利用^(15)N示踪研究不同肥力土壤棉花氮肥减施的产量与环境效应  

Using ^(15)N tracing technique to study the yield and environmental effect of decreasing N fertilization on cotton in different fertility fields

作　　者：李鹏程[1] 郑苍松 孙淼 刘绍东 张思平 王国平[1] 李亚兵[1] 陈静 赵新华 董合林[1] 

机构地区：[1]中国农业科学院棉花研究所/棉花生物学国家重点实验室,河南安阳455000

出　　处：《植物营养与肥料学报》2017年第5期1199-1206,共8页Journal of Plant Nutrition and Fertilizers

基　　金：国家科技支撑计划(2014BAD03B02);农业部公益性行业(农业)科研专项(201503121;201203096);棉花产业技术体系(CARS-18-17)资助

摘　　要：【目的】华北平原棉区中等肥力棉田经济最佳施氮量为300 kg/hm2左右,这一结果仅从产量效应得出,未充分考虑棉花对氮肥的回收利用和土壤中氮肥的残留。探讨低肥力土壤施氮量及施氮比例对棉花产量及氮肥利用率的影响,以及低、中、高肥力土壤条件下等量施氮效应,旨在为棉花减氮增效提供理论依据。【方法】田间试验选择了高(S1)、中(S2)、低(S3)三个肥力水平的地块,其全氮含量分别为0.83、0.74、0.60 g/kg。低肥力地块设置低氮(N1 113 kg/hm^2)、中氮(N2 225 kg/hm^2)、高氮(N3 338 kg/hm^2)3个氮肥用量;中肥力和高肥力地块设低氮量处理,氮肥两次追施在苗期与初花期进行,氮肥比例为1∶2;此外,设置低肥力土壤低氮量,氮肥追施在苗期与初花期进行,氮肥分配比例为1∶1。在吐絮70%时采集棉株和土壤样品,用^(15)N技术分析了棉株氮素吸收来源、籽棉产量、棉株氮肥回收率和土壤氮肥残留率。【结果】低氮处理,土壤肥力对棉花籽棉产量无显著影响,随土壤肥力提升,棉株吸收氮素来源于肥料的比例下降,相对增加了对土壤氮素的吸收。棉花植株^(15)N回收率随施氮量增加显著下降,随土壤肥力提高呈下降趋势,低肥力土壤与中肥力土壤间棉花植株^(15)N回收率差异不显著,但显著高于高肥力土壤。高肥力土壤^(15)N残留率高于低肥力土壤和中肥力土壤。^(15)N损失率随施氮量和土壤肥力提高显著增加。低土壤肥力低氮量条件下氮肥分配比例1∶2处理籽棉产量高于1∶1处理。低肥力土壤条件下,中氮处理籽棉51N积累量相对高于高氮和低氮处理,籽棉产量较优。【结论】在较低土壤肥力条件下,施氮225 kg/hm2籽棉产量和氮回收率均优于施氮338 kg/hm^2,氮肥损失率较低,减氮增效是可行的。高肥力土壤条件下减少氮肥投入可减少肥料的浪费。[ Objectives ] In the medium fertility field of cotton area in the Yellow River catchments, the North China Plain, the economic optimum nitrogen （N） rate for cotton is 300 kg/hm^2, and the result was derived from cotton yield response to N fertilizer rate in field trials for many years, but the N application rate did not fully consider residual N in the soil of cotton field. This paper was to explore effects of different N application rates and ratios on seed cotton yield and N use efficiency under low fertility soil, and effects of the same N application rate under low, medium and high fertility soils in field conditions aimed to orovide a theoretical basis for N fertilization management of cotton. [ Methods ] Field trials of nitrogen fertilizer management were carried out using 15N tracer technique and cotton was used as tested material. Fields with soil total N content of 0.83, 0.74 and 0.60 g/kg were taken as high （$1）, media （S2） and low （S3） fertility fields for the experiment. Three N application rates were set up for the low fertility field： 113 kg/hm^2（N1）, 225 kg/hm^2（N2） and 338 kg/hm^2（N3）. The N fertilizer was divided into equal two parts and topdressed at the seedling and flowering stages. A treatment of twice N topdressing in ratio of 1 ： 2 was also setup in the low fertility field with low N rate. Cotton and soil （0-60 cm） were sampled at 70% boll opening stage, the contribution of N absorbed from fertilizer and soil were determined using 15N tracer technique. The seed cotton yield, and 15^N recovery rate of cotton plants were investigated. [ Results ] For the low N rate, the soil fertility had no significant effect on seed cotton yields, the plant N uptake proportion deprived from fertilizer was declined with the increase of soil fertility, while the N uptake proportion deprived from soil nitrogen was increased. The 15N recovery rate of cotton plants was decreased significantly with the increase of N application rate, and declined with increase of the soil fert

关 键 词：土壤肥力 棉花 施氮量 15^N回收率 产量 

分 类 号：S562[农业科学—作物学]