中国科学院水利部水土保持研究所机构知识库

摘要:通过大田试验，研究了减氮及秸秆深埋对土壤电导率、土壤硝态氮淋溶和玉米产量的影响，旨在为提高氮肥利用效率和保护环境提供理论依据。试验在中国科学院长武黄土高原农业生态试验站进行，供试作物为春玉米，品种为先玉335，采用半覆膜种植。试验设5个处理3个重复，处理包括不施氮（CK），常规施氮（CON1，N 250kg/hm²），常规施氮加秸秆（CON2，N 250 kg/hm²+秸秆），减量施氮（CR1，N 200 kg/hm²），减量施氮加秸秆（CR2，N 200 kg/hm²+秸秆）。测量了春玉米各生育期土层剖面土壤电导率，收获期土壤硝态氮含量和春玉米产量。结果表明：土壤电导率在分蘖期、拔节期在40-150cm出现峰值，在抽穗期、成熟期在40-200cm出现峰值，峰值范围下移。在土层60～150cm范围内，土壤电导率整体呈现CON2>CON1，CR2>CR1。与传统施氮相比，减量施氮减少了土壤剖面硝态氮含量，同时，采取秸秆深埋措施也能减少土壤剖面硝态氮含量，并延缓硝态氮的淋溶下移。与传统施氮相比，减量20%施氮增产9.59%。秸秆深埋条件下，其籽粒吸氮量、植株吸氮量、氮肥农学效率、氮肥偏生产力、氮收获指数高于无秸秆处理。秸秆深埋有利于提高土壤电导率，减少土壤硝态氮含量，阻控土壤硝态氮向下淋溶，提高玉米产量。

关键词:减量施氮；秸秆深埋；土壤电导率；硝态氮淋溶

Abstract：Through field experiments, the effects of nitrogen reduction and straw deep buried on soil electrical conductivity, yield of maize and residuals of soil nitrate nitrogen were researched, to provide theoretical support for improving the efficiency of nitrogen use and protecting the environment. Field experiments were conducted in the Changwu State Key Agro-Ecological Station. Pioneer 335, a high-yield spring maize hybrid, was planted with halfplastic film mulching．The experiment included 5 treatments with 3 replicates, no nitrogen fertilization application (CK), conventional nitrogen fertilization application (CON1, N250 kg/hm²), conventional nitrogen fertilization plus straw (CON2, N 250kg / hm²), reduced nitrogen fertilization application (CR1, N 200kg/hm²), and reduced nitrogen fertilization application plus straw(CR2, N 200kg / hm²). The soil electrical conductivity at different growth stages of spring maize was investigated in harvest period. The results show that：the peak of soil electrical conductivity at the stage of maize tillering and jointing appear at the soil profile 40-150cm, at the stage of maize heading and maturing the peak of soil electrical conductivity appear at the soil profile 40-200cm, and the peak range moved down. In the 60～150cm soil profile, the soil electrical conductivity showing that CON2>CON1, CR2>CR1. Compared with the traditional nitrogen fertilization application, the nitrogen reduction application reduced the nitrate nitrogen content in the soil profile. At the same time, the application of straw deep buried could also reduce the nitrate nitrogen content in the soil profile and postpone the soil nitrate nitrogen leaching. Compared with the traditional nitrogen application, 20% reduction of nitrogen fertilization the yield increased 9.59%. On the condition of deep straw buried, the grain nitrogen uptake, plant nitrogen uptake, agronomic efficiency of nitrogen fertilizer, partial productivity of nitrogen fertilizer and nitrogen harvest index were higher than those without straw treatment. Straw deep burying is beneficial to improve soil electrical conductivity, reduce soil nitrate nitrogen content, control soil nitrate nitrogen leaching and increase corn yield.

Key words: nitrogen reduction; straw deep buried; soil electrical conductivity; nitrate nitrogen leaching.