No abstract

Increased costs of annual establishment of small grain pasture associated with fuel, machinery, and labor are eroding the profitability of stocker cattle enterprises. Interest has therefore increased in development of cool-season perennial grasses that are persistent and high quality. This study occurred on 24 ha (divided into thirty 0.81-ha paddocks) located at the University of Arkansas Division of Agriculture Livestock and Forestry Branch Station, near Batesville. Two tall fescue (Festuca arundinacea Schreb.) cultivars infected with novel endophytes (NE), Jesup infected with AR542 endophyte (Jesup AR542), and HiMag infected with Number 11 endophyte (HM11) were established in September 2002. Jesup AR542 and HM11 were compared with endemic endophyte Kentucky 31 (KY-31) tall fescue; wheat (Triticum aestivum L.) and cereal rye (WR, Secale cereale L.) planted in September 2003, 2004, and 2005; and annual ryegrass [RG, Lolium perenne L. ssp. multiflorum (Lam.) Husnot] planted in September 2004 and 2005. Each year, 3 steers (3.7 steers/ha) were placed on each pasture for fall and winter grazing, and 5 steers (6.2 steers/ha) were placed on each pasture for spring grazing. Animal performance is presented by year in the presence of a year x treatment interaction (P < 0.01). Body weight gain per hectare of steers grazing NE tall fescue was greater (P < 0.01) than those of KY-31 and WR during 2003 to 2004, whereas in 2004 to 2005, BW gain per hectare of steers grazing NE and RG did not differ (P < or = 0.29) and was greater (P < 0.01) than that of WR, which was greater (P < 0.01) than that of KY-31. During 2005 to 2006, BW gain per hectare was greater (P < 0.01) for steers grazing RG than those of NE and WR, which did not differ (P > or = 0.14). Body weight gain per hectare was least (P < 0.01) for steers grazing KY-31. Average net return of NE tall fescue was greater (P < 0.01) than KY-31, but profitability of NE did not consistently differ from cool-season annuals. Across the 3-yr study, NE tall fescue produced net returns per hectare of $219; this level of profitability would require 4 yr for a new planting of NE tall fescue to break even. Novel endophyte tall fescues offer potential benefits related to decreased risk of stand establishment of annual forage crops, longer growing season, and acceptable animal performance.

Potential economic and environmental effects of broad versus targeted nitrogen use policies are evaluated in five Central High Plains subregions. Results indicate that per-acre restrictions are more effective than total nitrogen restrictions in reducing expected nitrogen losses in runoff and percolation, and reducing percolation losses at all probability levels. Because of the distribution of soils within subregions, targeting nitrogen reductions to more permeable soils may not produce the anticipated reductions in percolation. It may be more effective to target nitrogen restrictions on production systems than on soil types. Reductions in producer income are less for targeted than for broad policies.Agricultural chemicals and fertilizers have been cited as significant groundwater contaminants (Office of Technology Assessment). EPA reported that over seventy pesticides were detected in the groundwater of thirty-eight states, and forty-six pesticides found in groundwater in twenty-six states were from agricultural use (Office of Technology Assessment). Nitrates are the most commonly detected agricultural chemicals in groundwater. EPA estimated that more than half of the nation's wells contain nitrates, with about 1.2% of the community wells and 2.4% of the rural wells having concentrations above

Data envelopment analysis is used to calculate technical, allocative, economic, and scale efficiencies for fields enrolled in the University of Arkansas Rice Research Verification Program. The results reveal most fields have high technical and scale efficiencies, implying inputs are used in minimum levels necessary to achieve given output levels and fields are close to optimal in size. However, most fields exhibit allocative and economic inefficiencies and do not use inputs in the right combinations necessary to achieve cost minimization. Tobit analysis indicated allocative and economic efficiencies could be improved with better variety selection and better irrigation management.

A gronomy J our n al • Volume 10 0 , I s sue 5 • 2 0 0 8 ABSTRACT Th e objective of this study was to compare conventional tillage (CT), reduced tillage (RT), and no-till (NT) establishment of wheat (Triticum aestivum L.) and rye (Secale cereale L.) forage for stocker calves (Bos taurus). Animal performance was analyzed as a completely randomized design using the mixed procedure of SAS. In the 2002-2003 study, grazing-d ha −1 was greater (P < 0.01) for CT than RT, but NT did not diff er (P = 0.08) from CT and RT, while gain ha −1 was not aff ected (P ≥ 0.42) by tillage treatment. During 2003-2004, grazing-d ha −1 was identical for all pastures, but gain ha −1 of NT was greater (P = 0.05) than CT and RT. Grazing-d ha −1 was greater (P = 0.05) for NT than CT and RT in 2004-2005 and gain ha −1 tended to be greater (P = 0.10) for NT than CT and RT. During 2005-2006, grazing-d ha −1 of CT was greater (P = 0.03) than RT, but gain ha −1 did not diff er (P ≥ 0.81) among treatments. Establishment of small-grain pasture using NT and RT was as successful as CT when timely fall rains promoted small grain emergence and growth, while NT was superior to CT and RT when fall rains are delayed and soil water profi le can be maintained by summer chemical fallow.M.T. Bowman and M.S.