Mark A. Marsalis

Selecting Small-Grain Forages for the Southern High Plains

Abstract Information is lacking on the relative performance of small-grain forage types grown for hay or silage on the High Plains of New Mexico and West Texas. Tests were conducted from 2004 to 2008 at Clovis, NM, to determine long-term potential of common varieties and blends of species [wheat ( Triticum aestivum L.), triticale (x Triticosecale ), and oats ( Avena sativa L.)] in an irrigated production system. Eleven entries were tested in at least 3 years, including exceptionally wet (2005) and dry (2006) years. In any given year, all crops yielded greater than 2.5 tons of DM, and entry mean annual yields ranged from 4.0 to 5.3 ton DM/acre over the study period. Triticale or blends containing triticale yielded more wet forage than wheat alone. In general, nutritive value of wheat was greater than that of triticale and blends. One triticale entry exhibited similar DM yields and forage quality as those of the wheats. Under irrigation, small grains have the potential to produce acceptable yields of nutritious forage in between summer crops for feeding operations in the region. While wheat may yield less tonnage, it gives greater market flexibility and may better fit into double cropping systems because of its earlier maturity than triticale.

Dry Matter Yield and Nutritive Value of Cowpea and Lablab in the Southern High Plains of the USA

Abstract In addition to fixing N in the soil, legumes can be a good source of forage for livestock. The objective of this study was to assess the dry matter (DM) yield and nutritive value of two warm-season annual legumes (WSAL) as potential new forages for the Southern High Plains of the USA. Lablab bean ( Lablab purpureus L.) cv Rio Verde (RV) and Rongai (RO) and cowpea [ Vigna unguiculata (L.) Walp.] cv Iron and Clay (IC SEM = 0.357). Crude protein (CP) concentration was > 200 g/kg in all legumes, but it was 28.6 g/kg greater in cowpea than lablab. Additionally, NDF and ADF concentrations were lower in cowpea than lablab. Considering the higher DM yield and reasonable nutritive value, lablab has greater potential for forage production than cowpea and could be an additional source of forage for dairy or beef cattle in Southern High Plains of the USA.

Forage sorghum nutritive value: a review.

Francisco E. Contreras-Govea, Assistant Professor, Agricultural Science Center, New Mexico State University, Artesia, NM 88210; Mark A. Marsalis, Assistant Professor, Agricultural Science Center, New Mexico State University, Clovis, NM 88101; Leonard M. Lauriault, College Professor, Agricultural Science Center, New Mexico State University, Tucumcari, NM 88401; and Brent W. Bean, Professor and Extension Agronomist, Texas AgriLife Research and Extension Center, Amarillo, TX 79106

Soil Type Affected Cowpea Forage Nutritive Value

) and other annual forages often exhibit micronutrient deficiency in some high pH, high Ca, low P soils (4,5) common to the southwestern USA. Zaiter et al. (5) related iron chlorosis visual ratings to seed yield of edible dry beans. While the effects of Zn deficiency are less pronounced on cowpea straw and sorghum (

Enhances in Crude Protein and Effects on Fermentation Profile of Corn and Forage Sorghum Silage with Addition of Cowpea

Abstract This study was conducted to assess nutritive value of corn ( Zea mays L.) and forage sorghum [ Sorghum bicolor (L.) Moench] silage when ensiled with different proportions of cowpea [ Vigna unguiculata (L.) Walp.]. Corn and forage sorghum were harvested at the ½ milk line and late dough stages of kernel maturity, respectively, and cowpea was harvested at a vegetative stage in two consecutive years at New Mexico State University (NMSU), Agricultural Science Center at Clovis. All three crops were chopped using a conventional chopper. The main crops, corn and forage sorghum, were mixed with cowpea at main crop:cowpea ratios of 100:0, 75:25, 50:50, 25:75, and 0:100%. For each mixture, 1.1 lb of fresh material was vacuum sealed in a plastic bag and fermented for an average of 127 days, four bags per mixture. In both crops, crude protein (CP) increased as proportion of cowpea increased in the mixture. In addition, pH, lactic acid, and total acids increased in both crops when cowpea was added. Silage with 100% cowpea had the highest pH and lowest lactic acid concentration. It is concluded that mixing cowpea with corn and forage sorghum for silage increased CP concentration of the mixture. Additional research is needed to assess mixtures that produce silage with more desirable fermentation characteristics.

Selecting Sorghum Forages for Limited and Full Irrigation and Rainfed Conditions in Semiarid, Subtropical Environments

Sorghum (Sorghum bicolor L.) forage producers in semiarid regions must maximize yield with reduced irrigation. Dry matter yields of furrow-irrigated sorghum forage [conventional and photoperiod-sensitive sorghum-sudangrass (Sorghum bicolor var Sudanese) hybrids (SS and PS, respectively) and forage sorghum (FS)] managed for hay in cultivar evaluations (randomized complete blocks with four replications) were compared from two years each of full irrigation (FULL: 4 furrow irrigations/year, applying approximately 6 inches each; two harvests), limited irrigation (LIM: 2 furrow irrigations/year, applying approximately 6 inches each; two harvests), and no irrigation (NONE: one harvest). Significant (P < 0.05) sorghum forage type comparisons for annual yield were observed within FULL and LIM because SS outyielded FS when irrigated, with PS being intermediate (4.54 vs. 5.62 tons/acre for FS and SS within FULL, respectively, and 4.17, 5.04, and 5.38 tons/acre for FS, PS, and SS within LIM, respectively). Within NONE, PS outyielded SS, and FS was intermediate (1.59, 1.75, and 1.28 tons/acre for FS, PS, and SS within NONE, respectively). Seasonal precipitation distribution likely impacted yields. Results indicate that SS or PS hybrids are best for hay production when irrigation water is available and that FS and PS hybrids are better than conventional SS hybrids under rainfed conditions.

Managing Field Bindweed in Sorghum-Wheat- Fallow Rotations

Abstract Infestation of field bindweed ( Convolvulus arvensis L.) on farms in the semiarid, Southern High Plains is widespread and has led to significant reductions in crop productivity throughout the region. A 3-year study was conducted in a wheat ( Triticum aestivum L.)-sorghum [ Sorghum bicolor (L.) Moench]-fallow rotation at two locations to investigate the long-term suppression of field bindweed with chemical methods. Specifically, the effects of one, two, and three years of fall-applied herbicides on bindweed populations were of interest. Chemical treatments used at each location were: quinclorac (0.28 and 0.43 kg/ha); quinclorac + 2,4-D (0.28 + 0.56 kg/ha); dicamba (1.12 kg/ha); and metsulfuron (0.021 kg/ha). Results indicate that the third year of herbicide application may be critical in effectively suppressing field bindweed for more than one year. There were no differences among herbicide treatments between one and two years of application by the third year. All herbicides containing quinclorac and dicamba significantly reduced bindweed populations the following spring after application; metsulfuron alone was not considered effective in either short- or long-term suppression. Field bindweed control may be reduced when 3-year herbicide program begins following a fallow period without any tillage or crop competition.