Brief Summary of Minutes of Annual Meeting

The Western Nutrient Management Conference held March 8-9, 2001 attracted over 120 attendees from throughout the Western Region. The conference included a day and a half of technical presentations and a poster session. Printed proceedings were provided to all attendees and is now available online at http://www.css.orst.edu/nm.

An onion nutrient management guide was published cooperatively by Oregon, Washington and Idaho Cooperative Extension with technical review from WCC-103. It is available on-line at eesc.orst.edu in HTML and PDF format.

An annual meeting was held to share research and Extension projects that are in progress in the Western Region. State-by-state highlights of nutrient management research:

Gavlak/Alaska: Work in Alaska continues to focus on forage S fertility, C cycling under arctic conditions, alternative crop production, N fixation of perennial legumes, dairy waste management, and no-till forage stand renovation (SARE grant). Dairy waste research will conclude this summer with experiments on dairy manure source, application rates and timing on perennial grass hay stands and the residual effects of similar treatments on annual grass yield and nutrient uptake.

Arizona/Thompson: A wide variety of crops are grown in Arizona, including cotton, alfalfa, and durum wheat, which occupy the largest acreages in the state. Other important crops include lettuce, broccoli, citrus, melons, and a variety of other crops. Research is currently addressing nutrient management needs for a number of these crops. For example, several studies are completed or in progress focusing on N management for citrus. Experiments at the University of Arizona Citrus Agricultural Center near Phoenix on micro sprinkler-irrigated citrus suggest that recommended N rates can be significantly reduced for micro sprinkler-irrigated citrus. We found no response to N by newly planted navel oranges in their first two years of growth. Experiments on mature grapefruit have also shown that N rates for 5 to 9 year old grapefruit can be reduced to 0.3 to 0.7 lb N/tree/year, depending on age.

Westfall/Colorado: The cost/intensity of grid soil sampling necessary to identify the soil variability to develop accurate variable-rate technology (VRT) fertilizer maps is prohibitive for implementation of precision agriculture in most agronomic crops. Therefore, we have conducted research for three years to determine if production level management zones based on soil color from an aerial photograph, topography and the framers‘ management experience is an effective alternative to grid sampling. We have found that zone sampling is effective in identifying suites of soils that have different production potential. Yield levels are also identified by this method. In cases where zones are not accurately identified, we have found that the inclusion of electrical conductance data collected with a conductivity meter is effective in making finer zone distinctions and to separate inclusions of one zone in another that may not be identifiable using our former method.

Brown/Idaho:
Phosphorus placement for fall bedded and fumigated onions. Metam sodium (Vapam) fall fumigated onion beds reduce P availability in the spring planted crop, especially in low organic matter soils with lime. Banded P has potential for reducing P in surface runoff as well as increasing P utilization by onions. A three-year field study showed no advantages to banded P over broadcast P application. Wheat following these onions showed residual fumigation effects on available P over a year later.

Removal of P with a double crop forage system. An annual double crop forage system consisting of fall planted small grains taken as forage at the late boot stage in spring and followed by a normal season silage corn crop has potential for increasing the rate of P removal and soil P draw down in sites enriched excessively with animal wastes. Annual P removal has approached 60 lb per acre.

Christensen, Hart, Sullivan/Oregon.
We worked cooperatively with Washington State University (Stevens) and NRCS in the two states to adapt the generic national P Index for use in the Pacific Northwest. Separate Indexes were developed for cropping systems west and east of the Cascades. The west of the Cascades Index focuses on reducing the risk of P transport via winter runoff and erosion events. The east of the Cascades Index focuses more heavily on P transport associated with irrigation.

The Pre-sidedress Soil Nitrate Test (PSNT) is successfully used for silage and grain corn production in western Oregon. Sweet corn acreage exceeds acreage of silage or grain corn in western Oregon. We desired to know if the PSNT could be used for predicting processing sweet corn sidedress N need. For sweet corn, when the PSNT from the surface foot of soil plus sidedress N was 200 kg/ha or more, no economic advantage was found for additional fertilizer N. When the PSNT and sidedress N was less than 150 kg/ha, additional N always increased grower return. If the PSNT plus sidedress N was between 150 and 200 kg/ha, half the sites produced a return from additional N and half did not. In addition to the traditional use of the PSNT, which is to separate responsive from non-responsive sites, we were able to calibrate sidedress N for processing sweet corn.

Amacher, Kotuby-Amacher/Utah.
Two USGS open-file reports from the USGS Western U.S. Phosphate Project are now ready for release. One report summarizes selenium and other trace element concentrations in waste rock dump soils and undisturbed soils developed over phosphatic shale deposits (pre-mining baseline data), presents a model for Se mobilization from phosphatic shale, and proposes remediation strategies to minimize leaching and bioaccumulation of Se from waste rock dumps. The other report summarizes Se uptake by native and non-native plant species growing on a waste rock dump, a wetland below the dump, a reference wetland, and on native soils developed over phosphatic shale in a lease area.

USU Analytical Labs continue to operate on a cost-basis. We are hoping to do more research on methods. We are now doing manure analysis and offering new packages of soil analyses in association with CAFO efforts - through R. Koenig‘s insistence. We continue our work with the NAPT, Compost Analysis Program, and the US Golf Association Proficiency Testing Programs.

Stevens, R.G, Davenport/Washington:
A two year project looking at the effect of metal rates and sources on crop productivity and metal uptake in wheat and potatoes in cooperation with Bill Pan, Shiou Kuo and Jim Harsh is being finalized. See proceedings of WCC-103 meeting, March 2001.

Site Specific Crop Management as a Strategy for Reducing Nitrate Leaching Potential in the Columbia Plateau. The project goal is to evaluate and compare conventional and site specific fertilizer management strategies for nutrient management and develop recommendations for fertilizer management approaches to reduce the potential for nitrate leaching in irrigated row crop rotations.

Stevens, B/Wyoming: Current soil fertility research projects focus on K source, rate, and application timing (alfalfa), variety, N rate and K fertilization (malting barley), micronutrients and sulfur (sugar beet), and N management options including timing, source and placement.(dry bean).

Westermann/USDA-ARS, Idaho: Active research projects include:1)Phosphorus in rainfall simulated runoff on calcareous soils, 2)Phosphorus in irrigation runoff vs. soil P availabilities & P sources, 3) Phosphorus leaching losses and processes, 4)Modeling sediment and P losses in surface, 5)Genetic control on Zn uptake and response in beans

Proceedings of the Western Nutrient Management. Conference, Vol. 4. Mar 8-9, 2001. Salt Lake City, UT. Potash and Phosphate Institute, Brookings, SD. Available online at:
http://www.css.orst.edu/nm/WCC103/WNM_2001_Conf.htm