Field time constraints for farm planning models

Abstract

Resource limits for weather dependent constraints in farm planning models are often implemented as chance constraints. Procedures for setting right-hand sides for these constraints are often based on rules of thumb which are seldom updated. This paper presents an approach for validating these rules of thumb, and demonstrates the approach for a heavily used farm planning model. An evaluation of the robustness of chance constraints for equipment availability which are dependent on good (sufficiently dry) field time, is presented. Rules for setting constraints affected by good field time were found to be dependent on the tillage system(s) under consideration. These results imply a need for more research on setting availabilities of stochastic resources under alternative tillage systems.

Assessing the Impact of Alternative Water Pricing Schemes on Income Distribution

“…Two critical discrete stochastic variables representing, respectively, the price volatility of the commodities, and the rainfall variability are also included in the model (Arsham, 1996;Etyang et al, 1998;Maatman et al, 2002). Traditional linear programing, using average right-and-side values on water availability, tends to overstate the farm outcome, not only in poor weather years, but also on average, because of variability in rainfall.…”

“…Two critical discrete stochastic variables representing, respectively, the price volatility of the commodities, and the rainfall variability are also included in the model (Arsham, 1996; Etyang et al. , 1998; Maatman et al.…”

Cost‐effective nitrogen leaching reduction as influenced by linkages between farm‐level decisions

“…Due to differences in field time available, tillage and drilling dates for different crops will vary between the states of nature. This may have consequences for the economically optimal choice of crop mix and machinery system, as noted by Ekman (2000) and Eytang et al (1998). Incorporating weather variability results in a sequential decision problem.…”

Phosphonothioate Hydrolysis Turnover by Cp2MoCl2 and Silver Nanoparticles

“…These organophosphates are used as chemical warfare agents. Current methods to degrade phosphonothioates include incineration, alkaline hydrolysis, perhydrolysis, − methanolysis, − and adsorption. − There is a treaty-bound deadline of 2012 to eliminate stockpiled warfare organophosphates …”