Establishing and Evaluating Selected Cover Crops on Small Farms to Increase the Impact of Beneficial Arthropods on Crop Pests

Establishing and Evaluating Selected Cover Crops on Small Farms to Increase the Impact of Beneficial Arthropods on Crop Pests

Summary

Sustainable agriculture in the South is increasingly practiced on small farms with limited resources by farmers who live on the farms and therefore are committed to enhancing environmental quality and conserving natural resources.  This situation requires that farms be economically viable, preserve the natural resource base, and enhance the quality of life for the farmers and their families.  Moreover, both large and small farms play an important role in supporting the competitiveness and sustainability of U.S. rural economies.  Southern farmers continue to face many challenges, including marginal profitability and uncertain economic security.  One key production challenge for farmers in the South is the cost of effectively managing the myriad of pests that infest their crops.  Southern farmers must combat many insect pests, diseases, and weeds almost year-round.  In particular, Florida is at risk of agricultural loss by invasive pests due to its expansive tourism industry (84 million visitors a year) and multiple ports of entry. Hurricanes have been blamed for introducing a number of economically important invasive pests into the Gulf States (Florida, Alabama, Louisiana, Mississippi, and Texas), and the region’s warm and humid climate is favorable for pest establishment.

To support southern farmers’ efforts to manage pests sustainably, a unique, hands-on, whole farm “Living Extension IPM Field Laboratory” has been created at the University of Florida, Institute of Food and Agricultural Sciences (UF-IFAS), Suwannee Valley Agricultural Extension Center (SVAEC) with support from the USDA, NIFA EIPM-CS Program and the UF-IFAS Extension program.  This specialized IPM learning environment is used continuously to demonstrate how to enhance agro-ecological systems for specialty crop farmers and other clientele groups by adopting a diversity of beneficial cultural and ecological practices prior to use of chemical pesticides.  Thus, the IPM training program provides an infrastructure for delivering whole farm pest management practices.  Small farm specialty crop producers in the region have participated in training workshops at the SVAEC and now want to implement some of the sustainable IPM practices on their farms but require assistance in selecting appropriate cover crops and monitoring their impact on pest abundance and crop yields.  The practice of particular interest to the farmers is the use of cover crops to provide habitat for native beneficial arthropods but these practices have not been tested or demonstrated on small private farms in the region.

Currently, there are few effective and well-coordinated research and outreach programs designed to help southern small-holder farmers manage their pest problems.  This proposal was designed specifically to help them manage pests in fruit and vegetable crops by evaluating, demonstrating and communicating the use of cover crops to create habitats for beneficial arthropods.  IPM practices in this proposal focus on increasing types and abundance of beneficial arthropods that parasitize or prey on arthropod pests.  It is intended that these “first-adopters” will influence other farmers to plant cover crops to reduce the routine use of chemical insecticides.

The solution is to transfer beneficial arthropod and cover crop research results from the SVAEC and faculty in the southeast to local cooperating private farms by demonstrating the effectiveness of annual cover crops and associated natural enemies in reducing reliance on insecticides. Due to the short duration of this grant cycle, the focus of this research project will be on annual cover crops, including buckwheat, sunflowers, triticale, rye, sesame, and sunn hemp.  At SVAEC the best results were obtained by planting cover crops such as rye, triticale and sunn hemp in large blocks as a rotational crop on land after the cash crop was grown. Buckwheat and sunflower, on the other hand, were grown in strips within the cash crops.  Sunflower (Giganteus variety) was effective as a trap crop for stinkbugs.  Buckwheat planted in strips at SVAEC was the most effective in increasing beneficial arthropods. The research conducted at SVAEC showed the importance of making successive plantings of buckwheat throughout the year, every 30-60 days from March to November.

The project is being conducted at Hoover farm located 12 miles and Rooney farm 8 miles from SVAEC near Live Oak, FL.  Cooperators at both farms have participated in several trainings at SVAEC and expressed interest in implementing IPM practices on their farms.  The Hoover farm utilizes cover crops in their rotations for soil improvement, and both farms would like to include pest management in their cover crop planning.  In addition, the Hoovers collaborated with some members of this team (Hochmuth, Toro, and Treadwell) on a previous On-Farm SARE project to improve their organic fertility programs and are experienced with on-farm research.  The planting strategy for this project will be to establish temporary cover crops and strips of cover crops within the cash crop production areas to increase beneficial arthropod populations in the cash crops.

