Forage and cattle production during organic transition in dual-purpose wheat systems

Authors: HINSON, PHILIP - Texas A&M University; PINCHAK, BILL - Texas A&M Agrilife; Adams, Curtis; JONES, DAVID - Texas A&M Agrilife; RAJAN, NITHYA - Texas A&M University; KIMURA, EMI - Texas A&M Agrilife; SOMENAHALLY, ANIL - Texas A&M Agrilife

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2022
Publication Date: 12/19/2022
Citation: Hinson, P.O., Pinchak, B., Adams, C.B., Jones, D., Rajan, N., Kimura, E., Somenahally, A. 2022. Forage and cattle production during organic transition in dual-purpose wheat systems. Agronomy Journal. 115(2):873-886. https://doi.org/10.1002/agj2.21284.
DOI: https://doi.org/10.1002/agj2.21284

Interpretive Summary: In suitable climates, wheat systems can be ‘dual-purpose,’ utilized for both livestock grazing and grain production. These systems are prevalent in the U.S. Southern Great Plains region. Despite their prevalence, few of these systems are managed organically and organic research is very limited. To meet this need, we conducted a three-year (2018 to 2021) study near Vernon, TX to compare a dual-purpose wheat system during the organic transition period to a conventional system. Agronomic management practices were customized to the region in both systems. This report focuses on forage production, forage nutritive value, and cattle gain aspects of the system. The results showed that monthly standing crop biomass, rate of forage production, and forage nutritive value did not differ during the grazing period between systems in any year. Limited early-season precipitation resulted in slow forage growth in all years and inadequate forage production to support grazing in two of three years. In the year when grazing occurred, cattle performance did not differ between systems. Following the grazing period, the organic system trended toward lower forage production and crude protein than the conventional system, suggesting that in a “graze-out” scenario (i.e., season-long grazing and no grain production), the organic system might not support as much cattle production. This may be corrected by improving nitrogen availability in the organic system. Agronomic viability of the organic system, in terms of forage production, nutritive values, and cattle gains, was supported by its overall similarity to the conventional system.

Technical Abstract: Dual-purpose wheat (Triticum aestivum L. emend. Thell.) production systems (i.e., graze and grain) are prevalent in the U.S. Southern Great Plains region, though few of them are managed organically and organic research is very limited, particularly on forage and grazing aspects of the system. Therefore, the objective of this three-year study (2018 to 2021) conducted near Vernon, TX was to compare forage production, forage nutritive value, and cattle gains in transitional organic and conventional dual-purpose wheat systems. Forage data were collected each year during the early-season dual-purpose grazing period until maturity. Monthly standing crop biomass, rate of forage production, and forage nutritive value did not differ during the grazing period between systems in any year. Limited early-season precipitation resulted in slow forage growth in all years and inadequate forage production to support grazing in two of three years. In the single year when grazing occurred (2018/2019), cattle performance did not differ between systems. Following the dual-purpose grazing period, the organic system trended toward lower forage production and crude protein concentration than the conventional system, suggesting that in a “graze-out” scenario (i.e., season-long grazing and no grain production), the organic system might not support as much cattle production. The late-season divergence between systems could likely be minimized or eliminated by improving N availability in the organic system. Agronomic viability of the organic system, in terms of forage production, nutritive values, and cattle gains, was supported by its overall similarity to the conventional system.