实地氮肥管理对水稻根系形态生理和产量的影响

wo cultivars, Shanyou 63 (indica) and Lianjing 6 (japonica), were grown in field. Two nitrogen (N) managements, site-specific N management (SSNM, N application according to soil fertility, leaf color and growth status, and cultivar types) and farmers' fertilizer practice (FFP), were designed. This study investigated the effect of SSNM on roots growth and yield of rice. Results showed that the root dry weight in the FFP was higher than those in the SSNM before heading, whereas it was lower at and after heading. SSNM significantly increased the root-shoot ratio during the whole growing season. Compared with that under FFP, SSNM increased root oxidation activity(ROA) at and after panicle initiation, especially ROA per stem. SSNM increased the photosynthetic rate of the flag leaves after heading. Compared with FFP, SSNM increased grain yield by 7.2-9.4% and N use efficiency expressed as N partial-factor productivity (grain yield/amount of N applied) by 38-46%. The enhancement of root growth at the latter growing stage would account for the increase in grain yield and N use efficiency under SSNM.