紫色坡耕地玉米适产和环境友好的氮肥投入阈值

Threshold of Nitrogen Inputs of Yield and Suitable Environment of Purple Sloping Corn

为有效控制紫色丘陵区坡耕地养分流失,采用氮肥水平随机区组试设计验,利用模拟径流小区的方法,研究氮肥用量对坡耕地雨季土壤氮素流失及玉米产量的影响。结果表明,随着氮肥用量增加地表径流和壤中流的总氮流失浓度均呈增加趋势,以优化施氮量的200%的总氮素流失浓度最高,分别比对照总氮流失浓度高150%和1141%,其中,施肥对地表径流总氮流失浓度的影响仅表现在径流首次;氮肥用量与土壤氮素表观平衡呈线性关系（R2=0.986）,与玉米产量（R2=0.817）呈及生产1 kg玉米氮素流失量（R2=0.916）均呈二次曲线关系,氮肥用量为186.73 kg/hm2是兼顾环境因素的氮素投入阈值,氮肥用量为393.6 kg/hm2是玉米兼顾产量的氮素投入阈值,因此,为了保证粮食安全,有效控制农业面源污染,紫色坡耕地玉米适宜的氮肥用量范围在186.73-393.6 kg/hm2,结合本试验结果,氮肥用量为225 kg/hm2较好。

To effectively control the sloping farmland nutrient loss of purple hilly area,the randomized block blockstest at different levels of nitrogen fertilizer were designed,and the influence effects of nitrogen fertilizer levels on sloping soil nitrogen loss and corn yield during the rainy season were studied with simulated runoff plot method. The results showed that with the increased of nitrogen fertilizer amount the surface runoff and subsurface flow concentrations of total nitrogen loss performed an increasing trend,the total nitrogen highest loss concentration was 200 % optimized the amount of nitrogen,which surface runoff and subsurface concentrations of total nitrogen loss were 150 % and 1141% higher than that of control,respectively,and the effects of fertilization on total nitrogen loss concentration of the surface runoff was only by the first time; the nitrogen fertilizer dosage with soil nitrogen apparent balance performed a linear relationship（ R2= 986）,and with the corn yield（ R2= 0. 817） and production of 1 kg of corn the nitrogen loss（ R2= 0. 916） showed a significant quadratic curve relationship.Nitrogen fertilizer used 186. 73 kg / hm2 was nitrogen inputs into account environmental factors threshold. and used 393. 6 kg / hm2 was corn yield investment threshold. In order to ensure food security and effective control of agricultural nonpoint source pollution,the nitrogen fertilizer in the range of 186. 73-393. 6 kg / hm2 was suitable for the production of purple sloping land corn. According to tthe results,the best nitrogen fertilizer dosage of this region was 225 kg / hm2.