Abstract
Effects of previous crops with no-tillage on the growth of maize and symbiotic association with arbusculer mycorrhizal (AM) fungi were studied. Both the propagule density and colonization of arbuscular mycorrhizal fungi in the field with no-tillage were low when buckwheat was precultivated than when maize was precultivated in the previous summer season. It was due to stimulated association of maize with the propagule of AM fungi. The growth of maize and colonization of AM fungi at vegetative stage were also enhanced significantly by the no-tillage treatment after oat (host plant of AM fungi) cultivation. In particular, the cultivation until just before maize seeding greatly increased the association with AM fungi in no-tillage systems in the central region of Japan. It was assumed that colonization of AM fungi might be stimulated by no-tillage after oat cultivation, because the soil was kept undisturbed and the hypha network of AM fungi in the soil was maintained. However, the effect of tillage systems on the final yield of maize was not observed. It was concluded that the previous cultivation with no-tillage might provide a favorable environment for early dry matter production of maize in the field with depressed propagules.