ABT生根粉处理对玉米磷效率的影响

盆栽试验结果表明,ABT生根粉处理玉米种子具有明显的促进生根和加快植株生长的作用。达到最大生长量的80％时所需施肥量(外部磷需求),ABT生根粉处理和对照分别为15和40mgP/100g土、表明ABT生根粉处理明显提高了玉米磷效率。上述外部需求差别与体内需求无关,而主要取决于根/冠和磷吸收速率。在所有供P水平下,ABT生根粉处理的磷吸收速率均大于对照。根/冠在低P处理对照稍高.而后以AST生根粉处理为高。ABT生根粉提高了磷吸收速率,主要是由于纤细根、分枝根多,根毛长和密度大。施磷水平与玉米根系生长有明显相关性。低磷水平下,根/冠比大;地上部磷/地下部磷小;根系纤细根、分枝根多,根半径小,单位长度根的根毛数量多、长度大,这是玉米对低磷的一种适应性调节。

The Effect of ABT-rooting-powder on Phcsphorus Efficiency of Maize

ABT-rooting-powder (ABT) is a kind of plant growth regulators.The objective of thisresearch was to investig ate the effect and reason of ABT on P efficiency of maize.Comp ared to the CK(weter theatment), ABT couod promot root development and hasten shoot growth significantly. Toreach 80% of maximum yield maize with ABT and CK nee ded 15 and 40 mg p/100g soil respectively(externel P repuirement) This difference in external Prequirement cannot be explained by difference intheir internal P requirement, Both of them contained 0.28%P in shoot at 80%max.yield.Increasing P effi-ciency of maize by ABT was due to its root-shoot radio and influx rate.influx rate of ABT was higher thanthat of CK in all P fertilizer rate, root-shoot radio of ABT wax little lower in low-p-fertilizer rate andmuch higher in high p fertilizer rate than that of ck .The main reason for the higher influx of ABT wasmore slender root, small root radius and more root hairs. In soils low in availabl P, maize had higher root-shoot radio, lower shoot P / root p, more smallbranch root and root hairs.This is important for maize to satisfy a higher proportion of its P demandrepuirerd for maximum growth.