Impact of integrated application of fly ash and lime on nutrient availability, uptake and yield of lentil in acid soil under different fertilizer levels

Fly ash (FA), a coal combustion solid residue has been considered problematic waste due to challenges in its management and disposal issue. To address disposal challenges, the application of FA to agricultural soils offers a sustainable management strategy. FA exhibits liming properties and contains oxides and hydroxides of P, K, Ca, Mg, Fe, Mn, etc. making it both a nutrient source for plants and a soil amendment. Therefore, a pot culture experiment was conducted during winter of 2020 with lentil (Lens culinaris Medik.) cv. Malviya Viswanath as test crop in the net house of the Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi to investigate the impact of using FA either alone or in conjunction with lime in acid soil on nutrient availability and uptake by lentil crop. Application of FA, lime and different doses of fertilizers had significant impact on available N, P and K of soil among treatments. The application of 100 % recommended dose of fertilizer (RDF100 %) + 20 % lime requirement (LR20 %) + FA rate (FAR80 %) recorded significantly higher soil available N, whereas highest available P and K was registered with the treatment comprising RDF100 %+ FAR100 %. Application of FAR100 % had significantly increased available P and K of soil over control by 20.2 and 7.1 % respectively. The incorporation of FAR80 % along with RDF100 % and LR20 % resulted in the highest seed yield (5.7 g pot-1) among the treatments. Similarly, the application of FA in combination with lime and fertilizer had significant effect on macronutrient content and uptake by the crop. A positive linear relationship was observed between seed nutrient uptake and seed yield of lentil.