| As an important cultivation measure in the management of dryland farmland in northwest China,mulching can not only play the role of water storage and moisture conservation and increase crop yield,but also lead to changes in the soil microenvironment.Thus,this is necessary to study water and fertilizer status and biological traits.This study mainly focused on the effect of long-term straw mulching,plastic film mulching and no mulching of spring maize in the Weibei dry plateau area,on the soil moisture,nitrogen(N)dynamic distribution,soil enzyme activities.This study provides a more suitable mulching measure for maize planting in this area,and provide scientific basis and data support for improving crop yield and efficient utilization of soil nutrients.The main research conclusions are as follows:1.Two years of experimental data showed that plastic film mulching and straw mulching can effectively maintain soil water content and soil water storage during the entire growth period of spring maize,and reduce ineffective evaporation of water.Compared with no mulching,the soil water storage of plastic film mulching and straw mulching increased by 13.4% and 6.5%,9.1% and 5.4%,respectively.During the mature stage,the accumulation of soil nitrate N in the two years of mulching and straw mulching was about 10% and 5%,respectively,mainly concentrated in the 0-40 cm topsoil,and there was no significant difference among the three treatments.In other growth periods,soil nitrate N content was the largest under no mulching treatment,indicating that soil N was more easily absorbed and utilized by crops under the mulching environment.2.Mulching can significantly promote the enzyme activities of rhizosphere.Compared with long-term non-mulching,straw mulching significantly increased the hotspot area ofβ-glucosidase,leucine aminopeptidase and acid phosphatase in the rhizosphere.Plastic film mulching and straw mulching increased the hotspot area of β-glucosidase by 0.11 % and0.24 %,respectively.The rhizosphere distance was the widest(2.3 mm)under plastic film mulching and the narrowes(1mm)under plastic film mulching.The hot spot area of leucine aminopeptidase increased by 2.17 % and 0.64 %,respectively;the rhizosphere distance was the widest(4.8 mm)under mulching,and the shortest(2.5 mm)under no mulching.;the rhizosphere distance was the widest(4.8 mm)under mulching,and the shortest(2.5 mm)under no mulching.The hot spot area of acid phosphatase increased by0.29 % and 0.19 %,respectively;its rhizosphere distance was the widest(2.5 mm)under mulching and no mulching treatments,and the shortest(1.4 mm)under no mulching treatments.3.Compared with no mulching treatment,straw mulching can significantly improve the OTU quantity of soil bacterial community and changed the structural composition of soil fungal community.The quantity of OUT under straw mulching was higher than that of mulching(1505)and higher than that of no mulching treatment(1184).Straw mulching can significantly improve the α-diversity of soil bacteria,and no mulch is more advantageous for promoting the α-diversity of soil fungi.Different mulching measure were also selective for the dominant populations of soil bacteria and fungi.4.Compared with no mulching treatment,plastic film mulching and straw mulching significantly promoted the yield and biological characters of spring maize.The yield of spring maize increased by 24.9% and 11.8% under plastic film mulching and straw mulching,respectively,with significant differences among the three treatments.Compared with no mulching treatment,the dry matter accumulation of spring maize increased by 17.8%and 8.1% after the surface was covered with plastic film and straw.Biomass such as SPAD content of spring maize had a significant promoting effect after the different mulching.Compared with no mulching treatment,the SPAD values under straw mulching and plastic film mulching increased by 14.4% and 15.4,respectively;the leaf area index increased by8.8% and 44.3%;and the plant height increased by 4.8% and 11.4%,respectively. |
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