不同栽培措施下水稻基肥氮素利用率的15N示踪分析

Analysis of Nitrogen Use Efficiency of Base Fertilizer of Rice under Different Crop Management Practices by Using 15 N Labeling

通过15N示踪分析研究基肥氮素去向,旨在为水稻氮肥高效栽培提供理论和实践依据。以武运粳24号为试验材料,采用2年田间定点试验,通过增密减氮、前氮后移、轻干湿交替灌溉、增施饼肥等栽培措施,设置5种处理(氮空白区、当地常规栽培、综合管理措施1~3),研究不同栽培措施对水稻基肥氮素利用率的影响。结果表明,25.76%基肥氮素被植株吸收,24.46%残留在土壤中,49.78%损失到环境中。与当地常规栽培相比,综合管理措施能够显著提高作物对基肥氮的吸收比例(38.8%~61.3%),降低土壤中的残留比例(10.3%~24.8%),减少基肥氮向环境中的损失比例(1.8%~18.1%)。与当地常规栽培措施相比,综合管理措施在各生育期皆具有较高的氮素积累量;显著提升了植株对基肥氮素的吸收,减少了氮素损失,显著增加了氮素向籽粒中转运,且综合管理措施能改善土壤质量,具有较高的土壤脲酶及过氧化氢酶活性。综合研究结果表明,通过优化栽培措施能够显著提高植株对氮素的吸收,改善土壤质量,增加土壤氮素库容,提高基肥氮素利用率,增加作物产量。

The 15 N labeling was used to trace the fate of base fertilizer nitrogen through to provide theoretical and practical basis for the efficient nitrogen fertilizer management practices in rice.Wuyunjing 24 was used as the experimental material in a two-year field experiment.The effects of different cultivation measures on nitrogen use efficiency of rice base fertilizer were studied by using five treatments(nitrogen blank area,local conventional cultivation,and comprehensive management measures 1-3),such as increasing density and reducing nitrogen,shifting nitrogen before and after,light dry and wet alternate irrigation,and increasing cake fertilizer.The results showed that 25.76%,24.46%,and 49.78%of the nitrogen from the base fertilizer were absorbed by the plants,remained in the soil,and lost to the environment,respectively.Compared with local farmers’practice,integrated crop management can significantly increase the uptake ratio of basal nitrogen fertilizer by crops(38.8%-61.3%),reduce the residual ratio in soil(10.3%-24.8%),and reduce the ratio of basal nitrogen fertilizer entering the environment(1.8%-18.1%).Compared with the local farmers’practice,the integrated crop management had higher nitrogen accumulations all the growth stages;the integrated crop management significantly improved the nitrogen absorption of the basal fertilizer by the plants,reduced the nitrogen loss,and significantly increased the partitioning of nitrogen to the grains.The integrated crop management practices also improved soil quality,the activities of soil urease and catalase.The comprehensive research results showed that the nitrogen absorption of plants,the soil quality,the nitrogen storage capacity of soil,the nitrogen utilization rate of base fertilizer and the yield could be significantly increased by optimizing cultivation measures.