Christopher N. Boyer

Stochastic Corn Yield Response Functions to Nitrogen for Corn after Corn, Corn after Cotton, and Corn after Soybeans

Deterministic and stochastic yield response plateau functions were estimated to determine the expected profit-maximizing nitrogen rates, yields, and net returns for corn grown after corn, cotton, and soybeans. The stochastic response functions were more appropriate than their deterministic counterparts, and the linear response stochastic plateau described the data the best. The profit-maximizing nitrogen rates were similar for corn after corn, cotton, and soybeans, but relative to corn after corn, the expected corn yield plateaus increased by 12% and 16% after cotton and soybeans, respectively. Expected net returns increased for corn after cotton and soybeans relative to corn after corn.

Drivers of Price and Nonprice Water Conservation by Urban and Rural Water Utilities: An Application of Predictive Models to Four Southern States

This study examines water system characteristics, managers’ attitudes and perceptions toward water conservation, and future planning strategies that influence the adoption of water conservation programs for urban and rural communities. We surveyed water system managers in Oklahoma, Arkansas, Tennessee, and Florida; and we parameterized predictive adoption models for price-based (PC) and nonprice-based (NPC) conservation programs. Notably, results suggest that information about the price elasticity of water demand for a community does encourage PC and NPC adoption; and we found no evidence that PC and NPC adoption is jointly considered by water systems.

Factors Driving Water Utility Rate Structure Choice: Evidence from Four Southern U.S. States

Water utilities typically set residential water prices using one of three rate structures: increasing block rate (IBR), uniform rate (UR), or decreasing block rate (DBR). Historically, DBR has been the most widely used residential rate structure, but water utilities are increasingly switching to a UR or IBR structure. The literature suggests several possible motivations for rate structure decisions, but provides little empirical evidence to support these suggestions and largely ignores the role of water managers’ attitudes and perceptions in the rate structure decision. The objective of this study is to statistically assess factors that drive rate structure changes, specifically toward UR or IBR, in the southern US. We designed and implemented a survey of water utility managers in Arkansas, Florida, Oklahoma, and Tennessee, including rural to urban water utilities. Survey questions were selected based on water utility manager input and literature review and included rate structure changes, system characteristics, and attitudes and perceptions about factors likely to influence rate structure changes. The rate structure adoption decision is modeled using both multinomial logit and Heckman probit specifications. Our results suggest that different factors drive the adoption of UR and IBR, including fair prices for end-users, qualifying for government grants/loans, revenue concerns, treatment cost increases, and infrastructure investment needs.

EFFICIENCY OF PRE-PLANT, TOPDRESS, AND VARIABLE RATE APPLICATION OF NITROGEN IN WINTER WHEAT

Past research about the efficiency of nitrogen application in winter wheat (Triticum aestivum L.) based on source and timing has produced inconsistent results. The majority of the literature used data from few locations over short time periods. This study used a unique data set of yields and nitrogen quantities from 2002–2009 at ten different locations in Oklahoma, USA. The objective of this research was to determine wheat yield response for granular pre-plant, uniform foliar topdress, and variable rate foliar topdress. Topdress liquid nitrogen had a 19% higher NUE than pre-plant urea, and was the most profitable source of nitrogen.

The cost of feeding bred dairy heifers on native warm-season grasses and harvested feedstuffs

Heifer rearing is one of the largest production expenses for dairy cattle operations, which is one reason milking operations outsource heifer rearing to custom developers. The cost of harvested feedstuffs is a major expense in heifer rearing. A possible way to lower feed costs is to graze dairy heifers, but little research exists on this topic in the mid-south United States. The objectives of this research were to determine the cost of feeding bred dairy heifers grazing native warm-season grasses (NWSG), with and without legumes, and compare the cost of grazing with the cost of rearing heifers using 3 traditional rations. The 3 rations were corn silage with soybean meal, corn silage with dry distillers grain, and a wet distillers grain-based ration. Bred Holstein heifers between 15- and 20-mo-old continuously grazed switchgrass (SG), SG with red clover (SG+RC), a big bluestem and Indiangrass mixture (BBIG), and BBIG with red clover (BBIG+RC) in Tennessee during the summer months. Total grazing days were calculated for each NWSG to determine the average cost/animal per grazing day. The average daily gain (ADG) was calculated for each NWSG to develop 3 harvested feed rations that would result in the same ADG over the same number of grazing day as each NWSG treatment. The average cost/animal per grazing day was lowest for SG (

