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Custom Soil Resource Report <br />Vegetative Productivity <br />This folder contains a collection of tabular reports that present vegetative productivity <br />data. The reports (tables) include all selected map units and components for each <br />map unit. Vegetative productivity includes estimates of potential vegetative production <br />for a variety of land uses, including cropland, forestland, hayland, pastureland, <br />horticulture and rangeland. In the underlying database, some states maintain crop <br />yield data by individual map unit component. Other states maintain the data at the <br />map unit level. Attributes are included for both, although only one or the other is likely <br />to contain data for any given geographic area. For other land uses, productivity data <br />is shown only at the map unit component level. Examples include potential crop yields <br />under irrigated and nonirrigated conditions, forest productivity, forest site index, and <br />total rangeland production under of normal, favorable and unfavorable conditions. <br />Rangeland Productivity (Yuma County - Moser Pit) <br />In areas that have similar climate and topography, differences in the kind and amount <br />of vegetation produced on rangeland are closely related to the kind of soil. Effective <br />management is based on the relationship between the soils and vegetation and water. <br />This table shows, for each soil that supports rangeland vegetation, the ecological site <br />and the potential annual production of vegetation in favorable, normal, and <br />unfavorable years. An explanation of the column headings in the table follows. <br />An ecological site is the product of all the environmental factors responsible for its <br />development. It has characteristic soils that have developed over time throughout the <br />soil development process; a characteristic hydrology, particularly infiltration and <br />runoff, that has developed over time; and a characteristic plant community (kind and <br />amount of vegetation). The hydrology of a site is influenced by development of the soil <br />and plant community. The vegetation, soils, and hydrology are all interrelated. Each <br />is influenced by the others and influences the development of the others. The plant <br />community on an ecological site is typified by an association of species that differs <br />from that of other ecological sites in the kind and/or proportion of species or in total <br />production. Descriptions of ecological sites are provided in the Field Office Technical <br />Guide, which is available in local offices of the Natural Resources Conservation <br />Service (NRCS). <br />Total dry-weight production is the amount of vegetation that can be expected to grow <br />annually on well managed rangeland that is supporting the potential natural plant <br />community. It includes all vegetation, whether or not it is palatable to grazing animals. <br />It includes the current year's growth of leaves, twigs, and fruits of woody plants. It does <br />not include the increase in stem diameter of trees and shrubs. It is expressed in pounds <br />per acre of air-dry vegetation for favorable, normal, and unfavorable years. In a <br />favorable year, the amount and distribution of precipitation and the temperatures make <br />growing conditions substantially better than average. In a normal year, growing <br />conditions are about average. In an unfavorable year, growing conditions are well <br />below average, generally because of low available soil moisture. Yields are adjusted <br />to a common percent of air-dry moisture content. <br />Range management requires knowledge of the kinds of soil and of the potential natural <br />plant community. It also requires an evaluation of the present range similarity index <br />and rangeland trend. Range similarity index is determined by comparing the present <br />27