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40 2019 ND-CP 413905
- Điều hướng trang này:
- Land Evaluation and Site Assessment (LESA)
| Soil potential ratings (Beatty et al., 1979) are classes that indicate the relative quality
of a soil for a particular use compared with other soils of a given area. The following are considered in assigning ratings: (1) yield or performance level, (2) the relative cost of applying modern technology to minimize the effects of any soil limitations, and (3) the adverse affects of any continuing limitations on social, economic, or environmental values. Land Evaluation and Site Assessment (LESA) is used to define an approach for rating the relative quality of land resources based upon specific measurable features (USDA 1983). The California Agricultural LESA is intended to provide lead agencies with an optional methodology to ensure that significant effects on the environment of agricultural land conversions are quantitatively and consistently considered in the environmental review process. LESA is composed of two land evaluation factors, i.e. Land Capability Classification and Storie Index, and four site assessment factors, which are based on a given project’s size, water resources availability, surrounding agricultural land, and surrounding protected resource land. For a given project, each of these six factors is separately rated on a 100 point scale, weighted relative to one another and combined, resulting in a single numeric score for a given project, with a maximum attainable score of 100 points. Based upon a range of established scoring thresholds, the final score determines a project’s potential significance. A typical LESA may use up to 30 individual factors, many of which are subjective but transparent (Coughlin et al., 1994). All factors are then combined into 6 final factors before arriving at a single project rating. Chapter 2 – Historical development 9 Although yields may vary with many agro-environmental factors, they provide an extremely useful dataset of objective measurements that form the basis of many agricultural, environmental and food security policies. It is therefore not surprising that there are so many world-wide databases on yield and yield estimates (FAO, FSS Eurostat; and FAO, MARS; see Annex 2). Yields may be estimated by reference to yields on benchmark soils or may be predicted using crop models. tải về 0.57 Mb. Chia sẻ với bạn bè của bạn:
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