Spatial Variability of Plant Productivity and Soil Organic Carbon Changes
Project Lead: Dr. Bruno Basso
Summary: Caney Fork Farms is deeply committed to regenerating the soils and ecosystems across the farm.This project aims to quantify the changes in soil carbon and plant productivity over time and within the variable landscape that the land CFF presents. We analyzed images from NASA Landsat, ESA-Sentinel-2, and Planet to assess spatial and temporal variability of plant productivity. Plant productivity is important because it relates to yield and bottom line and to the building of soil organic matter. More productive plants lead to more roots and root exudates leading to greater carbon sequestration.
Based on soil samples collected in 2019, we were able to quantify differences in plant performance and soil organic carbon levels between different productivity zones. We used the SALUS crop and soil model to calculate the change in soil organic carbon between historic conventional management vs the regenerative practices CFF implemented in 2019.
In 2019 and 2022 a total of 630 soil samples were taken throughout the farm. The samples were grouped by 0 to 15 cm, 15 to 30 cm and 0 to 30 cm depth. For each depth, we interpolated the sample points to get the estimated Soil Organic Carbon for the whole farm, and compared it to the SSURGO information from 1988.
Using the average bulk density of 1.43, which was derived from 118 samples in 2020, we calculated the Carbon Stock in Mg/ha (Soil Organic Carbon * 10,000 * bulk density * depth). From 1988 to 2022, the Carbon Stock increased by 19 Mg/ha which equals to 0.6 Mg/ha per year. The Soil Organic Carbon increased from 1.18 % to 2.02 % which is a total increase of 71%. Between 1988 and 2019, the Soil Organic Carbon (SOC) increased by 0.02 percentage points per year. However, with the implementation of regenerative practices, the SOC began increasing at a rate of 0.07 percentage points per year from 2019 to 2022.
This analysis offers valuable insights into the concrete and measurable impacts of the farming practices at CFF. The SOC regeneration rate of 0.07 percent per year sheds light on the tangible shifts occurring underground at CFF, reminding us that the work at CFF is playing a vital role in global climate mitigation goals.