不同灌水定额下核桃树吸水根系分布研究

以8a生核桃树为研究对象,采用分层分段挖掘法研究核桃树根系的空间分布,探讨滴灌条件下不同灌水定额处理组对核桃根系的作用效应,分析土层深度与水平距离变化对根长密度的影响,并建立根系密度分布函数。研究结果表明:在核桃成熟期,根长密度的一维垂直分布中,吸水根系集中分布于0~60cm,水平方向,根系集中分布于0~90cm。在垂直二维吸水根长密度分布中,C1处理主要分布在垂向0~80cm、水平0~90cm的范围内,C2处理主要分布在垂向0~60cm、水平0~90cm的范围内,C3处理主要分布在垂向0~100cm、水平0~90cm的范围内,其中尤以C3处理的根长密度分布居多。对比二元二次回归模型,利用二元多次方程拟合根长密度、水平距离与土层深度之间的关系,其函数相关度较好,可以应用于灌水施肥策略调整。

Study on Fine Root Distribution of Walnut Trees Under Different Irrigation Quota

Taking eight-year-old walnut trees as the research object ,the spatial distribution of walnut root system was studied by means of dig methods from up to down ,the root distribution of walnut under different irrigation quota was tested ,the influence of soil depth and horizontal distribution variation on the root distribution of walnut is analyzed ,and the distribution function of root density is built .The results are as follows :during the mature period of walnut trees ,for the one-dimensional vertical distribution , fine root is concentrated at 0~60 cm ;for horizontal distribution ,root is concentrated at 0~90 cm .However ,for two-dimensional root distribution ,the main fine root distribution is concentrated in the range of vertical 0~80 cm and horizontal 0~90 cm for C1 treatment ,between vertical 0~60 cm and horizontal 0~90 cm for C2 treatment ,between vertical 0~100 cm and horizontal 0~90 cm for C3 treatment .The root length density distribution of C3 treatment accounts for large majority .Compared with binary quadratic regression model ,the binary multiple regression model is better to be used to analyze the relationship between root density ,horizon‐tal distribution and vertical distribution ,and can be used to adjust irrigation and fertilization strategy .