【摘要】 连续 4年的冬小麦定位试验证明 ,旱地施磷 (P2 O5)量在 75～ 30 0 kg/ hm2时 ,小麦的增产率基本随磷肥用量的增加而提高 ,但 P2 O5的增产作用和磷肥利用率却随磷肥用量的增加而降低 ;磷肥不仅当季增产显著 ,而且后效明显 ,第 1季施磷后在第 4季 P2 O5施用量 75 kg/ hm2 的增产率为 5 3.9% ,施用量 15 0 kg/ hm2 的增产率为6 4 .3% ,施用量 30 0 kg/ hm2 的增产率为 10 9.6 % ,1kg P2 O5累计增产小麦依次为 38.7,2 5 .5 ,15 .1kg,分别为第 1次效果的 2 .2 6倍、2 .38倍和 2 .85倍。磷肥的利用率随用量增加而降低 ,当季利用率低 ,累计利用率高 ,施 P2 O575～30 0 kg/ hm2时 ,当季利用率为 12 .0 %～ 4 .3% ,累计利用率达 2 5 .0 %～ 12 .4 %。更多还原

【Abstract】 Long term oriented experiment shows that if applying P (P 2O 5) is 75~300 kg/hm 2 in dryland through planting winter wheat for 4 years,increasing ration is enhanced with use dose, but increase function of P 2O 5 and use ratio of P fertilizer fall with add of application. Not only increases Phosphorus fertilizer the yield of temporal season but also later efficiency is evident. Increase production ration of applying P 75 kg/hm 2, 150 kg/hm 2, and 300 kg/hm 2 in fourth season is respectively 53.9%, 64.3%, and 109.6% after applying P in the first season, so increase yield of 1 kg P 2O 5 is respectively 38.7 kg,25.5 kg, and 15.1 kg,which are 2.26, 2.38 and 2.85 times of first applying P. Use ration of P fertilizer is low in that season, but accumulation use ration is high, such as use ration is 12.0% ～4.3% in that season and accumulation use ration 25.0%～ 12.4% with P 75～300 kg/hm 2.更多还原