How improving water infiltration leads to improved farm profitability

Water: it’s maybe the most precious resource on a farm. But when crop demand for water is too high, or plants don’t absorb water as efficiently as possible, this can mean both a waste of a finite resource — and lower profitability at your operation.

Declining water infiltration in the Mississippi Delta is an issue for the region’s farmers. And it’s not going away any time soon.

But improving your soil “wealth” is the key to unlocking better water absorption, healthier crops, and more profitability.

What causes higher demand / lower water infiltration in the Mid-South? 

The Mississippi Delta tends to have heavier clay soils, which can be prone to waterlogging. 

As climate patterns shift in the Delta and the region trends toward fewer — but more intense — rainfall events, rainfall distribution can also be a huge issue.  

Heavier rainfall tends to hit in the spring. Then in July and August, the weather usually gets really hot and dry. In other words: it’s often too wet during the times of the year when plants don’t need as much water. Then, when crops are in their prime time and demand more water, there’s not as much available. 

Two common issues arise here: First, the Delta’s heavy clay soils can slow water infiltration. This is made even worse by soil crusting, which can happen when prolonged tillage has degraded the soil structure. 

Second, there’s often compacted layers, usually about 6-8 inches down, that block plant roots from exploring soil below the compaction. This means crops can only use water in the top 6-8 inches of soil — and are missing out on much of the water stored deeper in the soil. Plus, these top 6-8 inches of soil can dry out quickly in warm weather. This forces the need to irrigate more frequently. 

This compacted layer also restricts downward movement of water, causing more runoff and evaporation. 

The downstream impact of your soil’s inability to retain water is the need for more irrigation, higher input and energy costs, and more hits to your bottom line.

How can you meet increasing demand and improve water availability? 

Build up soil biology: The healthier your soils, the better they can absorb water and nutrients. And the healthier your crop, the more profitability in your pocket.

For every 1% increase in organic matter, you increase the plant’s available water-holding capacity by 3%. An increase of 2% organic matter, for example, would lead to an additional holding capacity of nearly half (0.45) an inch. If five rainfall events hit during the growing season, this would lead to about 2.2 additional inches of available water. And while irrigation costs can be extremely variable, these extra 2.2 inches would save you about $5.70 per acre in water you didn’t have to pump. (These figures are based on our own cost data on our 5,000+ acres in the region.)

Integrate cover crops: Cover crops help prevent soil crusting and improve soil structure, both of which increase the overall infiltration rate. If you have good crop residue heading into the growing season, that also helps shield the soil from the sun and helps it stay cooler. This reduces evaporation, which increases plant available water content in the soil. 

Additionally, cover crops ensure living roots beneath the soil throughout the year. These root systems add more carbon and biomass to the soil — while also stimulating the biology that builds up the microbes and fungal organisms.

On our own Vayda acres, we’ve routinely seen higher moisture content after several years of cover cropping — so much so that we even start irrigating later than neighboring operations.

Reduce intensive tillage: Intensive tillage practices can harm soil structure. In the long run, this increases drainage issues, as well as the soil’s capacity to absorb water. 

These practices can also harm mycorrhizal fungi and microbes that help bind the soil together. With fewer of these organisms in the soil, it’s easier for soil to lose its structure — exacerbating drainage and water absorption problems. 

If you make plans to stimulate and grow your soil biology (for example, through cover cropping), this needs to be done in tandem with reducing tillage practices. Otherwise you could be erasing some of the benefits. 

Consider using biologicals: There are also several biostimulant products on the market that can help jumpstart biological content in the soil. There are many products that can increase the abundance of mycorrhizal fungi, for example, which help bind soil together and improve water infiltration.

Improve your soil health — in a way that works for your acres

There’s no one-size-fits-all approach to stimulating your soil health, increasing your soil’s ability to hold water, and boosting your overall crop health. 

Even on our own 5,000+ acres in the Delta, we’ve tested many strategies to build up soil health, including field trials with different cover crop mixes, reducing tillage on fields that were previously conventionally tilled, and experimenting with a variety of biologicals.  

Thanks to those on-the-ground lessons, combined with our soil science expertise, we design customized strategies for how farmers can use regenerative practices to improve their operation — and profitability. If you’re looking to reduce your water usage and build soil health, reach out to one of our local advisors for a consultation.