Research methods are lacking in regards to deep roots and resource uptake, therefore Deep Frontier developed methods that can be used to tell us more about uptake of mobile and immobile nutrients as well as uptake of water.

Additionally, in order to study the effects of deep rooting on carbon deposition and soil biology, the project developed DNA extraction methods. At Højbakkegård in Denmark we have established 12 root towers and 24 field plots in which we can study deep rooted crops and their interaction with the environment.

We used well-known methods such as minirhizotron methods for measuring roots and ¹⁵N isotope labelling for measuring deep root nitrogen-uptake activity and adapted existing methods for working in deep soil layers.

Method development was focused on:

• Ingrowth core techniques
• Drilling methods
• Isotope tracers for plant nutrients
• Isotopic labelled water to study water uptake
• Root biomass estimation through DNA extraction from soil