不同水肥耦合条件下水稻干物质积累与分配特征

2009年5—9月在湖北省灌溉试验中心站以优质水稻新两优香4为材料,采用长期淹灌和间歇灌溉2种灌溉模式,结合3种施肥(氮及磷肥)水平F1、F2、F3,研究了不同水肥耦合条件下水稻产量形成过程和干物质积累与分配特征。结果表明,不同水肥处理下水稻各生育期干物质积累的动态变化相似,分蘖前期水稻干物质的积累量随施肥的增加而上升,到一定程度则会下降,不同灌溉模式间的差别不明显。从分蘖后期到抽穗开花期,不同水肥处理水稻干物质的积累总量均明显增大,且不同处理间差异显著,F1、F2、F3处理抽穗开花期间歇灌溉模式干物质积累量比淹灌模式分别大12.1%、22.1%、61.9%。间歇灌溉模式水稻干物质净积累量(NDMA)和群体生长速率(CGR)峰值随施肥量的增加发生改变,由出现在低肥水平(F1)的抽穗开花期至乳熟期转变为高肥水平(F2,F3)的分蘖后期至拔节孕穗期,且NDMA和CGR显著增大。不同水肥处理水稻黄熟期干物质在各器官间的分配不同,但均表现出相同趋势,即由高到低依次为籽粒、茎、叶、根。不同灌溉模式水稻的收获指数随施肥量的增加而下降,淹灌模式下收获指数下降明显,相对F1处理,F2、F3处理下分别下降12.4%、17.9%。干物质积累过程的拟合结果表明,三次曲线模型比Logistic模型的拟合精度高。

Characteristics of Rice Dry Matter Accumulation and Distribution under Different Water and Fertilizer Treatment

Characteristics of rice dry matter accumulation and distribution in different water and fertilizer treatment,i.e.continuous submergence irrigation and alternate wet and dry irrigation(AWD) combined with three fertilizer level(F1,F2,F3),were studied in experimental farm of Centre Irrigation Experiment Station of Hubei province from May to Sep in 2009,the rice breed was Xin-Liangyouxiang 4.The results showed that the accumulation of dry matter of rice performed the same dynamic trends under different water and fertilizer treatment.The accumulation of dry matter of early stage of tiller growth increased firstly with the rise of use of fertilizer(N and P),then decreased in the sequel,no significant difference was found between different irrigation mode.The accumulation of dry matter of different water and fertilizer treatment increased evidently from later stage of tiller growth to tasseling stage and showed significant difference,the accumulation of dry matter of continuous submergence irrigation mode were respectively 12.1%,22.1%,61.9% bigger than that of AWD accordingly with the fertilizer level F1,F2,F3 at tasseling stage.The summit of net dry matter accumulation(NDMA) and community growth rate(CGR) of AWD changed from tasseling stage-milk stage at F1 to later stage of tiller growth-heading stage at F2 and F3,and increased significantly.The distribution of dry matter of organs of yellow maturing stage of different water and fertilizer treatment were different from each other,but performed the same trends,it was grain,stem,leaf,root.The harvest index of rice of different irrigation mode decreased with the rise of use of fertilizer.The harvest index of continuous submergence irrigation mode decreased obviously,comparing with F1,it respectively decreased 12.4% at F2 and 17.9% at F3.The regression for dry matter accumulation over the rice growing and developing course showed that it could be fit by cubic equation better than that by Logistic equation.