Private-Value Auction Versus Posted-Price Selling: An Agent-Based Model Approach

0.48/animal/grazing d) and highest for BBIG+RC (

Automatic Section Control Technologies and GPS Auto-guidance Systems Adoption in Cotton Production

1.10/animal/grazing d). For both BBIG and SG, legumes increased the average cost/animal per grazing day because grazing days did not increase enough to account for the additional cost of the legumes. No difference was observed in ADG for heifers grazing BBIG (0.85 kg/d) and BBIG+RC (0.94 kg/d), and no difference was observed in ADG for heifers grazing SG (0.71 kg/d) and SG+RC (0.70 kg/d). However, the ADG for heifers grazing SG and SG+RC was lower than the ADG for heifers grazing either BBIG or BBIG+RC. The average cost/animal per grazing day was lower for all NWSG treatments than the average cost/animal per day for all comparable feed rations at a low, average, and high yardage fee. Results of this study suggest that SG was the most cost-effective NWSG alternative to harvested feeds for bred dairy heifer rearing.

Economic and environmental implications of incorporating distillers’ dried grains with solubles in feed rations of growing and finishing swine in Argentina

An agent-based first-price private-value auction and an agent-based posted-price market are developed to compare these selling methods when buyers have private values. If the seller cannot impose a reserve price and has little uncertainty about the items value, the sellers expected revenue is highest in the posted-price market. Otherwise, the seller is better off selling the item with the auction. Using a genetic algorithm and Monte Carlo integration solved the agent-based models quicker and provided more precise answers than solving models with particle swarm optimization and using the trapezoidal rule for numerical integration. Copyright

Effects of optical sensing based variable rate nitrogen management on yields, nitrogen use and profitability for cotton

Using data from a survey of cotton producers in 14 US states, and a bivariate probit regression, this study examined the effects of the following measured parameters on the adoption of Automatic Section Control (ASC) technologies and GPS Auto-Guidance (AG) systems: age, education, farm size, field geometry, information sources, as well as the use of specific production practices and other Precision Agriculture (PA) technologies. Results suggest that younger, more educated producers, consulting farm dealers for information about PA technologies, using other PA technologies, and managing larger farming operations located in counties with more irregularly shaped fields are more likely to adopt ASC technologies and AG systems. Predicted adoption probabilities estimated using regression results suggest the use of other PA technologies and farm dealers as a source of precision farming information have the largest impact on the probability of adopting ASC by cotton farmers. Additionally, these results suggest farmers with operations in eastern Arkansas, western Tennessee, and a couple of counties in middle Tennessee are more likely to adopt ASC technologies. Producers in these regions had the highest percentages of users of other PA technologies and farm dealers to obtain PA information.

Consumers’ willingness to pay for local muscadine wine

The Argentinean swine industry has quickly expanded over the past decade, hence increasing the demand for swine feedstuffs. The growing supply of distillers’ dried grains with solubles (DDGS) from the emerging Argentinean corn-based ethanol industry is a potential feedstuff for swine producers. Using a multi-objective linear programming model, this study examined the economic and environmental concerns (i.e. cost and phosphorus content) associated with introducing DDGS in swine feed rations. Results suggest that including DDGS in swine diets concurrently minimized cost and phosphorus content. The results were extrapolated to the entire Argentinean swine industry and show that the inclusion of DDGS in swine rations could potentially save the Argentinean swine industry about 19.21 million US dollars annually and reduce phosphorus content by up to 5%. In addition, sensitivity analysis of DDGS price was conducted and the potential demand for DDGS from swine by growth category was derived.