典型双季稻田施磷流失风险及阈值研究

发布时间：2018-11-11 13:48

【摘要】：通过3年(2011—2013年)的双季稻田间小区试验,探明了不同施磷量对双季稻产量、土壤磷素积累、磷素流失风险的影响,并确定了土壤收支平衡的施磷阈值。研究结果表明:连续3年不同施磷量处理水稻早、晚季产量为5474~5552 kg·hm~(-2)和7096~7521 kg·hm~(-2),过量施用磷肥对水稻产量无显著增产效果,反而有减产的风险。施用磷肥后,土壤Olsen-P含量显著提高。田面水TP平均浓度与土壤中Olsen-P呈显著正相关关系;施磷后田面水磷素动态能用指数模型(Y=C_0·e~(k/t),k0)拟合,即随着磷肥施用量增加,田面水磷素流失风险增加。结合水稻产量效应、土壤磷素表观平衡和磷素环境风险,推荐研究区域早、晚稻施磷阈值分别为(48.53±7.07)kg P_2O_5·hm~(-2)和(56.87±7.90)kg P_2O_5·hm~(-2)。
[Abstract]:The effects of different phosphorus application rates on the yield, soil phosphorus accumulation and phosphorus loss risk of double-cropping rice were investigated by field experiments of three years (2011-2013), and the threshold value of phosphorus application in balanced soil income and expenditure was determined. The results showed that the rice yield was 5474N 5552 kg hm~ (-2) and 7096g 7521 kg hm~ (-2) in three successive years with different phosphorus application rates. The excessive application of phosphorus fertilizer had no significant effect on rice yield increase, but had the risk of reducing yield. The content of Olsen-P in soil increased significantly after the application of phosphorus fertilizer. There was a significant positive correlation between average concentration of TP and Olsen-P in soil. The dynamic energy of phosphorus in field surface water after phosphorus application was fitted with the exponential model (Y=C_0 e ~ (k / t), k _ 0), that is, the risk of phosphorus loss increased with the increase of application of phosphorus fertilizer. Considering rice yield effect, soil phosphorus apparent balance and phosphorus environmental risk, it is recommended that the study area be early. The P application threshold of late rice was (48.53 卤7.07) kg P_2O_5 hm~ (-2) and (56.87 卤7.90) kg P_2O_5 hm~ (-2) respectively.
【作者单位】：中南大学研究生院隆平分院;湖南省农业科学院/农业部长江中游平原农业环境重点实验室/农田土壤重金属污染防控与修复湖南省重点实验室;
【基金】：湖南省重点研发计划项目(2016JC2028)~~
【分类号】：S511;X712

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