Published on Thursday, April 2, 2020
Unfortunately, for many farmers, the story of the 2019 season has yet to be entirely written. The historically wet planting season across much of the Corn Belt not only challenged planting intentions but, for many, planting conditions were also compromised in an attempt to get the crop in the ground. The end result was many acres left fallow, wet areas of fields left unplanted or drowned out, and soil structure impaired due to planting conditions. Fields with compaction issues due to 2019 field conditions and unplanted or fallow acres will require specific management strategies to maximize production in 2020.
The root system provides the vast majority of plant nutrition. As roots grow through the soil, they either follow existing channels from prior seasons or penetrate and displace soil. A major obstacle to nutrient accessibility is soil bulk density. Excessive rainfall, compaction, and reduced soil organic matter all contribute to increased soil density. As bulk density rises, root elongation is hindered due to increased root-soil contact. For many farmers, changing weather patterns as well as the most recent growing season has led to increased soil density and thus reduced the accessible nutrient bank available to future crops.
Soil density, reduced soil oxygen, and fallow acres can all have another significant impact on crop nutrient supply. Each of these situations negatively influences soil health and reduces the population of a major ally within our soils, mycorrhizal fungi. These are beneficial fungi that are critically important to both nutrient uptake and water availability. Plant roots form an association with these mycorrhizal fungi. These fungi then inoculate the roots to form hyphae or fungal root extensions. The hyphae act as a web that contributes to aggregate stability and improves water infiltration. This beneficial relationship is critical to both overall root mass and root surface area. Along with increased root mass and surface area, a protein known as glomalin is produced abundantly on these hyphae. This protein is a major contributor to soil carbon and a food source to other soil microorganisms. Glomalin, as a carbon source, also biodegrades slowly and has been shown to persist up to 40+ years in the soil depending on climate and other soil parameters.
Impact of Enhanced Myccorhizae Populations:
1. ^ root mass and surface area.
2. ^ water availability and, thus, ^ photosynthesis as well.
3. ^ nutrient availability and nutrient cycling (especially nitrogen and phosphorus).
4. Improve soil aggregation > less crusting > greater water infiltration > increase CO2 release > increased yield
5. effect of fallow syndrome.
If last summer and fall’s weather thwarted your efforts to manage increased bulk density or fallow syndrome, then consider management efforts this spring to reduce the lasting impacts of 2019 and to adapt to changing weather patterns.
Images below are the result of an infurrow biological (mycorrhizae-containing product) in a 2019 corn crop following 2018 soybeans in Ohio.
Author: Luke Schulte
Categories: CropTalk, 2020
Tags: CropTalk, soil fungi, fungi activity