Dr. Clain Jones is Montana State University Extension’s soil fertility specialist. In this role he covers anything that has to do with fertilizer or nutrient cycling in both agriculture as well as home/garden systems. He started at MSU as a tenure track faculty member in 2006, and has ended up doing quite a bit of work with pulse crops over the years. He joins me today to talk about fertility in pulses, the importance of inoculation, nitrogen credits, soil pH, and the overall importance of pulse crops to soil health.

“Adding five pounds of sulfur per acre to lentils, what we found at least here in Bozeman, was that nitrogen fixation increased at a much faster rate than yield did. What that told us was that by applying sulfur, maybe we're not going to see a huge yield response, but we're going to contribute a lot more nitrogen both to that crop and to the next crop.” - Dr. Clain Jones

Dr. Jones stresses the importance of plant nutrition and pH when it comes to optimizing a pulse crop's ability to fix nitrogen. Limestone deposits in the soil can make pH values highly variable even within a field. This can make accurate soil testing a challenge. An acidic pH has a significant impact on rhizobia viability as they don’t tolerate low pH values very well. Along with pH, many micronutrients such as sulfur, potassium and phosphorus also need to be considered when assessing overall soil health and nitrogen fixation efficiency.

“We have low phosphorus because our high levels of calcium tie up that phosphorus making it less available to crops. Knowing that phosphorus is essential for nitrogen fixation, my gut feel is that phosphorus is probably the nutrient most limiting nitrogen fixation and probably pulse crop growth in our two state region.” - Dr. Clain Jones

This Week on Growing Pulse Crops:

• Meet Dr. Clain Jones, the Montana State University Extension’s soil fertility specialist
• Discover the impact of pH and micronutrients on a pulse crop’s ability to fix nitrogen
• Explore the recommended testing and values of soil nutrition to allow for optimal nitrogen fixation

Growing Pulse Crops is produced by Dr. Audrey Kalil and hosted by Tim Hammerich of the Future of Agriculture Podcast.