Abstract:

Taking the cultivation model that created the high-yield record for summer-sown soybeans in the Xinjiang Production and Construction Corps as the research object, the differences in effective accumulated temperature during the growth period, water and fertilizer management measures, dynamic accumulation of dry matter, spatial distribution of leaf area and pods and grains, and yield components were analyzed by comparing with medium and low-yield fields to clarify the key technical measures and population structure characteristics for high-yield formation of summer-sown soybeans, and to establish a high-yield cultivation model. The research showed that it was crucial to adopt the no-tillage precision sowing technology mode for summer soybean planting, with sowing as early as possible after wheat harvest. The high-yield field of summer-sown soybeans took 104 days from sowing (with the emergence water dripping) to maturity, and the accumulated temperature of ≥10℃ during the growth period was 2496.72℃. The total irrigation water was 4817.4 m³/hm², and the total fertilizer application was 502.5 kg/hm², with balanced irrigation and fertilization at each growth stage. The population structure characteristics were as followed: plant height was 72.5 cm, the number of harvested plants was 384000 plants/hm², the number of grains per plant was 73.58, the number of pods per plant was 30.00, the weight of grains per plant was 12.07 g, the accumulation of dry matter was 9941.33 kg/hm², and the harvest index was 0.46. During the podding stage, the photosynthetically active radiation gradually increased from bottom to top, the LAI was 4.03, the main stem had 13 nodes, and the leaf area and grain distribution were larger from the 6th to the 11th node. The analysis and comparison of the reasons for the yield differences among different plots showed that a higher effective accumulated temperature during the growth period, reasonable water and fertilizer input at each growth stage, sufficient population size, and uniform plant growth were the keys to achieving high yields of summer-sown soybeans.

Key words: summer sowing, no-tillage, soybean, yield levels, yield variation