减氮配施有机肥对华北平原夏玉米土壤水分及水氮利用的影响

Effect of Nitrogen Reduction and Combined Application of Organic Fertilizer on Soil Water Dynamics and Water and Nitrogen Use Efficiency of Summer Maize in North China Plain

为实现华北平原夏玉米的高产及水氮的高效利用,基于2年田间小区试验研究了不施氮肥(CK)、习惯施氮(CN,228kgN/hm^2)、氮肥减量(ON,152kgN/hm^2)以及氮肥减量与有机肥等氮配施(ONM,152kgN/hm^2)对夏玉米土壤贮水及水氮利用的影响。结果表明:夏玉米期间的0—160cm土壤贮水量受降雨和灌水的影响大,而在夏玉米拔节—成熟期生长耗水是引起土壤贮水变化的重要原因。处理ONM增加了0—160cm土壤贮水量,相比处理CN可提高8.8%~10.5%(p<0.05)。在2012夏玉米收获时,处理ONM和CN的0—40cm土壤含水量相比播前分别降低了14.5%(p<0.05)和5.7%。说明处理ONM消耗了更多的土壤水分。夏玉米的播种—苗期和拔节—抽雄期耗水量大,占到全生育期耗水量的55.1%~66.0%。相比处理CK和CN,处理ONM减少了播种—苗期的耗水,增加了拔节—成熟期的耗水,夏玉米水分利用效率均值也分别提高了8.9%和7.4%(p<0.05)。与处理CN相比,处理ONM的夏玉米产量和氮肥偏生产力分别提高了11.8%(p<0.05)和58.9%(p<0.05)。综上所述,在华北平原高产粮区,比习惯施氮减量1/3且与有机肥等氮配施不仅具有较高的土壤贮水,且增加了夏玉米产量,显著提高了水氮利用效率。

In order to achieve the high yield,and water and nitrogen efficient utilization,a 2-year field experiment was conducted in North China Plain to study the effects of various nitrogen application practices on soil water storage,and water and nitrogen utilization for summer maize.Four treatments were no nitrogen（CK）,traditional nitrogen（CN,228 kgN/hm^2）,reduced nitrogen（ON,152 kgN/hm^2）and combined nitrogen fertilizer and organic fertilizer（ONM,152 kgN/hm^2）.The results indicated that the variation in seasonal soil water storage was affected by precipitation and irrigation,and was also mainly affected by summer maize growth from the jointing to mature stage;soil water storage in the 0-160 cm soil layer of the ONM treatment increased compared with the CN treatment,with increases of 8.8%-10.5%in both years（p〈0.05）;the soil water content was lower at the end of the growing season than at the beginning in the 0-40 cm soillayer under ONM and CN treatments,with decreases of 14.5%（p〈0.05）and 5.7%,respectively,demonstrating that treatment ONM has consumed much more soil water;the summer maize water consumption from sowing time to seeding stage and jointing to tasseling stage was higher,which had accounted for 55.1%-66.0% of the total crop evapotranspiration;treatment ONM could decrease and increase water consumption during sowing time-seeding stage and jointing-mature stage,respectively,and the average of water use efficiency increased by 8.9%and 7.4%（p〈0.05）,compared with treatments CK and CN,respectively;for treatment ONM,the average of yield and nitrogen partial factor productivity was increased by 11.8%（p〈0.05）and 58.9%（p〈0.05）,respectively,compared with treatment CN.In conclusion,reducing the rate of nitrogen at 1/3 based on traditional nitrogen and combined application organic fertilizer can improve soil water storage,and increase summer maize yield and water use efficiency significantly.