Abstract
The effects of irrigation, fertilization and inoculation on the nodule formation of Vigna plants in a sand dune were studied during 1955-'59. The results obtained may be summarized as follows : (1) The amount of leaves, branches and roots were increased by fertilizing, and they were also considerably enlarged by irrigation. (2) There were signifficant differences on the nodule formation between fertilized plots and non-fertilized ones as well as between heavily irrigated plots and slightly irrigated ones. (3) The effects of inoculation on the nodule formation were not recognized without applying fertilizers. (4) Fertilization, irrigation and inoculation in the sand dune not only make the plants vigorsus in growth, but also favour the nodule formation, resulting in increasing the amount of nitrogen fixed from the air. Thus, they are considered to serve to increase the soil productivity in the sand dune
