红壤中菌根对柑桔磷肥效应的研究

取第四纪红壤,接种VA菌根真菌(Glomus citricolum)于枳(P(?)ncirus trif(?)liata)实生苗,以不接种为对照,各施用6种磷肥量,共12个处理.1987年和1988年两年重复的盆栽试验证明:(1)在红壤中枳的菌根发育良好,接种菌根真菌4个月后,检查枳实生苗的菌根感染率为30%左右,高的可达39.0%;(2)在红壤中每亩施25—125kg不同量的过磷酸钙对无菌粮枳实生苗的生长效应不明显,而接种菌根真菌后则能显著地促进枳实生苗的生长.4个月中,有菌根枳苗的株高比对照的增长1倍,主干粗度增40%-93%,植株鲜重增3—6倍;(3)菌根使枳苗地上部含磷量比对照多3—5倍;(4)土壤在不灭菌条件下,接种菌根真菌也有一定的效果.

STUDY OF MYCORRHIZA ON PHOSPHORUS UTILITY BY CITRUS IN RED SOIL

Potting experiments with sterilized red soil applied at six different amounts of phosphate fertilizer were carried out in 1987 and 1988. Trifoliate seedlings ( Poncirus trifoliata Raf.) inoculated with endo-mycorrhiza fungus (Glomus citricolum) were grown in each pot and seedlings without mycorrhizal inoculation were as control.Four months after treatment,the trifoliate seedlings formed typical vesicular-arbuscular mycorrhiza at an average infection of 30% or so with 39.0% as the highest. The growth of seedlings with mycorrhiza with superphosphate applications at rates of 25-125kg per-mu increased their stem hight,trunk diameter and plant fresh weight by 100%,40%-93%and 300%-600% respectively, as compared with the controls. The phosphorus content of upper part of seedlings with mycorrhiza were 3-5 times greater than that of control plants. In addition, under natural soil conditions, the mycorrhizal inoculation shoved some benefits for citrus seedlings in red soil as well.