When mankind began farming, soil physics was the most observable realm, and so soil physics was where we first developed a coherent theory. In the last few centuries, our analysis and measurement techniques allowed us to understand soil chemistry—the nutrients present and available for our crops. From first being able to measure soil nutrients, to establishing baseline expectations for common soils, to finally understanding what nutrient application choices should be made based on our measurements, took many decades of iteration and exploration.

As biological science matures, we stand on the frontier of understanding soil biology. A rich ecosystem of plants, animals, protists, nematodes, fungi, and more live in the soil that supports our cranberries—and we are beginning to be able to measure them. As we begin to learn what lives in our soils, it is likely we’ll be able to have as many new “levers to pull” to improve cranberry production, as we discovered through our exploration of soil chemistry and plant nutrition.

Part of Extension work is collaborating with partners to find expertise and funding to explore interesting topics. Together with Jamie Patton and Francisco Arriaga (of UW-Madison Division of Extension) and Andy Paolucci (of NRCS), I applied for and was awarded a SARE Mini-Grant for 2021. Provided by the Sustainable Agriculture Research and Education program, we received just over $2000—enough to conduct a preliminary study. For 2021 we will begin to explore soil health and soil biology in 5 production cranberry marshes.

Because this is an exploratory project, we are comparing a “healthy” and a “poor” bed of similar treatment in each of our partner marshes. For example, a Wood County marsh will be comparing two HyRed beds, two beds apart, which were planted within a year of each other—but one bed always has >50 barrel/ac higher yields than the other.

Our protocol will take a composite sample from the bed edge and a composite sample from the bed center of the “healthy” bed, and a composite sample from the edge and a composite sample from the center of the “poor” bed. Each of these samples will receive a battery of tests: the standard chemical analysis that growers use for their NMPs, as well as several “soil health tests” that have been developed over the last decade: cellulose decomposition, microbial respiration (“what is breathing in this soil?”), active carbon, potentially mineralized nitrogen and PLFA (phospholipid fatty acid) analysis (“what has cell walls in this soil?”), and others which will be provided by the UW Sustainable Soil Management Lab.

We are hoping to see whether there will be patterns or commonalities from each partner marsh’s “healthy” bed samples in contrast with their “poor” bed samples. For 2021, we are working with sandy marshes in Tomah, Cranmoor, City Point, Exeland, and Manitowish Waters. If we find correlations, next year we might expand to do more marshes, or we might broaden our methodology to test peat marshes as well. In return for participating, these 5 marshes will receive all of the test results for their marshes, and the whole industry will be able to learn from these pilot tests.

Stay tuned this fall for our results!

This article was posted in Cranberry and tagged Allison Jonjak, Cranberries, soil, soil health.