Roots That Reach: How Mycorrhizal Fungi Help Crops Thrive in Dry Conditions 

Inconsistent rainfall and increasing summer heat are pressing challenges for every grower. Whether you’re in a dryland corn system or irrigating in high-evaporation zones, your yield depends on how well your crops can access water—not just at the surface, but deep in the soil profile. 

That’s where mycorrhizal fungi make their biggest impact. By supporting the root zone with biological infrastructure, these beneficial fungi give plants access to water that untreated roots simply can’t reach. 

The Root of the Problem: Water Stress and Crop Failure 

Most yield loss during hot, dry spells occurs not from heat directly, but from plant stress due to shallow root systems and limited water uptake. In soils lacking microbial support, roots can’t expand as efficiently. As a result:

● Plants wilt or curl leaves 

● Pollination suffers 

● Kernel count drops 

This is especially damaging during the tassel, silk, and grain fill stages in corn and the pod set stage in soybeans. 

How Mycorrhizal Fungi Help 

Mycorrhizal fungi colonize plant roots and extend their reach through hyphae—tiny thread-like structures that can explore far beyond the root zone. These hyphae help in three critical ways: 

● Access Deep Water: Hyphae grow through micro-pores and crack networks to find and transport water to the plant 

● Improve Soil Structure: By binding soil aggregates with glomalin, fungi increase porosity and water-holding capacity 

● Reduce Evaporation Loss: Better soil aggregation leads to higher infiltration rates and less runoff 

According to New Phytologist (2015), mycorrhizal fungi can improve water uptake by as much as 40–60% in drought-prone soils. 

Field Results: The Difference in a Dry Year 

In 2022 Nebraska trials conducted by soil consultant Mike Petersen, corn treated with mycorrhizal fungi showed: 

● More Nodal Roots (44.4 vs. 37.6 in control) 

● Wider Stalks with stronger vascular flow 

● Higher Turgor Pressure during heat stress 

Even in periods with minimal rainfall and pivot downtime, fungi-treated plots remained visibly more robust than untreated neighbors. Plants stood straighter, leaves stayed open longer, and pollination was more complete. 

Growers using Farm Fungi’s MycoMaxx formulation also reported: 

● Less leaf curling in high temperatures 

● Faster recovery after irrigation or late rain events 

● Reduced lodging risk due to deeper root anchoring 

Resilience in Both Dryland and Irrigated Fields 

Many farmers assume biologicals like fungi are only useful in dryland scenarios. But fungi also: 

● Improve irrigation efficiency, by holding water longer and increasing root access ● Reduce the total inches of water required per bushel of yield 

● Help stabilize moisture gradients in sandy or uneven soils 

That means more yield per drop—no matter how you water.

Building a Drought-Ready Root System 

To prepare for water stress, apply fungi early—either in-furrow, as a seed treatment, or broadcast with cover crops. Once in place, fungi: 

● Colonize new roots as they grow 

● Create lasting networks that persist through seasons 

● Enhance plant resilience from vegetative stage through grain fill 

Best of all, once you reduce tillage and avoid early fungicides, the fungi begin to self-sustain. That means year-over-year water resilience grows, too. 

Don’t Just Pray for Rain—Plan for It 

You can’t control the weather, but you can control how your soil responds to it. By investing in mycorrhizal fungi, you’re giving your crops the root system they need to survive dry spells and thrive when water is scarce. 

Works Cited: 

● van der Heijden, M.G.A., et al. (2015). “Mycorrhizal ecology and evolution: the past, the present, and the future.” New Phytologist, vol. 205, no. 4, pp. 1406–1423. 

● Petersen, M. (2022). Tassle-Early Silk Trial Report. Internal Agronomic Study, New Age Farming. ● Soil Food Web Foundation. (n.d.). Magnificent Mycorrhizal Fungi. https://www.soilfoodweb.com