Aplicação de misturas granuladas NK e NS em cultivar de arroz (Oryza sativa) / Application of NK and NS granular mixtures in a rice (Oryza sativa) cultivar

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This study aimed to evaluate NK (urea and potassium chloride) and NS (urea and ammonium sulfate) fertilizers as granular mixtures and pastilles, in the rice cultivar IAC 202 in soil samples of different textures, from Fragiudult and Udult soils. Experiments were held in a greenhouse with controlled temperature and humidity, located in the experimental area of Soils Department, UFRRJ. The growth of rice plant s was evaluated for a period of 40 days, by means of morphological parameters (height, dry weight, tillers) as well as supply of nutrients in soil, and uptake of N and K by plants. The first experiment focused on effect of biuret contained in granular fertilizers, compared to the fertilizers free of biuret and mixed from raw products used in production of fertilizer as pellets. As for the morphological parameters, it was found that the biuret contained in pellets delayed, and in some cases, inhibited the plant growth when applied in large quantities. For the chemical attributes, in the two soil types, the treatments receiving biuret showed highest levels of Mg2+ compared to their equivalent mixtures, which may probably be due to inhibition in the absorption of this element by the plants. There was a greatest accumulation of NO3 - + NO2 - levels in both soils that received biuret. Possibly, because of biuret interference in nitrification, thus promoting accumulation of nitrite. The same happened for formation of ammonia in the soil, as biuret increased the concentration of soil NH4 +. Applications of biuret increased, in part, leaf N levels, which may be due to high concentration of this element, and that plants showed increasing in absorption of NO3 - and NH4 +, as well as greatest uptake of K+ when compared to the fertilizer mixtures. The second experiment aimed to evaluate effect of K+ fertilizers form (chips, pellets and pearl), and the biuret contained in pellets compared to pastilles with low levels of biuret. As to the form effect, the pellets fertilizers showed similar results to pearl commercial fertilizers (Super N and Urea fertilizer). The K+ in the NK chips showed a positive effect on rice plant growth. In relation to effect of biuret contained in the pellets, it was found the same pattern as in the first experiment, where the biuret delayed and inhibited the plant growth.

ASSUNTO(S)

fertilizante pastilhado chips fertilizer. biuret. ciencia do solo biureto. granulated fertilizer fertilizante granulado

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