| Based on the double cropping system of wheat-maize in North China, the effects of the combinations of two stubble mulching methods (mulching and no mulching) and three soil tillage methods (no tillage, moldboard plowing and subsoiling) after the harvest of wheat on the production, accumulation and distribution of photosynthetic matter and the grain yield of summer maize were studied. The results showed that the effects of stubble mulching + subsoiling on maize growth were the best, and that its leaf area index, leaf photosynthetic rate, dry matter accumulation and ratio of photosynthetic matter transported into grains were increased by 13.37%, 45.83%, 16.97% and 3.09% respectively, and its yield was increased by 15.9%, as compared with the treatment of no tillage + no stubble mulching. |