磷和土霉素对小麦和紫花苜蓿幼苗生长和根系发育的影响

采用盆栽试验的方法,研究不同磷添加量(0,20,80 mg/kg)和土霉素添加量(0,40,160 mg/kg)对小麦和紫花苜蓿幼苗生物量及根系发育的影响。结果表明:所有水平土霉素处理中,20,80 mg/kg磷处理的小麦地上部生物量均比不加磷时高,分别高22.7%～34.1%,10.0%～30.0%和9.1%～18.3%。除160 mg/kg土霉素加80 mg/kg磷的处理外,所有处理的苜蓿根生物量均小于不加磷和土霉素的对照。小麦的根长和根表面积随着土霉素添加量的增加总体上呈减少的趋势。总体来看,施磷显著促进了小麦幼苗地上部的生长,但对苜蓿幼苗生长的影响不显著。土霉素对苜蓿幼苗的根系发育有抑制作用。研究结果可为评价土壤中土霉素残留对作物早期生长的影响和指导合理施用磷肥提供理论依据。

Effects of Phosphorus and Oxytetracycline on Seedling Growth and Root Development of Wheat and Alfalfa

A pot experiment was conducted to study the effects of different levels of phosphorus (P) (0, 20, 80 mg/kg) and oxytetracycline (OTC) (0, 40, 160 mg/kg) on the biomass and root development of wheat and alfalfa seedlings. The results showed that at all OTC levels, the aboveground biomass of wheat in 20 and 80 mg/kg P treatments was greater than that when no P was added, being 22.7%~34.1%, 10.0%~30.0% and 9.1%~18.3% greater. Except for the 160 mg/kg OTC+ 80 mg/kg P treatment, root biomass of alfalfa in all treatments was less than that in the control without OTC and P, being 8.8% less. Root length and surface area of wheat decreased with increasing OTC level. Overall, P application significantly enhanced the aboveground growth of wheat, but had no significant effect on the growth of alfalfa. OTC inhibited root development of alfalfa. The results of the present study can provide a theoretical basis for evaluating the effect of soil OTC residue on seedling growth of crops and instructing proper application of P-fertilizers.