长期施肥对休闲季土壤呼吸温度敏感性的影响

发布时间：2018-04-18 09:32

本文选题：长期施肥 + 土壤呼吸温度敏感性　；参考：《中国农业科学》2017年16期

【摘要】：【目的】在农作物-休闲轮作系统中,研究长期施肥条件下休闲季土壤呼吸温度敏感性(Q10)的变化机理,为科学调控黄土高原雨养区的农田温室气体排放提供依据。【方法】依托长武农田生态试验站的长期定位施肥试验,在小麦收获后的休闲季测定不同施肥处理下(CK、N、NP、M、NPM)的土壤呼吸速率、土壤温度、土壤水分、底物的数量(土壤有机碳和根茬碳)和质量(土壤碳氮比和根茬碳氮比,依次简写为土壤C㑳N和根茬C㑳N),研究长期施肥影响休闲季Q10变异的机理。【结果】在休闲季,不同施肥处理下的土壤呼吸速率差异显著(P0.05),长期施肥导致土壤呼吸速率增加了6%—127%。土壤温度、土壤水分、底物的数量和质量均是影响土壤呼吸速率的重要因素(P0.05)。土壤温度对土壤呼吸速率的影响,利用指数关系模型进行拟合(P0.05),且土壤温度可以解释40%—57%的土壤呼吸变异性。而土壤呼吸速率对土壤水分的响应则用抛物线关系模型进行拟合(P0.05),且土壤水分可以解释56%—74%的土壤呼吸变异性。同时,底物的数量和质量对土壤呼吸速率的影响,利用线性关系模型进行模拟(P0.05),且底物的数量和质量可以解释高达66%—94%的土壤呼吸变异性。长期单施氮肥处理(N)对土壤有机碳影响不显著(P0.05),而NP、M和NPM处理下的土壤有机碳则增加了12%—36%。同时,N处理下的根茬碳减少了34%,而NP、M和NPM处理下的根茬碳则增加了15%—63%。N和NP处理下的土壤C㑳N影响不显著(P0.05),而M和NPM处理下的土壤C㑳N则增加了12%—13%。不同施肥处理下的根茬C㑳N则降低了8%—38%。在休闲季,长期施肥导致Q10降低了12%—56%,而长期施肥处理下Q10的差异与底物的数量(土壤有机碳和根茬碳)和质量(土壤C㑳N和根茬C㑳N)或者二者的交互作用密切相关(P0.05)。Q10随着底物数量和土壤C㑳N的增加均呈现出线性降低的趋势(P0.05),且底物的数量和土壤C㑳N可以解释61%—95%的Q10变异性,而Q10随着根茬C㑳N的增加呈现出线性增加的趋势(P0.05),且根茬C㑳N可以解释72%的Q10变异性。同时对Q10的贡献呈现出根茬碳根茬C㑳N土壤有机碳土壤C㑳N的趋势(2.16 vs.1.22 vs.0.48 vs.0.03)。【结论】在农作物-休闲轮作系统中,长期施肥通过影响底物的数量和质量影响休闲季Q10的变化,对科学评价黄土高原雨养区的农田温室气体排放具有重要意义。
[Abstract]:[objective] to study the change mechanism of soil respiration temperature sensitivity (Q10) under long-term fertilization in crop-leisure rotation system.To provide scientific basis for controlling greenhouse gas emissions from farmland in the rain-fed area of the Loess Plateau. [methods] Long-term fertilization experiment based on Changwu farmland ecological test station was carried out.Soil respiration rate, soil temperature, soil moisture, substrate quantity (soil organic carbon and stubble carbon) and quality (soil carbon / nitrogen ratio and stubble carbon / nitrogen ratio) were measured under different fertilization treatments in the fallow season after harvest of wheat, and soil respiration rate, soil temperature, soil moisture, substrate quantity (soil organic carbon and stubble carbon) and quality (soil carbon / nitrogen ratio and stubble carbon / nitrogen ratio) were measured.The mechanism of long-term fertilization affecting Q10 variation in fallow season was studied. [results] the difference of soil respiration rate in different fertilization treatments was significant (P0.05). Long-term fertilization increased soil respiration rate by 6-127%.Soil temperature, soil moisture and the quantity and quality of substrate were all important factors affecting soil respiration rate.The effect of soil temperature on soil respiration rate was fitted by exponential relation model, and the soil temperature could explain 40-57% soil respiration variability.The response of soil respiration rate to soil moisture was fitted with parabola relation model (P0.05), and soil moisture could explain 56% -74% soil respiration variability.At the same time, the effects of substrate quantity and quality on soil respiration rate were simulated by linear relation model, and the soil respiration variability of 66-94% could be explained by the quantity and quality of substrate.The effect of N on soil organic carbon was not significant (P 0.05), but that of soil organic carbon increased by 12% to 36% under NPM and NPM treatments.At the same time, the stubble carbon under N treatment decreased 34%, while the stubble carbon under NPM and NPM treatments increased 15-63.N and NP treatments had no significant effect on Con, but Con N increased 12-13g under M and NPM treatments.Con N of root stubble decreased by 8-38 under different fertilization treatments.In the leisure season,Long-term fertilization reduced Q10 by 12- 56.The difference between Q10 and substrate (soil organic carbon and stubble carbon) and quality (soil Con N and stubble Con N) or the interaction between them were closely related with the substrate quantity (soil organic carbon and stubble carbon) or the interaction between the two. P0.05N. Q10 was closely related to the substrate quantity (soil organic carbon and stubble carbon) or the interaction between the two.Both the increase of soil Con N and the amount of soil Con N showed a linear decreasing trend of P0.05N, and the quantity of substrate and soil Con N could explain 61-95% Q10 variability.Q10 showed a linear increasing trend with the increase of Con N in stubble, and Con N in stubble could explain 72% of Q10 variability.At the same time, the contribution to Q10 showed a trend of 2.16 vs.1.22 vs.0.48 vs.0.03N in soil organic carbon soil in stubble carbon stubble. [conclusion] in crop-leisure rotation system, long-term fertilization affects the change of Q10 in leisure season by affecting the quantity and quality of substrate.It is of great significance for scientific evaluation of greenhouse gas emissions from farmland in rain-fed areas of the Loess Plateau.
【作者单位】：宝鸡文理学院地理与环境学院/陕西省灾害监测与机理模拟重点实验室;
【基金】：陕西省科技厅自然科学基金项目(2015JM4136) 宝鸡市科技计划项目(16RKX1-14) 宝鸡文理学院博士科研启动费项目(ZK2017041) 陕西省教育厅项目(16JK1042)
【分类号】：S147

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