摘要
在一块66×100 m_2的平坦试验地中按10×10 m分格测定土壤湿度的分布表明,其表层(0—45 cm)是正态分布的。心土(45—90 cm)湿度呈非正态分布,可能与其中有一层持水性较高但厚薄不一的粘土层有关。表层取样4个时,其平均值的误差估值为0.024(g/g)。半方差分析表明,土壤湿度的空间分布是有结构的,其相关域约30 m。这种结构是稳定的,其稳定性亦为秩相关分析所证明。为了使样本符合独立原则,取样点之间的距离应≥相关域。在这个前提下,选定监测点的土壤湿度愈接近总体平均值,其误差可望愈小。
Results of soil water content by sampling at 77 nodes of 10×10m grid (Fig. 1) in a flat experiment field of 66×100m^2 indicated that the distribution of soil moisture of upper layer (0—45 cm) was normal distribution. The moisture of subsoil (45—90cm) was abnormal distribution which could be due to a clayey layer with high water capacity hurried there in different thickness The error estimates of the average moisture content of upper layer was 0.024(g/g) when 4 samples were taken. By the analysis of semivariance, it was shown that the spacial distribution of soil moisture was structural (Fig. 3). Its correlation range (lag)was about 30m. This spacial structure was stable, which was also proved by the analysis of rank correlation. Therefore, when monitering the soil moisture flutuation, the experimental error would be decreased by choosing the sampling locations at whtch their moisture content are as close as possible to the average of total values and their distances are corresponding to the correlation range
出处
《土壤学报》
CAS
CSCD
北大核心
1989年第4期309-315,共7页
Acta Pedologica Sinica
