The weed-killing and N-fertilizer-efficiency-enhancing effect of "Yellow Urea" on rice.

A series of experiments on the weed-killing performance and N-fertilizer-efficiency-enhancing effect of urea-based rice field weedicide named “Yellow Urea”were conducted on paddy soils in Zhejiang province.The observations indicated that the “Yellow Urea” might be an excellent weedicide for as its stable and entirely weed-killing performance as well as its promoting effect on the efficiency of nitrogen fertilizer and environment-friendly feature.During the rice growing period,the weed-killing percentage was stable than 92%.Also,the “Yellow Urea”proved to be an effective controller of the most common weeds such as Echinochloa crasgalli,Cyperus amuricus,Monnochoria vaginalis,Sagittaria pygmaea,Equisetum ramossisimun,Lindernia procubens,Marsilea quadriflolia,Lemna minor,Leptochloa chinensis,Heleocharis yokoscensis.More interestingly,the “Yellow Urea”showed a distinct effect on the transformation of nitrogen fertilizer in soil,thus the recovery of urea-N would be increased by one fourth,and the nitrate-leaching could be dropped by nearly one third.All these effects may be very important to the ecological conservation and environmental preservation in the rice growing regions.