Project Overview
Commodities
Practices
Proposal summary:
To address the challenges of high input costs and labor-intensive practices in pecan orchard management, this project proposes an innovative, sustainable solution that integrates perennial peanut as a ground cover, established using a no-till method suitable for grazing. Perennial peanut will reduce the need for mowing, decrease reliance on conventional fertilizers, enhance soil health, and support grazing cattle within the orchard. Given its high nutrient content, based on multiple research from the University of Florida, cattle grazing on perennial peanut perform better than on traditional bahiagrass. To address food safety concerns in pecan-cattle systems (e.g., nuts potentially contacting contaminants from cattle manure), we propose testing a 45-day withdrawal period before harvest.
Objective 1: No-Till Perennial Peanut Establishment
This project will evaluate the feasibility of a no-till method to establish perennial peanut under pecan orchards, utilizing the existing thin bahiagrass (Paspalum notatum) cover. By testing no-till establishment, we aim to significantly reduce the traditionally high costs and labor associated with perennial peanut planting, while also minimizing soil disturbance. Reduced disturbance can lessen weed competition, lowering the need for intensive weed management during the slow establishment phase of perennial peanut. In contrast to conventional tilling, this approach can also contribute to soil health benefits, such as increased organic matter and soil structure stability, both essential for long-term orchard productivity. Additionally, perennial peanut's nitrogen-fixing capabilities may reduce synthetic nitrogen inputs over time, offering a sustainable, cost-effective pathway for growers seeking to improve their orchard floor while enhancing soil fertility.
Objective 2: Safe Grazing Practices for Pecan-Cattle Systems
To address food safety concerns associated with grazing cattle in pecan orchards, this project will evaluate the effectiveness of removing cattle from orchards 45 days before nut harvest to mitigate contamination risks with pathogens such as E. coli and Salmonella. We will conduct comparative testing of surface contamination on pecans harvested from both grazed and ungrazed areas, providing a data-driven foundation for safe, integrated livestock practices. The goal is to validate this buffer period as an effective measure, ensuring that pecan-cattle systems can remain viable and safe for both consumers and producers. If proven, whic can allow pecan growers to integrate livestock for vegetation control and additional income, reducing orchard maintenance costs and fostering a more resilient, diversified system.
Expected Outcomes
By implementing and evaluating these two complementary solutions, this project aims to provide pecan growers with sustainable, cost-saving practices that improve their operation’s economic and ecological resilience. The no-till perennial peanut method could establish a model for low-cost, low-maintenance ground cover that benefits both soil health and nutrient cycling. Simultaneously, the development of safe grazing guidelines could make livestock integration in orchards more practical and attractive, offering an additional income stream without compromising food safety. Together, these strategies can support a diversified, resilient production system that enhances profitability, promotes soil health, and ensures product safety—critical factors for sustaining pecan operations in the Southern region.
Project objectives from proposal:
This project will use field-based research to assess both the no-till establishment of perennial peanut in pecan orchards and the food safety implications of grazing cattle in these systems. By exploring these objectives, we aim to advance sustainable orchard management practices that enhance productivity, improve soil health, and ensure nut safety.
Objective 1: No-Till Establishment of Perennial Peanut in Pecan Orchards
For this objective, we will evaluate perennial peanut establishment under a no-till system within the pecan canopy (shade) compared to traditional land preparation in open areas (full sunlight). Due to funding starting in April, the initial planting may occur in summer, a less favorable season for perennial peanut establishment. To address potential seasonal differences, we will plant again in the winter of the following year.
Experimental Design
Replication and Location: Four orchards will be used as replicates, with a 2-acre planting area in each. Control areas will be established using conventional preparation methods in similar soil types.
Planting Methodology: We will plant a 20-foot-wide strip of perennial peanut along the center of each 40-foot row, following recommended strip-planting guidelines to cover roughly 50% of the area. Planting will be conducted by a custom planter, meeting a minimum requirement (from the custom planter service) of 10 acres across all locations each year. The control (full sun, tilled) will be prepared following Extension guidelines, with two to three iterations of total vegetation control (broad spectrum herbicide) and tillage. For the no-till approach, vegetation will be mowed short. In both treatments, we will use a Bermuda King sprigger. After planting, the area will be rolled to ensure good soil-to-rhizome contact and moisture. Base fertilization will include recommended P and K plus around 30 lbs of N as ammonium sulfate to improve establishment.
Measurements and Data Collection
- Establishment and Ground Cover: Perennial peanut establishment will be visually graded using a grid quadrat to estimate percentage cover. Thirty random quadrats (2 ft x 2 ft with 4-inch cells) per orchard will be assessed, recording cover percentages of peanut, bare ground, and other species.
- Biomass and Nitrogen Contribution: Biomass samples will be collected before mowing by harvesting three 2-ft x 2-ft quadrats in each orchard, then sorted into perennial peanut and other plant material to determine peanut biomass proportion. Samples will be sent for laboratory analysis and crude protein content will provide an indirect nitrogen fixation potential.
- Weed Encroachment and Management: Weed encroachment will be tracked visually (grid) and through biomass assessments, comparing no-till plots with traditional controls to evaluate the impact of reduced soil disturbance on weed pressure. For summer planting, biomass will be cut once or twice in the season, depending on mowing requirements (for competition control). For witner planting (year two) we expect to harvest three times.
- Establishment Guidelines: We will record all activities and observations to develop no-till planting guidelines for perennial peanut establishment in orchards.
Data Analysis
Statistical Analysis: Analysis of variance (ANOVA) will be used to assess cover and biomass data, with factors including location, planting method, and season to evaluate differences between no-till and traditional methods. This will determine if no-till establishment effectively promotes perennial peanut growth while reducing weed presence in orchard systems.
Objective 2: Food Safety in Pecan-Cattle Grazing Systems
To address concerns about contamination from cattle grazing in orchards, we will evaluate whether a 45-day cattle removal period before harvest can mitigate risks of E. coli and Salmonella contamination. Since perennial peanut will not fully establish within the project timeline, we will use adjacent fields for this objective, comparing pecans from grazed and ungrazed areas to detect any contamination differences. Ideally, we would test a range of periods and exposures, but logistic limitations do not allow for a full factorial experimental approach.
Experimental Design
Sampling Locations: Four grazed and four ungrazed orchards will serve as replicates, enabling comparison of contamination levels in commercial orchards managed under typical practices.
Withdrawal Period: In the grazed orchards, cattle will be removed 45 days before harvest, following Teaxs A&M guidelines to allow contaminants to degrade before pecan harvest.
Measurements and Data Collection
- Pecan Sampling: Samples will be collected from both grazed and ungrazed orchards over two consecutive harvest seasons. Samples will be gathered at the cleaner after harvest to assess contamination risk under standard post-harvest conditions. Three samples from each orchard (replicate x treatment) will be collected separately, for a total of 24 samoples per year. Those sampels will be sent to a lab for microbial analysis.
- Laboratory Analysis: Pecan samples will be analyzed in a food safety lab for surface contamination (qualitative and quantitative assessment), focusing on pathogens common in livestock manure, such as E. coli and Salmonella.
Data Analysis
Statistical Analysis: Mean contamination levels between grazed and ungrazed samples will be compared using ANOVA, with additional threshold analysis to evaluate pecans from grazed orchards that align with industry safety standards.