【摘要】 为探求控制排水对油葵农田土壤氮素流失、氮肥利用效率以及产量的影响,设置生育期控制排水深度分别为40 cm（K1）、70 cm（K2）、100 cm（K3） 3个处理,选择明沟排水作为对照处理（CK）,开展了田间试验。结果表明:K1处理土壤NH₄⁺-N含量（质量比）最高,平均值为20.17 mg/kg,显著高于其他各处理（P<0.05）,较K2、K3、CK处理高31.36%、46.16%、15.22%。不同处理间土壤NO₃^--N含量差异性大于NH₄⁺-N。生育期灌溉后0～40 cm土壤NO₃^--N含量由大到小依次为K1、CK、K2、K3。不同处理NO₃^--N流失量均大于NH₄⁺-N,K1、K2、K3、CK处理NO₃^--N流失量较NH₄⁺-N分别高60%、52.63%、30.77%、58.82%。暗管排水处理,出口埋深越小,排水量越小,氮素流失量越小,控制排水稳定了地下水埋深变化。控制排水处理（K1、K2）提高氮肥偏生产力3.04%～11.15%,提高了养分吸收量。K1处理氮肥偏生产力最大,分别较K2、K3、CK处理增加4.54%、7.72%、11.15%（P<0.05）。K1处理能显著提高玉米产量（P<0.05）,较K2、K3、CK处理分别增加4.52%、7.69%、11.14%。油葵收获后,各处理0～100 cm土壤NH₄⁺-N含量为0.98～8.13 mg/kg,随着土层深度的增加土壤NH₄⁺-N含量减少,0～40 cm土层CK处理土壤NH₄⁺-N含量最大,较K1、K2、K3处理分别大11.65%、14.55%、18.19%（P<0.05）。相同处理相同土层NO₃^--N含量明显高于NH₄⁺-N含量;生育期灌溉后,0～10 cm土壤中NO₃^--N均随水向深层土壤运移,而K1处理将大多NO₃^--N聚集在20～40 cm土层中。在生长中后期,20～40 cm土层为油葵根系旺盛层,K1处理对土壤中氮素利用相对较高。综合油葵产量、土壤氮素变化规律、氮肥利用效率及氮素流失情况,适宜的排水方式为生育期控制排水深度40 cm（K1）。更多还原

【Abstract】 To explore the effect of controlling drainage on soil nitrogen loss,nitrogen fertilizer use efficiency and yield in oil sunflower farmland,the growth period control drainage depth was set to be40 cm（K1）,70 cm（K2）,and 100 cm（K3）,open ditch drainage was chosen as the control treatment（CK）,and field trials were carried out.The results showed that the soil NH₄⁺-N content of K1 treatment was the highest,with an average value of 20.17 mg/kg,which was significantly higher than that of other treatments（P<0.05）,and was 31.36%,46.16%,15.22% higher than that of K2,K3 and CK treatments.The NO₃^--N content of 0 ～ 40 cm soil after irrigation during the growth period showed the trend from large to small as K1,CK,K2 and K3.The loss of NO₃^--N in different treatments was greater than that of NH₄⁺-N.The loss of NO₃^--N in K1,K2,K3 and CK treatments was 60%,52.63%,30.77% and 58.82% higher than NH₄⁺-N,respectively.For the subsurface drainage treatment,the smaller the outlet depth was,the smaller the drainage and the nitrogen loss were,and the control of drainage stabilized the change of groundwater depth.The controlled drainage treatment（K1,K2）increased the partial productivity of nitrogen fertilizer by 3.04% ～ 11.15%,and increased nutrient absorption.The partial productivity of nitrogen fertilizer in K1 treatment was the largest,which was increased by 4.54%,7.72% and 11.15% compared with K2,K3 and CK treatments respectively（P<0.05）.K1 treatment can significantly increase corn yield（P<0.05）,which was 4.52%,7.69% and11.14% higher than that of K2,K3 and CK treatments,respectively.After the oil sunflower was harvested,the NH₄⁺-N content of 0 ～ 100 cm soil in each treatment was 0.98 ～ 8.13 mg/kg,and the soil NH₄⁺-N content was decreased with the increase of soil depth,the soil NH₄⁺-N content in 0 ～ 40 cm soil layer of CK treatment was the largest,which was 11.65%,14.55% and 18.19% larger than that of K1,K2 and K3,respectively（P<0.05）.The NO₃^--N content in the same soil layer under the same treatment was significantly higher than the NH₄⁺-N content.After irrigation during the growth period,the NO₃^--N in the 0 ～ 10 cm soil would flow to the deep soil with water,while most of the NO₃^--N in the K1 treatment would be accumulated in the 20 ～ 40 cm soil layer.In the middle and late stages of growth,the20 ～ 40 cm soil layer was the vigorous oil sunflower root layer,and the K1 treatment had relatively high nitrogen utilization in the soil.Considering oil sunflower yield,soil nitrogen change law,nitrogen fertilizer use efficiency and nitrogen loss,the suitable drainage method was to control the drainage depth of 40 cm during the growth period（K1）.更多还原