Changes in Alberta’s Grasslands Soil pH by Adopting the Adaptive Multi-Paddock Grazing System

Résumé

Grasslands account for a large percentage of earth’s terrestrial area. Soil is an important aspect of the global carbon cycle and plays a critical role in mitigating climate change. Due to poor land management, the grasslands have been greatly degraded, resulting in the grasslands becoming the most endangered ecosystem on the planet. Fortunately, there are several new techniques that can be implemented in order to help alleviate the negative impacts that the depleted grasslands have had on the earth. The Adaptive-Multi Paddock (AMP) grazing system is an innovative technique that has been introduced as a way to increase plant regrowth, improve animal performance, and increase soil organic carbon (SOC) levels. As SOC has been shown to be correlated to soil pH, there is potential for the AMP system to affect soil pH. To implement the AMP system, a rancher’s land would be divided into multiple small paddocks, and the cattle would be rotated between the paddocks more frequently. Non-AMP managed ranches include any ranch that uses traditional grazing techniques, such as low or high continuous grazing. The purpose of this project was to study the effects of the AMP grazing system on the pH of Alberta’s grassland soil. Soil samples were collected from AMP and Non-AMP managed ranches in Alberta. After the samples were separated into several layers, weighed, dried, and sieved, the pH of each soil section was recorded and analyzed. Using the data from the Albertan ranches, the AMP and Non-AMP managed ranches were compared. From this data, it appears that by using the AMP system, the pH was slightly lower across all soil depths. Soil also appeared to become more basic with each successive layer. Between Alberta’s four ecoregions, the average soil pH seemed to vary. In both AMP and Non-AMP managed ranches, the subsoil was more alkaline while the topsoil was more acidic, which could be a result of possible higher SOC concentrations. In future studies, the pH data from Alberta’s soils will be compared to the Saskatchewan and Manitoba data, which will represent all of Canada’s grassland soil. When the SOC data is collected, the pH and SOC concentration will be analyzed to establish a correlation. Ultimately, farmers might be reimbursed for the additional costs of adopting the AMP system because of the environmental benefits the system could have.