Water and Nitrogen Uptake in Upland and Swamp Rice

The water uptake per unit dry matter and nitrogen uptake perunit water absorbed of swamp rice (Dima) and upland rice (Kindinga)at three nitrogen levels equivalent to 23.6, 70.8, and 118,kg./ha. (20, 60 and 100 lb./acre) respectively were studiedunder tropical green-house conditions in Trinidad. The water uptake per unit dry matter produced was significantlygreater in Kindinga than in Dima at the three nitrogen levels.Additional nitrogen increased the water requirement of Kindingabut decreased that of Dima, the greater increase in Kindingabeing attributed to increase in leaf area. The efficiency of nitrogen absorption in terms of water transpiredwas greater in Dima than in Kindinga at the three nitrogen levels.