有机无机肥配施对新垦盐渍荒地玉米养分吸收利用的影响

Effects of combined application of organic and chemical fertilizers on nutrient uptake and utilization of maize in newly reclaimed saline soil

在甘肃引黄高扬程灌区,设置了氮肥与有机肥配合施用对新垦盐渍荒地玉米产量和养分吸收利用的影响试验。结果表明:施肥能显著提高玉米籽粒产量,增幅在13.4%-168.8%,过量施用氮肥会对玉米叶片造成伤害,影响秸秆产量,肥料配施条件下无论是中氮(300 kg·hm-2)还是高氮(600 kg·hm-2),有机肥的作用都非常突出。玉米植株的养分含量和养分吸收量均随施肥量的增加而显著提高,籽粒是吸氮和吸磷的主体,秸秆是吸钾的主体,有机无机肥配施能促进玉米对氮磷钾养分的吸收。本试验条件下,不同施肥处理的氮肥利用率为14.47%-20.74%,氮肥偏生产力为11.06-25.69 kg·kg-1,氮肥农学效率为3.04-11.40 kg·kg-1,氮肥生理效率为20.08-56.63 kg·kg-1,总体都比较偏低,主要原因是有机肥当季利用率低,对氮素总量的贡献太小。

A field experiment was carried out to study the effects of combined fertilization on yield as well as nutri-ent uptake and utilization of maize in newly reclaimed saline land in the high-lift irrigation area of Yellow River in Gansu Province . The results showed that fertilization could significantly increase the grain yield of maize by 13 .4% to 168 .8% .Excessive application of nitrogen fertilizer could injure the leaves and thus affect the straw yield .The effects of organic manure were very outstanding under the combined fertilization condition ,no matter with middle nitrogen （300 kg ·hm-2 ） or high nitrogen （600 kg·hm-2 ） .Both the nutrient contents and uptakes in maize plants were improved signifi-cantly with the increase of fertilization rate .Grain was the main organ for nitrogen and phosphorus absorption ,but straw was that for potassium absorption .Combined application of organic and inorganic fertilizers could promote the absorption of N ,P and K in maize .Under different treatments ,the nitrogen utilization ratio was 14 .47% to 20 .74% ,the partial factor productivity from applied N was 11 .06 to 25 .69 kg · kg-1 , the agronomic efficiency of applied N was 3 .04 to 11 .40 kg·kg-1 ,and the physiological efficiency of applied N was 20 .08 to 56 .63 kg·kg-1 ,being relatively low as a whole because of the lower utilization of organic manure and the little contribution of organic manure to total nitrogen sup-ply in the current year .