黑土坡耕地土壤有机质空间变异及其与土壤侵蚀的关系——以黑龙江省鹤山农场为例

选取黑龙江省鹤山农场面积为0.91 km²的典型黑土区的坡耕地作为研究样地。按横纵100 m间隔共采集101个样点,运用地理信息系统和地统计学相结合的方法研究分析0~15 cm土层有机质空间变异及其与土壤侵蚀的关系。结果表明：位于典型黑土区样地的有机质含量集中在3%~5%范围内,均值为4.13%,高于黑龙江省的有机质平均水平。有机质含量空间变异明显,且主要受土壤侵蚀的影响：高侵蚀区对应低有机质区,中度侵蚀区对应中等有机质区,沉积区对应高有机质区。顺坡种植平均坡度2.2°时,每侵蚀1 000 t/km²土壤,有机质含量降低0.8%。土壤有机质空间变异可采用球状模型表达,自相关明显,进一步表明土壤侵蚀导致的再分布。对比分析确定200 m采样间距能够能准确表达该区表层有机质含量的空间特征,为精准施肥提供了采样依据。

Spatial Variation of Soil Organic Matter on Black Soil Sloping Cropland and Its Relationship with Soil Erosion:A Case Study of Heshan Farm in Heilongjiang Province

In order to promote the management of soil fertility and precision agriculture effectively, provide some guidance for the soil and water conservation. A sloping cropland (0.91 km²) located in Heshan farm in Heilongjiang Province was selected as the research area,101 samples were collected by vertical and horizontal 100 m interval, for the study of spatial distribution of soil organic matter of the 0-15 cm top layer soil and the relation with soil erosion by the GIS and geostatistics math methods. The results showed that the average content of soil organic matter in typical black soil area was 4.13%, higher than the average level of Heilongjiang Province, and the proportion of organic matter content concentrated in the 3%-5%. Spatial variability of organic matter significantly which was mainly affected by soil erosion. High erosion area corresponds to low organic matter, erosion area in the corresponding medium organic matter content areas and sedimentary areas correspond to areas with high organic matter content. When the slope planted with an average gradient of 2.2°, per 1 000 t/km² soil erosion increased, accompanied with the content of organic matter will be reduced by 0.8%. The spatial variability of organic matter could be described by the spherical model, showed significantly spatial autocorrelation, further suggested that soil erosion causes the redistribution of soil organic matter. When the sampling interval is 200 m which based on the range, the interpolation of spatial distribution can accurately reflect spatial variability of organic matter content, to provide precision fertilizer sampling basis.