摘要
为探明不同水氮运筹对淋溶水中NO_3^--N时空分布特征以及施氮量和灌水定额对NO_3^--N淋失量的影响,进而制定安全有效的水氮运筹模式。试验采用裂区设计,主区为灌水定额,设置3个水平,分别为525(W1),750(W2),975(W3)m^3/hm^2。副区为施氮量,设置5个水平,分别为0(N0),80(N1),160(N2),240(N3),320(N4)kg/hm^2。每个灌水定额下有5种施氮量处理,共15个处理。并于2014—2015年连续2年进行田间试验。采用多孔PVC法和土钻法采集水样和土样,测定淋溶水中NO_3^--N浓度并计算NO_3^--N淋失量。结果表明,0—40cm埋深内,对比第1次灌水前后NO_3^--N浓度发现,随着施氮量的增加,W1水平下NO_3^--N浓度2年的平均增幅远低于W2和W3水平下NO_3^--N浓度2年的平均增幅。随着灌水定额的增加,N1、N2水平下的NO_3^--N浓度平均增幅远低于N3、N4水平下的NO_3^--N浓度平均增幅。NO_3^--N浓度平均增幅最大的为52.5%的W3N3。NO_3^--N浓度平均值最高的为8.29mg/L的W3N4。与0—40cm埋深内的各处理相比,40—80cm埋深的各处理NO_3^--N浓度整体下降,但整个生育期内淋溶水中NO_3^--N浓度的变化趋势与0—40cm埋深内相一致。80—120cm埋深内,施氮量、灌水定额以及两者的交互作用对NO_3^--N淋失量的影响呈极显著。当灌水定额一定时,2014年、2015年2年的NO_3^--N淋失量随着施氮量增加而递增,淋失率随着施氮量的增加而减少;当施氮量一定时,NO_3^--N淋失量及淋失率均随着灌水定额的增加而递增。鉴于根层内需要充足的NO_3^--N以被作物吸收,并保证NO_3^--N淋失量对地下水的污染在可控安全范围内,故推荐W2N3为适用于当地的水氮运筹模式。
This research would be helpful to figure out the temporal-spatial distribution features of NO_3--N in leaching water and the influence of two factors on NO_3--N leaching loss with different water and nitrogen management patterns.Then made a safe and effective water-nitrogen management pattern.The experiment used a completely random split plot design method.The main plot was irrigation quota with three levels（W1：525m3/hm2,W2：750m3/hm2,W3：975m3/hm2）.The split plot was nitrogen application with five levels（N0：0kg/hm2,N1：80kg/hm2,N2：160kg/hm2,N3：240kg/hm2,N4：320kg/hm2）.Every irrigation quota had five treatments with different nitrogen application rate.There were fifteen treatments in total.The field experiment was carried out in 2014,2015.Adopted the methods of porous PVC and soil auger to collect water and soil samples.Measured the concentration of NO_3--N in leaching water and calculated the leaching loss of NO_3--N.The results showed that：With the increase of nitrogen application,the two years＇ average increase of NO_3--N concentration by W1 was far below the two years＇ average increase of NO_3--N concentration by W2 and W3within the soil depth of 0—40cm.With the increase of irrigation quota,the average increase of NO_3--N concentration by N1 and N2were far below the average increase of NO_3--N concentration by N3 and N4within the soil depth of 0—40cm.The largest average increase ofNO_3--N concentration was 52.5% which belonged to W3N3.The highest average concentration was 8.29mg/L which belonged to W3N4.Compared with the treatments in 0—40cm soil depth,the NO_3--N concentration of treatments showed the overall declination within the soil depth of 40—80cm.But the change trend of NO_3--N concentration was consistent with the soil depth of 0—40cm.Within the soil depth of80—120cm,the leaching loss of NO_3--N was significantly influenced by the nitrogen application,irrigation quota,and the interaction of those two elements.When the irrigation quota was constant,the NO_3--N leaching loss of 2014,2015 would increase with the increase of nitrogen application.The NO_3--N leaching rate of 2014,2015 would decrease with the increase of nitrogen application.When the nitrogen application was constant,the NO_3--N leaching loss and NO_3--N leaching rate of 2014,2015 would increase with the increase of irrigation quota.The crop needed sufficient NO_3--N to absorb in root layer.The pollution of NO_3--N leaching loss on the groundwater should be controlled in the safety range.Considering the two aspects above,this research recommended the W2N3 as the best water-nitrogen management pattern for experimental region.
出处
《水土保持学报》
CSCD
北大核心
2017年第1期310-317,共8页
Journal of Soil and Water Conservation
基金
国家"十二五"科技支撑计划项目"内蒙古河套灌区粮油作物节水技术集成与示范"(2011BAD29B03)
关键词
水氮运筹模式
施氮量
灌水定额
硝态氮浓度
硝态氮淋失量
water-nitrogen management pattern
nitrogen application
irrigation quota
concentration of NO3--N
NO3--N leaching loss
