【作者】 张丁辰；

【导师】 王小彬； 蔡典雄；

【作者基本信息】 中国农业科学院 ， 生态学， 2012， 硕士

【摘要】 气候变化是当今世界面临的重大挑战，也是科学界的研究热点问题。土壤呼吸是土壤碳库向大气碳库输入碳的主要途径。研究表明，土壤碳库微小的变化就能导致大气中CO2浓度的巨大变化。目前，陆地生态系统中的土壤呼吸研究主要集中在森林和草原生态系统，农田生态系统研究较少。而我国农田土壤呼吸研究又主要集中于黄淮海、东北和长江中下游地区，对北方尤其是西北旱作区研究较少。虽然前人已经针对部分代表性区域做了相关研究，但仍有许多科学问题存在争议，需要进一步深入研究。本研究在农业部寿阳旱作农业试验站进行了田间试验，通过测定不同耕作措施与施肥处理下春玉米农田土壤呼吸速率、水热因素、作物产量等的动态变化，主要研究了：（1）不同耕作措施与施肥处理土壤呼吸季节变化规律及其对水热因素的响应程度；（2）不同耕作措施土壤CO2-C排放量；（3）不同耕作措施与施肥处理农田作物产量与水分利用效率；（4）不同耕作措施土壤碳汇/源效应，最终提出了寿阳旱作区农田最佳耕作与施肥管理措施。本研究得出的主要结论如下：1.寿阳地区春玉米农田生育期内土壤呼吸具有明显的季节变化特征，春、秋季较低，夏季最高。不同耕作措施土壤呼吸具有显著差异，其中免耕耕作土壤呼吸在春、秋季最低，夏季超过少耕和传统耕作达到最高；三种施肥处理平均土壤呼吸速率差异不显著。2.土壤温度和土壤湿度是影响土壤呼吸的重要因素。15cm土壤温度可以解释土壤呼吸变化的67%⁸2%；土壤呼吸温度敏感性系数Q10分别为2.02（传统耕作）、1.59（少耕）和2.47（免耕）。0¹0cm土壤湿度能够解释土壤呼吸季节变化的57%⁷6%；三种耕作措施对0¹0cm土壤湿度变化的敏感程度表现为免耕>少耕>传统耕作。3.基于土壤温度和土壤湿度的双因素模型（y=aebTWc）拟合结果显示，在0¹0cm和10²0cm土层土壤上，水热因子交互作用分别可以解释土壤呼吸变化的70%⁹0%和85%⁹0%；三种耕作措施土壤呼吸变化对水热因子的响应程度表现为少耕>传统耕作>免耕。4.少、免耕耕作较传统耕作措施提高了作物产量和水分利用效率，同时也提高了土壤呼吸强度；施用氮磷肥105kg·hm²处理产量最高。5.少、免耕耕作措施较传统耕作措施虽然提高了土壤呼吸强度，但土壤中也积累了大量的有机碳；少、免耕耕作土壤生育期内分别能够固碳2573和2838kgC·hm²，表现为碳汇，而传统耕作每年损失土壤碳1848kgC·hm²，表现为碳源。6.寿阳地区采用免耕耕作配施氮磷肥105kg·hm²能够有效地提高产量和水分利用效率，减少环境污染和土壤侵蚀，提高土壤固碳能力，是保证农田可持续生产的环境友好型管理措施。本研究的创新点是在寿阳地区首次采用双因素模型拟合了土壤水热交互作用对土壤呼吸的影响程度，为北方旱作农田土壤碳循环的研究提供了参数支持；揭示了寿阳地区旱作农田土壤呼吸测定方法之间的关系，为后续相关研究提供了关系转化公式；针对寿阳旱作区特点综合分析了各项效益指标，提出了该地区最佳耕作与施肥管理措施。更多还原

