The Automated Root Exudate System (ARES): a method to apply solutes at regular intervals to soils in the field

1) Root exudation is a key component of nutrient and carbon dynamics in terrestrial ecosystems. Exudation rates vary widely by plant species and environmental conditions but our understanding of how root exudates affect soil functioning is incomplete, in part because there are few viable methods to manipulate root exudates in situ. To address this, we devised the Automated Root Exudate System (ARES), which simulates increased root exudation by applying small amounts of labile solutes at regular intervals in the field.
2) The ARES is a gravity-fed drip irrigation system comprising a reservoir bottle connected via a timer to a micro-hose irrigation grid covering c. 1 m2; 24 drip-tips are inserted into the soil to 4-cm depth to apply solutions into the rooting zone. We installed two ARES subplots within existing litter removal and control plots in a temperate deciduous woodland. We applied either an artificial root exudate solution (RE) or a procedural control solution (CP) to each subplo...

1) 根系分泌物（root exudation）是陆地生态系统中养分与碳动态的核心组分。分泌物速率因植物物种与环境条件而异，但我们对根系分泌物如何影响土壤功能的理解仍不完整，部分原因在于缺乏可在原位（in situ）操控根系分泌物的可行方法。为此，我们设计了自动化根系分泌物系统（Automated Root Exudate System, ARES），该系统通过在田间定期施加少量易分解溶质来模拟根系分泌物增加的情况。
2) ARES是一套重力驱动滴灌系统，由储液瓶组成，储液瓶通过定时器连接到覆盖约1平方米的微管灌溉网格；24个滴头插入土壤4厘米深处，以将溶液施入根区。我们在温带落叶林内已有的去除凋落物样地与对照样地中设置了两个ARES子样地。我们向每个子样地施加人工根系分泌物溶液（RE）或程序性对照溶液（CP）……