Influence of organic amendments on acidic soil responsive crop groundnut (Arachis hypogaea L.)

The present study evaluated the comparative effects of organic amendments on physiology, growth, and yield of acidic soil responsive crop groundnut and soil physicochemical and biochemical (dehydrogenase, acid phosphatases, and glucosidase activity) parameters. The treatments comprise of control (recommended dose of fertilizer or RDF), lime at 25% (L25 + RDF) and 100% lime requirement (L100 + RDF), farmyard manure+ RDF, compost+ RDF, poultry manure+ RDF, and pig manure+ RDF. The impact of organic amendments was also investigated on root exudation and crop parameters in a controlled growth chamber. At active growth stage, organic amendment application especially poultry and pig manures maintained higher leaf cell membrane integrity, chlorophyll content and stomatal frequency/or density compared to other treatments. Soil available P under organic manure (particularly pig and poultry manure) or lime was significantly higher over control. In contrast, exchangeable acidity and readily soluble Al were significantly lower under pig and poultry manure. Increased soil P availability was due to P availability from manure, increased soil pH, exchangeable Ca + Mg, organic carbon and enzyme activities, and reduction in exchangeable acidity and readily soluble Al as evident by their significant correlation with soil available P. In conclusion, pig and poultry manures seems to be effective substitute of lime for amelioration of soil acidity by maintaining favorable soil pH, organic carbon and microbial biomass carbon, available nutrients, exchangeable Ca and Mg, enzyme activities, and thereby improved plant physiological condition. These findings confirmed the applicability of poultry and pig manures as recyclable low-cost farm wastes as alternative liming materials in acidic soils.