Location: Agricultural Systems ResearchTitle: Nitrogen fertilization I: Impact on crop, soil and environment
|GHIMIRE, RAJAN - New Mexico State University|
|PRADHAN, GAUTAM - Williston Research Center|
Submitted to: Intech
Publication Type: Book / Chapter
Publication Acceptance Date: 3/25/2019
Publication Date: 9/8/2019
Citation: Sainju, U.M., Ghimire, R., Pradhan, G. 2019. Nitrogen fertilization I: Impact on crop, soil and environment. In: Serra, A., editor. Nitrogen in Agricultural Systems. London, U.K.:IntechOpen. p. 1-24.
Technical Abstract: Nitrogen (N) is a major limiting nutrient to sustain crop yields and quality. As a result, N fertilizer is usually applied in large quantity to increase crop production throughout the world. Application of N fertilizers has increased crop yields and resulted in achievement of self- sufficiency in food production in many developing countries, including Nepal. Excessive application of N fertilizers beyond crops’ demand, however, has resulted in undesirable consequences of degradation in soil, water, and air quality. These include soil acidification, N leaching in groundwater, and emissions of nitrous oxide (N2O), a potent greenhouse gas that contributes to global warming. Long-term application of ammonia-based N fertilizers, such as urea, has increased soil acidity which rendered to soil infertility where crops fail to respond with further application of N fertilizers. This is a major problem in countries, including Nepal, where N fertilizers are continuously applied, sometime in excessive amounts, to increase crop yields, population density is high, and crop production needs to be enhanced to feed the growing population. Another problem is the groundwater contamination of nitrate-N (NO3-N) which can be a health hazard to human and livestock if its concentration goes above 10 mg L-1 in drinking water. The third problem is emissions of N2O gas which is 300 times more powerful than carbon dioxide in terms of global warming potential. Therefore, novel management practices are needed to reduce N fertilization rates and enhance soil and environmental quality while sustaining crop yields. This chapter examined the effect of N fertilization on soil and environmental quality and crop yields and discussed improved management techniques to reduce N fertilization rate, sustain crop yields, and improve soil and environmental quality, with a special context for Nepal.