Forage & Grain Report 2008
ABOUT THE COLLECTION
The Forage and Grain Report is one of several commodity-based agricultural research reports published by the University of Arizona.
This report, along with the Cotton Report, was established by Hank Brubaker, Extension Agronomist, after seeing a similar report published by Texas A&M University in the mid-1970’s.
The purpose of the report is to provide an annual research update to farmers, researchers, and those in the agricultural industry. The research is conducted by University of Arizona and USDA-ARS scientists.
Both historical and current Forage and Grain Reports have been made available in the UA Campus Repository as part of a collaboration between the College of Agriculture and Life Sciences and the University Libraries.
Contents for Forage & Grain Report 2008Barley and Wheat
Durum Production Practices
- Crop Coefficients for Estimating Small Grain Water Use, 2002
- Crop Coefficients for Estimating Small Grain Water Use, 2003
- Crop Coefficients for Estimating Small Grain Water Use, 2004
Sweet Sorghum for Ethanol
Herbaceous Wind Barriers for Irrigated Lands in ArizonaHerbaceous wind barriers are tall grasses or other non-woody plants established in narrow strips spaced across the field perpendicular to the prevailing wind direction. They are used on cropland to protect soils and crops from damaging effects of wind and wind-borne soil particles. They should also provide food and cover for wildlife. In Arizona, there is a need to identify herbaceous plants, commonly used for crops, which are effective in controlling soil erosion caused by wind on cropland. This trial was conducted at the Tucson Plant Materials Center and is composed of three hybrid grain sorghum (Sorghum bicolor (L.) Moench ssp. bicolor) types (‘SG-677’, ‘DS9300’, and ‘KS-735’), one forage sorghum (‘NK300’), one silage corn (Zea mays L.) type (‘N91-19’), and two grain corn types (‘Mexican June’ & ‘DX-93’). All sorghum types had good height, excellent retention of upright foliage, and excellent second year sprouting. It is apparent that sorghum can be a multi-year herbaceous wind barrier and when established will require minimal amounts of irrigation water to keep it growing and functioning as a multi-year herbaceous wind barrier. The two best performers for the sorghum varieties are ‘KS-735’ and ‘SG-677’. This information can be applied to the conservation practices such as Herbaceous Wind Barrier (603) and Cross-Wind Trap Strips (589C).
Feasibility of Obtaining Two Crops of Sweet Sorghum for Ethanol, MAC, 2006Sweet sorghum has potential as an energy crop in the Southwest since, compared to corn, it requires less fertilizer and water, is cheaper to grow, and requires less energy to process into ethanol. The purpose of this study is to determine the feasibility of obtaining two crops of sweet sorghum from a single seeding. Two cultivars of sweet sorghum were seeded at early and late dates at the Maricopa Agricultural Center in 2006. Two crops of sweet sorghum were obtained in our study with a short season cultivar Bundle King, but not with the longer season cultivar MMR 327/36. The ethanol yield of Bundle King of 213 gal/acre from two crops planted on April 7 was not significantly greater statistically than the ethanol yield of 162 gal/acre from a single crop planted on June 1. Bundle King is an inherently low yielding variety, as are most short season sweet sorghum cultivars that may be used for double cropping. Thus, the problem with double cropping is identifying a suitable cultivar along with increased harvest costs, despite the advantage of providing a more even supply of feedstock to an ethanol plant.
Crop Coefficients for Estimating Small Grain Water Use, 2004Crop coefficients are used to estimate water use from reference evapotranspiration values provided by weather stations. Four varieties of barley and durum were planted at the Maricopa Agricultural Center early December and early January and one durum variety was planted at the Yuma Valley Agricultural Center in late December and mid-February. Water use was estimated from neutron probe readings and crop coefficients were calculated by dividing water use by reference evapotranspiration. The crop coefficients calculated in this study peaked from 1.0 to 1.3, and the peak averaged about 1.16. Some differences were detected among planting dates and varieties, but it has yet to be determined if these differences are of practical significance.
