Soil moisture key to cropping conditions around area and state

When it comes to soil moisture, Texas agriculture is divided into “haves” and “have-nots.”

Texas A&M AgriLife Extension Service agronomists Calvin Trostle, Ph.D., in Lubbock, and Ronnie Schnell, Ph.D., in Bryan-College Station, said the soil moisture conditions have changed dramatically for parts of the state, while other parts continue to deal with various levels of drought.

East Texas and far West Texas, including El Paso County, are faring well and are considered out of the drought, according to the U.S. Drought Monitor.

Some parts, especially large swaths of Central Texas and the Panhandle, are mired in extreme, or D3, to exceptional, or D4, drought levels, according to the drought monitor. D3 drought levels indicate major crop and pasture losses as well as widespread water shortages and restrictions. D4 levels indicate exceptional widespread crop and pasture loss, and water shortages in reservoirs and wells at emergency stages.

Trostle said there are stark differences around the Panhandle, which range from moderate to exceptional drought levels. But even within the drought monitor’s picture of Texas’ water and soil moisture conditions, the local reality may be as bad or better than expected.

“There is a difference between the dark red versus red, but there are always the possibilities that local conditions could be very different,” he said. “If a producer gets 3 inches of rain over a few weeks, they are in a much different situation than what the map shows. We don’t get into or out of droughts quickly, but soil moisture is a big factor in the drought monitor and what growers are monitoring when planning their crop decisions.”

Soil moisture defined by rainfall deficits or deluge

Texas State Climatologist John Nielsen-Gammon, Ph.D., Bryan-College Station, said dry parts of the state have been experiencing below-normal rainfall and drought conditions for years. As a result, conditions across the state reflect the long- and short-term weather patterns.

The state is no longer stuck in a La Niña pattern, which means Texas should expect normal chances for rain. La Niña delivers above-normal temperatures and below-normal rainfall for most of the state.

But Nielsen-Gammon said many areas are so deep in drought that it will take time and multiple rain events to return to normalcy. Over the past 90 days, most of the western half of Texas has received 50% of its normal rainfall while parts of deep East Texas have received 150% of their normal rainfall.

“East Texas normally gets a lot more precipitation in winter anyway, but that pattern was exaggerated this winter,” he said. “There is really no dividing line to the drought. Most of it has been going on for years, and what we see around the state reflects the long-term rainfall deficit versus short-term rainfall that might improve the situation some.”

Nielsen-Gammon said there is a decent chance for precipitation in drier areas of the state over the coming weekend.   

Soil moisture: Catch it. Keep it. Reap it.

Trostle and Schnell are hopeful rainfall will materialize in their respective regions. Brazos County and surrounding counties are not experiencing drought, according to the monitor, but Schnell said the topsoil needs moisture after a dry spell followed heavy rains in December and January.

“We have good deep moisture, but if the current dry spell moves into another week, it could impact sorghum plantings,” he said. “We caught really good rains over winter, but it’s been dry for weeks now, and the topsoil is dried out.”

Schnell said most corn plantings in southern and Central Texas started in late February due to warmer-than-normal soil temperatures, and that seeds were planted deeper in some fields to reach enough moisture to get the crop started. 

Trostle said some farmers might like clean, tilled fields, but that goes against principles he recommends to operations in drier areas or dealing with drier-than-normal conditions.

His three-phrase rule of thumb for rainfall is “Catch it. Keep it. Reap it.”

Catching and keeping moisture represents added crop value, Trostle said. For example, in cotton, 1 inch of incremental water equals about 60 pounds of fiber yield per acre, or around $48-$50 per acre with current prices.  

“Do you have stubble or a cover crop that can catch that rainfall and slow down the water enough to soak in and prevent it from running off the field?” he said. “Keeping it starts with minimizing tillage because you can lose half an inch of rainfall by disturbing the soil. That could be $25 of cotton per acre. Reaping it is just taking advantage of the moisture and doing everything possible to maximize its impact on your yield.”

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