As Ogallala Aquifer Declines, Sorghum and Pearl Millet Arise as Alternatives for Texas High Plains Livestock

New research published last April in the journal Crop Science conducted by scientists from the Texas Tech University looked into the possibility of producing forage pearl millet and foraged sorghum as alternative forage crops to corn for feeding Texas livestock, as the Ogallala Aquifer declines.

The study investigated the effects of deficient irrigation on the forage yield and physiology of these three forage crops.

Producers and growers in the semi-arid region of the Texas High Plains are worried about sustaining the dairy and beef industries, because of the declining irrigation source which is needed in corn production, which in turn is used as silage and feed-grain for cattle.

The Texas High Plains consists of 41 counties located in northern Texas, which cover roughly 39,500 m2. It stretches from Oklahoma's state borderline on its north and east side, to New Mexico's state borderline on its west side. To the south, it is bordered by the city of Lubbock, Texas.

The major industries in the High Plains Region are primarily centered around transporting natural resources, agriculture, and agricultural processing. The sectors with the highest concentration in this region are animal production as well as aquaculture.

Animal production, together with aquaculture, represents 35.1% of the total jobs in the state, with 8,957 jobs (as of the 2018 Regional report of the Texas comptroller). Meanwhile, food manufacturing comprises 15.5% or 14,460 jobs. For crop production, it is 23.0% or 4,830 jobs, and for support activities for forestry and agriculture, it is 24.0% or 2,762 jobs.

For the crops, the Ogallala Aquifer serves as the primary irrigation source. It is the largest aquifer in America, ultimately supplying the needs of the grains of the High Plains, America's breadbasket.

Now, it is rapidly declining due to its continued unsustainable use, forcing the region's states to confront the prospect of economic disaster for the entire area.

Now, there is a move to look for an alternative, forage crops that are water-efficient to sustain the region's dairy and beef cattle production.

The new study was conducted for two years. It evaluated the physiological responses from different varieties of corn, pearl millet, and sorghum when they are subjected to different irrigation conditions, including conditions simulating dryland. The study collected various physiological and environmental data, such as stomatal conductance, canopy temperature, and leaf water potential.

The study also looked into the influence that these responses had on nutritive values and biomass production.

The results of the study showed that sorghum has more favorable physiological responses. It produced higher biomass under conditions of decreased water or water stress in comparison to corn and pearl millet.

Sorghum's nutritive value is lower than that of corn; however, it is a viable alternative crop for growers considering the current declining water supply from the Ogallala Aquifer, because it can produce higher biomass even with less water.

Management can be adjusted by mixing forage sorghum with nutritional supplements to compensate for sorghum's lack of nutritional content and attain the required feed quality for cattle, while at the same time sustaining profitability.