Assessing the impact of cattle stubble grazing on soil health and future productivity to enable sustainable crop-livestock integration

Commodities

Practices

Cattle ranchers face increasing challenges in securing adequate fall forage due to drought, reduced hay availability, and increasing costs of harvested forages. A critical question is whether allowing cattle to graze crop residual post-harvest or cover crops can provide a viable feed source without adversely affecting soil health and future crop yields. Concerns about the potential negative impact of cattle grazing, such as soil compaction and its subsequent effects on crop growth, prevent farms from offering these lands for grazing (Bell et al., 2011). Cattle pressure can be managed with cross-fencing; however, the high costs of fencing and labor prevent this solution. Geo-fencing (also known as virtual fencing) provides an alternative solution. These systems use tones and electric pulse administered by an animal-worn collar to confine them to a software-defined area (Campbell et al., 2023).

The primary objective of this project is to determine if geofencing managed grazing of crop residuals and cover crops can supplement fall and/or winter forage needs and positively impact the farm field. To achieve this, we will monitor soil health, physiochemistry, and subsequent crop yield across each study area. The study will be conducted at multiple locations across Montana, with three treatments at each site: an un-grazed field area, a field area grazed without geo-fencing, and a field area grazed with cattle pressure managed via geo-fencing. Producers raised a concern that leaving a significant part of the field ungrazed may be a challenge. Therefore, to accommodate the request, we will have big fields (hectares or larger), one grazed without geofencing, and another field grazed with cattle pressure managed using geofencing. Inside each of these fields, we will have three sub-regions (approximately 6 m x 6 m each) as an enclosure, which will be used as an ungrazed control. During the grazing period, we will collect high-resolution data via ground-based and aerial methods to analyze the spatial and temporal dynamics of fall grazing and forage availability in the field. Using these collected data, we will conduct a benefit-cost analysis to support farmers in making informed decisions about adopting geofencing for cattle grazing management.

This project originated from conversations with producers about the potential of geo-fencing to control cattle in crop residual and/or cover crop grazing. This project will provide growers with evidence-based recommendations on the benefits of fall/winter grazing of crop residuals with geo-fencing systems.

Objective A: Assess the impact of fall cattle grazing on soil health indicators.

Objective B: Utilize geo-fence collar data to evaluate the spatial and temporal distribution of grazing behavior and nutrient dispersion.

Objective C: Utilize UAVs to evaluate the spatial and temporal variability in fields affected by grazing and measure crop yields.

Objective D: Quantify the economic benefits of fall stubble grazing.

Objective E: Disseminate research findings through education and outreach activities.