环渤海沿海区域土壤养分空间变异及分布格局

SPATIAL VARIABILITY AND DISTRIBUTION PATTERN OF SOIL NUTRIENTS IN BOHAI COASTAL AREA

大尺度研究土壤养分空间变异和分布,是实现区域平衡施肥和精准化农业的重要前提,大批量土壤养分的实验室分析比较费时费力且耗资较大,地统计及GIS插值技术可以有效解决这一问题。利用432个采样点,进行环渤海沿海区域0-30 cm和30-60 cm土层土壤养分空间变异和空间分布格局研究。土壤养分指标包括土壤碱解氮、有效磷、速效钾、有机质及全氮。对各土壤养分指标进行传统统计和地统计分析并采用kriging进行空间插值成图。结果表明：同一养分指标变异程度在0-30 cm和30-60 cm土层均相近;各养分指标在两土层均具有良好的空间结构性;研究区土壤有效磷和速效钾含量相对丰富,碱解氮、有机质和全氮含量较缺乏,总体而言本研究区域土壤养分较缺乏,30-60 cm土层各养分含量较0-30 cm土层更加缺乏。

To study spatial variability and distribution of soil nutrients on a large scale is an important prerequisite for regional balanced fertilization and precision agriculture,but rather time-consuming,labor-consuming and costly because it involves large volumes of soil samples that have to be collected from the fields and analyzed in lab for contents of soil nutrients. The geostatistical and GIS interpolation techniques available can help effectively solve this problem. Based on the 432 soil sampling sites in the Bohai coastal area,spatial variability and distribution patterns of soil nutrients in 0 ～30 cm and 30 ～ 60 cm soil layers of the region were explored. Soil nutrients,such as alkalytic nitrogen,available phosphorus,readily available potassium,organic matter and total nitrogen,in the samples were measured for conventional statistical and geostatistical analyses and mapping using the kriging spatial interpolation method. Results show that the variations of the same one nutrient element in the 0 ～ 30 cm and 30 ～ 60 cm soil layers were the similar in degree,and all theelements varied moderately except potassium,which did quite vigorously. The nutrients were higher in the 0 ～ 30 cm soil layer than in the 30 ～ 60 cm one in mean content. All the nutrient indicators in the two soil layers show good spatial structure. The soil in the studied area is relatively rich in available P and readily available K,but rather poor in alkalytic N,organic matter and TN. Generally speaking,the soil is rather infertile and the 30 ～ 60 cm soil layer is more than the 0 ～30 cm soil layer.