Forage Potential of Pearl Millet and Forage Sorghum Alternatives to Corn under the Water-Limiting Conditions of the Texas High Plains: A Review

Abstract

Core Ideas• Declining groundwater supplies, the increasing cost of irrigation, and excessive summer dryness threaten the sustainability of corn production in the Texas High Plains (THP).• Forage sorghum and pearl millet are potential alternatives to corn silage.• Sorghum and pearl millet are likely to replace much of the corn silage crop in the THP. AbstractDiminishing irrigation water from the Ogallala aquifer to produce forage crops is jeopardizing the beef and dairy industries in the Texas High Plains (THP). The principal feed ingredient of the beef and dairy sectors is corn (Zea mays L.) silage, which is produced near the feeding operations to minimize transport costs, unlike concentrated feed, which can be transported long distances. The declining pumping capacity of irrigation wells hinders the ability to sustain a supply of water for profitable corn production in the THP. Forage sorghum [Sorghum bicolor (L.) Moench] and pearl millet [Pennisetum glaucum (L.) R. Br.] are known for their ability to tolerate drought and heat, which enables them to produce high forage yields with less water than corn. Pearl millet and sorghum can also be harvested as hay, greenchop, or silage like corn. Introduction of the brown midrib (BMR) trait into pearl millet and sorghum has enhanced their nutrient composition. Brown midrib is a genetic trait associated with reduced lignin synthesis, resulting in enhanced digestion of forage fiber in the bovine (Bos taurus) rumen, thereby increasing weight gain and milk production per ton of forage fed over non-BMR types. Therefore, BMR forage sorghum and BMR pearl millet could be potential alternative forage crops where water is insufficient to grow corn silage in the THP. Hence, the objective of this review paper is to compare the water use efficiency, nutritional composition, associated antinutritional compounds, animal performance, and potential yields of BMR forage sorghum and BMR pearl millet with corn.

Effect of deficit irrigation on physiology and forage yield of forage sorghum, pearl millet, and corn

“…Br.] can be grown over a range of water supply, from dryland to full irrigation (Bhattarai, Singh, West, & Saini, 2019). Seasonal water requirement of forage sorghum is about 350–700 mm and it is 400–600 mm for pearl millet, which is much less than the water requirement of corn that is 700–900 mm (Enciso, Porter, Fipps, & Colaizzi, 2004; Lee et al., 2012; Porter, 2010).…”

“…Seasonal water requirement of forage sorghum is about 350–700 mm and it is 400–600 mm for pearl millet, which is much less than the water requirement of corn that is 700–900 mm (Enciso, Porter, Fipps, & Colaizzi, 2004; Lee et al., 2012; Porter, 2010). Corn silage is primarily used in beef and dairy nutrition due to its grain yield, which boosts dry matter digestibility, net energy concentration, and ensiling characteristics (Bhattarai et al., 2019). Grain yield also enhances milk yield and weight gain of dairy and beef cattle, respectively (Brunette, 2014; Hassanat, 2007).…”

Seeding and nitrogen fertilization effects on the yield and quality of brachytic dwarf brown midrib forage sorghum hybrids

“…Forage sorghum [ Sorghum bicolor (L.) Moench] has become an alternative forage for dairy producers in several regions in the United States. The lower water requirements of forage sorghum (Howell et al., 2008; Lamm, Stone, & O'Brien, 2007; Martin, 1930; Merrill, Tanaka, Krupinsky, Liebig, & Hanson, 2007; Miron et al., 2007) have made it an attractive alternative not only in arid irrigated regions, such as Texas, New Mexico, and California, but also in the mid‐Atlantic region where corn ( Zea mays L.) production can be limited on shallow or coarse textured soils (Bhattarai, Singh, West, & Saini, 2019). Forage sorghums can also be double‐cropped following small grains harvested for forage in the mid‐Atlantic United States, which can add up to 3 ton acre −1 to the seasonal forage yield.…”

Crop modeling defines opportunities and challenges for drought escape, water capture, and yield increase using chilling‐tolerant sorghum

“…Furthermore, early planting practices can facilitate integrating the crop into a double crop rotation to maximize farm productivity (Burow et al, 2011 ). For these reasons, it is believed that the early season chilling tolerance trait would make the crop more competitive for farmers and an alternative option to outperform traditional crops with high water demand and less adapted to dryland systems (Bhattarai et al, 2019 ).…”