【Abstract】 Climate change is a major challenge we face in today’s world, also is a hot issue in the scientificcommunity. Soil respiration is the main route of importing carbon form soil carbon pool to atmosphericcarbon pool. Studies have shown that small changes of soil carbon pool can lead to huge changes of theCO2concentration at atmosphere. At present, researches about the soil respiration in terrestrialecosystems mainly focus on the forest and grassland ecosystems, few on the farmland ecological system.In China, farmland soil respiration studies centralize in the Huang huai hai area, northeast of China andthe middle and lower reach of Yangtze River, but there is less research in the North Area, especially inthe Northwest Arid Zone. Even though predecessors have done some research for some representativeareas, there are still many scientific issues in dispute, which need for further in-depth study. This studyconducted a field experiment in the Ministry of Agriculture Rainfed Agriculture Experiment Station,Shouyang, by measuring the dynamic changes of soil respiration rate of the spring maize under differenttillage and fertilization, water and heat factors, and crop yields, we investigated:（1） respiratory seasonvariation and its response to water and heat factors under different tillage and fertilization treatments;（2）different tillage soil carbon dioxide emissions;（3） crop yield and water use efficiency under differenttillage and fertilization treatments;（4） different tillage soil carbon sink source effect, and ultimately putforward the best farming and fertilizer management measures which are suitable to rainfed farmland inShouyang.Conclusion:1. At Shouyang area, there is a significant seasonal variation of soil respiration in spring maizegrowth stage, generally, lower soil respiration in spring and fall, and the highest in summer. Accordingto different tillage practices, soil respiration has significant differences, which are as follows: onno-tillage farming, soil respiration reaches the lowest level in spring and fall and in summer soilrespiration achieves the highest on over reduced tillage and conventional tillage farming. The averagesoil respiration rate was almost the same after three different types of fertilization treatment, so there isno significant effect.2. Soil temperature and soil moisture is an important factor affecting soil respiration.15cm soiltemperature can explain the changes of soil respiration from67%to82%; soil respiration temperaturesensitivity Q10are2.02（conventional tillage）,1.59（reduced tillage） and2.47（no-tillage） separately.0¹0cm soil moisture is able to explain57%to76%of the seasonal variation of soil respiration; threetillage practices on0¹0cm of soil moisture changes in the sensitivity of the performance ofno-tillage> reduced tillage> conventional tillage.3. Based on soil temperature and soil moisture two-factor model （y=aebTWc）, on0¹0cm and10²0cm soil layer, the interaction of heat and water factors respectively can explain the change of soilrespiration from70%to90%and85%to90%; three tillage measures changes in soil respirationresponse to combination of soil water and heat expressed as reduced tillage> conventional tillage> no-tillage.4. Compared with conventional tillage, reduced tillage and no-tillage farming not only improvedcrop yield and water use efficiency, but also increased soil CO2-C emissions; application of nitrogen andphosphorus105kg·hm²deal with the highest yield.5. Compared with conventional tillage, reduced tillage and no-tillage farming increased soil carbondioxide emissions, but accumulated a large amount of organic carbon in the soil; reduced tillage,no-tillage farming can sequestrate carbon about2573and2838kgC·hm²separately in spring maizegrowth stage, as a carbon sink, while conventional tillage annual loss of soil carbon about1848kgC·hm², expressed as carbon source.6. Shouyang area used no-tillage farming with nitrogen fertilizer phosphate105kg·hm², which caneffectively improve the crop yield and water use efficiency, reduce environmental pollution and soilerosion, and improve soil carbon sequestration capacity. This is environment-friendly managementmeasures to guarantee the sustainable production of farmland.The innovation of this study is the first time used double factors model which simulates thecombination of soil water and heat to fit the degree of influence on soil respiration in Shouyang area,which for Northern Arid Soil carbon cycle research provides a parameter support; which reveals therelationship among methods of dry farmland soil respiration determination in there and for follow-upstudy provides conversion formula; according to the various indexes from comprehensive analysis aboutthe characteristics of Shouyang area, we put forward the best farming and fertilizer managementmeasures which are suitable to this region.更多还原