Plants are major drivers of soil structure dynamics. Root growth creates new macropores and provides essential carbon to soil, while root water uptake may induce crack formation around roots. Cracks can facilitate root growth as they provide pathways of least resistance and improve water infiltration and soil aeration. Due to the lack of suitable quantification methods, knowledge on the effects of root water uptake on soil crack formation remains limited. In the current study, we developed a time-lapse imaging platform that allows i) simulating root water uptake through localized soil drying and ii) quantifying the development of two-dimensional crack networks. Customized soil boxes that were 50 mm wide, 55 mm high and 5 mm deep were designed. Artificial roots made of dialysis tubes were inserted into the soil boxes and polyethylene glycol solution was circulated through the tubes. This induced a gradient in osmotic potential at the contact area (150 mm²) between the soil and the dialysis tubes, resulting in controlled soil drying. Drying intensity was varied by using different polyethylene glycol concentrations. Experiments were conducted with three soils that were subjected to three drying intensities for 6.5 days. We developed a time-lapse imaging system to record soil crack formation at two-minute intervals in twelve samples simultaneously. Resulting crack networks were quantified with an automated image analysis pipeline. Across soils and drying intensities, crack network development slowed down after 24–48 h of soil drying. The extent and complexity of crack networks increased with drying intensity and crack networks were larger and more complex in the clay and clay loam soil than in the silt loam soil. Smaller and less complex crack networks were better connected than larger and more complex networks. These results demonstrate that the platform developed in this study is suitable to quantify crack network development in soil due to simulated root water uptake at high temporal resolution and high throughput. Thereby, it can provide information needed to improve our understanding on how plants modify soil structure.

植物是土壤结构动力学的主要驱动力。根系生长会产生新的大孔并为土壤提供必要的碳，而根系吸收水分可能会导致根系周围形成裂缝。裂缝可以促进根系生长，因为它们提供的阻力最小，并改善了水的渗透和土壤通气。由于缺乏合适的量化方法，关于根系水分吸收对土壤裂缝形成的影响的知识仍然有限。在当前的研究中，我们开发了一个延时成像平台，该平台允许i）通过局部土壤干燥模拟根系水分吸收，ii）量化二维裂缝网络的发育。设计了定制的土壤箱，其宽度为50毫米，高55毫米，深5毫米。将由透析管制成的人工根插入土壤箱中，并使聚乙二醇溶液在管中循环。这在接触区域（150 mm）上引起了渗透势的梯度²）在土壤和透析管之间，从而控制土壤干燥。通过使用不同的聚乙二醇浓度来改变干燥强度。实验是对三种土壤进行了6.5天的三种干燥强度的实验。我们开发了一个延时成像系统，可以同时记录十二个样品中每两分钟一次的土壤裂缝形成情况。用自动图像分析管道对产生的裂缝网络进行了量化。在整个土壤和干燥强度下，土壤干燥24-48小时后，裂缝网络的发展变慢了。裂缝网络的程度和复杂性随干燥强度的增加而增加，粘土和黏壤土中的裂缝网络比粉壤土中的裂缝网络更大，更复杂。较小和较不复杂的裂纹网络比较大和较复杂的网络更好地连接。这些结果表明，由于在高时间分辨率和高通量下模拟的根系吸水量，本研究开发的平台适合于量化土壤中的裂缝网络发展。因此，它可以提供增进我们对植物如何改变土壤结构的理解所需的信息。