The following are six abstracts which were accepted for the 2006 Annual Conference as examples. There are two from each category (symposia, oral, poster) including one with a research theme and one with a more educational/outreach/public engagement theme.

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Most US agri-environmental programs have multiple objectives. The largest US programs—CRP and EQIP—have diverse environmental objectives that include enhancing soil quality, water quality, and wildlife habitat. In the 2002 farm bill, equity concerns were also evident in the requirement for “regional equity” in allocating conservation funds and reduced use of conservation priority areas to determine program enrollment. The recently implemented CSP seeks to improve environmental performance and, as a matter of equity, reward producers who have already achieved a high level of environmental performance. Some also see CSP as a step toward “green payments”—merging farm income and agri-environmental payments into a program that serves both purposes.

How funding is allocated among these concerns will affect environmental outcomes and farm incomes. When programs serve more than one objective, trade-offs are inevitable. While only policymakers can determine the right balance of objectives, economic analysis can help to describe the trade-offs they will face.

Several specific questions will be addressed:

• Does an index (or ranking mechanism) for prioritizing applications provide policy makers with an effective lever for altering environmental and economic outcomes in a multi-objective program?
• How might the balance between rewarding stewardship and stimulating new conservation affect environmental cost-effectiveness?
• What trade-offs can policy makers expect if they attempt to combine agri-environmental and income programs into a “green payments” program?
• How do critical uncertainties (such as the relative environmental value of funding various, producers, land, and conservation practices) affect the balance among objectives?

In 2003, SWCS published the results of a study on Conservation Implications of Climate Change: Soil Erosion and Runoff from Cropland. This investigation cited a number of studies showing that trends in frequency of heavy rain events in the continental USA have been increasing in most regions, especially since 1970. The SWCS report estimated that intense precipitation events may increase rates of erosion and runoff by more than double the rate of rain increase, with impacts varying greatly across regions. As a follow up, paired SWCS projects on “Planning for Extremes” are underway on the Ontario and US sides of the Great Lakes basin that further examine rainfall trends and their potential impacts, and begin to examine management measures that can be taken to address the likely increases in erosion and polluted runoff. Two white papers are being developed, with respective focus on each side of the border, and a final joint workshop to discuss results and implications will be held in early November 2006, funded largely by the Joyce Foundation in the US and the Walter and Duncan Gordon Foundation in Canada. This symposium is designed to highlight updated background information that will inform the 2006 Planning for Extremes workshop, including the preliminary results for Ontario.

This symposium consists of 3 presentations:
 •Planning for Extremes, Implications for Great Lakes Basin (Bruce & Dickinson)
 •Climate Change Impacts on Soil Erosion in Midwest United States with Changes in Crop Management (Nearing)
 •Climate Change and Conservation Practices: Impact of Extremes on Water Budget (Hatfield)

The 301,000-ha watershed of the Mackinaw River is a major contributor of sediments and nutrients to the Illinois River. Because row crop agriculture comprises over 90 percent of the land use in the Mackinaw River watershed we focused on addressing the effectiveness of agricultural best management practices (BMP) at improving ecological integrity of a small watershed. Although positive impacts of specific BMPs have been documented for a given farm or field, there is little evidence of the effectiveness of BMPs at the watershed scale and consequently their effectiveness has been questioned. We present an ongoing 6-y paired watershed study designed to demonstrate the (1) effectiveness of focused outreach on BMP implementation and (2) cumulative effects of BMPs on hydrology, water quality, and biological resources of a 4000-ha subwatershed of the Mackinaw River. During the first five years, participation in cost share programs and the number and types of BMPs implemented were tracked in an experimental and controlled watershed in conjunction with monitoring of instream hydrology, water quality and biological resources. Increased BMP implementation in the experimental watershed significantly reduced baseflow nitrate and suspended sediment concentrations compared to the control watershed; however, nitrate concentrations in the experimental watershed still exceeded 10 mg/L almost five months per year over the study period. This study shows that surface BMPs alone will not improve the overall biological health of local watersheds and illustrates that reduction of nutrient and sediment loads at a watershed scale will require intercepting and retaining tile drainage.

Nitrate losses from subsurface drain tiles have been implicated in promoting hypoxia in the Northern Gulf of Mexico. Targeted management strategies may help achieve significant reductions in nitrate loss with minimum cost. Our hypothesis was that this goal could be achieved by growing narrow strips of deeply rooted perennial forages directly over tile lines. We tested this hypothesis in a field experiment on a Clarion-Nicollet-Webster soil association near Waseca, Minnesota. Plots (23 m wide by 30 m long) of grass or alfalfa were established with central tile drains after installing diversion tiles through a set of established patterned, 13-cm diam. plastic tiles. These original tiles served as the undisturbed drainage system and varied from 1.0 to 2.1 m deep. Calibrated tipping buckets measured water flow and grab samples of water were collected 2 or 3 times per week for nitrate. Established strips of alfalfa or grass did not alter annual tile water flow, but may have increased ‘flashiness.’ Smaller nitrate-N concentrations in tile water were most apparent after the strips were well established and in plots with shallower tiles. Flow-weighted annual nitrate-N concentrations were higher for corn and soybean (15 mg N/L) than for the strips (4 mg N/L) during 2004 and 2005. In contrast to nitrate concentration, perennial strips reduced annual loss of nitrate-N more with deeper tiles. The land required to achieve specific reductions in nitrate loss varies with tile arrangement and spacing, but this targeted conservation practice appears to be practical, effective, and relatively low cost.
 

Sample Poster Presentation Abstract #1

Title: Predicting Nitrogen Fertilizer Recommendations for Corn Using an Active Sensor

Author(s): Adam E Dellinger(1), John P Schmidt(2), Douglas B Beegle(1)

Affiliation(s): (1)The Pennsylvania State University, University Park, PA 16802, (2)USDA-ARS, University Park, PA 16802

Active sensors, mounted on agricultural equipment, can be used to estimate N (nitrogen) status in corn. This has the potential to improve N fertilizer recommendations that will reduce NO3 loss to the environment. This study examines the relationship between remotely sensed data and corn yield and considers ways to translate this information into sound sidedress N recommendations for corn. Four research sites with unique cropping histories in Centre County, PA were planted to corn in 2005 with three different pre-plant treatments (zero, 56 kg N ha-1 as NH4NO3, and approximately 56 kg N ha-1 as manure) and seven sidedress rates (0, 22, 45, 90, 135, 180, and 280 kg N ha-1 as NH4NO3) in 9.1 x 4.5 m plots. Nitrogen fertilizer and manure was surface applied. From early May until mid-July, georeferenced canopy reflectance data in the 590nm and 880nm wavelengths were taken each week from the third row of each six-row plot. Inorganic soil N, chlorophyll meter readings, late season stalk nitrate, and grain yield were measured.

Preliminary results from two field sites suggest a significant relationship between light reflectance and the Economic Optimum N Rate (EONR; r2=0.984). The EONR in a field following corn for the zero and manure pre-plant treatments were 150 and 132 kg N ha-1, respectively; whereas in a field after soybeans, the respective EONR’s were 34 and 48 kg N ha-1. Initial results indicate that employing a ground-based active sensor is a viable option for predicting site-specific N sidedress rate recommendations.