increase, perhaps as high as percent, of reactive nitrogen levels throughout the environment.
The excess levels of nitrogen and phosphorus have caused the once-beneficial nutrients to become pollutants. Roughly half the nitrogen in synthetic fertilizers escapes from the fields where it is applied, finding its way into the soil, air, water, and rainfall. After soil bacteria convert fertilizer nitrogen into nitrates, rainstorms or irrigation systems carry these toxins into groundwater and river systems.
Accumulated nitrogen and phosphorus harm terrestrial and aquatic ecosystems by loading them with too many nutrients, a process known as eutrophication. Nutrient pollution is a causal factor in toxic algae blooms affecting lakes in China, the United States, and elsewhere. Parts of the Gulf of Mexico are regularly afflicted in this manner. Nitrogen accumulation in water and on land threatens biodiversity and the health of native plant species and natural habitats.
In addition, fertilizer application in soil leads to the formation and release of nitrous oxide, one of the most harmful greenhouse gases. Want to keep learning? This content is taken from University of Reading online course,. This content is taken from University of Reading online course. See other articles from this course. This article is from the online course:.
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