Noel R. Gollehon

Manure Management for Water Quality Costs to Animal Feeding Operations of Applying Manure Nutrients to Land

Nutrients from livestock and poultry manure are key sources of water pollution. Ever-growing numbers of animals per farm and per acre have increased the risk of water pollution. New Clean Water Act regulations compel the largest confined animal producers to meet nutrient application standards when applying manure to the land, and USDA encourages all animal feeding operations to do the same. The additional costs for managing manure (such as hauling manure off the farm) have implications for feedgrain producers and consumers as well. This reports farm-level analysis examines on-farm technical choice and producer costs across major U.S. production areas for hauling manure to the minimum amount of land needed to assimilate manure nutrients. A regional analysis then focuses on off-farm competition for land to spread surplus manure, using the Chesapeake Bay region as a case study. Finally, a sectorwide analysis addresses potential long-term structural adjustments at the national level and ultimate costs to consumers and producers.

Economic impacts of federal policy responses to drought in the Rio Grande Basin

region’s scarce water supply. This paper presents an analysis of the impacts of severe and sustained drought and of minimum in-stream flow requirements to support endangered species in the Rio Grande watershed. These impacts are investigated by modeling the physical and institutional constraints within the Rio Grande Basin and by identifying the hydrologic and economic responses of all major water users. Water supplies, which include all major tributaries, interbasin transfers, and hydrologically connected groundwater, are represented in a yearly time step. A nonlinear programming model is developed to maximize economic benefits subject to hydrologic and institutional constraints. Results indicate that drought produces considerable impacts on both agriculture and municipal and industrial (MI) uses in the Rio Grande watershed. In-stream flow requirements to support endangered species’ habitat produce the largest impacts on agricultural water users in New Mexico and Texas. Hydrologic and economic impacts are more pronounced when in-stream flow requirements dictate larger quantities of water for endangered species’ habitat. Higher in-stream flow requirements for endangered species in central New Mexico cause considerable losses to New Mexico agriculture above Elephant Butte Reservoir and to MI users in Albuquerque, New Mexico. Those same in-stream flow requirements reduce drought damages to New Mexico agriculture below Elephant Butte Reservoir and reduce the severity of drought damages to MI users in El Paso, Texas. Results provide a framework for formulating federal policy responses to drought in the Rio Grande Basin.

Irrigation in the American West: Area, Water and Economic Activity

This article examines irrigation in the American West based on consistent Federal data sources. Irrigation is discussed using three measures: irrigated area, water use in irrigation, and the sales value of crops produced. We find that irrigation accounts for about three-quarters of the value of crops sold from about one-quarter of the harvested cropland in the West. In accomplishing the higher sales, irrigated agriculture accounts for three-quarters of the water withdrawn and most of the water use in the West.

WATER CONSERVATION IN IRRIGATED AGRICULTURE A STOCHASTIC PRODUCTION FRONTIER MODEL

A stochastic production frontier model of irrigation is used to analyze sources of economic inefficiency in irrigation practices of Nebraska com producers and the extent that field information from soil moisture monitoring, commercial scheduling and/or weather reports increases economic efficiency. The results indicate that farm irrigation practices have an average technical efficiency of 81% (defined as the ratio of actualized production to maximum potential production for a level of inputs). Field information from moisture sensors can improve technical efficiency by 3.9%. The value of information provided by moisture sensors depends on the technical efficiency of the farmer and ranges from

Nutrient Management Programs, Nitrogen Fertilizer Practices, and Groundwater Quality in Nebraska’s Central Platte Valley (U.S.), 1989–1998

58.23 per hectare for an efficient farmer to

CONFINED ANIMAL PRODUCTION AND MANURE NUTRIENTS

40.29 for an inefficient producer. The elasticity of derived demand for water is estimated to be −1.095.

Western irrigation response to pumping costs: A water demand analysis using climatic regions

Given the societal concern about groundwater pollution from agricultural sources, public programs have been proposed or implemented to change farmer behavior with respect to nutrient use and management. However, few of these programs designed to change farmer behavior have been evaluated due to the lack of detailed data over an appropriate time frame. The Central Platte Natural Resources District (CPNRD) in Nebraska has identified an intensively cultivated, irrigated area with average groundwater nitrate-nitrogen (N) levels about double the EPAs safe drinking water standard. The CPNRD implemented a joint education and regulatory N management program in the mid-1980s to reduce groundwater N. This analysis reports N use and management, yield, and groundwater nitrate trends in the CPNRD for nearly 3000 continuous-corn fields from 1989 to 1998, where producers faced limits on the timing of N fertilizer application but no limits on amounts. Groundwater nitrate levels showed modest improvement over the 10 years of this analysis, falling from the 1989-1993 average of 18.9 to 18.1 mg/l during 1994-1998. The availability of N in excess of crop needs was clearly documented by the CPNRD data and was related to optimistic yield goals, irrigation water use above expected levels, and lack of adherence to commercial fertilizer application guidelines. Over the 10-year period of this analysis, producers reported harvesting an annual average of 9729 kg/ha, 1569 kg/ha (14%) below the average yield goal. During 1989-1998, producers reported annually applying an average of 162.5 kg/ha of commercial N fertilizer, 15.7 kg/ha (10%) above the guideline level. Including the N contribution from irrigation water, the potential N contribution to the environment (total N available less estimated crop use) was estimated at 71.7 kg/ha. This is an estimate of the nitrates available for denitrification, volatilization, runoff, future soil N, and leaching to groundwater. On average, between 1989-1993 and 1994-1998, producers more closely followed CPNRD N fertilizer recommendations and increased their use of postemerge N applications--an indication of improved synchrony between N availability and crop uptake.