[Effects of nutrient and water regimes on lodging resistance of rice]

A field experiment was conducted to study the effects of nutrient and water regimes on lodging resistance of rice plant by measuring and comparing the morphological and physical traits and the K2O and SiO2 contents of rice basal stems. The results indicated that a combined application of chemical fertilizers and organic materials, especially and rice straw (CS), could markedly increase the diameter, wall thickness and weight of basal stems, but reduce plant height, which resulted in the effective increase of snapping resistance (RS) and marked decrease of lodging index (LI). The effectiveness of the combined application of chemical fertilizers and rice straw (CS) on the increase of lodging resistance of rice plant was greater in alternate wetting and drying (AWD) and controlled irrigation (DRA), compared to continuous waterlogging (CWL). In addition, the combined application of chemical fertilizers and organic sources, especially with rice straw (CS), greatly increased the K2O and SiO2 contents in rice basal stems, especially in alternate wetting and drying (AWD) and controlled irrigation (DRA). Correlation analysis showed that the wall thickness, weight and snapping resistance of basal stems were significantly positively correlated to the K2O and SiO2 contents in rice basal stems (P<0.05 or P<0.01) in alternate wetting and drying (AWD) and controlled irrigation (DRA).