拔节期追肥及灌水对膜孔灌玉米农田硝态氮分布及累积的影响

The Effect of Irrigation and Nitrogen Fertilizer at Jointing Stage on Soil Nitrate Nitrogen Distribution and Accumulation of Maize under Film Hole Irrigation

通过室外小区试验,分析了拔节期追肥和灌水对膜孔灌玉米土壤硝态氮分布和累积的影响。研究表明,施肥量越大,土壤硝态氮浓度峰分布越宽;施肥量增加,硝态氮淋洗效应增强,并且这种影响在距离膜孔中心较近时明显。拔节期追施肥料后灌水,对后期土壤剖面硝态氮分布仅在灌水定额较高时表现出较大的影响。适当的增加施肥量,对收获后土壤剖面硝态氮累积量的影响较小。灌水量越大,下层土壤硝态氮累积量越大,距膜孔中心水平距离越近累积作用越明显。在试验条件下,建议玉米拔节期追施氮肥约为112 kg/hm2,灌水定额不大于525 m3/hm2。

Through an outdoor plot test,the effect of fertilization and irrigation amount on distribution and accumulation of soil nitrate nitrogen at the jointing stage of maize under film hole irrigation is studied.Studies have shown that the wider distribution of soil nitrate nitrogen concentration peaks increase with the larger the fertilization amount.The nitrate leaching effect is enhanced with the increased fertilization amount,and this effect is obvious when it is close to the center of the film hole.Watering after applying fertilization in jointing period,the distribution of nitrate nitrogen in the soil profile at the later stage shows a great effect when the irrigation amount is higher.Appropriate increase in fertilizer application has little effect on nitrate accumulation in soil profiles after harvest.The greater amount of nitrate nitrogen accumulates in the lower soil layer with the greater amount of irrigation.The closer to the center of the film hole in horizontal distance,the cumulative effect is more obvious.Under the experimental conditions,it is recommended in this paper that the nitrogen fertilizer is about 112 kg/hm^2 at the jointing stage and the irrigation quota should not exceed 525 m^3/hm^2.