This study addresses the issue of soil fertility maintenance in relation to crop yield and farm income growth in general in the west African semi-arid tropics. It describes the structural and the input-output characteristics of food crop production and soil fertility management inside a typical village of southern Upper-Volta and then proceeds to infer from cross-section variations the relationships among the existing soil fertility management practices, soil fertility, crop yields, farm income, resource productivities and the average intensity of land utilization. These inferences are used to identify the technical changes as well as the input and output substitutions that characterize the adjustment mechanism of the cropping system vis-a-vis land use intensification. The technical, social and economic factors that explain and constrain the maintenance and the improvement of soil fertility and thereby limit the growth and the development of the cropping system are pointed out together with the types of agricultural research orientations and rural development policy actions that are most needed to effectively and efficiently relax the major constraints. The cropping system has been shown to be composed of five soil-crop management rings, with varying intensities of land utilization, that conceptually surround the household's habitat. Physical measures of soil fertility suggested that the cropping system more or less maintains or improves the chemical fertility of soils on upland but fails to do so on lowland. However, on upland and over the long term, an intensification of cultivation may have some adverse effects on the physical status of the soil and lead to a decline in field capacity. Statistical measures of yields, farm income and resource productivities following the intensity of land use scale suggested than an increase in the intensity of land utilization caused by an increasing demand for arable lands has no adverse effect on crop yields, farm income and resource productivities. This is made possible by the adjustment mechanism of the cropping system vis-a-vis land use intensification. The main feature of the adjustment process is besides out-migration, a substitution of red sorghum for millet and white sorghum, accompanied by a substitution of mineral and organic fertilizers for fallow.

thesis submitted to the Faculty of Science in fulfilment of the requirements for the degree of Doctor of Philosophy. March 17, 2015. / A two-level facility location problem (FLP) arose in the transport network of maize crop in Tanzania has been studied. The three layers, namely, production centers (PCs), distribution centers (DCs) and customer points (CPs) are considered in the two-level FLP. The stochastic e ect on the two-level FLP due to rainfall in the network links, between the DCs and CPs, has been studied. The ow of maize crop from PCs to CPs through DCs is designed at a minimum cost under deterministic and stochastic scenarios. The three decisions made simultaneously are: to determine the locations of DCs (including number of DCs), allocation of CPs to the selected DCs, allocation of selected DCs to PCs, and to determine the amount of maize crop transported from PCs to DCs and then from DCs to CPs. We have modelled the problem and generate results by optimizing the model with respect to optimal location-allocation strategies. We have considered two networks, the existing network and an extended network. In the existing network there are four PCs, ve DCs and ninety three CPs. In the extended network three additional DCs are considered. For the modelling purpose we have used the rainfall data from 2007 - 2010 in each week for 17 weeks. The optimized results for the existing network have shown improvements in cost saving compared to the manually operated existing network. In the extended network, the results have shown much more e cient and cost saving distribution system compared to the results of the existing network.

The demand for biofuels continues to increase due in part to government standards and promotion as well as the ambitious goals set by various companies and industries. Camelina is considered to be an ideal energy crop because of its low input requirements, suitability for marginal soils, and naturally competitiveness with weeds. A partial equilibrium model with a break-even price approach is used to estimate the potential supply curves for Camelina in Idaho, Montana, Oregon, and Washington. The supply curves are used to determine if the 50 million gallon goal set by the "Farm to Fly" initiative can be met. Given the current price of Camelina, $0.15/lb, the estimated supply of Camelina in all 4 states is 1,756,076,887 lbs and 1,493,684 acres. This estimation assumes that if the wheat-Camelina rotation is more profitable than the current crop rotation, then all of the acres will be converted to a wheat-Camelina rotation. When a 5% adoption rate is applied to the low and the intermediate rainfall zones and a 1% to the high rainfall zones, the number of acres converted to Camelina decreases to 72,213. These results suggest that given current market conditions, the supply of Camelina in the Northwest is not enough to meet the biofuel goal without an increase in yield and government promotion. / Graduation date: 2013

Using crops for fuel generates concerns over competition with food uses. As Rajagopal et al (2009) asserts, “In 2008 the world entered a food crisis amid record-high commodity and energy prices that induced hunger and political unrest in developing countries, by export restrictions in top grain-producing countries”. This took place at the same time when biofuel production, reached its pinnacle in developed countries. This paper examines the effect that biofuel prices and or production has had on food prices in Brazil and U.S. by employing the panel cointegration and Dynamic Ordinary Least Squares (DOLS) method of analysis. In regressing food prices as a function of demand and supply factors, such as oil prices, biofuel prices, interest rates and biofuel production, the study found that the increase in biofuels production over the past eighteen years has had a significant impact on food prices. Over the period January 1995- December 2013, the study estimates that a one hundred percent increase in biofuels production across time and between countries results in the increase of food prices by 21,9%. The study therefore rejects the null hypothesis that states, biofuel production does not have a statistically significant negative impact on food prices in U.S. and Brazil. , and accepts the alternative that biofuel production does have a statistically significant negative impact on food prices in U.S. and Brazil. Other predictors of food prices that the study revealed as significant were oil and interest rates. Policy recommendations for other countries like South Africa are therefore, made based on the results obtained.

