|Kunze, Bruce - USDA-NRCS|
|Lieser, Michael - USDA-NRCS|
|Weiser, Hal - USDA-NRCS|
Submitted to: World Congress of Soil Science
Publication Type: Proceedings
Publication Acceptance Date: August 21, 2002
Publication Date: August 21, 2002
Citation: OLNESS, A.E., KUNZE, B., LIESER, M., WEISER, H., RINKE, J.L. PRECISION CHEMICAL ANALYSIS OF SOILS TO SUPPORT PRECISION MANAGEMENT DECISIONS. PROCEEDINGS 17TH WORLD CONGRESS OF SOIL SCIENCE. BANGKOK, THAILAND. 14-21, AUGUST 2002. PAPER 125. P. 1-8. 2002. Interpretive Summary: Differences in soils need to be described in order to obtain better use of fertilizers. Standard soil tests are tedious, costly and often analyze for only one nutrient. A new resin method permits a determination of 20 or more elements from a single extraction. Through use of this method, the differences between four common soils in the Northern Great Plains was determined. We studied the Barnes, Buse, Langhei, and Svea loam soils. Common soil tests showed little differences between the soils. The most fertile soil was the Svea; it had the least amounts of resin-extractable calcium and magnesium but the largest amount of phosphorus. The least fertile soil was the Langhei; it had the largest amounts of resin-extractable calcium and magnesium and the least amounts of phosphorus. In the Langhei and Buse soils, sulfur seemed complexed with calcium. The Buse soil has little sulfur compared to the other soils. The results show that each soil is different and this suggests that different management practices are needed to obtain their best uses. The results strongly suggest management approaches for each soil to crop producers and extension agents. The results provide guidance to scientists for testing different fertilizer types and methods of application.
Technical Abstract: Technological advances in application of fertilizers and crop cultivars have expanded the potential for more precise management of soil. Resin-extraction, an alternative method of characterizing soils, coupled with inductively coupled plasma (ICP) provides information about the relative activity of several elements simultaneously. Twenty-three sites of Barnes and Buse soils were sampled over a 170,000 km**2 region. In addition, adjacent Langhei or Svea soils were sampled at several sites. Soil cores were withdrawn to a depth of 60-cm but only the A or Ap horizons (8- to 15-cm depths) were subjected to resin-extraction and extracts were analyzed by ICP. Data were statistically analyzed using SAS PROC GLM. Resin-extractable P and bicarbonate extractable P concentrations were examined for correlation. Soils in this region have developed on glacial till and are characterized by substantial calcium carbonate in the subsoil and, in the cases of Buse and Langhei soils, in the A and Ap horizons. For the Barnes and Svea soils, elements commonly present as oxyanions were extracted on the anion exchange resin. However, for the Langhei and Buse soils, as much as 90% of the readily extractable oxyanions were found on the cation exchange resins. This was attributed to the very large amounts of resin-extractable Ca obtained (mean = 27.9 µmoles g-1; single extraction with Soil-CEC:resin-CEC 10). Bicarbonate-extractable P was weakly correlated to resin extractable P; however, each soil showed a unique relationship. The results suggest that each soil should be managed as an individual and that banded applications of fertilizer P, S, and Mg may be more beneficial than broadcast additions.