[目的]本文旨在探究甘肃河西灌区农田生态系统土壤养分限制及其循环规律，明确不同施氮处理下青贮玉米植株与土壤间的稳态性特征。[方法]以2022-2023年甘肃省河西灌区4种施氮处理N0(习惯施氮量)、N1(减氮10％)、N2(减氮20％)、N3(减氮30％)青贮玉米为研究对象，分析不同施氮处理下植株和土壤有机碳(OC)、全氮(TN)、全磷(TP)含量及其生态化学计量特征变化和植株与土壤间的内稳性特征。[结果]2年试验结果表明，不同施氮处理下青贮玉米土壤OC、TN、TP含量均在0～10cm 土层达到最高。4种施氮处理下，N0处理植株器官养分含量均显著升高;N1处理0～30 cm 土层土壤OC、TN、TP含量均最高，且OC、TN、TP高于其他施氮处理11。79％～41。88％、8。80％～39。28％、5。31％～31。29％;随着施氮量的减少，土壤及植株养分含量显著降低。土壤C/N值在各土层及不同施氮处理下较为稳定;植株(叶片、根系)N/P均值(1。06、1。03)均小于植株氮限制阈值(14)，说明植株生长受氮元素的限制。在N0和N1施氮处理下，植株(叶片、根系)OC、TN、TP含量及化学计量比均呈绝对稳态;在N2施氮处理下，植株叶片TP含量呈敏感态，在N3处理下，植株根系OC、TP、C/N均呈敏感态。[结论]减氮10％处理不仅提高了河西灌区青贮玉米土壤肥力、养分存留及作物生长适应能力，还减少了生产投入比并增加产量。
Effects of nitrogen application on soil-plant stoichiometry and stability of silage maize in Hexi irrigation area
[Objectives]The paper aimed to explore the soil nutrient limitation and its circulation law of farmland ecosystem in Hexi irrigation area,and the steady-state characteristics between silage maize plants and soil under different nitrogen application treatments were clarified.[Methods]Taking silage maize under four nitrogen application treatments N0(habitual nitrogen application rate),N1(nitrogen reduction by 10％),N2(nitrogen reduction by 20％)and N3(nitrogen reduction by 30％)in Hexi irrigation area of Gansu Province from 2022 to 2023 as the research object,the changes of organic carbon(OC),total nitrogen(TN),total phosphorus(TP)contents and their ecological stoichiometry characteristics of plants and soils under different nitrogen application treatments and the internal stability characteristics between plants and soils were analyzed.[Results]The results of two years showed that the contents of OC,TN and TP in silage maize soil reached the highest in 0-10 cm under different nitrogen treatments.Under the four nitrogen treatments,the nutrient content of plant organs increased significantly under N0 treatment.The contents of OC,TN and TP in 0-30 cm soil layer were the highest under N1 treatment,and the contents of OC,TN and TP were 11.79％-41.88％,8.80％-39.28％and 5.31％-31.29％higher than those under other nitrogen treatments,respectively.With the decrease of nitrogen application rate,the nutrient content of soil and plant decreased importantly.The soil C/N value was stable under different soil layers and different nitrogen treatments.The average value of N/P(1.06,1.03)of plants(leaves,roots)was less than the threshold of plant nitrogen limitation(14),indicating that plant growth was limited by nitrogen.Under N0 and N1 treatments,the OC,TN,TP contents and stoichiometric ratios of plants(leaves and roots)showed absolute steady state.Under N2 treatment,the TP content of plant leaves was sensitive,and under N3 treatment,the OC,TP and C/N of plant roots were sensitive.[Conclusions]The 10％nitrogen reduction treatment not only improved the soil fertility,nutrient retention and crop growth adaptability of silage maize in Hexi irrigation area,but also reduced the production input ratio and increased the yield.
万方数据
维普
