土壤学报2023，Vol.60Issue(6)：1687-1698,12.DOI:10.11766/trxb202204060097
耕层厚度对潮土中化肥氮素转化的影响
Effects of Plough Layer Thickness on the Transformation and Fate of Fertilizer Nitrogen in Fluvo-aquic Soils with Different Textures
摘要
Abstract
[Objective]Soil fertility is significantly influenced by plough layer thickness.However,it is still not clear how the transformation and fate of fertilizer nitrogen(N)in fluvo-aquic soils would be affected by plough layer thickness.[Method]In this study,a soil column simulation experiment in the field was conducted throughout three crop cultivations.The experiment was performed in a completely randomized design with six treatments including two plough layer thicknesses(15 and 25 cm)and three soil textures(sandy loam,sandy clay loam and loamy clay).A 15N-labeled tracer technique was used to evaluate the dynamics of fertilizer-derived organic N,fixed NH4+ and mineral N in 0-40 cm soil layer and the fate of fertilizer N in soil-crop systems.[Result]The transformation of fertilizer N in soil-crop systems was significantly affected by plough layer thickness,and showed the same varying tendency among different textural soils.The residual fertilizer N existed mainly in the form of organic N,which accounted for more than 83%of the total residual fertilizer N and played a pivotal role in the storage and supply of fertilizer N.Increasing plough layer thickness degraded the conversion of fertilizer N to fixed NH4+ pool,while increased the stocks of fertilizer-derived organic N in 0-40 cm soil layer.In the current season after fertilizer N was applied,the average value of fertilizer-derived organic N stock in soils with 25 cm plough layer thickness(PLT-25)was averagely 8.9%higher than that in soils with 15 cm plough layer thickness(PLT-15).The stocks of fertilizer-derived mineral N under PLT-25 treatments were also higher than that under PLT-15 treatments in the current and subsequent crop cultivations;promoting the fertilizer N uptake by crops.The N use efficiency under PLT-25 treatments in the first two crop cultivations was about 8.0%higher than that of PLT-15 treatments,while the current seasonal loss rate and cumulative loss rate of fertilizer N were 12.3%and 9.1%lower,respectively.The stocks of fertilizer-derived organic N in sandy clay loam and loamy clay were significantly(P<0.05)higher than that in sandy loam,while the trend was the opposite for the stocks of fertilizer-derived fixed NH4+.And the fertilizer-derived mineral N stock was usually to be higher in sandy loam.Overall,the percentage of recovery of applied fertilizer N in crops and soil under sandy loam treatment was significantly(P<0.05)lower than that in sandy clay loam and loamy clay.Also,the percentage of cumulative loss of fertilizer N in sandy loam was 20.4%and 18.2%higher than that in sandy clay loam and loamy clay,respectively.[Conclusion]The fluvo-aquic soils with higher sand content have lower fertilizer N storage capacity,restricting the enhancing of N use efficiency.For fluvo-aquic soils with different textures,increasing plough layer thickness could improve the annual N use efficiency and the residual amount of applied fertilizer N in the current season.This,could be released for crop uptake in the subsequent crop cultivation.In typical fluvo-aquic soil areas,increasing the plough layer thickness may be a potential means for regulating the transformation and fate of applied fertilizer N,increasing fertilizer N retention,enhancing the fertilizer N uptake by crops and minimizing fertilizer N loss in soil-crop systems.关键词
潮土/耕层厚度/土壤质地/氮肥转化与去向/氮肥利用率Key words
Fluvo-aquic soils/Plough layer thickness/Soil texture/Transformation and fate of fertilizer nitrogen/Nitrogen fertilizer use efficiency分类
农业科技引用本文复制引用
丁世杰,杨文亮,信秀丽,张先凤,朱安宁,杨娇,任国翠,李梦柔..耕层厚度对潮土中化肥氮素转化的影响[J].土壤学报,2023,60(6):1687-1698,12.基金项目
国家自然科学基金项目(41877023)和江苏省农业科技自主创新资金项目(CX(20)2003,CX(21)1009)资助Supported by the National Natural Science Foundation of China(No.41877023),the Agriculture Science and Technology Innovation Fund of Jiangsu Province,China(Nos.CX(20)2003 and CX(21)1009) （41877023）
