Belowground resource sharing in mixed tree– crop systems: methods to better understand belowground interactions

Cropping systems based on carefully designed species’ mixtures over time (in terms of crop sequences) and/or space (within a farm or landscape) reveal many potential advantages under various conditions, both in temperate and tropical agriculture1,2,3,4. In general, annual crops are expected to be relatively shallow-rooted while perennial plants, including trees, can have roots extending deep below the crop root zone, giving a foundation to the safety-net hypothesis.