Phosphorus critical levels and availability in lowland soils cultivated with flooded rice

Lowland soils present a great potential for the flooded rice crop. This work aimed to estimate critical levels of P in waterlogged soils cultivated with rice using Mehlich 1 and anion exchange resin as soil-P extractors, compare the performance of these extractors as for the evaluation of the P availability, and study the soil-P fractions involved in the P nutrition of the rice crop. Studied soils consisted of four Histosols: Low Humic Gley (GP), Aluvial (A), Humic Gley (GH) and Bog Soil (O) which were previously cultivated with beans. The experimental design was completely randomized, in a factorial scheme, using four soils, five P rates (75, 150, 300, 500 and 800 mg dm-3) and two liming treatments (with and without liming), with three replicates. After 60 days of flooding, soil samples were submitted to P extraction by Mehlich 1 and resin, and phosphorous fractionation. Two rice plants were cultivated in pots containing 3 dm³ of waterlogged soils. The labile P and the moderately labile P of the soils contributed for rice nutrition. The two tested extractors presented efficiency in the evaluation of P availability for the rice cultivated in lowland waterlogged soils.

Bibliographic Details

Main Authors:	Mariano,Isabela Orlando dos Santos, Fernandes,Luiz Arnaldo, Faquin,Valdemar, Andrade,Alex Teixeira de
Format:	Digital revista
Language:	English
Published:	Escola Superior de Agricultura "Luiz de Queiroz" 2002
Online Access:	http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000100017
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