| This study investigated the effects of different combinations of straw returning modes on corn growth and development,photosynthetic characteristics,mechanical properties of the stalk,soil nutrient content,and yield in the humid and cool area of eastern Jilin Province,aiming to provide theoretical support for the production practice of straw returning in the humid and cool area of eastern Jilin Province.In this study,corn "Kandan 22" was used as experimental material,and field experiments were carried out from 2018 to 2020.A total of 12 treatment combinations were set up,including straw removal from the field,straw deep turning returning to the field and straw powder returning to the field.They are successive years deep turning(SSS),successive years powder rake(FFF),successive years out of the field(LLL),deep turning-out of the field-powder rake-deep turning(LFS),powder rake-deep turning-out of the field(FSL),powder rake-powder rake-deep turning(FFS),powder rake-deep turning-powder rake(FSF),deep turning-powder rake-powder rake(SFF),deep turning-powder rake-powder rake-Deep turn-powder rake(SSF),deep turn-powder rake-deep turn(SFS)and powder rake-Deep turn-deep turn(FSS).Detected and analyzed the effects of straw returning pattern combination on maize growth and development,photosynthetic characteristics,stem mechanical characteristics,soil nutrient content,and yield.The results show that:1.Different combinations of straw returning modes affected the growth and development of maize.Compared with LLL,the maize plant height under FSL was increased by 7.23% and that under SFF was decreased by 5.78%.The leaf area index(LAI)of the LLL treatment group increased the most,reaching 23.1%.The LAI values of the FSL treatment combination were the highest in both years,with an increase of 10.5%.FFS treatment had the largest increase in plant dry matter weight(9.2%),while FSL treatment had the largest increase in plant dry matter weight(6.4%)in two years.Compared with 2019,maize plant height,leaf area index,and dry matter weight in 2020 increased by 1.1-2.5%,1.2-21.3%,and 4.1-12.6%,respectively.2.Different combinations of straw returning modes had effects on photosynthetic characteristics and SPAD number of maize leaves,the combination of FSL treatment had the highest SPAD number,which was 0.4% to 7.4% higher than 2019 in 2020.The net photosynthetic rate(Pn)of FSL treatment group was significantly higher than that of other treatment groups,showing a trend of FSL >LFS>SLF >FFS >FSF >FFF >SSS >SFF >FSS >LLL >SSF >SFS.The stomatal conductance(Gs)of the FSL treatment group was the largest,while that of the SSF treatment group was the smallest.Compared with the LLL treatment group,the FSL treatment group increased by 34.7%,while SSF decreased by 18.5%.The intercellular co2 concentration(Ci)showed the trend of FSL >SSF>SFF >FSF>LLL >FFF >SSS >FFS >LFS >FSS >SLF >SFS,and FSL treatment group had the largest increase,up to 11.9%.FFS treatment decreased the transpiration rate(Tr)by 23.5%,while LLL treatment increased the transpiration rate by 10.1%.3.Different combinations of straw returning modes affected the mechanical properties of corn stalks,and the puncture strength of corn in the FSL treatment group increased the most,with the increase of 4.5%,9.7%,1.2%,4.1%,2.6%,and 5.2%from the second to the seventh segments,respectively.The FSL treatment group also had the largest increase in transverse strength,which was significantly higher than the LLL treatment group,and was 33.2%,28.8%,33.5%,17.6%,12.9%,46.7%,15.5%higher than LLL treatment group from the first segment to the seventh segment,respectively.4.Different straw returning pattern combinations affected soil nutrient composition,and total nitrogen,total phosphorus,and organic matter contents in the LFS treatment group increased by 14.8%,10%,and 14.7%,respectively.The total potassium content in the FSL treatment group increased the most by 2.7%,and the contents of total nitrogen,total phosphorus,total potassium,and organic matter in the FSL treatment group were the highest.Compared with 2019,organic matter content increased by 1.1%,total nitrogen content increased by 0.5%,total phosphorus content remained the same,and total potassium content increased by 2.7%.5.Different combinations of straw returning modes had an impact on maize yield and yield composition.Compared with 2019,SSF treatment had the largest increase in 100-kernel weight,which increased by 14.7%.Grain number increased by 21.6% in FSL treatment.The yield of FSL treatment was the highest in both years,and the total weight reached 22426.77 kg·hm-2,which was 879.63kg·hm-2 higher than that of the previous year,increasing by 7.5%.Choose the FSL treatment combination help the development of agriculture in the humid and cool area of eastern Jilin.In conclusion,FSL straw returning mode combination can effectively increase soil organic matter content,increase yield,and help the sustainable development of agriculture in the wet and cool area of eastern Jilin Province. |