Please read the abstract in the 00front part of this document / Dissertation (MSc (Agricultural Economics))--University of Pretoria, 2007. / Agricultural Economics, Extension and Rural Development / unrestricted

Eastern Virginia grain producers face production and marketing decisions under conditions of considerable yield and price variability. Traditionally MOTAD and other risk programming models have relied on the variability of historical returns series as a proxy for the risk an individual producer experiences. The mean forecast deviation method provides an alternative to the standard method of calculating deviations for MOT AD models. This method was applied to an eastern Virginia cash grain farm to provide a farm plan based on expected prices during the first week of February. The acreages of com, soybeans, and small grains were specified based on soil type, government program participation, sales at harvest, storage, pre-harvest hedging, and post-harvest hedging. The expected farm plans for the 1987 crop year resulted in participation in the government commodity programs at all levels of risk aversion and for each crop and soil type. Elimination of government commodity programs from the model resulted in two major findings: wheat and barley doubled cropped with soybeans preformed well on both soil types and at all levels of risk aversion, and given 1987 expected prices, idling lower quality land was a profitable decision at all levels of risk aversion. / Master of Science

The Canadian greenhouse gas offset system was proposed and developed with the objective of assisting Canada in achieving its Kyoto target by means of low cost emission reduction. This study estimates the potential of agricultural soils in Canada to provide carbon credits. Carbon sequestration practices such as moderate till, no-till and perennial crop activities were considered in the analysis. Crops under different tillage regimes, hay and alfalfa were also included in the study. Simulation analysis was undertaken using the Canadian Regional Agricultural Model (CRAM) for carbon prices ranging from $5 to $100/t of CO2e. Carbon credits generated as a result of the sequestration activities were estimated by endogenizing a carbon price for the sequestration activity into the CRAM model. The analysis was done regionally, provincially, and nationally. Two scenarios were investigated; one that included tillage practices and perennial crops (Policy All) and the other that only included tillage practices (Policy Till). Cropping pattern changes, carbon sequestration levels, carbon revenues, and adoption rates were estimated in the simulation. In addition, the role of transaction costs in the offset system was also examined. / The results of the simulation indicated that crop shifts towards hay and alfalfa occurred in the Policy All scenario, while practice shifts towards moderate and no-till occurred in the Policy Till scenario. Simulation analysis indicated that carbon sequestration levels vary by province and region. Among the provinces, the Prairie provinces had the highest carbon sequestration levels ranging from 50 percent under the Policy Till scenario, while under the Policy All scenario it was close to 97 percent. Nationally at a medium price of $15/t of CO2 approximately 1.08 Mt of CO2 and 0.11 Mt of CO2 were sequestered under Policy All and Policy Till scenario. When transaction costs were included in the analysis, approximately 30 to 40 percent less sequestration from the baseline was estimated. The results varied by province and region.

No description available.

This research simulates the response of the Quebec cropping sector to the introduction of carbon credit revenue which could be made available through the implementation of a greenhouse gas emissions trading and offset system in Canada. Eligible carbon sequestering practices investigated in the simulations include adoption of moderate tillage and no-till as well as the conversion to a permanent cover crop. Monetary demand for greenhouse gas emissions offsets from the cropping sector is endogenized in the objective function of the Canadian Regional Agriculture Model (CRAM) which has been modified to account for the simulations and for the disaggregation of the single crop region of Quebec into eleven sub-regions. Changes in the cropping sector induced by the introduction of seven different carbon price levels, ranging from $1/t CO2 to $100/t CO2, are compared to a baseline. Variables covered in the simulation results include: relative profitability of carbon sequestering crops/technology; adoption rates of moderate tillage and no-till; carbon sequestration levels; carbon credit revenue; cropping pattern, crop production and livestock. / Results indicate that carbon sequestration in agricultural soils could only contribute a minor share of the total emission reduction in Quebec, even with very high carbon price levels. At a carbon price of $15/t CO2, it is estimated that changes in tillage practices and permanent cover would result in an additional 12,328 t CO2 per year sequestered by the cropping sector in Quebec. However, some regions display higher adoption rates of carbon sequestering practices than other regions and appear to be more responsive to the price incentive. The introduction of a monetary demand for GHGE offsets from the cropping sector induces some changes in terms of cropping pattern and crop production level, while it has almost no impact on the livestock sector.

No description available.