Effect of sand application and flushing during the sensitive stages on rice biomass allocation and yield in a saline-sodic soil.

摘要

Since gypsum may be precipitated and constrained in saline-sodic soil dominated by carbonate and bicarbonate salts, sand has been applied to improve physical and chemical properties of the soil. On the other hand, rice was sensitive to salinity during the vegetative stage, reproductive stage and spikelet filling growth stage. However, few studies have been reported on the interactive effects of sand application and flushing during the sensitive stages on rice. To analyze the effects of sand application and flushing during the sensitive stages on the rice biomass partitioning between shoot and root, grain yield and its components in a saline-sodic soil, a split-plot design was adopted with sand application (SA) as the main plots and flushing during the sensitive stages (FL) as the subplots conducted. These treatments included no sand application and normal irrigation treatment (CK), no sand application and flushing during the sensitive stages on basis of normal irrigation treatment (NF), sand application and normal irrigation treatment (SN) and sand application and flushing during the sensitive stages on basis of normal irrigation treatment (SF). Rice plant biomass which was allocated to shoots increased in ascending order in the CK, NF, SN and SF treatments during the growing stage, and rice yield also increased in the same order. SA and FL both significantly influenced the yield and yield components, except spikelets per panicle (SP) in FL. In non-SA treatments, all the investigated yield components except SP were higher in NF than that of CK. In FL treatments, all the investigated yield components, except SP, and kernel weight were higher in SF than that of NF. Panicles m-2 in non-FL treatments contributed more to the variation of yield than seed weight per panicle (SWP) while the reverse was true in FL treatments. Percent filled spikelets accounted for the most variation for SWP at each treatment mainly influenced by low air temperature. Study results indicated that the compounded short-term effect of SF is feasible while a single amendment had a limited effective impact on rice growth and yield. Additional research is needed to develop management strategies appropriate for mitigating adverse effects on the most sensitive reproductive stage.