Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016
Performing Department
(N/A)
Non Technical Summary
In 2019, Georgia had 102 certified organic farms and currently represents only 0.6% of the nation's organic farms in Georgia (USDA-NASS, 2019). In contrast, for conventional fresh vegetable production, GA ranks number four in the nation and has a $1.2 billion farm gate value (CAED, 2022). Given the large conventional vegetable industry, Georgia is not capitalizing on increased consumer demand for organically grown produce. Nelson et al. (2015) determined in a survey of Georgia farmers, that the perception and potential for lower crop yields and a lack of demonstrated success were the top influences that prohibited the adoption of organic certification or practices. In the 2022 National Organic Farmer Survey conducted by the Organic Farming and Research Foundation (OFRF), farmers ranked controlling weeds (67% of respondents) and nutrient management (43% of respondents) as two of the top four production challenges. Further, the OFRF recommend research for integrated weed management that is farmer collaborative, "fine tunes" current methods (tillage and tarping), and for research and develop strategies that manage weeds and restore soil health during transition production (Snyder et al., 2022). Addressing weed management, soil fertility, and organic matter are of critical need to encourage more organic vegetable producers and increasing the scale of organic production in the Southeast U.S. It is difficult for organic small to mid-sized farmers to acquire land given current land costs. In Georgia, The Conservation Fund's Working Farm Fund is working directly with Georgia Farmers to acquire land, conserve farmland, and scale up organic production for the wholesale market with a goal of reaching 200 farmers. However, available land is often unmanaged farmland that was previously in old pastures. This derelict land comes with the potential for compaction, residual herbicides, poor soil fertility, and persistent weeds, especially Bermuda grass. These issues represent further challenges to organic producers and can cause significant lags in their time to profitable production. Cover crops have been shown to decrease weed populations, increase soil carbon, increase soil N fertility, decrease soil bulk density, and increase yield in following cash crops. While tarping (silage or black plastic) land slated for production has shown to be effective on weed control, this method is not always affordable or practical for farmers in mid-size farms and does not improve the soil fertility or organic matter. Based on methods for no-till drilling forages into Bermuda pasture in the South we propose a method for no-till drilling cover crops directly into derelict land and will create on-farm tests for farmers to measure weed pressure and potential for residual herbicides. Through on-farm field studies and studies conducted at the University of Georgia research farm, we will determine how different cover crops and different cover crop entry time (Fall versus Spring) can impact weed species and following vegetable crop production. Through these studies, we will address how different competition mechanisms of weed suppression we can outcompete and deplete perennial weeds (through shading) in this land while simultaneously improving soil fertility and quality for the following cash crops. Through developed tools, on-farm demonstrations, online and written Extension outreach, and through collaboration with non-profits and farmer-collaborators, we will share this information with farmers, Extension, agricultural professional, and the scientific community. Providing farmers with more access to research (based on their needs), we can address issues in organic production in the Southeast and help aid in farmer profits and availability of organic produce. REFERENCESCAED: University of Georgia Center for Agribusiness and Economic Development. Ag Snapshots 2022. Available at: https://caed.uga.edu/content/dam/caes-subsite/caed/publications/ag-snapshots/2022CAEDAgSnapshotsWeb.pdf (Accessed 11 April 2022).Nelson, M.C., E. Styles, N. Pattanaik, X. Liu, and J. Brown. 2015. Georgia farmers' perceptions of production barrier in organic vegetable and fruit agriculture. Presented at the Southern Agriculture Exonomics Assocaition's2015 Annual meeting Atlanta, GA. Jan 31-Feb 3 2015.Snyder, L., M . Schonbeck, and T. Velez. 2022. Outcomes and recommendations from the 2020 National Organic and Transitioning Farmer Surveys and Focus Groups. Organic Farming Research Foundation. Santa Cruz, CA. Available at: https://ofrf.org/wpcontent/uploads/2022/03/OFRF_National-Organic-Research-Agenda-NORA_2022.pdf. (Accessed 5 Apr. 2022). USDA-National Agricultural Statistics Survey. 2019. Organic Survey. Available at: https://www.nass.usda.gov/Publications/AgCensus/2017/Online_Resources/Organics/index.php (accessed 11 April 2022).
