灌浆乳熟期土壤水势对苏打盐渍土水稻产量及生理性状的影响

摘要

To explore the effects of soil water potential at grain filling-milky stage on rice yield and physiological traits in saline-alkali soil,we measured grain yield,dry matter production,leaf physiological traits and leaf area under soil water potentials of 0kPa(WP0 ),- 1 5 kPa(WP-1 5 ),- 30 kPa(WP-30 )and CK (continuously flooded).The results showed that yield of rice differed significantly under different soil water potentials,being the highest under WP0 ,while being the lowest under WP-30 .Compared with the CK,WP-1 5 and WP-30 ,rice grain yield under WP0 increased by 4.03%,1 9.90 % and 26.05 %,respectively and the increased 1000-grain weight and seed setting percentage may contribute to its higher grain yield.The root dry matter production under WP0 was significantly higher than that under CK at grain filling-milky stage.The dry matter accumulation of root and abroveground part under WP0 were significantly higher than those under CK ,WP-1 5 and WP-30 after 1 5 days of rewatering.With the decreasing soil water potential,the leaf relative water content and leaf area index decreased with insignificant difference.The content of proline and electrical conductivity under CK were significantly lower than those under WP0 ,WP-1 5 and ,WP-30 .The chlorophyll contents showed a trend of WP0 >CK> WP-1 5 > WP-30 .The 1000-grain weight,seed setting percentage, root activity,dry matter production and chlorophyll contents of rice in soda alkali-saline soil increased under moist irrigation at the grain filling-milky stage,so in soda alkali-saline soil continuously flooded irrigation is not necessary. Moist irrigation method could improve not only rice yield ,but also water resource-use efficiency.%为明确在苏打盐渍土水稻灌浆乳熟期不同土壤水势对其产量构成因素和生理性状的影响,设置4个土壤水势,即WP0(土壤水势0 kPa)、WP-15(土壤水势-15 kPa)、WP-30(土壤水势-30 kPa)以及 CK(淹水并保持水层),研究了苏打盐渍土水稻灌浆乳熟期不同土壤水势对产量构成、干物质积累、叶片生理特性以及叶面积的影响.结果表明,水稻灌浆乳熟期进行土壤水势调控,WP0产量最高,比 CK、WP-15、WP-30分别增产4．03％、19．90％和26．05％,千粒重和结实率的提高是实现高产的主要原因；根部干物质积累量 WP0显著高于对照；复水后15 d,WP0处理地上部分干物质量和根干物质量显著高于CK 和其他两个处理；随土壤水势降低叶片相对含水量和叶面积指数下降,但 CK 与 WP0差异不显著；各处理电导率和游离脯氨酸含量均高于 CK,含量随土壤水势的降低而增加；而叶绿素含量 WP0高于 CK,WP-15和 WP-30均低于 CK,CK 与 WP0之间差异不显著.苏打盐碱地水稻在灌浆乳熟期不必持续淹水灌溉,湿润灌溉可增加水稻结实率、千粒重、根系活力、地上部分干物质积累量以及叶片叶绿素含量,从而提高水稻产量并节约了水资源.