Harnessing Agricultural Potential of Degraded Alkaline Soils through Combined Use of Municipal Solid Waste Compost and Inorganic Amendments

Abstract

ABSTRACT Management of degraded alkali soils is an overriding challenge for agricultural production. Salt toxicity and lack of organic matter and available nutrients are major causes for poor soil fertility and low productivity. Amelioration of these soils through inorganic amendments is costly. A field experiment with six treatment combinations of different doses of organic and inorganic amendments was conducted during 2014 to 2016 on highly alkali soil, with the hypothesis that the integration of organic and inorganic amendments may offer a pragmatic solution for sustainable reclamation and harnessing their productivity potential. From our study, it was observed that combined use of municipal solid waste (MSW) compost @10 Mg ha−1 with reduced dose of gypsum or phosphogypsum (25% gypsum requirement, GR) increased soil bulk density, infiltration rate, exchangeable sodium percentage (ESP), soil organic carbon (SOC), and available N by 11%, 54%, 14%, 10%, and 13%, respectively, over the control. Integrated use of organic and inorganic amendments also increased soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP), and dehydrogenase activity by 56.85, 82.90, 78.80, and 101.00%, respectively, over the control. These changes in soil properties resulted in a profound effect on crop productivity on widely distributed alkali soils in India and other arid and semi-arid regions of the world. Therefore, application of municipal solid waste compost in combination with inorganic amendments can be a sustainable approach for restoration of degraded alkali lands for harnessing their productivity potential and the monetary savings of inorganic amendments amounting about US$ 433 ha−1, which can be utilized for the amelioration of more alkali lands.