Options for reducing the negative effects of nitrogen in agriculture
After addition to farms by fertilizer, crop residues, biological fixation and animal excreta, nitrogen can be lost through gaseous emission, runoff and leaching to contaminate the atmosphere and water bodies, and cause adverse health effects. The efficiency of fertilizer hitrogen can be increased and losses reduced, by matching supply with crop demand, optimizing split application schemes, changing the form to suit the conditions, and use of slow-release fertilizers and inhibitors. In addition, agronomic practices such as higher plant densities, weed and pest control and balanced fertilization with other nutrients can also increase efficiency of nitrogen use. Efficiency of use by animals can be increased by diet manipulation. Feeding dairy cattle low degradable protein and high starch diets, and grazing sheep and cattle on grasses high in water soluble carbohydrate result in less nitrogen excretion in urine and reduced ammonia volatilization.
作 者： J. R. Freney 作者单位： CSlRO Plant Industry, G.P.O. Box 1600, Canberra, A.C.T. 2601, Australia 刊 名： 中国科学C辑（英文版） SCI 英文刊名： SCIENCE IN CHINA SERIES C (LIFE SCIENCES) 年，卷(期)： 2005 48(z2) 分类号： P5 关键词： options for reducing the negative effects nitrogen in agriculture