Fertilization, liming, nutrient availability, and rice and bean yield in a levelled soil

Abstract

The effects on nutrient availability and rice and bush bean yield, of soil levelling and limestone and fertilizer treatments were evaluated in a Podzolic soil at the Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão (CNPAF), in Goianira, State of Goiás. The levelling of the soil created a fertility gradient that influenced the yield of both crops. Regardless of treatment, the yields increased linearly from the less fertile plots, (those which had the top soil removed by levelling), to the more fertile ones, at lower heights, in which the top soil was relocated. Among the factors making up the treatments (combinations of limestone, NPK fertilization, and Zn fertilization), only NPK fertilization significantly increased rice yield, and only for the BR IRGA-409 cultivar. Bean yield was not affected by any treatment. In all plots the final contents of extractable soil iron and manganese, measured after the completion of the experiment, were higher than the initial ones, the greater values ocurring in the plots with higher organic matter. Iron toxicity was observed in the rice cultivar BR IRGA-409, mainly in these plots.