CIAT December 19, 2014 by Acarvajal

 http://ciatblogs.cgiar.org/soils/lets-think-deeper/#sthash.B3Ddhqyq.dpuf

This is the invitation from Ngonidzashe Chirinda, a soils researcher at CIAT that is more than interested in finding a concrete answer to a complex challenge in deeper layers of soils: how do we cost-effectively get the carbon to deeper soils layers? In order to store more of it and in that way contribute in reducing greenhouse gases emission that feed global warming and climate change.

To answer this question we need to begin by rethinking and redesigning farming with crop rooting in mind. Moreover, we need to figure out ways of addressing an even more complex challenge of ensuring that there is money in farmer’s pockets, sufficient and high quality food on their tables, while lowering carbon dioxide concentrations in the atmosphere.

Results from part of Ngonidzashe’s recent research work, conducted in Denmark (Aarhus University) and published in Catena, indicate that soils in deeper (>30 cm) layers have more non-complexed clay and thus have higher potential to store more C.

Whereas most research has focused on shallower soil depths (0-30 cm depths), there are several general differences between shallow and deep soils that make the later important to consider for carbon storage. For instance, low but highly variable microbial biomass and activity has been observed in deep soils. Several studies indicate that organic matter becomes older and less biodegradable with depth signifying a decrease of C quality and increased stabilization with depth. Compared to shallower depths, C in deeper soil layers is generally enriched in microbial-derived C compounds and depleted in energy-rich plant biomass. Limited to no soil disturbance in deeper soils reduce vulnerability of C stored in this depths to loss.

“So, what we need to do is to find ways of exploiting the storage potential in subsoil” remarks Ngonidzashe when he explains that for example, is imperative to design and practice cropping systems that include deep rooting plants species to exploit more soil volume, reduce dependence on external inputs, maximize the C storage potential of soil and thus also contribute towards climate change mitigation. It is time to think and go deep since with C storage deeper is better. “This is how we end this year with an invitation to think differently and deeper “, says Ngonidzashe.

- See more at: http://ciatblogs.cgiar.org/soils/lets-think-deeper/#sthash.B3Ddhqyq.dpuf