Effects of Summer Cover Crop Planting, Compost Application, and in-Season Fertigation on Organic Strawberry Production.

Interest in organic strawberry production is growing recently among producers in Florida, the second largest strawberry producing state in the U.S. In response to the increasing organic strawberry acreage, more up-to-date research-based information is needed for optimizing the organic strawberry cropping systems. The objective of this study was to explore the impacts of summer cover crop planting of sunn hemp before fall planning of strawberry, compost application at cover crop termination, and in-season fertigation on organic strawberry production. The field trial was conducted in certified organic land at Citra, FL. Sunn hemp was planted at two seeding rates of 44.9 and 67.3 kg/ha in July 2016 with a summer fallow control. The cover crop was terminated at 60 days after seeding. A plant-based compost product was applied at sunn hemp termination with no compost as the control. Containerized plants of Sensation^TM Brand ‘Florida 127’ strawberry were transplanted on 10 October 2016. Three rates of nitrogen fertigation were applied including 0, 100%, and 150% of the standard rate, while every plot received a preplant application of nitrogen at 78.5 kg/ha. A split plot design with 4 replications was used, with sunn hemp planting and compost application the treatment combinations in the whole plots and in-season fertigation rates in the subplots. Strawberry harvests took place during November 2016 to May 2017. Interestingly, sunn hemp planting at the seeding rate of 67.3 kg/ha resulted in a significant reduction in marketable fruit number and weight as well as total fruit weight compared with the seeding rate of 44.9 kg/ha. However, sunn hemp planting at either seeding rate did not differ significantly from the summer fallow control in terms of strawberry yield performance. The whole-season fruit yield was not affected by compost application, whereas it was significantly increased by 100% and 150% nitrogen fertigation rates.