Animal Health Component
50%
Research Effort Categories
Basic
30%
Applied
50%
Developmental
20%
Goals / Objectives
Breaking new ground is a difficult task for any farmer. New organic farmers and farmers transitioning to organic vegetable production often purchase or expand on land that has previously been in pasture or is derelict farmland (land that has been previously farmed but not recently managed). In the Southeast U.S., this land is usually the most affordable and commonly available land for new farmers and has the added benefit that it can rapidly undergo organic certification due to having previously laid fallow. However, breaking new ground and turning this land into productive cropland can be time consuming, laborious, and expensive. This land is commonly in need of heavy fertility inputs and is dominated by perennial weed species, especially Bermuda grass which can be incredibly difficult to kill and persistent in the South. Our long-term goals are to create research-based management strategies focused on farmer needs that will lead to reduced inputs and time, increase the number of organic certified acres, incentivize the switch to organic vegetable production, and encourage more sustainable practices in Georgia and the Southeast. Our project directly addresses farmer identified needs for alternative and rapid approaches to combat perennial weeds and poor soil fertility on derelict farmland primarily composed of old pasture. Through the use of no-till drilled cover crops directly into derelict land and Bermuda grass pastures, farmers can decrease weeds and hasten soil fertility as they transition this land to organic cash crop production. Additionally, through a state-wide survey, we will identify common weed and fertility issues encountered by farmers that purchase this type of land. Using this information, we will create on-farm tools that address weeds and residual herbicides. By doing so, we help farmers identify issues and aid in land-use decisions that often lead to the lag in profitable production for organic farmers on new land. Specific objectives of this grant are to:Survey land commonly available for organic transition in the Southeastern U.S. and evaluate weed community composition, residual herbicide carryover, soil fertility, and soil organic matter.Develop two on-farm diagnostic tools: 1) the Germinable Seed Bank Assay and 2) the Residual Herbicide Assay in Southern Soils for use by farmers and Extension.Reduce weeds and improve soil fertility and quality in derelict land/pasture through no-till drill cover crops by determining the effect of management practices on weed suppression, cover crop quality, soil N fertility, soil organic matter, and vegetable cash crop yield and health compared to traditional tillage techniques and silage tarping. Management practices under investigation will include: a) no-till drill cover crop entry time (planting fall or spring), b) cover crop species, and c) the addition of poultry litter at cover crop planting.Ensure timely research-based information through outreach and education to help farmers, agricultural professionals (Extension Agents, NRCS, FSA, Consultants), and students make the best decisions possible when transitioning new land to organic production.
Project Methods
Objective 1:Collaborating with The Working Farm Fund, Georgia Organics, and UGA County Extension Agents, 25 locations representative of land typically available to transitioning organic farmers will be sampled across the state of Georgia in Year 1 from October 2022 to Feb 2023. Points will be surveyed for initial plant communities and weed biomass and evaluated for abundance, distribution, diversity and community analysis. Soil compaction will be determined in 10 locations. To determine initial soil fertility, aminopyralid concentrations, and germinable weed seed banks, 30 samples per location/site will be taken. Soils will also be analyzed for soil physical, chemical and biological characteristics (texture, pH, water release curves, routine analysis, CEC, total N, total C, loss on ignition carbon, organic matter fractionation, inorganic N, CO2 microbial flush, and rapid N indicators). Soil will be analyzed in replicates of three for this survey (with the exception of herbicide analysis in replicates of two) and germinable weed seed banks measurements will be taken 5 and 7 weeks after assay initiation with three replications per site. Objective 2:The Germinable Seed Bank Assay will be created using data collected in the soil survey from Objective 1. The Residual Herbicide Assay created in this project will build on work done by Washington State University (http://whatcom.wsu.edu/ag/aminopyralid/ Bioassay2011.pdf ) and Fauci et al. (2002). Five soils will be selected from the Objective 1 survey that represent a range of chemical, physical, and biological characteristics. Soils will be brought to 60% field capacity and then spiked with 5 treatments of aminopyralid to supply concentrations of 0.1, 1, 5, and 10 µg kg-1. Soils will be placed in 0.5 L pots and Pea (Pisum Sativa) will be planted four per pot with four replications per soil x aminopyralid treatment (Fauci et al., 2002). Plants will be monitored for germination rates and scored based on visual injury from 0-100 (dead) on a weekly basis for 6 weeks. Two weeks after planting, soil samples will be taken from each replication to determine the aminopyralid concentration. Objective 3: This study will be conducted on certified organic land at the UGA Organic Research Farm (Watkinsville, GA) and