Effect Of Corn Straw Return On Dry Matter Accumulation And Yield Of Spring Soybean

This article to explore border irrigation quantity of corn straw returned to the influence of the dry matter production and yield of spring soybean,with 27 new soybean varieties as materials,field experiment was carried out,four straw counters-field set processing 0 kg·hm-2(A),6 000 kg·hm-2(B),12 000 kg·hm-2(C),18 000 kg·hm-2(D),to study the different quantity of corn straw returned on 27 new soybean photosynthetic characteristics,dry matter accumulation and allocation,flowers form and the impact of production.The main findings are as follows:1.Straw returning can effectively increase leaf area index,SPAD value,photosynthetic potential,total photosynthetic potential and photosynthetic rate of spring soybean,all of which are C>B>D>A,while intercellular CO2 concentration(Ci)is C<B<D<A.The difference of leaf area index was mainly caused by the difference of 5-12 node leaf area index.2.With the increase of corn straw mulching amount,the total dry matter accumulation of soybean showed A trend of increasing first and then decreasing.The straw mulching treatment B,C and D increased by 9.7%to 26.8%compared with the control treatment A,and the highest value of the straw mulching treatment C was 1848 g·m2.The amount of nutrients transferred from straw to grain under straw mulching treatment increased by 68.2%to 169.9%,and the transfer rate increased by 2.9%to 7.2%.Petiole transfer at different nodes increased by 45.1%-146.0%and transfer rate increased by 2.8%-10%compared with control A.3.With the increase of the amount of corn straw returned to the field,the number of flowering,pod setting and total cavity of soybean increased first and then decreased,all of which showed as C>B>D>A.The total flower number of B,C and D increased by 12.1%,29.0%and 5.1%compared with that of A.Total pod number increased by 33.1%,39.7%and 22.9%.The total number of cavities increased by 24.3%,28.7%and 8.9%.The differences between treatments were mainly due to the differences in the number of flowering at 3-9 nodes and the number of pod setting at 5-10 nodes.4.The yield of soybean was increased by returning corn straw to the field,and the yield of soybean was higher(5172.5-5361.4 kg·hm-2)when the yield was 6 000-12 000 kg·hm-2.The number of pod per plant in the straw mulching treatment B,C and D increased by 32.6%,39.2%and 22.9%respectively compared with the control treatment A.Grain number per plant increased by 10.4%,13.1%and 6.7%respectively compared with control A treatment.5.Under the conditions of this experiment,the suitable amount of corn straw returned to the field for high yield of soybean was 6 000-12 000 kg·hm-2,and the increase in the amount of corn straw returned to the field decreased the yield increase of soybean.