Soil acidity as affecting micronutrients concentration, nitrato reductase enzyme activity and yield in upland rice plants

Edemar Moro, Carlos Alexandre Costa Crusciol, Heitor Cantarella, Adriano Stephan Nascente, Adriana Lima Moro, Fernando Broetto

Abstract


The lowest grain yield of rice under no-tillage system (NTS) in relation to the conventional system may be due to the predominance nitrate in the soil and the low nitrate reductase activity. Another reason may be caused by micronutrient deficiency because of superficially soil acidity corrections. Therefore, the objective of this study was to evaluate the changes caused by soil pH in the N forms in the soil, micronutrients concentration in rice plants, nitrate reductase activity, yield of rice and its components. The experiment was performed in a greenhouse conditions. The experimental design was a completely randomized in a factorial three (levels of soil acidity) x five (micronutrients sources) with four replications. The addition of micronutrients does not affect levels of nitrate and ammonium in the soil; soil acidity significantly affects levels of nitrate and ammonium in the soil, concentration of micronutrients in rice plants and crop yield and its components; medium soil acidity (pH 5.5) result in medium to high levels of Cu and Fe, medium level of Zn and Mn, high nitrate reductase activity, resulting in higher dry matter, tillers, panicles, spikelets, weight of 100 grains and hence grain yield.


Keywords


Oryza sativa; Soil fertility; Soil acidity; Yield; No-tillage system.



DOI: http://dx.doi.org/10.5433/1679-0359.2013v34n6Supl1p3397

Semina: Ciênc. Agrár.
Londrina - PR
E-ISSN 1679-0359
DOI: 10.5433 / 1679-0359
E-mail:  semina.agrarias@uel.br
Este obra está licenciado com uma Licença  Creative Commons Atribuição-NãoComercial 4.0 Internacional