| There are many problems exsist in the agricultural water use just as the irrigation methods are extensive, the irrigation water use efficiency is low and et.al. in our country. Especially in recent years, the theme of conservation-oriented is promoted, so improving water use efficiency and reducing the cost of water in the field of agriculture have been got more attention, and they are worth to research. In particular, researching the quantitative and qualitative relationship soil during physical parameters and their infullences in soil infiltration from the microscopic point of view base on the soil transfer function are more important. And soil bulk density as an important input variables, explore the characteristics become more important.Soil density is that the compaction or porosity situation of clay, sand, silt and the aggregates reunited by the smaller particles or reunion structure arrangement. Comprehensive evaluation and research on soil density is actually evaluation of soil structure to one extent. There is a close relationship between soil bulk density and soil compaction conditions, soil particle density and other factors. In this paper, soil bulk density is considered as a factor to relate the soil density condition, its characteristics are further analyzed, and the relationship between it and the related factors are researched.Based on the National Natural Science Foundation project "on regional scale soil infiltration parameters study of multiple non-linear transfer function", the nine kinds of soil in experimental field from JinZhong basin of Shanxi province are the main study objects, the field soil in Pingyan county, Jinzhong plain and Xiaohe irrigation area are also the test objects. In the agricultural production cycle, soil bulk density and moisture content are track determined, a comprehensive system analysis of quantitative and qualitative in soil bulk density is did, the variation of soil density under different initial conditions is researched, the linear prediction model is constructed between the soil bulk density and the factors of it, then inorder to reveal the characteristics of soil bulk density, analysis the quantitative relationship between soil structure and moisture content, reaearch the annual variation characteristics of soil density, and construct the linear regression model to forecast the soil density. The results shows that thers is a relatively close quadratic function correlation relationship between soil bulk density and moisture in a certain soil moisture range, below this range of moisture content, soil bulk density suddenly decreases, and tends to a stable value, but it still larger than alpha. In the agricultural production cycle, under the combined effect of factors of irrigation and rainfall, soil bulk density increases; the increase extent of loose soil density ia large than it of compacted soil; the claycontent and initial soil bulk density are significantly impact the soil density, through the two parameters (soil clay content and initial soil bulk density) linear regression model to predict soil density is feasible and the accuracy is comformed.The results provide important theoretical basis and technical support for water-saving irrigation technical parameters and improving surface irrigation, and it is important for improving the efficiency of field water use. Also it can further excavat water-saving potential, and add new argument content for realizing a low cost, high utilization water-saving technology. It is of important theoretical significance and practical value on developing, using and managing soil water resources in the agricultural areas.The change process of soil bulk density in arable layer is analyzed, and the mechanism is comprehensively elaborated. However, because of the soil texture types involved in this article are not comprehensive, the soil bulk density characteristics are not fully reflected, futher study on the ablity to guide agricultural production of other areas is needed. |
PDF Full Text Request