Control of Nitrogen Transformations in Soils.

摘要

Compounds that can effectively retard nitrification and urea hydrolysis in soils are clearly desirable because nitrate formed by nitrification of nitrogen fertilizers applied to soils undoubtedly contributes to nitrate pollution of water resources,and most of the problems associated with the use of urea as a fertilizer result from the rapid hydrolysis of urea by soil urease. The effectiveness of the nitrification inhibitors studied was markedly affected by soil type,soil temperature,and substitution of urea for ammonium sulfate as the source of nitrifiable nitrogen. Most of the inhibitors were considerably more effective at 15C than at 30C. Studies of the effects of three patented nitrification inhibitors (N-Serve,ATC,and CL-1580) on transformations of urea N in soils showed that these compounds had little,if any,effect on urea hydrolysis but greatly retarded nitrification of the ammonium formed by urea hydrolysis and markedly increased gaseous loss of urea N as ammonia. Studies of the effects of 10urease inhibitors had little effect on nitrification when applied at the rate of 10microgram/g of soil.