论文部分内容阅读
高钾肥常减少叶片Mg和Ca的浓度，且容易造成叶片和植株萎蔫，但增加P肥可以增强冬小麦对Mg和Ca的吸收，从而提高冬小麦叶片的Mg和Ca的浓度。土壤温度过低会降低P的有效性和吸收量，对此，本试验在两种根际温度条件下测定了P和K对小麦矿质元素组分的影响。400μMP处理比起50μMP处理，小麦地上部Mg的含量提高20％；而25℃根际温度处理比15℃根际温度处理的小麦地上部Mg含量高出9％。类似地，高P处理的植株总Mg吸收量和Ca吸收量提高36％。把K浓度由400μM提高到800μM，可以把小麦地上都Mg的浓度提高13％，Ca浓度提高7％。在田间，当土壤温度低于15℃时，20或28kg／ha的P处理可以提高高秆羊茅草（FestucaarundnaceaSchreb）叶片的Mg和Ca的含量。当对照区叶片的Mg和Ca含量分别低于2．0和4．0mg／g（引起杂草萎蔫的临界值）时，施用P肥可以把Mg和Ca的含量提高到临界值之上。施P的同时再施Mg，可以提高叶片Mg的含量，但是在不施用P肥的情况下施Mg会降低叶片Ca的含量。P营养远比根际温度更能影响植株叶片Mg和Ca的含量和对Mg和Ca的吸收量。
High K fertilizer often reduced the concentration of Mg and Ca in leaves and could easily lead to wilting of leaves and plants. However, increasing P fertilizer could enhance the absorption of Mg and Ca in winter wheat and increase the Mg and Ca concentrations in winter wheat leaves. Soil temperature is too low will reduce the effectiveness and absorption of P, this test in two rhizospheric temperature conditions were measured P and K on the mineral elements in wheat. Compared with 50μM treatment, the content of Mg in wheat shoot increased by 20% compared with 50μMP treatment. The rhizospheric temperature at 25 ℃ was 9% higher than that of 15 ℃ rhizosphere temperature. Similarly, the total Mg uptake and Ca uptake by high-P treated plants increased by 36%. Increasing the K concentration from 400 μM to 800 μM increased the concentration of Mg in the wheat ground by 13% and the Ca concentration by 7%. In the field, 20 or 28 kg / ha of P treatment increased the Mg and Ca content of leaves of tall fescue (Festucaarundnacea Schreb) when soil temperature was below 15 ℃. Application of P fertilizers increased the levels of Mg and Ca above the cut-off value when the Mg and Ca contents of leaves in the control area were below 2.0 and 4.0 mg / g, respectively (causing the weed wilting threshold). Applying P at the same time and then applying Mg could increase the content of Mg in the leaves, but applying Mg in the absence of P fertilizer reduced the content of Ca in the leaves. P nutrition is far more influential than the rhizosphere temperature Mg and Ca content of leaves and Mg and Ca uptake.