Why Do You Need to Know About Soil Microbes and Soil pH?

Handful of soil

Two WSU Extension workshops hosted by WSU Farmers Network have some ideas.

Soil is alive. A handful of soil can have thousands, millions, even billions of living organisms. Each of them fulfills a role, or several roles, in decomposing organic matter, stabilizing carbon, dissolving minerals, capturing nutrients, and converting nutrient to the forms that are available for crop uptake. These microbial activities define the functions of healthy soil. You might think of them as the organs of a living organism, all working together. Managing soil like managing a living system is important for crop health, resilience to dramatic environmental change, and reduced pesticide and herbicide use.

In addition to soil management practices such as tillage and cover cropping, crop rotation can also impact soil microbial health. For example, certain canola and camelina varieties provide “biofumigation effect” which can reduce soilborne pathogens, however, careful incorporation of them in crop sequence or including a companion crop is needed because they can also impact beneficial soil organisms. Nitrogen fixation bacteria have ability to create nitrogen fertilizer for crops. Most of us are know that legumes have a capability to fix nitrogen, some free-living bacteria are also capable to fix nitrogen.

Those little things that live in the soils can have big impact on soil health and crop productivity. Soil Health in Eastern Washington: Little Things, Big Impact workshop is specially designed to discuss how to manage our soils to ensure friendly environment for these little things and to raise awareness of practices that can affect crop productivity due to their impacts on soil microbial activities. A farmers’ panel will share their on-the-ground experience with cover cropping.

Soil pH is one of the most important factors in soil microbial health. When pH is low, the soil becomes an unfriendly environment for nutrients availability, beneficial microbial community, microbial activities that contribute to nutrients availability and disease suppression. The optimum soil pH is near neutral. Although there is no impact to crop productivities when pH is above 5, farmers may want to start taking actions to maintain the soil pH to prevent soil pH drop below 5. Several professors who have extensive experience working in the area of soil acidy will explain why in the Palouse Soil Acidity in 2020 workshop.

One of the quickest methods to maintain or increase soil pH is to apply lime. The cost of lime is a great challenge to many farmers. Whether the investment will be offset by yield benefits is a critical question has to be answered. The farmers’ panel consisted of experienced farmers in lime applications on their farms will share their experience in this workshop. In addition, most of farmers in the dryland area don’t have experience and equipment for liquid or dry lime applications. Dr. Jim Durfey, the agricultural technology and precision agricultural specialist, will discuss equipment options for farmers in this workshop.

For registration, please contact Carol McFarland at carol.mcfarland@wsu.edu.