| In this study,the soybean variety Jiyu 86 was used as the test material,and a comparative experiment was conducted in a large area to study the effects of three tillage methods:traditional combined land sowing,fall deep-turned land sowing,and stubble no-till sowing on soybean agronomic traits,yield,photosynthetic physiological indexes,and soil characteristics,in order to investigate high-yielding tillage methods suitable for soybean in Jilin Province and provide some theoretical basis.The results showed that.1.the SPAD values and net photosynthetic rate of the lower and middle leaves of soybean in the late reproductive stage were significantly higher in the fall deep tillage treatment than in the traditional combined tillage treatment,with better photoprotection ability,higher leaf area index,and slower senescence process of the lower and middle leaves.Compared with the traditional combined land preparation treatment,the soil hardness of 0-20 cm in the fall deep-tilled layer was less,the soil temperature was higher at 5 cm during the seedling stage and 10 cm during the branching stage of soybean,the moisture content of the tillage layer was higher at the pod initiation stage,and the soil respiration rate was highest at the seedling and flower initiation stages.Compared with the traditional combination treatment,the fall deep tillage treatment significantly increased the pod weight,number of grains per plant,grain weight per plant,100-grain weight and dry matter weight of soybean at maturity,with a yield of 3654.0 kg/hm~2,an increase of 13.8%compared with the traditional combination treatment.2.The SPAD values of the upper leaves in the first stage of fertility and the lower leaves in the second stage of fertility were significantly higher in the stubble-free treatment than in the traditional combined land preparation treatment,and the net photosynthetic rate,effective quantum yield,electron transfer rate,photoprotective capacity and leaf area index were significantly higher in all periods than in the traditional combined land preparation treatment.Soil hardness,soil moisture,and soil respiration rate were higher in the no-tillage treatment than in the conventional combination treatment,and root growth was more dominant.The stem thickness,number of main stem nodes,pod weight per plant,pod number,grain number,grain weight per plant,100 grain weight and dry matter weight of soybean in the no-tillage treatment were significantly higher than those in the conventional land preparation treatment,and the yield was 3556.0 kg/hm~2,which was 10.8%higher than that in the conventional land preparation treatment.3.The plant height,pod height and soil respiration rate of soybean in the fall deep tillage treatment were significantly higher than those in the no-tillage treatment,but the stem thickness,grain number per plant,dry matter mass,leaf area index,root dry weight,soil hardness and soil moisture were significantly lower than those in the no-tillage treatment.Compared with the fall deep-tillage treatment,the no-tillage treatment significantly increased SPAD,net photosynthetic rate,effective quantum yield,and electron transfer rate in the upper leaves of soybean;in the later stages of soybean reproduction,SPAD and net photosynthetic rate in the lower leaves of the fall deep-tillage treatment were dominant and decreased slowly.In summary,the stubble no-till treatment was able to improve photosynthetic physiological characteristics of soybean,and root growth was more advantageous.Under the condition of reducing frequent soil disturbance and cost input,the yield was significantly higher than that of traditional combined land preparation treatment and not significantly different from that of straw deep-till treatment,and the stubble no-till treatment showed greater advantages. |
