Rice uptake of P, K, Mg, Ca and S as influenced by water stress, vermiculite and cultivar

Abstract

The effects of four irrigation levels and two vermiculite treatments on the P, K, Mg, Ca and S uptake by rice (Oryza sativa L.) cultivars IAC 47, IRAT 13 and IET 1444 were measured in a greenhouse experiment using soil surface samples (0 cm -20 cm) of a Dark-Red Latosol (Haplusthox). The treatments included the irrigation levels corresponding to 55%, 70%, 85% and 100% of maximum evapotranspiration with and without vermiculite incorporation in the soil at 10% concentration on volume basis. The irrigation treatments were administered daily from the beginning of the reproductive phase until harvesting. The incorporation of vermiculite into the soil increased P, K and Mg uptake and decreased Ca. However, it did not affect S uptake. Water stress decreased P and K uptake but did not affect Mg, Ca and S. There were differences among the cultivars concerning nutrient uptake. The distribution of absorbed nutrients in the plant varied with water stress intensity, nutrient and cultivar.