Farmer collaborators are interested in learning how the different approaches to cover crop integration, within and adjacent to the crop production area, will influence the density and diversity of beneficial arthropods and their effect on pests, crop quality and yield.  By comparing the history of insecticide use on the farms prior to cover crop integration for pest management with two years of data from this project, we anticipate a reduction in the frequency, quantity and type of insecticide applications; increased confidence and experience in cover crop use for pest management; and successful outreach to the broader farm community.

Objectives/Performance Targets

This on-farm research project is designed to demonstrate how to deploy cover crops on operating farms so that the species and populations of beneficial arthropods will be increased. We also will teach farmers how to increase their skill in identifying beneficial arthropods that are attracted to cover crops and how to maintain and enhance these populations on the farm year-round. The first step was be to map both private farms so farmers can visualize existing and future habitat locations relative to production areas and other farm features.  Next, research sites for the cash crops and cover crop strips on these farms were selected by the cooperating growers.

Strip plantings of selected annual cover crops, such as buckwheat, sunflower, rye, triticale, and sunn hemp were established on both farms, but there is an emphasis on buckwheat cover crop strips for data collection purposes.  For the buckwheat cover crop strips, seeds were planted using farmer-owned seeders and methods. Strips of cover crops were established using best management practices for fertilizer, irrigation and weed management on the two farms.  Trials conducted at SVAEC showed the importance of providing adequate water and fertilizer for buckwheat plots in the dry, deep, sandy soils typical of the Suwannee Valley. On the Hoover farm, plots of buckwheat and other annual cover crops were established in strips within the cash crop fields to be protected. The primary crop area in the 2014 season on the Hoover farm included tomato and pepper.  On the Rooney farm, there is no idle land because blueberry and blackberry are permanent plantings; therefore, cover crops will be planted in drive rows and around the perimeter of the five acre blueberry field.

The cover crop plots were planted beginning in spring and summer of 2014.  During the 2014 season, both farms evaluated various buckwheat planting strategies to best fit their farming practices. The planting strategies will follow a schedule so that cover crop habitat is maintained year-round.  This strategy is essential to maintain beneficial arthropod populations at high levels because they need pollen and nectar sources as well as physical habitat.  The cover crop plantings on these farms will provide habitat for several beneficial arthropods that parasitize or prey on pests.  Based on three prior years of observations and monitoring beneficial arthropods in such plantings, the populations increase very quickly, within one year from establishing the habitat areas. 

Data was collected in three or four sets of buckwheat cover crop strips and adjacent cash crops as well as from three cash crop areas without buckwheat strips at each farm. Pest and beneficial arthropods were sampled in the plots and crops bi-weekly beginning when the plants first start to grow and support arthropods.  Ten sweep net samples were made in the center of each of three buckwheat plots, adjacent cash crop areas, and cash crop areas without adjacent buckwheat plantings. Each of the experimental cash crop areas with buckwheat were minimum of one-half acre and each of the experimental cash crop areas without buckwheat will also be a minimum of one-half acre on the Rooney Farm, and at least one-tenth acre on the Hoover Farm. The arthropods from each sample were placed in a plastic bag and returned to SVAEC to be identified to species, when practical.  Otherwise the taxonomic family was noted or type of arthropod, e.g., spider. 

These farms will be demonstration sites for farmers in the region to visit.  The two cooperating farmers fully participated in the project in 2014. 

Accomplishments/Milestones

The following article was written by Candice Pollack (SSARE) with contributions from Lei Lani Davis (UF), and Robert Hochmuth (UF) after a visit by Candice Pollack to the Hoover and Rooney Farms in the summer of 2014. The article was printed in the local newspaper, Suwannee Democrat and also posted on the Southern SARE web site.

(http://www.southernsare.org/News-and-Media/Press-Releases/Using-Cover-Crops-for-Pest-Management-on-Small-Farms).

 (http://www.suwanneedemocrat.com/news/local_news/local-farmers-learning-new-tactics-to-beat-crop-pests/article_7e4cd554-7593-51b0-8436-2b10156319f0.html).

(Article narrative begins here) LIVE OAK, Florida – Two small farmers in Live Oak, Florida are partnering with University of Florida Extension to determine how cover crops can be used to manage insect pests.

In a newly funded On-Farm Research Grant, “Establishing and Evaluating Selected Cover Crops on Small Farms to Increase the Impact of Beneficial Arthropods on Crop Pests,” strips of sunflower and buckwheat are being incorporated into crop fields to act as trap crops for pests and as attractants for beneficial predatory insects and pollinators as well.

