In eastern Africa, ecologists have found that when mobile pastoralists abandon their temporary encampments, the accumulation of burned animal dung, wood, and other organic waste enriches the concentration of nutrients (e.g., calcium, phosphorous, magnesium) essential to soil health, in comparison to other soils without prior human habitation. These nutrient-enriched soils promote glade development and greater biodiversity. Geoarchaeological research on the time depth of this anthropogenic “nutrient hotspot” phenomenon has demonstrated that soils at several archaeological sites in southern Kenya still remain enriched in these soil macro- and micro- nutrients after several thousand years. However, soil scientists and geoarchaeologists do not yet understand how these anthropogenic soils vary over the extensive geographic conditions of eastern Africa. The discovery of a Pastoral Neolithic site (ca. 3000 BP) at Luxmanda on the Mbulu Plateau, Tanzania, provides an opportunity to examine if similar patterns of nutrient enrichment can be detected in a different geological and climatic zone. In this paper, we use geochemical and sedimentary analyses to determine how archaeological soils at Luxmanda differ from adjacent off-site soils and known archaeological soils in Kenya, as well as from computationally derived soil nutrient models for eastern Africa. Our results indicate that soils derived from anthropogenic sediments and ashy dung are 4 to 16-fold more abundant in soil macro nutrients relative to off-site or modeled values. This pattern fits previous studies’ observations that elevated macro- and micro-nutrients in soils are strongly correlated with ancient pastoralist habitation sites. We conclude that anthropogenic soils found at Pastoral Neolithic archaeological sites may be a valuable, but unappreciated, soil resource in eastern Africa.

在东部非洲，生态学家发现，当流动的牧民放弃其临时营地时，燃烧过的动物粪便，木材和其他有机废物的积累会丰富土壤健康所必需的营养物质（例如钙，磷，镁）的浓度。到没有人类居住的其他土壤。这些富含营养的土壤促进了林间空地的发展和更大的生物多样性。关于这种人为“营养热点”现象时间深度的地质考古研究表明，肯尼亚南部几个考古现场的土壤在几千年后仍保持着这些土壤大量和微量营养素的富集状态。但是，土壤科学家和地球考古学家尚未了解这些人为土壤在东非广阔的地理条件下如何变化。 在本文中，我们使用地球化学和沉积学分析来确定卢森堡的考古土壤与邻近的异地土壤和肯尼亚已知的考古土壤以及东部非洲通过计算得出的土壤养分模型之间的差异。我们的结果表明，相对于异地或模型值，人为沉积物和粪便粪便中的土壤富含大量的宏观营养素，含量高出4至16倍。这种模式符合以前的研究结果，即 土壤中大量和微量营养元素的增加与古代牧民的栖息地密切相关。我们得出的结论是，在新石器时代牧区考古遗址发现的人为土壤可能是东部非洲有价值的但未被重视的土壤资源。