John P. Ritten

Optimal Rangeland Stocking Decisions Under Stochastic and Climate-Impacted Weather

A Stochastic Dynamic Programming (SDP) model is developed to analyze optimal stocking rates in the face of weather uncertainty and potential climate change projections. The model extends previous work modeling grazing as a predator‐prey relationship. Attention is given to profit maximizing decisions when growing season precipitation is unknown. Comparisons are made across results from a model that utilizes constant growing season precipitation in all years. Results suggest that optimal stocking rates and profitability decrease in climate change scenarios with increased precipitation variability as compared to the historical stochastic weather scenario.

Economically Optimal Stocking Rates: A Bioeconomic Grazing Model

Abstract A dynamic bioeconomic model that examines economically optimal stocking rate decisions while taking into account changes in forage availability is presented. The model presented here focuses on economically optimal stocking decisions while taking into account changes in the forage resource. The model is parameterized for a stocker operation in central Wyoming. Regardless of the scenario analyzed, the general rule of 50% utilization is determined to be an economically sound management strategy. The factors most heavily influencing economically optimal stocking rate decisions are forage growth rates and the Michaelis Constant. Both grain prices and cattle prices impact financial returns yet do not directly impact optimal stocking decisions by cattle producers.

Profitability of Carbon Sequestration in Western Rangelands of the United States

Abstract Concerns over climate change have increased interest in carbon sequestration in agricultural lands. While the per-hectare carbon capture potential of rangelands is less than either cropland or forests, existing research suggests modest changes in carbon storage on rangelands can potentially alter the global carbon cycle. This paper examines the potential firm-level revenues from voluntary carbon offset programs, such as the Chicago Climate Exchange (CCX) Rangeland Soil Carbon Offset program. We estimate revenues for short-term voluntary offsets given historical prices and prices projected with potential cap-and-trade legislation. We also estimate revenues assuming 100-yr offsets are required to meet international sequestration standards. Simulation results indicate a relatively wide range of modest revenues from recent CCX contracts and carbon prices. The analysis suggests that recent carbon prices or low-end projected prices from cap-and-trade legislation are not likely to encourage producer participation. Medium and high carbon price projections for cap-and-trade legislation may make carbon sequestration a more attractive option for rangeland managers, but given potential requirements for projects to meet international guidelines for greenhouse gas offset projects, many issues remain before range managers may be interested in carbon sequestration as an enterprise. Resumen La preocupación sobre el cambio climático ha aumentado el interés en el secuestro de carbono en tierras de uso agropecuario. Mientras que el potencial de captura de carbono en pastizales es menor que en tierras agrícolas y bosques, investigaciones sugieren que cambios modestos en el almacén de carbono en pastizales potencialmente alteran el ciclo global del carbono. Este artículo examina el ingreso potencial a nivel de empresa en programas voluntarios para la compensación de carbono tales como el programa de Compensación de Carbono en Pastizales del Chicago Climate Exchange (CCX). Estimamos ingresos en el corto plazo por compensaciones voluntarias dado precios históricos y precios proyectados con potencial con legislación de tope y compra-venta. También estimamos ingresos asumiendo 100 años de compensación tal como es requerido para cumplir los estándares internacionales de captura. Resultados de simulaciones indican relativamente amplio margen de modestos ingresos de contratos recientes del CCX y precios del carbono. El análisis sugiere que los precios recientes del carbono o proyectos de menor importancia de la legislación tipo tope y compra-venta no tienen posibilidad de encontrar la participación de los productores. La proyección de precios medianos y altos del carbono de la legislación tope y compra-venta podría hacer más atractiva la opción de captura de carbono para los manejadores de pastizales pero, dado los requerimientos potenciales para proyectos que cumplan con los lineamientos internacionales para la compensación de proyectos de gases de efecto invernadero, muchos aspectos están presentes antes de que los manejadores de pastizales pudieran estar interesados en el secuestro de carbono a nivel empresarial.

Long-term farming systems research in the central High Plains

In recent decades, there has been growing interest among farming and scientific communities toward integrated crop– range–livestock farming because of evidence of increased crop production, soil health, environmental services and resilience to increased climatic variability. This paper reviews studies on existing cropping systems and integrated crop– range–livestock systems across the USA which are relevant in the context of summarizing opportunities and challenges associated with implementing long-term crop–range–livestock systems research in the highly variable environment of the central High Plains. With precipitation ranging from 305 to 484mm and uncertain irrigation water supply, this region is especially vulnerable to changing moisture and temperature patterns. The results of our review indicate that diverse crop rotations, reduced soil disturbance and integrated crop–livestock systems could increase economic returns and agroecosystem resilience. Integrating agricultural system components to acquire unique benefits from small- to mediumsizedoperations,however,isachallengingtask.Thisisbecauseassessmentandidentificationofsuitablefarmingsystems, selection of the most efficient integration scheme, and pinpointing the best management practices are crucial for successful integration of components. Effective integration requires development of evaluation criteria that incorporate the efficiency of approaches under consideration and their interactions. Therefore, establishing the basis for more sustainable farming systems in the central High Plains relies on both long-term agricultural systems research and evaluation of short-term dynamics of individual components.

