不同水肥条件对杨树生物量的影响

针对神木试区因水肥不协调而导致大面积低效低产林的现状,以1龄杨树幼苗为指示植物,采用3因子5水平二次正交旋转回归设计,盆栽试验研究了不同水肥条件下,水、氮(N)、磷(P)3因子对杨树生物量的协调效应。结果表明,在试验条件下,水分对杨树生物量影响最大,其次是磷肥和氮肥,说明水分是影响杨树生物量的主导因素。水分和氮肥、氮肥和磷肥间存在交互效应,且水分和氮肥的交互作用>氮肥和磷肥的交互作用,而水分和磷肥的交互作用不明显。3个因素中,N,P2个因素对杨树生物量的边际效应较为敏感,说明合理施肥对改善杨树的生长状况有重要意义。以上结论说明,黄土高原低效低产林改造的根本途径是增加土壤含水量,培肥土壤,改善其水肥不协调的状况。

Effect of different water,N and P content on the bio-mass of poplar

According to inconsistency of water and fertilizer on Shenmu,study was carried out by using regression design with three factors and five levels,centered on coupling of water and fertilizer,and based on pot experiments and quantitative analysis to poplar,which studied the bio-mass effect of three factors to poplar under the different conditions of water and fertilizer.The result was that,under the experimental conditions,the sequence of effect of three factors on bio-mass is water>N>P,and water is the leading factor;the sequence of relative effect of all factors is water and N>N and P,and the relative effect of water and P is not notable;N and P have more sensitive marginal effect on bio-mass of Poplar,which showed the suitable fertilizer has very important role in improving its growth.Therefore the countermeasures for low-efficiency and production forests are to enhance soil moisture,fertilize suitably,and improve the status of inconsistency of water and fertilizer.