Effect of mineral and organic amendments on rice growth and yield in saline soils

Abstract

Globally, the agricultural soils area where crop yields are affected by salinity has increased. This research aimed to evaluate the outcome of the edaphic application of mineral and organic amendments upon the growth and yield of irrigated rice in saline soils of Yaguachi, Ecuador. INIAP FL-1480 variety was selected for the experiment and grown with conventional cultural practices. A randomized complete block design with leonardite, gypsum, vinasse, compost, sugarcane filter cake, pig manure and control treatments, with four replicates, was used. Results indicated that application of compost was always associated with the highest accumulation of essential macronutrients in the rice grain, whereas no significant differences were found in leaves. Macronutrients were absorbed in the following sequence K = N > Ca > P > = S > Mg, while micronutrients Fe > Mn > Zn > Cu > B. While vegetative growth was not affected; reproductive growth was visibly influenced by the amendments application. Compost, sugarcane filter cake and leonardite induced superior yield values when compared to the control. Participant yield components with significant statistical differences were panicle-length, filled-grain-proportion and mainly a 1000-seed-weight. A non-significant mean harvest index of 0.35 and a grain-straw relationship of 0.65 were obtained for compost. Considering all the evaluations, the response to compost usage was always superior to or not exceeded by any other amendment, which leads to point it out as the best amendment for these soils, maybe because it favors plant soil nutrients availability. Response to amendments confirms their importance for rice crop management in the area.