[Characteristics of paddy field nitrogen leakage and runoff in rice-duck farming system].
A field experiment was conducted to study the characteristics of paddy field nitrogen (N) leakage and runoff under rice-duck farming (MRD), conventional farming (MR), and conventional farming with flooding (CK). Comparing with that under MR, the paddy field under MRD had a notable decrease of N (especially NO3- -N) concentration in its leaked liquid; but this concentration was tended to be increased, compared with that under CK. After 7-9 days of fertilization, the NH4+ -N and NO3- -N concentrations in paddy field surface water were higher under MRD than under MR. However, owing to the no draining and the higher band, the paddy field under MRD had a notable reduction of drainage, resulting in a marked decrease of N runoff than that under MR. Comparing with MR, the paddy field under MRD had an addition of nitrogen supply from duck dung, a reduction of N leakage and runoff, a lesser application of chemical nitrogen fertilizer, and more nitrogen uptake by rice plant. Both the reduction of N input and that of N output in rice-duck farming system were nearly equal in quantity.
Yu
Xiang
X
Ministry of Agriculture Key Laboratory of Crop Physiology and Ecology in Southern China, Nanjing Agricultural University, Nanjing 210095, China. yx003@163.com
Wang
Qiang-sheng
QS
Wang
Shao-hua
SH
Liu
Zheng-hui
ZH
Wang
Xia-wen
XW
Ding
Yan-feng
YF
D000383:Agriculture / Q000379:methods*; D000818:Animals; D002681:China; D004372:Ducks / Q000254:growth & development*; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000517:prevention & control; D005308:Fertilizers; D009584:Nitrogen / Q000032:analysis*; D012275:Oryza / Q000254:growth & development*; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D012987:Soil / Q000032:analysis*
D005308:Fertilizers; D000644:Quaternary Ammonium Compounds; D012987:Soil; D009584:Nitrogen