The Improvement of Yield and Quality of Soybeans in a Coastal Area Using Low Input Technology Based on Biofertilizers

Indonesia is an archipelagic country, having vast coastal areas which have not been utilized optimally for crop cultivation because their poor soil properties become a limiting factor for plant growth. It is, therefore, necessary to use cultivation technology, such as the use of biofertilizers to overcome this limiting factor. The objective of this study was to determine the appropriate biofertilizers for improving the quality of soybean seeds, the rhizosphere environment, and the soybean yield in a coastal area. The study was conducted in Bengkulu, Indonesia, using Randomized Complete Block Design, with a single factor, namely biofertilizers. Six treatments were applied, namely the addition of Arbuscular Mycorrhizal Fungi (AMF), phosphate–solubilizing fungi (PSF), Rhizobium (R), AMF+PSF, R+AMF, and R+PSF. The results of this study showed that, in general, the inoculation of biofertilizers could increase the yield of soybeans in the coastal area, as indicated by the higher yield of plants in this study than those as described in the literature. The dual inoculation of PSF+AMF resulted in the highest protein content, the largest populations of PSF and AMF, the highest percentage of root colonization of AMF, plant phosphorus concentration and absorption, the weight of seeds per plant and yield. Meanwhile, the highest fat content of seed was found in the plants inoculated with PSF. In coastal soil, the dual application of biofertilizers, namely PSF and AMF, should be done, instead of a single application. Further studies are needed to increase the protein content and to reduce the fat content of soybean seeds