Soil Respiration And Carbon Emission Estimation Under Different Tillage And Fertilization On Dry Farming Spring Maize In Shouyang

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.