02296naa a2200301 a 450000100080000000500110000800800410001902200140006002400390007410000220011324501190013526000090025452014350026365000150169865000140171365000090172765000190173665000100175565000190176565000130178465000170179765000140181465000180182870000200184670000250186670000260189177300770191720919642018-05-25       2018    bl uuuu     u00u1 u    #d  a1983-40637 a10.1590/1983-40632018v48506662DOI1 aREIS, A. F. de B.  aGrowth and nutrient contents in lowland rice due to phosphorus and potassium fertilization.h[electronic resource]  c2018  aIn order to reach an optimum and sustainable production, growers must know the fertilizing potassium (K) and phosphorous (P) application rates. The present study aimed to determine the rice development in response to combined rates of P and K, on Plinthaquults (380-400 g kg-1 of clay), under high and low fertility conditions, in the tropical lowland plain of the Araguaia river, Brazil. Three field experiments were performed, each one consisting of a completely randomized factorial block design, with three replications. Treatments included a combination of six K2O rates (0 kg ha-1, 30 kg ha-1, 60 kg ha-1, 90 kg ha-1, 120 kg ha-1 and 150 kg ha-1) with six P2O5 rates (0 kg ha-1, 30 kg ha-1, 60 kg ha-1, 90 kg ha-1, 120 kg ha-1 and 150 kg ha-1). No interaction effect between P and K rates was observed for the evaluated variables in any fertility level/year. Phosphorous application under low fertility conditions, as well as K under high fertility conditions, affect overall crop nutrition, tillering capacity, yield components and grain yield of lowland rice, though no effects were observed due to the P application in high fertility soils and K in low fertility soils. Under high fertility conditions, the grain yield increment rate due to the K application was 4.04 kg ha-1, whereas in the low fertility areas, such as recently cleared fields, a maximum yield of 7,161 kg ha-1 was achieved by applying 140 kg ha-1 of P.  aPhosphorus  aPotassium  aRice  aTropical soils  aArroz  aArroz Irrigado  aFósforo  aOryza Sativa  aPotássio  aSolo Tropical1 aNASCENTE, A. S.1 aALMEIDA, R. E. M. de1 aCHAGAS JÚNIOR, A. F.  tPesquisa Agropecuária Tropicalgv. 48, n. 2, p. 98-108, apr./jun. 2018.