the Love is Love Cooperative Farm (Mansfield, GA). There will be two different cover crop entry points (Fall and Spring) with following tomato and broccoli cash crops (respectively) to determine the effects of timing on weed suppression, soil fertility, and system success. For each cover crop entry point, we will determine the effect of cover type (two cover crops, silage tarp, or no-cover) and the effect of the addition of poultry litter on at cover crop planting on weeds, soil fertility, soil organic matter, and cash crop yield. Plots will be organized in a randomized complete block design with the cover type as main effect and the addition of poultry litter applications as split plots within each main treatment. Prior to planting, soils will be analyzed for soil physical, chemical and biological characteristics and germinable weed seed bank analysis. Initial weed biomass and species population will be determined and plots will be mowed. Poultry litter (routine analysis performed at the UGA AESL) will be surface-applied (equivalent to 6000 kg ha-1) to appropriate plots just prior to planting. Cover crops will be direct drilled into the pasture using a compact no-till grain drill with a small seed box (Fall entry point: crimson clover and rye; Spring entry point: Sudan grass and cowpea) and watered overhead to ensure adequate germination. Silage tarps will be laid at cover crop planting. During the cover crop growing season, cover crop and weed biomass/speciation will be determined 2-3 months after planting. At cover crop termination, cover crop biomass, total weed biomass, and weed speciation will be determined. Cover crops will be analyzed for lignin, hemicellulose, carbohydrates, total C, and total N and mineralizable N. Soils will be sampled for total N, total C, organic matter, and inorganic N. Four weeks after cover crop termination beds will be prepped for cash crop planting using chisel plowing followed by harrowing. Soils will analyzed and the germinable weed seed bank for each plot will be determined. Two rows spaced 6-ft (1.8 m) center to center will be planted in each plot. Tomatoes (c.v Defiant) and broccoli (c.v. Emerald Crown) will be hand-planted at 50 and 20 cm in-row spacing respectively. Pest management will be done in accordance with UGA Extension recommendations for organic production. Three times during the growing season and at harvest, inorganic N in the soil will be determined. Cash crop N uptake will be determined twice during vegetative growth and biomass and N uptake will be determined at harvest for the fruit and plant. Weed pressure will be determined on a bi-weekly basis. Weed biomass and speciation will be determined just prior to whole plot weeding. Cash crops will be harvest and rated for quality and yield. Weather data will be collected for each farm using the UGA Automated Environmental Monitoring Network (AEMN) weather stations. Data Analysis: All data collected in objectives 1, 2, and 3 will be analyzed using linear mixed techniques implemented in SAS PROC GLIMMIX (SAS/STAT 14.2; SAS Institute Inc., Cary, NC) to determine significant differences in treatment effects on soil characteristics, weed populations, and plant yield parameters. N mineralization data and plant uptake data will be used to determine plant uptake and N availability and the N balance for each treatment and plot. Objective 4:Data, tools, and publications will be shared with farmers, Extension, professionals, and the scientific community. Our advisory panel will help with evaluation during the project and specific efforts will evaluated individually. Effort 1: Deliver new knowledge on weeds, weed species, potential herbicide issues, and soil fertility issues for farmers on new/derelict land. Evaluation 1: Development of Germinable Weed Seed Bank and Residual Herbicide Assay for farmer and Extension use. Creation of web-based publications for use by Extension and producers (2), Webinars (1) and peer-review articles (2). Effort 2: Deliver new knowledge for farmers looking to use cover crops that are no-tilled drilled into derelict land and determine the immediate effects on weed management (particularly Bermuda), germinable weed seed banks, soil N fertility, and soil organic matter. Evaluation 2: Demonstrate and measure findings with UGA and on-farm field studies using organic vegetable cash crops. Generate a management program for best practices for decreasing weeds and increasing soil fertility. Create Extension publications (1), Webinars (1), and peer-review articles (2) Effort 3: Increase student understanding of weeds, cover crops, and N fertility in organic production systems through hands-on class projects and case studies. Evaluation 3: Evaluations of student knowledge from class room and field learning sessions with students through interactive whole class studies and graded assignments. Effort 4: Increase in Extension agent's knowledge and skills in organic transitions and organic production systems and their capacity to provide technical support for sustainable agriculture practices. Evaluation 4: Pre and post evaluations of agent knowledge after in-service trainings (3). Effort 5: Increase in farmers knowledge and skills in organic transition, N and weed management, cover crop planting in organic production systems, and of services and research provided by UGA. Evaluation 5: Post evaluations of farmer knowledge after conference presentations, workshops and webinars. Farmer/Researcher collaborative fields days (2) and workshops for new farmer outreach.