A farmers guide to evaluate soil health using physical, chemical, and biological indicators on an agricultural field in Alaska

Abstract

Farmers across Alaska face many challenges. These challenges include climate extremes, wind and water erosion, weed pressure, crop pests, and nutrient-poor soils. Cover crops, crop rotation, crop residue, and tillage management are common conservation practices used to address soil related resource concerns. Research in the continental United States has shown that these soil conservation practices improve soil health. Resource managers are trying to determine the usefulness of soil health indicators to assess conservation practices in Alaska. The objective of this project was to provide Alaskan farmers, conservation planners, and land managers with a background on soil health, soil health indicators, soil health assessments, and the use of conservation practices to improve soil health. Establishing linkages between soil conservation practices and soil health indicators will allow individuals to focus conservation efforts on improving soil conditions, evaluate soil management practices and techniques over time to determine trends, make qualitative comparisons of soil health among management systems, and provide tested measures of soil health (indicators) that will allow farmers and land managers to make more informed resource decisions. Numerous studies were conducted across Alaska to gauge the success of cover cropping, crop rotation, and reduced tillage (no-till). Improvements in physical, chemical, and biological indicators were documented. After one year of study, most cover crops resulted in lower bulk density at the soil surface compared to conventional tillage. Among the cover crop treatments, the perennial forage grass Timothy (Phleum pratense var. Engmo) ranked highest in soil organic matter, soil water content, and improvement to the soil structure. Preliminary data from this project has been gathered to develop an Alaska specific Soil Health Assessment Card and supplementary User Guide.