Improving Soil Health

May 31, 2019

Texas Tech biologist researcher Natasja van Gestel is working with area cotton producers to help them improve their soil’s health. The healthier the soil, the more carbon can be removed from the air and the better soil can absorb water – a diminishing resource on the South Plains. Van Gestel’s research seeks to encourage producers to use no-till practices. 

 

For decades, farmers have pumped water from the Ogallala Aquifer to irrigate their crops. That dwindling resource won’t last forever. That’s led one Texas Tech biologist, Natasja van Gestel, to a rare collaboration with cotton producers in 33 fields in the region to study how soil health can help with water use. 

"If we can build up organic matter in the soil and improve the soil structure and aggregates, it will all help with the soils being able to retain more water. If it rains, so two things, if the soils have better aggregate structure or just general better soil structure, then the water can actually infiltrate more into the soil. Also with good soil structure if the soil structure is covered and combined with the good structural integrity of the soil, you don't have as much water running off of the land. So more of the water that hits the soil can actually go into the soil."

Van Gestel’s study of soils is aided by the growers themselves as part of an ongoing Grower Citizen Science Project, which receives funding from Cotton Incorporated and the Buddy Davidson Foundation. The farmers will send CO2 sensor data to van Gestel using their smartphones.

"This is another really neat thing about working with the growers. They have cell phones and they can actually use the device themselves and they'll send me the data. So it's really nice how we are working together with each other and sharing knowledge because I actually am not a farmer, as I mentioned earlier, so I'm learning a lot of things from them and in return they are learning a lot of things from us. It's really a nice two way interaction."

She says that cotton producers who till their fields can lose soil structures that help make those acres healthier. 

"Microbes are really important in the carbon and nitrogen cycles, and what happens when they till the soils is they break up the hyphae that fungi are making. These are little fillaments of the fungus and so essentially they're kind of like root systems, they're trying to get nutrients and hyphae to travel everywhere."

Van Gestel sees soil health in agricultural production as being beneficial to not just the cotton producers, whose crop yields would likely improve. 

"We want to make the soils better than they are currently and improving the carbon status of the soil is one key element. Because if you improve the carbon, if you have higher carbon in the soil because you have more organic matter in the soil, that comes with so many other benefits. Not just because we can reduce the rate of climate change potentially because it can store so much additional carbon and draw that down from the atmosphere, but also because the growers can benefit from it. When the soils are doing better, when the soils have more organic matter, it comes with so many more benefits that it's a win-win situation."

She says that she and the cotton producers she’s working with likely aren’t motivated by the same things in this research. But each can learn. 

"I don't think that climate change is at the forefront, it really is about yield, it is a business. This is why working with them is great because I'm interested in the fact that it helps fight climate change, but it also helps people, and so to me it's the best of both."

If the structure in soils improves so that water infiltrates more deeply, it can have ancillary benefits to the cotton plant itself. 

"So if you have better soil structure then the water can also enter a little bit deeper into the soil and then the plant roots can grow a little bit further down as well. So when it can grow further down, it won't be as stressed with the high temperature extremes by the soil surface."

There is a shift, van Gestel says, toward no till. But producers need to be patient as it can take a few years to see the benefits. She says no-till practices and leaving crop or plant residue in fields to create a physical barrier to reduce rainfall runoff will be increasingly necessary.

"We will have to, because we just don't have the water necessary for irrigation any more, so we're trying to improve the soils while we can as much as possible. It will help us in the long term."