The influence of coated urea on yield and quality of vegetable crops and nitrogen balance in calcareous Chao soil.

摘要

A pot experiment was conducted in a glasshouse to investigate the effect of coated fertilizers in calcareous Chao soil on uptake and balance of nitrogen (N), yield and quality of vegetable crops. Results indicated that 2 kinds of texture of calcareous Chao soils applied with coated urea, increased the first seasonal celery (Apium graveolens L.) yield by 11.5-15.2% and N uptake by 5.9-9.5%. Ammonia volatilization was reduced by 14.2-14.9% while N loss of leaching and denitrification was reduced by 25.5-28.3%. N remained in soil was enhanced by 32.0-37.3% and the utilization efficiency of N increased by 20.1-27.9% compared with urea. The concentration of NO₃--N decreased by 44.2-58.9% while vitamin C obviously increased in celery shoots. The yield of lettuce (Lactuca sativa L.) increased by 14.4-35.2% (after effect).