Effects of Phosphorus on Grain Quality of Upland and Paddy Rice under Different Cultivation

Abstract

We investigated how upland and paddy japonica rice responded to phosphorous (P) fertilizer under two cultivation methods. The upland rice Zhonghan 3 and the paddy rice Yangfujing 8 were both grown under moist cultivation (MC, control) and bare dry cultivation (DC) with three P levels, low (LP, 45 kg/hm2), normal (NP, 90 kg/hm2) and high (HP, 135 kg/hm2). As P level increased, grain yields of both upland and paddy rice increased under DC. There were no significant differences in grain yields between HP and NP for either rice, although upland rice slightly increased and paddy rice slightly decreased in grain yield. Under DC at LP, Zhonghan 3 showed a higher head milled rice rate and better appearance, cooking and eating qualities than at HP or NP. Yangfujing 8 was similar to Zhonghan 3 except that Yangfujing 8 had better appearance quality at NP. Under MC, Zhonghan 3 had a higher head milled rice rate at LP and better cooking and eating qualities at NP. Yangfujing 8 was similar to Zhonghan 3 except in appearance quality. DC improved head milled rice rate and appearance quality of both upland and paddy rice, and cooking and nutrient qualities of paddy rice. Compared with paddy rice, upland rice had better processing, nutrient and eating qualities. The results suggest that upland and paddy rice respond differently to cultivation method and phosphorus level.