Root growth, water potential and yield of irrigated wheat
Root growth, water potential and yield of irrigated wheat
复制标题
灌溉小麦的根系生长、水势和产量
作者：
H. Mishra;T. Rathore;V. S. Tomar
1983 - 1984年和1984 - 1985年在Phoolbagh粘壤土上研究了小麦根长密度、中午叶水势和产量的变化（典型Haplaquoll）和贝尼粉质粘壤土（Aquic Hapludoll）在北方邦的Tarai地区，（0.4 - 0.9 m，SWT）和中等深度（0.8 - 1.3 m，MWT）地下水位条件下的6种水分处理：灌水（I 0）、冠根始灌（I1）、冠根始灌和乳灌（I2）、冠根始灌、最大分蘖和乳灌（I3）;在冠根发生期，分蘖、开花、乳量最大（I4），在冠根发生期，分蘖、开花、乳量、面团量最大（I5）。在面团阶段（播种后115天，DAS）达到最大生根深度（0.8米，SWT和MWT条件下1.05米），更强烈的影响，在地下水位深度的波动比水分制度。在湿润条件下（I2- I5），根系主要集中在地下水位界面处及以上，且具有较大的水平发育，而在干旱条件下，（I 0和I1），由于上层土壤水分不足，（0.45 m）侵入较低层位，垂直分布较大，叶片受水分状况（I1- I5）影响不显著;丰水年（1983 - 1984年）高达94 DAS，干旱年（1984 - 1985年）高达74 DAS，但此后受到严重影响。与水方案I1- I5在一个潮湿的年份和I2- I5处理在一个干旱的年份，在任何一个地下水位深度的粮食产量没有显着差异，但有一个（非显着）的趋势，降低产量增加土壤水分亏缺。在I2和I3两个处理中，SWT处理的平均产量分别为5130和5200 kg ha ~（-1）。同样，在I3的MWT下，它是5188 kg ha-1，在I4制度下，5218 kg ha-1。结果表明，在SWT和MWT条件下，灌溉量分别超过120和180 mm，不会提高产量。在Tarai情况下，根据SWT下的I2和MWT条件下的I3计划进行灌溉似乎比非常潮湿的制度（I5）更有效。
Abstract Root length density (LV), mid-day leaf water potential (Ψleaf) and yield of wheat were studied in 1983 – 1984 and 1984 – 1985 on a Phoolbagh clay loam (Typic Haplaquoll) and on a Beni silty clay loam (Aquic Hapludoll) in the Tarai region of Uttar Pradesh under naturally fluctuating shallow (0.4 – 0.9 m, SWT) and medium-depth (0.8 – 1.3 m, MWT) water table conditions with six water regimes: rainfed (I0); irrigation at cown root initiation (I1); at crown root initiation and milk (I2); at crown root initiation, maximum tillering and milk (I3); at crown root initiation, maximum tillering, flowering and milk (I4); and at crown root initiation, maximum tillering, flowering, milk and dough (I5). Maximum rooting depth (0.8 m under SWT and 1.05 m under MWT conditions) was attained at the dough stage (115 days after sowing, DAS) and was more strongly influenced by fluctuations in water table depth than by the water regime. For wet regimes (I2– I5), roots were concentrated at and above the water table interface and had greater horizontal development, whereas in dry regimens (I0 and I1), due to deficient moisture conditions in the upper soil layer (0.45 m) they invaded lower horizons and had a greater vertical distribution Ψleaf was not significantly affected by water regime (I1– I5) up to 94 DAS during a wet year (1983 – 1984) and up to 74 DAS during a dry year (1984 – 1985), but was significantly affected thereafter. Grain yields with water regimens I1– I5 during a wet year and for the I2– I5 treatments during a dry year at either water table depth were not significantly different, but there was a (non-significant) trend to lower yield with increasing soil water deficit. Under SWT in I2, the average grain yield wsa 5130 kg ha–1 and under the I3 regime, 5200 kg ha–1. Likewise, under MWT in I3, it was 5188 kg ha–1 and under the I4 regime, 5218 kg ha–1. The results indicate that application of irrigation of more than 120 and 180 mm under SWT and MWT conditions, respectively, did not raise yield. Irrigation given as per schedule I2 under SWT and I3 under MWT conditions in the Tarai situation, appears to be more effective than a very wet regime (I5).