A Multi-Period Analysis of Two Common Livestock Management Strategies Given Fluctuating Precipitation and Variable Prices

Many areas of the US recently endured a severe drought and management strategies to cope with the lack of forage production varied. A multi-period mathematical model is presented that estimates the outcomes of two common producer responses to changes in precipitation, partial liquidation and purchasing hay, given fluctuating cattle prices over a long term planning horizon. Results were further summarized with regression analysis and selected elasticities were calculated to reflect the sensitivity of outcomes to variability in precipitation and livestock prices. Although little impact was seen from utilizing additional hay as a strategy during drought, producers who follow this strategy are in a position to market more animals immediately post drought in general, resulting in better long run financial outcomes. Elasticity estimates suggest that profitability is more sensitive to variability in prices but that optimal choices of management strategies are more sensitive to variability in precipitation.

Economic Impacts of Increasing Seasonal Precipitation Variation on Southeast Wyoming Cow-Calf Enterprises☆

ABSTRACT Knowledge regarding the economic impacts of predicted increases in seasonal precipitation variability on cowcalf enterprises, through influences of precipitation on both forage and cattle productivity, is needed by land managers for developing risk management strategies. Here we use existing forage production and cattle performance data from the northern mixed-grass prairie, coupled with spring precipitation and economic data, in a ranch-level mathematical programming model. We estimate economic impacts across a 35-yr planning period with 100 iterations of different price cycles including five levels of increasing spring precipitation variation (10%, 20%, 30%, 40%, and 50% increases), examining the impact of resulting forage production and calf gain. Annual expected profit variability increases largely due to the increase in herd number variability rather than variability in calf gains. Overall, as seasonal precipitation variation increases, higher annual expected profit variability results in greater risk of negative returns from cattle. An important implication from our results is that the positive benefits of wet years do not overcome the negative impacts of the dry years given relationships among precipitation, forage production, and calf gains used in ourmodel. Results indicate greater profitability in generally maintaining lower herd numbers as seasonal precipitation becomes more variable. The results also illustrate the need for producers to diversify their operation and/or income sources if they are to cope with increased precipitation variability even if mean annual precipitation remains constant.

Agriculture and ranching

Agriculture in the Southwest has distinctive features that influence how the sector responds to climate variability and change. First, the region accounts for more than half of the nation’s production of high-value specialty crops (fruits, vegetables, and nuts). California has the most counties where specialty crops (including melons and potatoes) account for a large share of total agricultural sales (Figures 11.3). Other areas that are important in terms of specialty crops include southwestern Arizona, the San Luis Valley of Colorado, and chili- and pecan-growing areas of New Mexico (along the Rio Grande Valley).

Using State and Transition Models to Show Economic Interdependence of Ecological Sites at the Ranch Level

ABSTRACT US government agencies are adopting state and transition models (STMs) for rangeland evaluation, monitoring, and management. This research demonstrates advantages of combining STMs and ranch economic models. A dynamic optimization framework casts management decisions—stocking rates and brush control—in the context of ranch profitability over a suite of ecological sites. Markov processes characterize the likelihood of state transitions. The ranch model shows economic interdependence of multiple ecological sites. Ecological site combinations producing the most forage are not the most economically advantageous. The state of one ecological site influences the forage value elsewhere and ultimately the intensity at which a ranch is stocked. Likewise, brush control benefits depend importantly on the state of all ecological sites.

Using State and Transition Models to Determine the Opportunity Cost of Providing Ecosystem Services

ABSTRACT A ranch-level model using state-and-transitions models for three ecological sites is used to determine the tradeoffs of providing various ecosystem services. The hypothetical ranch is located in northern Colorado and is based upon area average ecological site characteristics and livestock production practices. Management decisions include stocking rate and brush control. The model includes exogenous factors such as precipitation and fire. The model solves for optimal decisions over an infinite planning horizon using stochastic dynamic programming. Results showthat a ranch cannot provide all ecosystem services in tandemat their highest level, implying that land managers must decide which ecosystems service theywant to provide. Also, it is much cheaper in terms of foregone profitability for a ranch to continue to provide a specific ecosystem service that is already provided by the ranch rather than try to transition the ranch to a new ecological state in order to provide a service currently not provided.

Expected Net Benefit of Vaccinating Rangeland Sheep against Bluetongue Virus Using a Modified-Live versus Killed Virus Vaccine

Recurring outbreaks of bluetongue virus in domestic sheep of the US Intermountain West have prompted questions about the economic benefits and costs of vaccinating individual flocks against bluetongue (BT) disease. We estimate the cost of a BT outbreak on a representative rangeland sheep operation in the Big Horn Basin of the state of Wyoming using enterprise budgets and stochastic simulation. The latter accounts for variability in disease severity and lamb price, as well as uncertainty about when an outbreak will occur. We then estimate the cost of purchasing and administering a BT vaccine. Finally, we calculate expected annual net benefit of vaccinating under various outbreak intervals. Expected annual net benefit is calculated for both a killed virus (KV) vaccine and modified-live virus vaccine, using an observed price of