Effects Of Straw Returning On Maize Yield,Root And Topsoil Environment

In this experiment,maize was used as the research object,using split-plot design with three replications and simulation of soil tillage and straw incorporated with root-box.Straw treatment was the main plot,and the two levels of inter-row straw incorporated to field(S1)and inter-row no straw returning to field(S2).The depth of returning to field(D)was split-plot,which was 15cm(D1),30cm(D2)and 45cm(D3)respectively.The method of incoporation to field(T)was burying(T1)and mixing(T2)respectively.Using soil digging method,through the inter-row incorporate straw to study on growth and development of maize root system.Studying on the relationship between aboveground and underground.To explore the suitable method of soil cultivation and fertilization for the establishment of reasonable plough layer,and provide a theoretical basis for the application of straw.The results showed that:1.The inter-row straw incorporation could significantly prolong the physiological function of maize leaves and slow the senescence of leaves.Inter-row straw incorporation and deep tillage could significantly increase the SPAD value of maize leaves,which was beneficial to plant photosynthesis.However,there was no significant difference in the plant height of maize plants between the lines.2.The inter-row straw incorporation could significantly promote the growth and development of maize roots,and the inter-row straw incorporation and suitable tillage could delay the senescence of maize roots.The dry weight of the roots showed a wide and deep distribution with inter-row straw incorporation and deep tillage.Inter-row straw mixing could increase the dry weight of root in deep soil,and the inter-row straw burying could delay root senescence.The inter-row straw corporation and deep tillage increased the root length of maize and reduced the root senescence.Inter-row straw mixing could increase the root length,but the inter-row straw burying significantly slowed root senescence.Inter-row straw incorporation and deep plowing also had the function of improving the root index of single grain,which was beneficial to absorb nutrients and water,and laied the foundation for grain filling and increased yield.3.The inter-row straw incorpiration could improve the soil water holding capacity,and reducing the soil compaction,and the continuous inter-row straw incorporation could increase the buffering capacity of soil water,and effectively improved the topsoil environment.The soil water content of maize at different growth stages was significantly increased with inter row straw incorporation.Increasing straw depth could effectively improve the soil water holding capacity.There was no significant difference in the water holding capacity between the inter-row burying and mixing straw returning.The inter-row straw incorporation and deep tillage decreased soil compaction significantly,but there was no significant difference between the inter-row burying and mixing straw.According to the difference of the degree of damage of maize plants(Leaf MDA content)after drought or water logging treatments,it could be concluded that the inter-row straw incorporation and deep plowing could effectively enhance the buffering capacity of soil water.4.The inter-row straw incorporation could alleviate the harm of drought or water logging on the yield of maize.By the drought or water logging hazards,Inter-row straw could improve maize ear traits(single spike weight,ear length,yield increased significantly,and bald tip length decreased significantly).In particular,the inter row straw incorporation and deep plowing could effectively resist drought or water logging hazards,and obtained relatively high yields,but there were no significant difference between the years.This experiment showed that inter-row straw incorporation could increase soil water holding capacity,continuous inter-row straw could reduce soil compaction,increased soil moisture buffering capacity.Inter-row straw incorporation could improve the root growth environment,promoted the growth and development of root system and the absorption of water and nutrients.Therefore,a reasonable method of inter-row straw incorporation can optimize the maize root and topsoil environment,coordinate the upper and underground growth and development,and lay a good foundation for yield increase.The burying straw 30 cm can not only increase the yield after drought or water logging,but also reduce the economic input,which is suitable for the inter row straw incorporation in the region.