Effect of sowing date and density synergy on stalk characteristics and yield of soybean in strip-intercrop
This study aimed to investigate the effects of sowing date and density on stalk characteristics and yield formation of different plant architecture soybean varieties under soybean-corn strip intercropping. Two variet-ies with different of maturity periods,Nanxiadou 25 (ND25,intermediate-late maturing,branching type) and Qi-huang 34 (QH34,early maturing,primary stem type) were selected to assess the effects of sowing date (S1:mid-May,S2:late May,S3:early June,3 periods repeated in 2021 and 2022) and density (D1:81,000 plants hm-2,D2:101,000 plants hm-2,D3:140,000 plants hm-2,D4:171,000 plants hm-2) on the plant architecture and yield of soy-beans in strip intercropping. Increasing density at the same sowing period resulted in shade avoidance behavior characterized by increased plant height,reduced stem diameter,increased average node length and slenderer plants in all varieties,resulting in lower stem bending force and higher lodging rate. Simultaneously,the increasing in den-sity intensified intraspecific competition and self-shading,while reducing plant biomass per plant. The delay in sow-ing at the same density decreased stem diameter,stem bending force,and biomass per plant for each variety,while the average node length increased. For ND25,there was a decrease in plant height and lodging rate,whereas for QH34,there was a increase in plant height and lodging rate. The average number of branches for each treatment was 4.07 and 0.53 for ND25 and QH34,respectively,and the average branch yield contribution for each treatment was 55.30％ and 5.82％,respectively. With delayed sowing,the yield of ND25 followed the order:S1<S2<S3,while the yield of QH34 followed:S1>S2>S3. With increased density,the yield of ND25 followed:D1>D2>D3>D4,while the yield of QH34 followed:D3>D2>D1>D4. In summary,appropriate late planting and moderate thinning were beneficial for ND25,while appropriate early planting and moderate density were beneficial for QH34,and the synergy between primary stem and branching could increase soybean population yield. It is recommended to plant ND25 appropriately late and thinly at 81000 plants hm-2 (D1) in early June (S3),while QH34 should be planted ap-propriately early and densely at 140000 plants hm-2 (D3) in mid-May (S1) for optimal yield and plant architecture.
万方数据
维普
