Yield correlations with nutrients in leaves of rice cultivated in a Red-Yellow Latosol

Abstract

Residual influence of micronutrient fertilization in rice (Oryza sativa L.) crop in a virgin Red-Yellow Latosol was studied during two years. Increases in rice yield above 800 kg/ha/year were due to Zn even in the smallest doses of 2.8 kg/ha, which were sufficient to get almost optimum yield. The critical level of Zn in the leaves and in the soil was 10.6 ppm and 3.1 ppm, respectively. There were positive correlations between yield and the Zn and K content in the leaves, and negative correlations with N, P, Mg and Cu. The correlations coefficient between Zn in the soil and in the leaves was 0.877, and the regression was liner. Zn lixiviate in the soil up to 20cm and 40cm of depth.