Effect Of Vertical Deep Rotary Tillage With Additional Organic Fertilizer On Soil Quality And Maize Growth In Saline Soils

Maize,as one of the main crops grown in the saline areas of Yinbei,Ningxia,has experienced a series of problems such as increased soil salinization and reduced soil fertility due to long-term shallow tillage and heavy application of chemical fertilizers,which have reduced maize yield.Therefore,by changing tillage practices and increasing the application of organic fertilizers are effective measures to alleviate this series of problems at present.In this study,maize was used as the research object,and two tillage methods,traditional tillage and vertical deep rotary tillage,were set up with different organic fertilizer levels of 0 kg-hm-2,7500 kg-hm-2,15000 kg-hm-2,and 22500 kg-hm-2 to investigate maize agronomic traits,physiological characteristics,maize seed yield,and to deeply analyze the physical and chemical properties,enzyme activity and The purpose of this study is to provide a better understanding of the relationship between the physical and chemical properties,enzymatic activity and microorganisms in the saline soils of northern Yinbei.The aim was to provide a theoretical basis for selecting the best tillage method and organic fertilizer dosage for maize farmland in the saline area of north Yin.The main results of the study are as follows:1.During the two-year period,vertical deep-rotation tillage reduced soil bulk density by 15.5%-28.1%,increased soil porosity by 11.8%-20.3%,and increased soil water content by 25.0%-44.6%compared with conventional tillage;soil bulk density gradually decreased and porosity and water content gradually increased with the increase of organic fertilizer application under both tillage methods.2.Vertical deep rotary tillage reduced pH by 1.1%～2.8%and salinity by 2.8%～11.1%compared with conventional tillage.Soil salinity and pH decreased slowly with the increase of organic fertilizer under both tillage methods.8.5%～9.0%lower soil salinity and 9.1%～11.3%lower pH in 2022 than in 2021.3.deep rotary tillage increased soil alkaline N,effective phosphorus,fast-acting potassium and organic matter content during the two-year period compared with conventional tillage;soil alkaline N,effective phosphorus and organic matter content were highest with organic fertilizer application of 22,500 kg/hm-2.soil alkaline N,effective phosphorus,fast-acting potassium and organic matter content increased by 1.1%to 1.8%,2.1%to 11.5%,5.4%to 10.5%and 0.6%to 4.7%,respectively,in 2022 compared with 2021,5.4%～10.5%and 0.6%～4.7%.The activities of alkaline phosphatase,sucrase,urease and catalase differed among treatments,but alkaline phosphatase,sucrase and catalase activities were all higher in the A2B4 treatment.4.the microbial activity of the soil was low during 2021 due to salinity.microbial diversity in 2022 showed:at the bacterial level,Observed index,Chao1 index and ACE index increased by 5.6%,4.5%and 1.0%,respectively,under the vertical deep rototilling technique compared to the conventional tillage technique;Observed index,Chao1 index and ACE index were higher in the treatment with organic fertilizer(B4)than in the other treatments,Chao1 index were higher than other treatments.At the fungal level,Chao1 index and ACE index were 19.28%and 3.5%higher,respectively,in vertical deep rotary tillage compared with conventional tillage;Observed index,Chao1 index and Shannon index were higher under treatments with organic fertilizer(B4 and B3)than the other treatments.5.Proteobacteria,Acidobacteriota,Actinobacteria,Microgenomates,BacterDidetes,Chloroflexi,Verrucomicrobia,and Planctomycetes were the main bacterial dominant groups;Ascomycota,unidentified,and Basidiomycota were the main fungal dominant groups in the soil in 2021 and 2022.6.under the interaction of vertical deep rototilling and increased organic fertilizer application,the malondialdehyde content of maize leaves showed a trend of increasing and then decreasing with the advancement of the reproductive period,proline showed a decreasing trend,and POD,SOD and CAT enzyme activities showed a gradual increase.2022 compared with 2021,POD,SOD and CAT enzyme activities increased by 0.7%～4.7%,2.5%～12.3%,and 0.1%～1.6%.7.The interaction of vertical deep rototilling and additional organic fertilizer technology increased spike weight,spike grain weight,100 grain weight,spike grain number and yield in 2021 and 2022,but only spike grain weight,spike grain number and yield were significant under two-way ANOVA.economic efficiency was 3.9%～11.0%higher in 2022 than in 2021.