Spatial Variability Of Soil Characteristics On Different Land Use Types In The Yellow River Delta

Soil characteristics spatial variability is one of the important attributes of soil, and its sources of variation includes random variation and system variation. Land use, as the combined reflection of human activities of land use, has important implications to the various elements of the ecological environment and is the most common,direct and profound factors to influence the soil quality. The Yellow River Delta is the major agricultural reserve resources of our country, and the greatest soil quality characteristics is poor nutrient and high salt content. The Kenli County which lies at the entrance of the Yellow River is its typical representative. Based of the extensive collection of land-use information of Kenli County, our study sampled nine land use patterns, and through the descriptive statistical analysis and geostatistics to the characteristics of soil samples, and further studied the soil spatial variability characteristics of the different land use type and the reasons of these variation, then reacted the soil properties spatial variability regular of different land use patterns in the entire Yellow River Delta, further providing reference for the land distribution, rational use and the development of the scientific basis for agricultural policy of Yellow River Delta.From the descriptive statistical analysis, there are profound impacts to soil characteristics from land use in Kenli County.The impact of various nutrient elements by land use is extremely significant, and a common trend is that the nutrients in vegetable plots and fruit ranch are higher than the grain and the woodland land is between the two. The change of soil organic matter content under different land use patterns is extremely significant, and the amplitude is between 2.97g/kg and 19.11g/kg. The fruit ranch is highest and its content is 6.43 times of shine field. The change trends of available N, P and K similar to the organic matter. The change of soil salt content among different soil use types is obvious, and the amplitude is between 1.57g/kg and 35.29g/kg. The shine field is highest and its content is 22 times of the woodland. The large quantity fertilizer is the main reason of salt accumulation in vegetable plot and fruit ranch. Due to the unique microclimate the woodland has lower salt content.Geostatistics can reveal the soil characteristics spatial variability under different land use patterns and its main tool is the semi-variogram. The nugget variance and sill of vegetable plot are great in nutrients spatial variability, showing the random factors, such as fertilization,farming measures and cultivation system, played a leading role in its variation, and spatial correlation is weak and develops to homogenization direction. Shine field and wild grass ground are contrary, in soil nutrients, structural factors, such as climate, parent material, topography, soil type, which make up a major position, and at the same time it also results strong spatial correlation. Meanwhile, the reason of soil characteristics variation of paddy field,maize field,soybean field,cotton field and fruit ranch in the of the skin are more complex, which affected accompanied by structural and random factors. Structural factors can lead the strong spatial correlation of soil nutrients, and random factors make it weakened, and different terrain, different soil, topography and different management measures can produce different variations structure.Spatial variability of soil properties is influenced by a variety of factors; therein to the sampling is an important aspect. The sample size directly relates to the coefficient of variation of the soil characteristics. Soil available P required most sampling points fewer than 5% tolerances because of the largest coefficient of variation. Meanwhile, the required numbers reduce along with the improvement of the mean error. Through draw out according to a certain points space and configuration from the original grid sampling point and spatial interpolation, and then statistic and compare them, the sampling points are more of available P due to the coefficient of variation is larger, and only project b (draw off one line spacing at lengthwise and the spaces are 10* 5m) can through the mean no significant difference test; meanwhile, all samples of organic matter distribution could pass the test. Therefore, the degrees of spatial variability are different owning to the various soil properties, and they should be designed to fit the distinction.In the land utilization and crop development layout of Yellow River Delta, should fully consider the biology and ecology of different crops. According to different soil nutrient content and characteristics of salt, adjust crop structure in order to achieve good economic returns.