Cow Manure Compost Promotes Maize Growth and Ameliorates Soil Quality in Saline-Alkali Soil: Role of Fertilizer Addition Rate and Application Depth

Abstract

Soil salinization and alkalization is a global problem restricting agricultural production. This study compared different fertilizer regimes (addition rate and application depth) on maize growth and soil quality in saline-alkali soil. Cow manure compost was applied with addition rates of 6, 12, 18 and 24 t·ha−1, and application depths of 5 and 20 cm, along with 0.6 t·ha−1 mineral fertilizer, and compared to a control treatment with only mineral fertilizer application. Results indicated that cow manure compost application could promote maize growth and ameliorate soil quality in saline-alkali soil. Increasing cow manure compost addition rate alleviated soil salinity better than alkalinity, while increasing compost application depth could reduce soil alkalinity more effectively than soil salt content. Moreover, increasing cow manure compost addition rate improved soil organic matter and soil nutrient content, thus promoting shoot growth and maize yield. However, increasing cow manure compost application depth could boost root growth, and further absorbed more nutrients to promote maize yield. Cow manure compost application increased maize yield by 6.0% to 28.4% with a maximum yield of 8.14 t·ha−1 in a treatment with compost addition rate of 24 t·ha−1 and application depth of 20 cm. Comprehensive evolution of soil quality, maize growth and maize yield, cow manure compost addition rate of 24 t·ha−1 and application depth of 20 cm along with 0.6 t·ha−1 mineral fertilizer application is suggested for use in saline-alkali soil.