Distribution Characteristics Of Saline Soil Carbon And Nitrogen Of Different Formation Period In The Yellow River Delta

Small changes in terrestrial soil carbon pool significantly affecting the global carbon cycle. Therefore, the soil carbon cycle is a hot research field of global climate change.Soil nitrogen cycle is closely related to the carbon cycle, it's also important content of the global biogeochemical cycles.Yellow River Delta as China's youngest land, Soil development time is short, Uniform background, Land Use history is simple and clear, and the area continues growing, it is one of the most important resources in the back land area.In this paper, based on the typical coastal saline area of the Yellow River delta as the study area, Select typical land plots in the Yellow River delta lobes of different periods, With its 1 meter deep soil as the research object, to sample area space dynamic change instead of time, using space-time iterative method to explore the distribution and influence the formation mechanism of soil carbon and nitrogen in different periods of the Yellow River delta, in order to provide new ideas and the basic data for the construction of regional carbon and nitrogen cycles Theories and Models. The main results are as follows:(1)According to previous divided and identified research on the Yellow River delta lobe,in accordance with the principles of the new leaflet covering old leaves flap, using MapGis software, drawing the Modern Yellow River Soil's partition map. The Yellow River Delta is divided into eight regions by different formation periods, each area represents soil of different formation period.(2)On the whole, soil organic carbon content of the average range of unused land and farmland was 2.33~ 4.06 g / kg and 2.82~ 6.09 g / kg, below the average level of the nation.Through single factor variance analysis was carried out on the soil organic carbon data found that, formation have significant impact on all levels of soil organic carbon content, with the increase of soil depth, the level that formation impact on soil organic carbon content becomes higher. In the horizontal direction, the shorter the soil forming period, organic carbon content is relatively higher, with the decrease of soil formation, soil increase farm is bigger than the growth of unused; On the vertical section, with the increase of the depth of soil organic carbon and gradually reduce,0 ~ 40 cm of the upper soil organic carbon content is relativelyhigh.(3)On the whole, soil inorganic carbon content of the average range of unused agricultural land and farmland was 9.51~10.21 g / kg and 10.84~12.01 g / kg, below the average level of the nation. Through single factor variance analysis was carried out on the soil inorganic carbon data found that, formation's effect was not significant on the 0 ~ 20 cm soil,but formation have significant impact on other levels of soil inorganic carbon content. In the horizontal direction, with the increase of soil formation, soil inorganic carbon content in an s-shaped curve fluctuation change, first increase then decrease. The shorter the soil forming period, the more agricultural reclamation is beneficial to the increase of the inorganic carbon content in the soil. On the vertical section, with the increase of the depth of soil organic carbon and gradually reduce,0 ~ 40 cm of the upper soil organic carbon content is relatively high. Eight different formation of soil inorganic carbon in the vertical section put up four types of distribution: High- low- high- low, high- low- high- low- high, low- high- low,high- low profile.(4)On the whole, Total nitrogen content of the average range of unused agricultural land and farmland was 0.24~0.41 g / kg and 0.25~0.72 g / kg, below the average level of the nation.Through single factor variance analysis was carried out on the Total nitrogen data found that,formation's effect was not significant on the 0~20 cm soil, but formation have significant impact on other levels of Total nitrogen content. With the increase of soil depth, the level that formation impact on Total nitrogen content becomes higher. The change features of soil total nitrogen is similar to the organic carbon in horizontal and vertical direction. In the horizontal direction, the shorter the soil formation, the higher the content of soil total nitrogen. On the vertical section, with the increase of soil depth, unused land and farmland total nitrogen average line continuously to reduce, but the magnitude of the reduce is different.(5)The correlation of soil organic carbon, inorganic carbon and total nitrogen, pH in The Yellow River delta: The study found that soil organic carbon and total nitrogen content was significantly positively correlated;Soil organic carbon content and pH was a significant negative correlation;Soil inorganic carbon and total nitrogen content and pH had no significant correlation.(6)Soil organic carbon, inorganic carbon and total nitrogen reserves change range of 0 to40 cm soil layer in The Yellow River delta are 0.62~2.56 kg.m-2 ? 2.24~4.85 kg.m-2 ?0.06~0.36 kg.m-2, The land development of the new delta soil can significantly increase thesoil carbon and nitrogen storage,but carbon and nitrogen storage are reduced after the land development and utilization of the old delta soil.