2018 ASHS Annual Conference

Cover crops can be used in an organic farming system to enhance soil quality and reduce weed pressure, potentially leading to higher yields and revenue that may offset their cost. Partial budgets were developed for three different cover crop treatments in an organic strawberry cropping system study. The treatments were sunn hemp (Crotalaria juncea L.), hairy indigo (Indigofera hirsuta L.), and a mix of these two with slender leaf rattlebox (C. ochroleuca G. Don) and American jointvetch (Aeschynomene americanca L.). The study aimed to determine how the treatments affected profits relative to a no-cover-crop, weedy control system in the context of a Florida winter organic strawberry production season. A trial was conducted at the Plant Science Research and Education Unit in Citra, FL to obtain yield and cost data. Cover crops were established in July 2016 and terminated that September. Four strawberry cultivars were transplanted into plastic-mulched, raised beds in October and harvested from November 2016 through April 2017. Horticultural researcher interviews, previously developed budgets, and Agricultural Marketing Service data were integrated with the experimental data to produce partial budgets for each treatment. Yield and cost data were averaged over the four strawberry cultivars and four replications. The sunn hemp and mix treatments both increased profits relative to the no-cover-crop control while the hairy indigo treatment decreased yield and thus decreased profits relative to the control. A sensitivity analysis was performed to determine hypothetical profit outcomes under differing yield and price scenarios. In all scenarios, hairy indigo reduced profits relative to the control while sunn hemp and the mix increased profits. Compared to the control, the additional profit of sunn hemp was greatest in low-yield scenarios while that of the mix’s was greatest in high-yield scenarios. Impacts on profit relative to the control across all scenarios ranged from ($5347) per acre for hairy indigo to $6287 per acre for the mix. A breakeven analysis showed that the seed cost of sunn hemp would need to increase 9.31 times for it to have the same profit as the control. The seed cost of the mix would need to increase 16.67 times to break even with the control. Hairy indigo does not break even at any seed cost. Further research into less visible effects such as accrued soil quality benefits and reduced weed management costs is warranted to fully capture the economic benefit of various cover crops.