Establishment of Potential Leguminous Cover Crop, Vigna marina for High-Salinity Soil Conditions

The saline soil has electrical conductivity (EC) of more than 4 dS mL−1 (approximately 40 mM NaCl) in the root zone at 25 °C and an exchangeable Na concentration of 15%. From an agricultural perspective, the presence of neutral soluble salts may inhibit the development of most crop plants. However, a tropical legume grows in nutrient-deficient, high-salinity sandy soil, known as Vigna marina, which has the potential as a leguminous cover crop under high-salinity soil conditions. The symbiotic connection with root-nodulating bacteria had been established, which was adapted to these hard circumstances and contributes to nitrogen fixation. Thus, these cover crops may contribute to low input of sustainable agriculture systems. As a potential leguminous cover crop, V. marina can reduce soil environmental stress conditions and improve soil fertility and nutritional status. The development and nodulation of V. marina were better established under high-salinity soil conditions compared to conventional leguminous cover crops, Pueraria javanica and Mucuna bracteata. V. marina could quickly outgrow P. javanica and M. bracteata and was a potential alternative leguminous cover crop, especially for high-salinity soil conditions.