群体分布对夏大豆产量和水分利用效率的影响

在田间试验条件下研究了群体不同分布对夏大豆产量构成和水分利用的影响.夏大豆‘鲁豆4号'(Glycine max cv. Ludou 4)在同一群体密度(3.09×10~5株/hm~2)下设5种分布方式,即行距×株距分别为A:18 cm×18 cm,B:27 cm×12 cm,C:36 cm×9 cm,D:45 cm×7.2 cm,E:54 cm×6cm.结果表明,群体分布影响夏大豆的产量、叶片水分特征和水分利用效率(WUE).A、B处理的产量显著高于D、E处理(P<0.05),其他处理间均无显著差异;随着行距加大,单株有效荚数、粒数及百粒重呈下降趋势;叶片相对含水量(RWC)、水势(Ψw)和渗透势(Ψs)随生育进程的推进呈整体下降趋势,其中,A、B处理RWC、Ψw 和Ψs的平均值均显著高于D、E处理,E处理的Ψw在日变化的正午阶段明显低于其他处理;WUE与行距呈负相关(R=-0.935~*),与产量呈正相关(R=0.997~(**)),其中,A、B处理的WUE显著高于其他处理(P<0.05),D、E处理极显著低于B处理(P<0.01).夏大豆植株相对均匀分布的处理可改善产量构成因素及叶片水分状况,进而形成较高的产量,提高水分利用效率.

Effect of population distribution on yield and water use efficiency in summer soybean

One approach to improve summer soybean yield and water use efficiency (WUE) is to identify appropriate crop population distribution pattern. The objective of this investigation was to investigate the effect of different population distribution patterns on yield, yield components, and WUE in summer soybean. The experiment was carried out from June to September in 2007 at Agronomy Experimental Station of Shandong Agricultural University. The summer soybean (Glycine max cv. Ludou 4) was grown under 5 distribution patterns with the same plant population(3.09×10~5plant/hm~2).The row spacing(cm) plant spacing(cm) was A: 18 cm×18 cm, B: 27 cm×12 cm, C: 36 cm×9 cm, D: 45 cm×7.2 cm, and E: 54 cm×6 cm respectively. Yield, leaf water character, and water use efficiency were affected by the population distribution of summer soybean. The yields in case of A and B were significantly higher than in case of D and E (P<0.05), while no significant differences were found among other treatments;The number of productive pod, seed per plant, and 100-seed weight declined gradually with the increase crop spacing;The yield had a positive correlation with seed number in main stem(R=0.994~(**)) and 100-seed weight(R=0.893~*);Leaf relative water content(RWC), water potential(Ψw), and osmotic potential(Ψs) declined gradually with crop growth, The average of RWC, Ψw and Ψs in case of A and B was all significantly greater than in case of D and E, Ψw in case of E was obviously lower than other treatments at noon in the daytime;The WUE was negatively correlated (R=-0.935~*)with the row spacing, but positively correlated (R=0.997~(* *)) with the yield. The WUE in case of A and B was significantly higher than other treatments (P<0.05), and that of D and E was significantly lower than in case of B (P<0.01).These results indicate that the summer soybean population with relatively uniform distribution would improve the yield components and leaf water conditions, consequently develop high yield, and increase WUE.