关键词: 急性毒理试验, 急性毒理试验

Abstract:

This experiment is aimed at mitigating the problem of the short green period of Zoysia japonica and extending its green period. In greenhouse experiment, two-factor randomized block design was utilized to research on the influence of different concentrations of urea (0, 5, 10, 15 g/L) and EDTA-Fe (0, 20, 60, 100 mg/L) on the soluble sugar and chlorophyll contents of Zoysia japonica. The field experiment focused on the effect of different application intervals (non-fertilized, fertilized weekly, fertilized biweekly, fertilized triweekly) upon the green period of Zoysia japonica by randomized block design. The result indicated that the best concentrations of fertilizer applications were: 10 g/L for urea and 60 mg/L for EDTA-Fe. The best concentration and frequency of fertilizer application on leaf blades in the fall to extend the green period was 1 L/m2 and once per week, which can prolong 14 days comparing to the check. The electroconductibility and root vigor of the blades were both weaker than those of the check, which showed that the cold resistance of Zoysia japonica can be reduced in some way after being applied with urea and EDTA-Fe in the concentration and frequency above. Such undesired effect can not be eliminated after the winter period yet. Consequently, to prolong the green period of Zoysia japonica, meanwhile, to increase its cold resistance properly, phosphorus and potassic fertilizers can be applied as cooperation.