水分管理和播种量对旱直播水稻产量形成的影响

Effect of Sowing Rate and Water Management on Yield Formation of Dry Direct Seeding Rice

为探明旱直播水稻模式下播种量和水分管理对产量和水分利用效率的影响,在旱直播模式下,设置裂区试验,主处理为旱管(DM,干(重旱)湿交替灌溉)和水管(WM,常规淹水灌溉),副处理为播量1(SO,22.5 kg/hm^(2))和播量2(SS,37.5 kg/hm^(2)),考察对产量、叶面积指数、籽粒灌浆动态、叶片衰老及水分利用效率的影响。结果表明:旱管处理的水稻产量低于水管处理,提高播种量后两者产量差距缩小11.6个百分点,主要因为提高播种量后显著提高了有效穗的数量,旱管播量2的有效穗数量比旱管播量1提高23.7%,也使其群体LAI的提高6.8%,但是播量提高均使其他产量构成因子降低。旱管处理后的植株叶片衰老速度高于水管处理,两年平均高19.9%,提高播量进一步加剧了衰老进程。旱管播量1处理的水分利用效率低于水管处理,提高播量后,旱管水分利用率比水管提高5.47%,且比旱管播量1提高12.05%。旱直播旱管模式提高播种量后可改善群体质量,显著提高水稻产量和水分利用效率,为旱直播水稻技术在缺水条件下的稳产打下基础。

In order to explore the effects of sowing rate and water management on the yield and water use efficiency(WUE)under dry direct seeding rice,field experiments were conducted to compare the effects of Dry-management(DM,hard alternating wet and dry),Watermanagement(WM,flooding irrigation),Sowing amount-one(SO,22.5 kg/hm^(2))and Sowing amount-second(SS,37.5 kg/hm^(2))on grain yield leaf area index,grain filling dynamics,leaf senescence and water use efficiency.The Results were as follows:the rice yield of DM treatment was lower than that of WM treatment,and the yield gap between DM and WM was reduced by 11.6%after increasing the sowing amount mainly because the number of effective panicles was significantly increased.The number of effective panicles of SS treatment was 23.7%higher than that of SO treatment,and LAI was increased by 6.8%,but all the other yield components decreased.The senescence rate of leaves of DM treatment was higher than that of WM treatment by 19.9%across two years average,and the senescence process was slightly increased by increasing sowing amount.The WUE of DMSO was lower than that of WMSO,but increased by 5.47%after increasing the sowing amount And the WUE of DMSS was higher than DMSO by 12.05%.It can be conclude that increasing seeding amount can improve population quality significantly increase rice yield and water use efficiency,which laid a foundation for stable rice yield under the condition of water shortage for DDS technology.