Soil Management to Improve the Sustainable Productivity of Winter Fresh Market Vegetable Crops in Miami–Dade County

Miami-Dade is one of major counties in the United States to produce winter fresh market vegetables.  However, the major challenges for local growers are the gravelly soil lying on the hard-bed rock, intensive nutrient leaching caused by torrential summer rainfall, a vulnerable Everglades environment adjacent to the agricultural area, and a shallow aquifer. All these features make soil management crucially important to sustain the productivity of vegetables in this particular area. Cover crops, such as sunn hem and velvet bean, grow vigorously during the rainy summer, can scavenge residual nutrients applied from previous season and accumulate in plant tissues. This approach, on one hand, can reduce nutrient leaching, and on the other hand, it can improve soil fertility after incorporated into the soil for vegetable growth. In addition, growing sunn hemp can effectively suppress root-knot nematodes that are one of dominant pests in vegetable crops, especially okra, tomato, and peppers. Other practices, such as applications of compost and soil amendments, can also improve soil nutrient withholding and increase crop yield of winter vegetables.