Effect of Slag Based Gypsum on Nutrient Uptake and Yield of Rice (Oryza sativa L.) in an Alkaline Soil

A pot culture study was undertaken to study the effect of slag based gypsum as a source of nutrient to the rice crop in an alkaline soil. The treatments included recommended dose of fertilizer (RDF) as control, 450, 600, 750 and 900 kg ha-1 of slag based gypsum (SBG) along with RDF. The treatments were replicated thrice and complete randomized design (CRD) was followed for statistical analysis. The results revealed that application of 750 kg SBG ha-1 recorded significantly higher rice grain (8.85 g pot-1) and straw (9.00 g pot-1) yield when compared with other treatments. Further, application of 750 kg SBG ha-1 recorded higher nitrogen (N) (137.68 mg pot-1), phosphorus (P) (48.37 mg pot-1) and potassium (K) (45.38 mg pot-1) uptake by rice grain and also a significantly higher exchangeable calcium (Ca) (12.19 c mol (p+) kg-1) and magnesium (Mg) (12.93 c mol (p+) kg-1) in post-harvest soil. Whereas, application of 900 kg SBG ha-1 recorded higher N (75.64 mg pot-1), P (17.95 mg pot-1) and K (49.78 mg pot-1) uptake by rice straw and also higher pH (8.95), electrical conductivity (EC) (1.28 dS m-1), available N (160.53 kg ha-1) and available sulphur (S) (182.50 kg ha-1) in post-harvest soil. Moreover, application of 900 kg SBG ha-1 was also reported to give higher micronutrient uptake and availability in post-harvest soil of our studies.