麦季牛场肥水灌溉对冬小麦-夏玉米产量与磷吸收利用及土壤剖面分布的影响

在华北平原灌溉区，采用冬小麦 夏玉米周年轮作田间试验，研究麦季牛场肥水灌溉对冬小麦和夏玉米产量、磷吸收量、磷累计利用率及土壤积累的影响.结果表明：麦季肥水灌溉能显著提高冬小麦和夏玉米产量，冬小麦产量随肥水带入磷的增加先增加后降低，肥水灌溉带入137 kg P₂O₅·hm^-2时冬小麦产量最高，磷的当季利用率较高，分别为7646.4 kg·hm^-2和24.8%，肥水灌溉带入过量磷会降低冬小麦产量和磷当季利用率；夏玉米产量和磷素吸收量随冬小麦季肥水灌溉带入磷量增加而增加，后季夏玉米产量增加2222.4～2628.6 kg·hm^-2，磷吸收量增加13.9～21.1 kg·hm^-2.农民习惯施肥处理夏玉米当季施磷88 kg P₂O₅·hm^-2时，与不施肥处理相比，夏玉米产量增加2235.0 kg·hm^-2.随着牛场肥水灌溉年限的推移，作物增产效果逐渐明显，冬小麦 夏玉米轮作体系作物累计磷利用率逐年升高，6季作物收获后，磷累计利用率达40.0%～47.7%.试验条件下，
冬小麦 夏玉米轮作体系进行2次肥水灌溉是较经济安全的灌溉模式.

Effects of irrigation using dairy effluent on grain yield,phosphorus utilization and distribution in soil profile in winter wheat summer maize rotation system.

Field experiments of winter wheat summer maize rotation were conducted in North China Plain irrigation area to explore the effects of wheat season irrigation with dairy effluent on grain yield, phosphorus uptake, accumulative phosphorus usage efficiency and phosphorus accumulation in soil. The results showed that the irrigation with dairy effluent significantly improved the yields of winter wheat and summer maize. With the increasing of P₂O₅ carried by dairy effluent into soil, winter wheat yield increased at first and then decreased. When the P₂O₅ increased 137 kg·hm^-2, winter wheat yield increased to the maximum (7646.4 kg·hm^-2) and the phosphorus utilization rate was the highest (24.8%). But excessive phosphorus decreased the winter wheat yield and phospho rus utilization efficiency. Summer maize yield and phosphorus uptake increased with the increase of P₂O₅ carried by dairy effluent. The summer maize yield increased by 2222.4-2628.6 kg·hm^-2 and the phosphorus uptake increased by 13.9-21.1 kg·hm^-2 in contrast to the control (CK). Under conventional phosphorus fertilization at 88 kg·hm^-2, and the summer maize yield increased by 2235.0 kg·hm^-2 compared with CK. As the time of irrigation with dairy effluent increasing, the grain yield increased more significantly. The cumulative phosphorus utilization in this rotation system increased year by year. After six seasons of crop harvest, the cumulative phosphorus utilization rate increased into 40.0%-47.7%. Under the experimental condition, two times of irrigation with the dairy effluents in the winter wheat summer maize rotation system was the best operating mode.