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关于作物生产力与土壤侵蚀关系的研究大多基于两条假设:试验立地的所有土壤特性在开垦时是一致的;立地生产力在侵蚀发生之前是始终如一的.这种假设把受蚀立地上的任何产量减少都归于侵蚀的危害.由于在景观中,耕作时遭受中度到剧烈侵蚀的土壤的变异性很高,所以两条假设通常都是错误的.多数轻微起伏的景观在开垦之前已被侵蚀定形.在这样的景观中,土壤结构特性不同于原初的土壤物质,这是风化时间不一的结果.关系到其它景观因素的土壤表面形状和位置导致生长季节可利用水分总量的差异.只有很少的土壤侵蚀对生产力影响的研究和侵蚀景观中自然的土壤变异性以及土壤生产力的影响作了适当的考虑.多数地区缺乏原始土壤的本底数据.近年侵蚀对土壤生产力的影响已进行过大量的野外研究.在多数研究中,研究者都把土壤生产力的衰退归因于侵蚀的日益严重.即在同一田间收集从轻度、中度到剧烈侵蚀面积上的产量数据并进行对比,因为整个田间的经营措施是一致的,所以假定产量差异是侵蚀的结果.这种方法过于简单,忽视了其它几项因素.景观水文学和土壤物理学特性影响土壤生产力,作物产量随这些特性的变化而不同.因此,把作物产量在侵蚀和轻度侵蚀土壤上有差异的原因只归于侵蚀的结论令人怀疑.如果对研究者的数据的正确性没有疑?
Much of the work on the relationship between crop productivity and soil erosion is based on two assumptions: All soil properties at the site of the experiment are consistent at the time of reclamation and site productivity is consistent until erosion occurs. This assumption treats any production on the eroded site The reduction is attributed to the damage caused by the erosion of the soil, which is often erroneous due to the high variability of the soil under moderate to severe erosion during the cultivation in the landscape. Most of the slight ups and downs of the landscape have been eroded prior to reclamation In such landscapes, the structural characteristics of the soil differ from the original soil material as a result of varying degrees of weathering, and the difference in total available water during the growing season, depending on the shape and location of the soil surface associated with other landscape factors, Due consideration is given to the study of the impact of small soil erosion on productivity and to the natural variability of soil erosion and to the impact of soil productivity in most areas lacking background data of the original soil The impact of erosion on soil productivity in recent years has been extensively studied In most studies, researchers attributed the decline in soil productivity to erosion Ie growing in the same field and comparing yield data from mildly to moderately to severely eroded areas because production variability is the result of erosion as the operating measures across the field are consistent Simple and neglected of several other factors. Landscape hydrology and soil physics characteristics affect soil productivity and crop yields vary with these characteristics. Therefore, the reasons for differences in crop yields between eroded and mildly eroded soils are attributed to The conclusion of the eclipse is questionable. If there is no doubt about the correctness of the data of the researcher?