Effect of Conservation Tillage on Soil Respiration, Organic Carbon, Moisture and Yield of Wheat /Maize System on North China Plain

Conservation tillage management can improve soil properties and reduces soil CO2 emission. We determined soil CO2 flux rate, soil moisture, crop yield, soil organic carbon (SOC) and total nitrogen (TN), on North China Plain throughout a 3-year period. Tillage systems were rotary tillage without crop residues (CT), rotary tillage with straw incorporated into the soil (RS), and no-tillage with crop residues used as mulch (NTS). Soil respiration was measured with a LI-8100. Soil samples were collected at 0-20cm to determine SOC and TN. Dichromate oxidation and Kjeldahl methods were used to determine SOC and TN, respectively, and the gravimetric method was used to identify soil water content. The crops were winter wheat (Triticumaestivum L. ) and summer maize (Zea mays L. ). During the wheat and maize growing period, NTS reduced C02 compared with CT and RS. At 0-20cm depth, NTS increased SOC stock by 17.077 and 3.82 % compared with CT and RS, respectively. NTS maintained higher TN and compared with CT and RS. At soil surface layers NTS had higher soil moisture compared with CT and RS. However the crop yields under NTS were less than those recorded under RS, but were higher than what recorded under CT. Thus, this study suggests that NTS is suitable for North China plain farmers in the short term, but further research is needed on its long term effects on soil properties, respiration, and yield.