Soil quality benefits us all

Soil quality or soil health is a reflection of the soil’s ability to support plants and animals, maintain or enhance water and air quality, and support human health and habitation (Karlen et al 1997). It covers a wide range of interrelated physical, chemical, and biological characteristics.

Soil properties that can be impacted include soil organisms, fungi, biota, respiration, texture, pH (acidity or alkalinity), and organic matter. For example, organisms in the soil break down crop residues to release nutrients including nitrogen and soil fungi that helps with soil structure.

Soil biota are pH dependent, which means there is lower biological activity in acid soils or highly alkaline soils, and though texture is fixed depending on where you live. Improving organic matter can improve drainage, aeration, water holding capacity and nutrient retention (McGuire et al 2017: 1). Soil properties are influenced by their environment, which means they are affected by climate, geology, and vegetation and by humans who are contributors to erosion, nutrient management, water availability, and plant selection.

There are many soil quality properties that can be tweaked depending on the desired management goals. A nationally recognized guide is the Cornell Soil Health Assessment, which measures 10 properties and comes up with an overall soil health rating. Unfortunately, that assessment was developed for soils in the northeast United States and may not reflect conditions present here in the Columbia Basin. However, whether you are a small gardener or a commercial grower, anyone can use an improved crop as an indicator of soil quality incorporating the effects of different soil properties using improved management.

Columbia Basin soils are light textured and can be prone to wind erosion during windy periods especially during the spring and fall when soils are most likely to be bare. Maintaining crop residues can help keep soils in place. Even in our dry climate irrigating soils with low infiltration rates that have been intensively tilled can cause low water uptake, poor drainage, and crusting. Native soils in our dry climate generally have organic matter percentages of less than 1 percent so improving and adding annual additions of organic matter can be beneficial for many factors.

Whatever management can be done to improve soil quality will help reduce erosion, improve nutrient cycling and soil tilth, reduce impacts of soil borne disease, and improve water holding capacity and infiltration. Using a variety of annual cover crops, practicing residue management, rotating crops and experimenting with organic soil amendments alone or in combination will improve the fertility and sustainability of our home gardens..

For answers to gardening questions, contact the Master Gardeners at the WSU Grant-Adams Extension office at 754-2011, Ext. 4313 or email your gardening questions to ga.mgvolunteers@ad.wsu.edu. Visit our web page at http://grant-adams.wsu.edu.