Maleny krasnozem soil was not suitable for chickpea growth unless it was limed to raise pH. Low pH of this soil may also have affected nodulation, VAM infection and phosphorus nutrition. In Gatton and Warwick black soils, chickpea grew very well. Soil disturbance increased VAM infection, but not plant growth nor P uptake, probably because of restricted root growth as a consequence of compaction in undisturbed soils. The large amount of available P in Gatton soil did not inhibit VAM infection.
The Warwick soil where chickpea had grown 1 year previously produced larger dry matter yield, nodule number, VAM infection and P uptake than the soil where chickpea had grown 5 years ago. This may be due to small differences in soil physical and chemical properties, as well as the differences in Rhizobium and VAM fungal spore populations. Shoot dry matter, nodulation, shoot P content increased with increasing P supply in both sterilized and unsterilized Warwick and Maleny soils. Plant growth was particularly reduced in sterilized Maleny soil because of poor P nutrition in absence of VAM. The
plants grown in Warwick soil were less responsive to P application than in Maleny soil. VAM infection decreased with increasing P supply in both Warwick and Maleny soils, but more pronouncedly in the former soil indicating relatively higher dependence of plants on VAM for P uptake in Maleny soil than in Warwick soil.