Cover Crops for Soil Health: demonstration of on-farm trial

The Lower Rio Grande Valley (LRGV), a four-county area in deep south Texas, is a promising region for organic farming with an estimated 2.1 million acres of arable land. With the sub-tropical climate prevailing in the region, the LRGV boasts a year-round growing season. However, this also poses agronomic challenges to farmers: year-round pest management and maintenance of soil health. For organic farmers, the major weed management technique is intensive tillage during the late summer months, exposing soils to the intense heat and high winds characteristic of this season in the region. This technique has been costly to the farmers as well as soil health –high winds stirring up large dust clouds and blowing away the topsoil is common. Cover cropping, which has become a national trend among organic farmers are desperately needed but based on countless interactions with producers across the region, very few have even seen cover crops successfully employed, or are weary of the short-term impacts on soil moisture and associated forgone income. In preliminary trials, a local area farmer reported a reduction of 400 lbs/acre of sorghum following cover crops compared to control sites with no cover—resulting in a loss of income of about $30 per acre. Questions remain regarding effective implementation of cover crops. For example, species and combinations of cover crops are appropriate for this region, especially during the harsh summer season and where water is the limiting factor, ideal times and techniques to plant and terminate for each cover crop species.