Microbial inoculants improve growth and yield of spring maize in saline-alkali soil

CHEN Cong; ZHAO Weixia; ZHAO Zhi

doi:10.13522/j.cnki.ggps.2024027

Abstract：[Background and Objective]Saline-alkali soil is characterized by excessive salt and alkali content,poor physical and chemical properties.Efficient utilization,improvement and development of saline-alkali soil resources is important for food security.Microbial amendments are a green and efficient method for improving saline-alkali soil.This study is to explore the efficiency of microbial inoculants in improving the properties and productivity of saline-alkali soils.[Method]Salt-tolerance critical contents in different growing stages of spring corn in the saline-alkali soils were obtained first in 2022 before soil amendment.In 2023,the saline-alkali soil was amended by building drainage ditch,organic fertilization and drip irrigation.The soils were further amended by microbial inoculants applied in different ways:i)applying 600 kg/hm2 of solid microbial amendments as base,ii)applying 300 kg/hm2 of solid microbial amendment as base coupled with applying 75 L/hm2 of liquid microbial inoculants at the jointing stage and the heading stage,respectively,iii)applying 300 kg/hm2 of basal solid microbial amendment coupled with applying 75 L/hm2 of liquid microbial inoculant dynamically based on the critical salt tolerance contents measured in 2022.The control was soil without microbial amendment.[Result]The salt tolerance critical content at the seedling stage,jointing stage,heading stage and filling stage were 1.77,2.28,5.07 g/kg and 5.27 g/kg,respectively.Compared to 2022,amending the soil in 2023 increased seedling emergence rate by 34.4%to 70.1%,and grain yield by 4.20 t/hm2 to 8.62 t/hm2.Compared to the control,microbial amendment increased plant height,leaf area index,above-ground dry matter mass and relative chlorophyll content of the leaves by 9.9%-17.1%,38.4%-56.1%,26.7%-32.0%and 9.2%-11.2%,respectively,and grain yield by 30.6%-36.0%.Dynamically applying microbial amendment based on soil salt content significantly increased the seedling emergence rate,growth index and grain yield.[Conclusion]Our results show that combining drainage ditches,organic fertilization and microbial amendments can substantially improve productivity of the saline-alkali soil for spring corn.Specifically,applying 300 kg/hm2 of solid amendments as base coupled with dynamically applying 150 L/hm2 of liquid microbial inoculants based on salt tolerance critical content was most effective to improve productivity of the soil.