Rice yield and nitrogen uptake as influenced by drought and by vermiculite incorporation in the soil

Abstract

The effect of three drought period durations (zero, four and eight days) and two vermiculite treatments (with and without incorporation in the soil at 10% concentration on volume basis) on the rice yield and nitrogen uptake was studied in a greenhouse experiment. The soil used in this study was a Dark-Red Latosol (Haplustox) collected from a depth of 0 cm – 20 cm. The drought periods were simulated by withholding the irrigation during panicle emergence. The vermiculite incorporation has improved some soil chemical properties but did not affect grain yield and its components. However, it increased dry matter yield. It also did not affect the nitrogen uptake. The grain yield, its components and the dry matter yield were decreased with increasing drought period duration. However, on the other hand, the nitrogen uptake increased. Rice plants absorbed soil nitrogen in the same proportion as nitrogen derived from fertilizer, regardless of the drought period duration.