Conservation tillage had initial roots in the Great Plains, but the current adoption of conservation tillage, especially no-till, lags behind in the rest of the United States. This paper documents the results of a recent survey of Oklahoma producers, which was conducted to assess the current status of conservation tillage in the state. Based on responses from 1,703 producers, econometric analysis was conducted to identify factors explaining the observed use of conservation tillage practices in Oklahoma. The survey found that conventional tillage remains the most common tillage practice among Oklahoma producers. According to the survey, conventional tillage is used on 43.2% of the state's total acreage, conservation tillage on 26.7% of the total acreage, and reduced tillage on the remaining 30.1% of the crop acreage. A Tobit model was developed to explain patterns of tillage use based on producer characteristics and their perceptions on how conservation tillage performs relative to conventional tillage according to various economic and agronomic factors. The Tobit model identified operator age, farm size, crop rotation, knowledge, and erosion control as highly significant factors explaining the observed use of conservation tillage. The model results also identified potential constraints to conservation tillage adoption and use in the Southern Plains, suggesting that the unique needs of mixed crop-livestock farming systems, and the dominant winter wheat (Triticum aestivum L.) monoculture, hinder further diffusion of conservation tillage. Future policy should consider addressing the needs of Oklahoma producers, particularly crop producers heavily engaged in livestock activities, as well as finding viable rotation crops to provide alternatives for the winter wheat monoculture.

Cotton (Gossypium hirsutum L) genetically modified to express protein(s) derived from the soil bacterium Bacillus thuringiensis (Bt), and specifically toxic to caterpillar (Lepidoptera) pests, has been sold commercially since 1996. On the continent of Africa, only South Africa has approved the commercial use of Bt cotton. Recently, over three field seasons (2003–2005), second‐generation Bt cotton (Bollgard II, Monsanto Co., St. Louis, MO) was tested in confined field trials in the west African country of Burkina Faso. Observations of pest density, seed cotton yields, and the cost of insecticide sprays were evaluated in an economic model under a wide range of theoretical Bt technology cost premiums to determine the potential relative profitability of Bt cotton and conventional cotton. Results averaged over three seasons indicate a Bollgard II yield advantage of 15% under conditions of low to moderate lepidopteran pest pressure, while insecticide sprays were reduced by two‐thirds in the Bt cotton plots. According to the economic model, Bollgard II remained profitable to the grower throughout the range of theoretical technology premiums evaluated ($0–75 per hectare) and was represented by economic gains of $79 to 154 per hectare. Due mainly to the relatively low pest densities encountered at these research sites, the authors suggest that the model results presented may, in fact, underestimate the profitability of Bt cotton in Burkina Faso.

Africa has been hesitant to adopt agricultural biotechnology, lagging behind global trends over the past decade. One exception is Burkina Faso, a West African country that commercially released 125,000 ha of Bt cotton in 2009. Bt cotton may serve as a working example of how African countries can enhance sustainability using modern, science-driven technology to increase production levels while reducing input use and energy consumption. This paper reports the potential impact that Bt cotton can have on sustainability in Burkina Faso's cotton sector based by summarizing empirical evidence from previously published studies. Based on the summary of published data collected from six years of field trials and producer surveys, Bt cotton increased cotton yields by an average of 21.3% and raised income by $106.14 per ha. Using an energy balance model, the introduction of Bt cotton would also result in a 6.6% saving in energy use. The significant increase in productivity and economic returns could be the catalyst for Burkina Faso, and other African countries, to emerge from the decade or so of stagnation and regain their competitive stance in world cotton markets while providing environmental and social benefits.

Cotton is one of the most important crops in West Africa and is a major catalyst of economic development in rural areas, but the sector has suffered from a decline in the world cotton price after 1999. This article exploits an unusual data set following 82 farmers over 14 years, from 1994 through 2007, to estimate a Nerlovian supply response model for cotton, maize, sorghum, and millet in long-term rotation. The resulting system of equations is estimated with two-stage least squares (2SLS), showing that this sample of Malian cotton producers have responded to prices in a relatively inelastic manner, with supply elasticities only about one-half of those estimated for producers in developed countries. Policy reforms could help producers respond more easily to prices changes, as well as to raise average productivity levels. Copyright (c) 2009 International Association of Agricultural Economists.

With the rapid growth of swine (Sus scrofa domestica) production in the Oklahoma Panhandle, animal waste management has become a growing concern. Field experiments were conducted to evaluate the long-term eff ects of equivalent nitrogen rates of swine lagoon effl uent (SE), beef manure (BM), and commercial fertilizer on the yield and economic returns of irrigated corn (Zea mays L.) grown on calcareous Gruver silt loam soil (fi ne, mixed, superactive, mesic Aridic Paleustoll) near Goodwell, Oklahoma. A randomized, complete-block, split-plot design with three replications was used to test the main eff ects of N source (NS) and equivalent N application rates (NR) of 56, 168, and 504 kg N ha -1 . Both BM and SE generated signifi cantly (P < 0.05) higher corn yields than anhydrous ammonia (AA) across the main eff ect of NS. Greater separation of mean corn yields was found among NS as the equivalent NR rate was increased from 56 to 504 kg N ha -1 with the following rankings (P < 0.05): AA = BM = SE at 56 kg N ha -1 , BM = AA ≥ SE at 168 kg N ha -1 , and SE > BM > AA at 504 kg N ha -1 . Both SE and BM generated signifi cantly (P < 0.05) higher economic returns than AA. Th e highest ranked alternatives of economic returns were generated by SE×504 and BM×168. Results indicate that SE and BM can be economically viable substitutes for commercial fertilizer, bringing higher yields and economic benefi ts to producers in the Oklahoma Panhandle. ).Abbreviations: AA, anhydrous ammonia; BM, beef manure; IRR, applied irrigation; NR, equivalent nitrogen rates; NS, nitrogen source; N56, nitrogen applied at 56 kg N ha -1 ; N168, nitrogen applied at 168 kg N ha -1 ; N504, nitrogen applied at 504 kg N ha -1 ; SE, swine lagoon effl uent; YR, year.