Applications Nitrogen Fertilizers

Fig. I. Effect of nitrogen fertilizer application on crop of irrigated com (maize) in state of Washington. It should be pointed out that the very high yields were obtained under experimental, carefully controlled conditions. Although much higher yields are obtained in some regions, the average yield in the United States is 87.3 bushels/acre (5489 kilograms/hectare). The world average is 45 bushels/acre (2829 kilograms/hectare)...

Increasing the rate of nitrogen fertilizer application affected the relative proportions of some of the essential oil components (Martin et al., 1985). At higher N rates, limonene and other monoterpene concentrations decreased to very low values, while those of sedanolide and phthalides increased to above 75% (D Antuono et al., 2002). 

Table 4.3. Guidelines for nitrogen fertilizer application based on N...

A nitrification inhibitor that is fully effective would be expected to (1) increase efficiency in the use of nitrogen fertilizers, especially on coarse-textured soils where rainfall is high, or extensive irrigation is practiced (2) make more feasible the practice of fall applications of ammonia (3) make less critical the time of nitrogen fertilizer applications and the need for split applications and (4) reduce nitrogen losses that may occur via nitrite decomposition or reaction with organic matter. Whether the benefits to be expected are sufficient to more than offset the costs of the chemical, and the additional steps involved in its use, is a practical matter that must be determined by the user for his particular soil and cropping system. 

The linkage between the biosphere and the atmosphere has to be assumed to have been in equilibrium prior to the current industrial age. Nitrogen species (NOx, N2O, N2), emitted from plants, soils and water into the atmosphere, which are biogenically produced within the redox cycle between nitrification and denitrification, will be oxidized to nitrate and return to the biosphere. This cycle has been increasingly disturbed since the beginning of the Industrial Revolution more than 100 years ago. The most important aspect in the anthropogenically-modified N cycle is the worldwide increase of nitrogen fertilizer application. Without human activities, biotic fixation provides about 100 Tg N yr" on the continents, whereas... 

Kowalenko CG (2000) Influence of sulfur and nitrogen fertilizer applications and within-season sampling time on measurement of total sulfur in orchardgrass by six different methods. Communications in Soil Science and Plant Analysis 31 345-354. 

Watcins, K. B., Lu Yao-Chi, Wen-yuan, Huang. Economic and environmental feasibility of variable nitrogen fertilizer application with carry-over effects. Journal of Globd Positioning System. Vol. 23, >fo 2,401 26. 

Average nitrogen fertilizer applications in China s provinces in 1995. 

Correlation between nitrogen fertilizer applications and riverine flux of nitrogen. 

Highest Average Annual Nitrogen Fertilizer Applications to Major Crops during the Mid-1990s... 

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