Crop Coefficients for Estimating Small Grain Water Use, 2003Crop coefficients are used to estimate water use from reference evapotranspiration values provided by weather stations. Two varieties of barley and durum were planted at the Maricopa Agricultural Center in late November and early January. Water use was estimated from neutron probe readings and crop coefficients were calculated by dividing water use by reference evapotranspiration. The crop coefficients calculated in this study peaked at 1.0 or less in contrast to published values which generally peak around 1.2. The crop coefficients were lower at the later planting, and there appear to be differences between barley and durum and among barley varieties.
Crop Coefficients for Estimating Small Grain Water Use, 2002Crop coefficients are used to estimate water use from reference evapotranspiration values provided by weather stations. Two varieties of barley and durum were planted at the Maricopa Agricultural Center in late November and early January. Water use was estimated from neutron probe readings and crop coefficients were calculated by dividing water use by reference evapotranspiration. The crop coefficients calculated in this study peaked close to 1.2, similar to published values, except for the short season barley cultivar Barcott which had much lower values than the other cultivars.
Small Grains Variety Evaluation at Maricopa, Coolidge, and Yuma, 2008Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.
Predicting Wheat Growth Using the CSM-Cropsim-CERES - Wheat Crop ModelCSM-Cropsim-CERES -Wheat is a crop growth model that predicts crop development stages, among other things, using genetic coefficients for vernalization and photoperiod. We used this model to predict flowering date for 12 durum varieties seeded in trials at Maricopa and Yuma from 1998 to 2006. The difference between simulated and measured flowering date averaged 4 days without genetic coefficients and improved to 3.5 days if genetic coefficients for flowering and vernalization were included for each variety.
Can Preplant Fertilization of Small Grains be Eliminated, 2008The results of this study support the practice of not applying nitrogen at planting time even if the soil N level is low. Highest yields were obtained if the nitrogen that would have been applied at planting time was applied at the 5-leaf stage in addition to the N that would normally be applied at this time. If the preplant N application is skipped, the crop nitrogen status must be monitored carefully and N fertilizer should be applied by the 5-leaf stage to avoid a yield reduction. If a large amount of N is applied at the 5-leaf stage, lodging may be encouraged.
Survey of Durum Production Practices, 2007Durum growers were surveyed in cooperation with the USDA’s National Agricultural Statistics Service to determine production practices and their effects on yield and protein in the 2006 growing season. The survey was conducted in three regions: West (Yuma and La Paz counties), Central (Maricopa, Pinal, and Pima counties), and East (Cochise and Graham counties). Most of the durum in Arizona is grown in these three regions. We obtained responses from 83 out of an estimated 166 durum growers (50%) representing 46,331 out of 79,000 acres (59%). Durum was grown following cotton (41%), vegetables (27%), lettuce (16%), or other crops. The major varieties were Orita (30%), Kronos (25%), Ocotillo (16%), and Sky (11%). Herbicide was applied on 64% of the acreage. Flood irrigation systems accounted for 69% of the acreage, followed by furrow (17%). The crop was irrigated 6-7 times on average. The predominant soil texture was a sandy clay loam (36%), followed by sandy loam (35%) and clay loam (12%). The average planting date (germination irrigation applied) was December 21 in the Central region, January 4 in the West region and February 7 in the East region. The seed was planted at an average rate of 165 lbs/acre. Phosphorus was applied to only a third of the acreage, but when it was applied, the rate averaged 71 lbs P2O5/acre. Nitrogen rate averaged 224 lbs N/acre. Increased yield was associated with amendment application in the West region; certain varieties, amendment application, seeding rate between 120 and 159 lbs/acre, and nitrogen rate over 200 lbs N/acre in the Central region; and a seeding rate between 140 and 159 lbs/acre in the East region. Increased grain protein was associated with a previous crop of lettuce, lack of phosphorus application, and irrigation number in the West region; and a seeding rate of 140 to 159 lbs/acre and lack of phosphorus application in the East region. This survey documents associations, not cause-and-effect relationships, among durum production practices, yield, and protein.