施磷量对旱地全膜双垄沟播玉米产量土壤速效磷和磷肥利用率影响

针对黄土高原半干旱区春玉米全膜双垄沟播栽培中施肥不科学和磷肥利用率低的问题,2011—2013年在甘肃省定西市安定区设置了三年定位试验,研究了P2O5投入量为0 kg·hm-2(CK)、120 kg·hm-2(P1)、240kg·hm-2(P2)和480 kg·hm-2(P3)对春玉米产量、土壤速效磷及磷肥利用效率的影响。结果表明:磷肥能显著增加玉米产量,但过量投入磷肥会使玉米减产,玉米产量整体表现为P1P2P3CK;在同一生育时期,随着施磷量的增加,土壤速效磷累积量呈增加趋势;随着种植年限延长,施磷处理土壤速效磷累积量增幅呈增大趋势,与2011年播前基础量相比,2013年收获后累积量增加53.6%~208.5%;磷肥利用率随施磷量的增加而降低,优化施磷量下,磷肥当季和累计利用率达到最大,为15.51%、13.91%。综合考虑玉米产量、磷肥利用率和生态环境安全,P2O5的投入量以120 kg·hm-2为宜。

Effects of phosphorus rate on maize yield, soil available phosphorus and phosphorus use efficiency by double-bed and furrow-sowing with full plastic film mulching in semi-arid field

To focus on the issues of unscientific fertilizer application and lower phosphorus use efficiency by double -bed and furrow-sowing with full plastic film mulching on the semi-arid Loess Plateau ,the effects of phosphorus rate (0 kg ·hm - 2 (CK) ,120 kg·hm - 2 (P1) ,240 kg·hm - 2 (P2) and 480 kg·hm - 2 (P3)) on maize yield ,soil available phosphorus and phosphorus use efficiency were studied from 2011 to 2013 by using randomized block design .The results showed that yield was significantly increased by application of phosphorus ,but went decreased by excessive input of phosphorus .Ef-fects on yield followed the order of P1 > P2 > P3 > CK .The accumulation of soil available phosphorus was elevated with the increase of phosphorus at the same growth stage ,the increment of soil available phosphorus accumulation by phospho -rus treatments was higher than that by no phosphorus treatments .Compared with the basic phosphorus before sowing in 2011 ,the accumulation of phosphorus in 2013 after harvesting was increased by 53 .6% ~ 208 .5% .The phosphorus use efficiency became decreased as phosphorus increased .The quarter and accumulative phosphorus use efficiency reached maximums of 15 .51% and 13 .91% ,respectively .Taking comprehensive considerations of maize yield ,phosphorus use efficiency and the ecological environment security ,the suitable phosphorus input (P2O5 ) was 120 kg·hm - 2 .