“We are trying to find out what we can do to limit our chemical applications,” said Bradley Hoover, of Hoover Farms. The young farmer owns 20 acres of about 50 different types of vegetables, all certified organically grown and sold in the wholesale market. “The benefit of using plants to manage pests has not yet been realized on the farm in the past, and that’s what we are trying to do here. For example, what beneficial insects are attracted to buckwheat and how are they managing pests?”

In his field of tomatoes and peppers, Hoover, with the help of University of Florida Extension agents Bob Hochmuth, Elena Toro, and program coordinator Lei Lani Davis, has planted rows of sunflowers and buckwheat along the field perimeters, as well as additional rows of buckwheat in the center. The study compares the cover crops to the control (no cover crop plantings) to see where they fit into integrated pest management practices.

Davis said that the sunflower attracts stinkbugs, specifically the leaf-footed bug, which aggressively attacks tomatoes and peppers.

“The sunflower is acting as a trap crop, keeping the pest away from the farm’s cash crop,” said Davis.

In addition, buckwheat attracts a wide array of beneficial insects, including native pollinators.

Across town, near Wellborn, Scott and Billie Rooney with Rooney’s Front Porch Farm, are looking at the same two cover crops, but evaluating their effectiveness in fruit production. Stinkbugs easily make a meal of their U-pick blackberry and blueberry plants. The Rooney’s Front Porch Farm is open for U-pick in June and much of July and they can be found at (http://rooneyfarm.com/) or 386-963-5037.

“We are only in our first year of the study, but we are not seeing as many stinkbugs in the berries as we’ve had in the past,” said Billie Rooney.

Billie and her husband have already made some keen observations participating in the project. For example, she said that the sunflowers bordering the woodland contain more leaf-footed bugs than the sunflowers bordering their hair sheep grazing pasture.

“Is there something in the woods that’s acting as an overwintering host for the leaf-footed bug? We’d like to find out more about where they are coming from,” said Rooney.

Davis said that the Rooneys are also interested in planting a winter small grain known as triticale in their grazing pastures. Triticale, it turns out, also acts as a trap crop for stink bugs and will attract the early flights of stink bugs before the sunflower crop is planted and ready.

“We are treating this first year of the two-year study as a learning curve,” said Davis. “We want to see what will work best for the grower to manage pests and reduce pesticide use.” (End of newspaper article narrative).

The 2014 season was spent developing a strip cropping practice on the two farms. The adopted practice was selected by the farmers to best suit their current cultural practices and also to have the greatest likelihood of long term adoption on their farms. The Rooney farm selected three strip cropping areas, two on the perimeter and one in the middle of a five-acre blueberry planting. The Hoover farm presented a more challenging process in the selection of the strip cropping strategy.  The challenge involved how to incorporate the strips into seasonal vegetable planting areas, maintain weed populations efficiently, and to plant strips in such a way farm equipment did not track over the buckwheat plantings.

Trap crop plantings of rows of sunflower were implemented very successfully at both farms. Sunflowers were planted on the perimeter of the cash cropping areas at both the Hoover and Rooney farms. The sunflower plantings were targeted at leaf-footed bug populations and at both locations, worked very well. Additional cover crop areas were established at the Hoover farm, including rye for a winter cover, and sunn hemp for a summer cover crop. Strips of triticale were established on both farms in December of 2014 to establish an early spring trap crop option for the stink bug population complex. Triticale becomes attractive to stink bugs much earlier than sunflowers and is important in trapping the early season stink bugs and leaf-footed bugs. The strategy of incorporating triticale is likely to become very important at the Rooney farm with blueberries and blackberries because these two crops are much more prone to early season damage by stink bugs in comparison the later season fruiting vegetable crops like tomato and pepper at the Hoover’s farm.

Impacts and Contributions/Outcomes

The first year (2014) of this project was spent developing the protocol that will fit the farmer’s cultural practices. Most outcomes and impacts are targeted at being documented in the 2015 season. However, the outcome reported at both farms in 2014 was the successful implementation of sunflower trap cropping areas. The sunflower cultivar, ‘Giganteus’, was successfully used to attract stink bug species, but mainly, leaf-footed bugs to the sunflower plantings. The stink bug populations were managed as needed with appropriate and labelled insecticide applications on both farms. The outcome reported at both cooperating farms was the selection of a buckwheat strip cropping system that fit their cultural practices. The selected strategies will be implemented in 2015 as a consistent methodology to establish buckwheat cover crop strips. Summer and winter cover crops were established at the Hoover farm to improve soil health and to increase populations of beneficial insects and other arthropods.

Collaborators: