| Agricultural production produces a large volume of crop straw,which is rich in carbon,nitrogen,phosphorus,and other nutrients.However,most areas still burn straw directly,resulting in the waste of a large amount of straw resources.The rational use of straw can increase the content of soil organic matter and improve the characteristics of soil,thereby increasing crop yield and quality.Soybean(Glycine max)cultivar "Ji yu 86" was used as the test material,This experiment utilized three planting modes of no-tillage straw double-row sowing(NTS-D),no-tillage straw single-row sowing(NTS-S)and traditional combined land preparation double-row sowing(NTS-D)to study the effects of no-tillage straw planting mode on soybean yield,agronomic traits,SPAD value,photosynthetic rate,chlorophyll fluorescence parameters,leaf area index,dry matter accumulation,root traits and soil characteristics,and the results showed the following:The influence of no-tillage straw planting on soybean yield was determined.The two no-tillage straw planting modes were significantly higher than the CT mode in terms of stem thickness,number of nodes,number of single plant pods,weight of single plant pods,grain weight of a single plant and yield.The two no-tillage straw planting modes can optimize the constituent factors of soybean yield,so that higher yields of soybeans can be obtained,NTS-D and NTS-S mode yield increased by 25% and 13.8% respectively compared with CT mode.The influence of no-tillage straw planting on soybean physiological indicators was determined.The two no-tillage straw planting modes increased the leaf SPAD value,net photosynthetic rate,maximum photosynthetic quantum yield,electron transfer rate,and actual quantum yield in the late growth period,which reduced the non-photochemical fluorescence quenching coefficient,The indicators of the no-tillage straw planting mode decreased slowly,and the photosynthetic indices of the middle and lower leaves of soybean were still higher,which was more conducive to promoting the photosynthesis of leaves.This provides more photosynthetic products for soybean grains,resulting in higher yields.The effect of no-tillage straw planting on the soybean leaf area index(LAI)was determined.After the R1 stage,compared with the CT mode,the LAI of the two no-tillage straw planting modes increased faster with the growth process.Except for the three planting modes in the V5 stage,there were no significant differences in the two no-tillage straw planting modes in the remaining four periods,and the soybean LAI was significantly improved.The effect of no-tillage straw planting on the accumulation of dry matter in soybean was determined.The weight of soybean dry matter of the three planting modes gradually increased with the growth process,and the advantages of two no-tillage straw planting modes on the accumulation of soybean dry matter after the R1 stage begin to reflect,and the soybean leaves accumulated more dry matter after the R1 stage.This expanded the source of photosynthetic products,and the rapid accumulation of soybean stem dry matter may promote the transportation of photosynthetic products between different nodes,This is conducive to the rational distribution of photosynthetic products of different internodes to soybean grains,thereby improving the total dry matter accumulation of soybeans.The effect of no-tillage straw planting on soybean root indices was studied.The root length of the two no-tillage straw planting modes was significantly lower than that of the CT mode during the whole growth stage,The average diameter of the roots and their volume and dry weight were significantly higher than that of the CT mode,the volume was significantly higher than those of the CT mode.The root surface area was significantly higher than that of the CT mode in the R5 and R7 stages.The effect of no-tillage straw planting on soil indicators was studied.The two no-tillage straw planting modes significantly reduced the soil temperature in the early stage,and the impact on soil temperature gradually decreased with the advancement of the growth process.The two no-tillage straw planting modes significantly increased the soil moisture during the entire growth period.Except for the two no-tillage straw planting modes in the R3 stage,the soil hardness was significantly lower than that of the CT mode.In addition,the rest of period was significantly higher than that of the CT mode,and the weather in R3 period was dry and rainless.The mulching of straw on the ground in no-tillage straw planting mode was conducive to the retention,of water by the soil.Thus,the hardness was low,and the two no-tillage straw planting modes in V3 and R1 stages significantly promoted the soil respiration rate. |
