ECONOMIC ANALYSIS APPROACHES TO POTATO-BASED INTEGRATED CROP SYSTEMS: ISSUES AND METHOD
In response to stagnating yields and mounting pest problems, Michigan potato growers are investigating ways to bring manure and cover crops back into potato production systems. The alternative systems bring benefits and costs for monetary net returns, the variability of net returns, and environmental impacts. This paper reviews the likely yield and biological system effects of alternative potato production systems that incorporate manure and cover crops. After briefly considering research designs for gathering experimental versus farm field data, it reviews four economic analysis methods for evaluating alternative systems. All methods are illustrated with examples. First, for evaluating comparative average profitability, it reviews a) enterprise budgets, b) partial budgets, and c) break-even analysis. Second, for integrating environmental impacts into profitability analysis by using monetary measures of environmental effects, it introduces "green" budgets. Third, for evaluating efficiency trade-offs between profitability and environmental impacts, it covers trade-off frontiers. Finally, for comparing the variability of returns across systems (including for risk-averse decision makers), it introduces analysis of variance and stochastic dominance. These methods provide a basic set of tools for the economic analysis of changes in potato-based crop systems that should be adequate for most static comparisons of annual crop management practices.
The evaluation of basal respiration and some chemical properties of soils under cover crop treatments in a cherry orchard
Effects of different cover crops (CCs), mechanical cultivation and herbicide treatments on some soil chemical properties [pH, EC, total N, available P, exchangeable cations (Ca, Mg, K, Na) and the DTPA-extractable micronutrients (Fe, Mn, Zn, Cu)] and basal soil respiration (BSR) were investigated in a cherry orchard from 2013 to 2014. The present study was conducted in a cherry orchard located at the Experiment Station of Black Sea Agricultural Research Institute in Samsun province on the Northern side of Turkey. CC treatments, included Trifolium repens L. (TR), Festuca rubra subsp. Rubra (FRR), Festuca arundinacea (FA), T. repens (40%)+F. rubra rubra (30%)+F. arundinacea (30%) mixture (TFF), Vicia villosa (VV) and Trifolium meneghinianum (TM). Control treatments included mechanical cultivated (weed-free), herbicide treated (weed-free) and control plots, i.e., bare ground plots (with no cover crop) were allowed to become weedy. The experiment was conducted in a randomized complete block design with four replicates. The CCs were mowed in the flowering stages of the plants. After 90 days following seed harvest, soil samples were collected from two depths (0-20 and 20-40 cm) in each plot. All cropping species showed positive effects on soil chemical properties and BSR. The CC treatments decreased soil pH and exchangeable Na and increased EC, total N, available P, exchangeable cations (Ca, Mg, K) and the DTPA-extractable micronutrients (Fe, Mn, Zn). Effects of mechanical cultivation and herbicide treatments on soil chemical properties and BSR values were not found significant for both soil depths as compared to control (p<0.01). Results of the study showed that CCs, especially TR and VV treatments as legume plants improved soil chemical properties and BSR values in short term period. However, longer term studies are needed to evaluate the long-term effects of these sustainable management practices which have the potential to improve soil quality variables are encouraged.
A Risk Efficiency Analysis of Crop Rotations in Saskatchewan
Spring wheat and fallow have dominated land use practices in Saskatchewan for the 1971–85 period, despite the urgings of soil scientists, crop scientists and agricultural economists to reduce fallow area and to diversify into other crops. This paper demonstrates that if production and marketing risks associated with various rotations are considered, there is close correspondence between rotations that are selected via stochastic dominance and actual producer behavior with respect to fallow use in crop rotations. Gross margins for a number of hypothetical rotations are calculated for the 1971–85 period and are analyzed using stochastic dominance and mean-variance trade-off criteria. Resulting risk efficient sets are found to be a reasonable explanation of actual producer behavior over the time period examined. 
 
 
 
La culture du ble de printemps et la jachere ont domine les pratiques d'utilisation des terres en Saskatchewan pendant la periode de 1971 a 1985, malgre les interventions des specia-listes des sols et des cultures et des econornistes agricoles en faveur d'une reduction des superficies laissees en jachere et d'une diversification des cultures. Dans le present article, nous demontrons que si I'on tient compte des risques de production et de commercialisation inherents a divers types de rotation, il existe une correspondance etroite entre les rotations choisies par voie de dominance stochastique et le comportement reel du producteur face au recours a la jachire dans la rotation des cultures. Nous avons calcule les profits bruts cor-respondant e un certain nombre de rotations hypothetiques pour la periode de 1971 a 1985 et nous en avons fait I'analyse a I'aide du critere de la dominance stochastique et du critere du compromis de la variance moyenne. Les valeurs de I'efficacite du risque que nous en avons tirees ont permis de fournir une explication raisonnable du comportement reel des producteurs pendant la periode de temps etudiee.