Nitrogen fertilization II - management practices to sustain crop production and soil and environmental quality

Authors: Sainju, Upendra; GHIMIRE, RAJAN - New Mexico State University; PRADHAN, GAUTAM - North Dakota State University

Submitted to: Intech
Publication Type: Book / Chapter
Publication Acceptance Date: 6/25/2019
Publication Date: 9/8/2019
Citation: Sainju, U.M., Ghimire, R., Pradhan, G. 2019. Nitrogen fertilization II - management practices to sustain crop production and soil and environmental quality. In: Rigobelo, E. and Serra, A., editors. Nitrogen Fixation. London, U.K: IntechOpen Limited. p. 1-22. https://doi.org/10.5772/intechopen.86646
DOI: https://doi.org/10.5772/intechopen.86646

Interpretive Summary: Nitrogen deficiency is the nutrient stress with the greatest potential to limit plant growth in cropping systems. Development of an economical method for producing synthetic, chemically-fixed nitrogen fertilizer has provided an affordable means for farmers to add supplemental nitrogen to their crops since the mid-20th century. Nitrogen fertilizer increases crop yields while reducing dependence on pre-industrial sources such as green manure crops and livestock manure. Conversely, excessive use of chemical nitrogen fertilizers reduces nitrogen-use efficiency, which is an economic loss, and can degrade soil and environmental quality by increasing soil acidification, nitrate-nitrogen leaching, and nitrous oxide gas emissions. Acidified soil is less productive than soil with a neutral pH; nitrogen leaching presents a health concern when nitrate-nitrogen contaminates drinking water sources, and nitrous oxide is a potent greenhouse gas. In some situations, applying too much nitrogen fertilizer can also negatively affect crop yield and quality. In order to address these problems associated with over-application of nitrogen fertilizers in modern cropping systems, researchers re-evaluated management techniques such as crop rotation, cover cropping, application of manures and composts, integrating crop and livestock production, and applying lime to neutralize soil acidity. The results summarized in this publication show that these practices reduce the amount of synthetic nitrogen fertilizer applied or, in the case of liming, correct nitrogen fertilizer’s negative effect on the soil, allowing farmers to sustain crop yields while improving soil and environmental quality.

Technical Abstract: Improved management practices can be used to sustain crop yields, improve soil quality, and reduce N contaminations in groundwater and the atmosphere due to N fertilization. These practices include crop rotation, cover cropping, application of manures and compost, liming, and integrated crop-livestock system. The objectives of these practices are to reduce the rate of N fertilization, enhance N-use efficiency, increase crop N uptake, promote N cycling and soil N storage, and decrease soil residual N. This chapter discusses improved management practices to reduce N fertilization rate, sustain crop yields, and improve soil and environmental quality. The adaptation of these practices by farmers, producers, and ranchers, however, will depend on social, economic, soil, and environmental conditions.