s:661:"TI The tree root safety-net in agroforestry 
AU Cadisch G 
AU van Noordwijk, M. 
AB In the humid tropics, available nitrogen in soil is easily leached down to depths where it cannot be reached by crop roots, reducing farm profitability and potentially causing pollution downstream. Crop roots are shallow during early growth stages, and on many acid soils crop roots are restricted to the surface soil. Inter cropping with deep rooting trees can increase fertilizer use efficiency - deep tree roots can act as a safety-net, intercepting and recycling nitrogen. However, not al trees are suitable, and mixing trees and crops has other consequences as well. 
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