public marks

PUBLIC MARKS from paleorthid with tags "soil science" & research

26 February 2007

transect points: Soils and its role in a changing climate

Most soil scientists agree with the unvalidated concept that soil carbon levels will likely decline in step with temperature increases. Higher biological activity will result in more decomposition of organic matter. One certainly sees a similar relationship between soil carbon and temperature when comparing the effect of elevation, aspect and latitude. That we have yet to validate it is telling.

11 February 2007

Ammonia: a candidate for nitrogen transfer

In mycorrhizal associations, the fungal partner assists its plant host with nitrogen and phosphorus uptake while obtaining photosynthetically fixed carbon. Recent studies in mycorrhiza have highlighted the potential for direct transfer of ammonia from fungal to plant cells. This presents a new perspective on nitrogen transfer at the mycorrhizal interface, which is discussed here in light of recent progress made in characterizing a large array of membrane proteins that could fulfil the function of transporting ammonia.

04 January 2007

transect points: Sombroek's Challenge - Terra Preta Nova

The Godfather of Terra Preta, soil scientist Wim Sombroek (1934 - 2003) enjoyed a lifelong fascination with enhanced soil. The importance of plaggen soil in his native Netherlands impressed him at an early age, and early in the 1960's, he recognized in the Amazonian Dark Earths something familiar and precious. Before his passing, he assembled specific soil scientists challenged them to discover the process for making and sustaining a modern equivalent of the bio-char enhanced terra preta, what he termed terra preta nova. A great opportunity in answering Sombroek's challenge lies is surmounting the opacity of mutualistic rhizospheric species to traditional analytical approaches: only 1% of rhizospheric species are cultureable ala petri dish. We don't have a robust body of culture-independent studies against which to compare Terra Preta, so we are doubly challenged to reverse-engineer the phenomenon. Considering Wim Somboek's many noteworthy accomplishments, the perspective of his international leadership, and the late-in-life timing of his challenge, one senses he is pointing us to a mystery fundamental to understanding soil in new and exciting ways. This happens at a time when the soil science profession is in dynamic transition and sorely in need of a unifying vision. Wim Sombroek has given soil scientists a most welcome and worthy quest.