|Blank, Robert - Bob|
Submitted to: Technical Report
Publication Type: Other
Publication Acceptance Date: 10/15/2006
Publication Date: 12/3/2007
Citation: Blank, R.R., Norton, J. 2007. Chapter 4 – Soil Chemical and Physical Properties. In: Final Technical Report. Integrated Restoration Strategies Towards Weed Control on Western Rangelands. CREES Agreement #2001-52103-11322. p. 42-69.
Interpretive Summary: In association with a multi-disciplinary study in Utah, Nevada, Idaho, and Oregon to restore rangelands degraded by the exotic annual grass cheatgrass, we quantified soil chemical and morphological characteristics. In one study, we investigated soil profiles and replicated 0- to 10- and 10- to 20-cm surface samples at the eight cheatgrass-dominated project study sites and paired adjacent sites dominated by native sagebrush-steppe vegetation. Results show differences in soil structure, pH, and the distribution and composition of soil nutrients and organic matter. We suspect that this variation may result from a combination of past site disturbance (e.g., fire frequency, grazing management), the length of time cheatgrass has dominated the site, and basic soil properties that control ecological resistance to change. In another study, we quantified the effect of topical application of sucrose, which is used to immobilize nitrogen, on soil nutrient availability. Sucrose application in general decreased nitrogen availability, but did not affect tissue concentration of nitrogen in cheatgrass. Availability of Mn was increased by sucrose addition. Overall, nutrient availability was greatest immediately following herbicide application and declined rapidly. Large-scale use of herbicides may exasterate the risk of plant invasion due to elevated nutrient availability.
Technical Abstract: Grant reporting protocols did not allow a technical abstract.