Conjoint Use of Chemical Amendments and Municipal Solid Waste Compost for Amelioration of Degraded Sodic Soil

Abstract

Presence of salts in soil is one of the major challenges for restoration of degraded sodic lands. Reclamation of these soils through chemical amendments like gypsum and phosphogypsum is too expensive for marginal farmers. To provide a realistic solution for ameliorating sodic soils, through conjoint use of lower dose of chemical amendments with municipal solid waste (MSW) compost, a field experiment was conducted during 2015-16 to 2017-18 at ICAR-CSSRI, Research farm, Shivri, Lucknow (26°47′58′′ N, 80°46′24′′ E).The experiment was conducted on highly sodic soil having pH2 9.8, EC2 1.47 dS m-1, and ESP 78. Reduced dose of gypsum or phosphogypsum @ 25% of gypsum requirement (GR) in combination with MSW compost @10 t ha-1 resulted in significant improvement in the soil physical, chemical and microbial properties over the recommended dose of gypsum or phosphogypsum (50% of GR). Combined use of gypsum or phosphogypsum @ 25% of recommended dose of gypsum along with MSW compost @ 10 t ha-1 increased about 10% soil organic carbon content, 13% available N, 42% bacterial population and 200% fungal population; and reduced 14% exchangeable sodium percentage over the recommended dose of inorganic amendments. With the application of gypsum @ 25% GR + on-farm MSW compost @ 10 t ha-1,the soil bulk density decreased by 11% and the infiltration rate increased by 54% as compared to initial values. With the introduction of this approach there is saving of about 50% amount of inorganic amendments that can be utilized to reclaim double the degraded sodic lands and improve food security of resource poor farmers in the region. This also saved about 35.6% reclamation cost on account of reducing gypsum dose.