山东省苹果园氮、磷、钾三要素的营养状况

1981～1986年根据山东省苹果自然分布区选代表性果园约20个,按主要物候期进行矿质营养元素调查、测定。按各国通用的采样时间—新梢停长期(6月/下旬～7月/上旬)营养枝中部叶的氮、磷、钾含量为标准,山东省苹果园的适宜范围为氮2.0%～2.5%、磷0.18%～0.22%、钾1.2%～1.4%;细根(直径<2mm)分别为0.7%～0.9%、0.08%～0.10%、0.3%～0.5%。不同品种对三要素的需求量不同,如国光对氮、磷的需求量多于红星。钾則相反,红星高于国光。氮素含量是决定植株生长势与产量的主导因素。萌芽期细根内的氮、磷、钾含量能反映植株的生长势,一般生长健壮的植株,氮、磷、钾含量,尤其氮素营养高于弱树,钾含量随着生长势的增强而增加。营养枝不同节位叶(基部、中部、顶部)的氮素含量与果园管理水平及植株生长势有关。一般管理水平较高的果园、生长健壮的植株,营养枝中部叶氮含量最高,基部叶最少;管理水平差的园片、生长势弱的植株則表现为依节位递增或两头大、中间小。

STUDIES ON STATUS OF NITROGEN, PHOSPHORUS AND POTASSUM IN APPLE ORCHARDS IN SHANDONG PROVINCE

The present study was carried out during 1981-1986 in nearlytwenty orchards which could represent the natural distribution ofapple trees in Shandong Province, When the growth of spring shootsceased (from late June to early July), the optimum ranges of N, Iand K content (%DW) in the leaves on mid-parts of long shootswere 2.0-2.5, 0.18-0.22 and 1.2-1.4, respectively, and those offine roots (<2mm diameter) were 0.7-0.5), 0.08-0.10 and 0.3-0.5,respectively. The demand of apple trees for N, P and K wasdifferent among the varieties. For instance, there was greaterdemand for N and P in cv. Ralls than in cv. Starking, but greaterdemand for K in cv. Starking than in cv. Ralls. It was demonstratedthat N content had some dominant effects on tree vigor and yield,and that N, P and K content of fine roots during the sproutingperiod could indicate tree vigor. N, P and K content (especially N) of sturdy trees was generally higher than that of weak trees; themore vigorous the trees were, the higher K content of the trees was.There was a relationship between N content in the leaves on differentparts of long shoots and the status of orchard management & treevigor. In general, N content of the leaves on mid-parts washighest and N content of basal leaves was lowest in well-managedorchards and sturdy trees; N content of top leaves and basal leaveswas higher than that of the leaves on mid-parts or N contentincreased following the location of leaves upward in poorly-managedorchards and weak trees.