Researchers are increasingly able to capture spatially referenced data on both a response and a covariate more frequently and in more detail. A combination of geostatisical models and analysis of covariance methods may be used to analyze such data. However, very basic questions regarding the...

We estimated the economic benefits resulting from controlling soybean aphid infestation by using a multi-regional competitive dynamic equilibrium model. Results indicate that the reduction of soybean production resulting from a soybean aphid infestation is largely absorbed by reducing soybean...

The impact of livestock grazing on water quality, especially erosion and sedimentation, is an important concern in the southwestern United States. In response to Federal and State regulations, Best Management Practices (BMPs) for rangeland management are being developed and implemented in many...

Estimation of uncertainty using agronomic models typically requires a Monte Carlo study with a large number of simulations. Parallel computation dramatically speeds repetitive computation of this sort. The use of a Beowulf cluster parallel computer offers a low cost method of parallel computing...

Rangelands and pastures are found in every state and cover 55% of the land surface of the United States. Taken as a whole, from Western deserts and grasslands to meadows and woodlands, rangelands comprise some 364 million ha or 80% of the land in the 17 Western states. The vast expanses and...

In many regions of the U.S., low dissolved oxygen (DO) is a common freshwater impairment. States, territories, and tribes of the U.S. are required by federal law to develop Total Maximum Daily Loads (TMDLs) for waters not meeting established DO standards. Regulators and other professionals are...

Although the U.S. Congress established the Total Maximum Daily Load (TMDL) program in the original Clean Water Act of 1972, Section 303(d), it did not receive attention until the 1990s. Currently, two methods are available for tracking pollution in the environment and assessing the effectiveness...

The use of scouting and economic thresholds has not been accepted as readily for managing weeds as it has been for insects, but the economic threshold concept is the basis of most weed management decision models available to growers. A World Wide Web survey was conducted to investigate...