Comprehensive evaluation of periodic productivity of combined tillage mode in wheat-maize double cropping areas

Abstract: Aiming at the problems of traditional tillage in Huang-Huai-Hai double cropping area, such as soil structure destruction, excessive power consumption, increase of soil compaction and the nutrient enrichment of surface weeds in the surface soil layer resulted by continuous no tillage, the four years combined tillage(CT) from 2013 to 2016 of "ploughing-no tillage-subsoiling-no tillage" was designed in the wheat-corn double cropping area in this study, taking continuous no tillage (CN) and continuous ploughing(CP) as control, the comprehensive evaluation method was used to evaluate the cycle productivity of the combined tillage mode. During the experiment, the soil structure indexes and soil nutrient indexes were measured, and the agricultural materials, machinery, labor cost and crop yields of different tillage modes were statistically analyzed. On this basis, the comprehensive evaluation method was used to evaluate the periodic productivity of different tillage modes. The results showed that, the CT improved the quality of soil structure, reduced the soil bulk density in 0-30 cm soil layer effectively, the average soil bulk density was smaller 0.089 and 0.125 g/cm3 than that of CN and CP. CT increased the content of total nitrogen, rapid available phosphorus and rapid available potassium in 0-30 cm soil layer, but no significant impacts on the available nitrogen content, the organic carbon content was higher 0.36 and 0.61 g/kg respectively than that of CN and CP, the organic carbon concentration distribution was balanced between the soil layers of 0-10, >10-20 and >20-30 cm, but not balanced of CN and CP. CN only increased the soil nutrient in 0-10 cm soil layer, while CT increased the soil nutrient in >10-20 cm soil layer. CT and CN reduced the costs and increased the input, the total investment of CT and CN was not difference significantly, and saved 3 069 and 3 969 yuan/hm2 respectively than that of CP. The total crops yields and total output of CT were significantly higher than that of CN and CP, CT improved the material utilization rate, the labor conversion rate and input-output ratio. The comprehensive evaluation scores of CT, CN and CP were 4.85, 3.8 and 1.7, respectively, the score of CT was significantly higher than that of CN and CP, the periodic productivity of CT was the highest. This study can provide a reference for the improvement of tillage modes in wheat-corn double cropping area, and promote productivity improvement and cost saving.