Maximizing carbon storage for cotton in sandy soil, experts weigh in

LUBBOCK, Texas (KCBD) - The agriculture community gathered in Lubbock to share some knowledge on Friday, including how to retain more carbon in West Texas soil.

The Ecological Landscape Alliance explains:

Carbon sequestration, also known as “carbon storage,” is the amount of carbon in soil, usually measured as a mass per volume, and is desirable because soils with more carbon generally provide more ecosystem services, things that make ecosystems healthy places to live for people: they hold more water, are less prone to erosion, and hold more nutrients for plants. In healthy soils, carbon inputs (photosynthesis) roughly equal outputs (plant root and soil respiration). Carbon enters the soil two ways: plant material deposition on the surface, and root exudates from living plants. Carbon stays in the ground by microbial transformations, mineral sorption, and chemical recalcitrance.

Experts say in West Texas, increasing carbon levels is challenging and slow, but possible.

Soil expert Katie Lewis says historically, maintaining carbon was a way to enrich soil.

“We can do this through different farming techniques like no till, where seeds are planted directly without removing crop residue, like sticks and dead leaves,” Lewis said.

“No till does absolutely nothing for us. When it comes to increasing our organic carbon levels, we have to have the additional crop in the system to start to see an increase,” Lewis said.

Researchers found carbon storage is greater using cover crops, especially in sandy soil like we have here.

“This is a 22% reduction in net losses of CO2 with the cover crop compared to the conventional tillage system,” Lewis said.

Specifically for a cotton system, researchers looked at 23-year period and discovered a potential to increase carbon storage by using cover crop and no till practices.

“We’re seeing with our cover crops, point two or two to two and a half tons of carbon per acre increases, compared to the continuous cotton conventional tillage system. So when we think about that over a 20-year period, that comes out to about point one tons of CO2 carbon per acre per year,” Lewis said.

While changes may be small, Lewis says any carbon kept in the soil and out of the atmosphere is beneficial.

The Texas Ag Forum continues Saturday at the FiberMax Center for Discovery, 1121 Canyon Lake Drive here in Lubbock. You can find registration info and agenda details here.

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