生土施肥对黍子根系生长及生理生态效应的影响

Effects of Fertilizing in Immature Soil to Broomcorn Millet Root Growing and Its Physiological Ecology

以肥力极低的生土为基质,通过盆栽试验研究生土施肥对黍子根系生长及生理生态效应的影响,结果表明,生土地施用磷、氮肥,可以不同程度地增加黍子根系的干重、总根数、总根长、总吸收面积及活性吸收面积。单施钾的效果不明显,但在施用氮磷的基础上施钾,具有明显的加合效应。磷不仅是生土地上黍子产量与品质形成的第一限制因素,也是生土地土壤肥力形成的原始起动因素。氮、磷、钾三要素对黍子根系的影响顺序为磷>氮>钾。有机肥对根系的生长有明显的促进作用,尤其是前期。发达的根系促进了根际微生物群落的迅速繁殖,从而提高了根际土壤脲酶和磷酸酶的活性,这种结果促进“根土系统”向着熟化方向发展,使生土地上的黍子当年可获得正常产量。

The biological responses of broomcorn millet root system to manure, N, P and K fertilizer in immature soil were studied on the experimental farm of Shanxi agricultural university with pot culture. The results indicated that N and P fertilization stimulated its root growing, increased its root weight, root number, root length, total and active root absorbing area, and therefore increased the yield of broomcorn millet. The effects of broomcorn millet root growing were not obvious, if only K fertilizer was used. However, combined P, N and K fertilizer with proper rate significantly enhanced the growing of broomcorn millet root. P fertilizer was not only the key factor to get high yield and high quality in immature soil, but also the original active element to soil fertility. The barren soil can be improved rapidly by using P fertilizer. The effect of N, P, K to broomcorn millet root growing was P〉 N〉 K. Manure supply can also promote root growing, especially in its earlier growing. The results also showed the strong root promoted soil microbe to multiply rapidly. As a result, the soil enzyme activities of urease and phosphorylase increased. The results of the interactions of root and soil fastened the root and soil system developing towards mature direction. So broomcorn millet yield in immature soil reached the normal level in the very year.