Acessibilidade / Reportar erro

DISPONIBILIDADE DE FÓSFORO PARA PLANTAS DE ARROZ AVALIADA POR EXTRATORES QUÍMICOS

Phosphorous avaliability to rice plants was evaluated in an experiment under greenhouse conditions using an acid and low phosphorus soil. Five fertilizers (Alvorada rock phosphate-FNA, amonion monophosphate-MAP, simple superphosphate-SFS, triple superphosphate-SFT and magnesium termophosphate-TM), three rates (100, 200 and 300 mg P dm-3 of soil), one control and ten plants of rice/pot were used. Phosphorus in soil samples were analized using the following extractants: Mehlich-1, Olsen and resin. Dry matter, P content and P absorved by the shoot were correlated with the P recovered by the three chemical methods. The MAP and SFS at the rate of 200 mg P dm-3 of soil, allowed the highest dry matter accumulation in above ground parts of rice plants. The MAP and SFS at the rate of 200 mg P dm-3 of soil, allowed the highest dry matter in above ground parts of rice plants. Differences among soil chemical P-extractants and a positive correlation with the evaluated parameter were observed. Olsen's extractants showed were the best correlation with rice response to rates and sources of P.

fertilization; phosphorus; soil analysis; Oriza sativa; extractants


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