In-field carbon dioxide removal via weathering of crushed basalt applied to acidic tropical agricultural soil

Fredrick J. Holden, Kalu Davies, Michael I. Bird, Ruby Hume, Hannah Green, David J. Beerling, Paul N. Nelson ABSTRACT: Enhanced weathering (EW) of silicate rocks such as basalt provides a potential carbon dioxide removal (CDR) technology for combatting climate change. Modelling and mesocosm studies suggest significant CDR via EW but there are few field studies. This study aimed to directly measure in-field CDR via EW of basalt applied to sugarcane on acidic (pH 5.8, 0–0.25 m) Ultisol in tropical northeastern Australia, where weathering potential is high. Coarsely crushed basalt produced as a byproduct of gravel manufacture (<5 mm) was ...

Soil Improvement: The Step Beyond Men of the Trees Remineralization Trials

Western Australia is semi-arid, with annual rainfall on the same order as Africa’s Sahel. Our soils are ancient many millions of years old. Ages of weathering and leaching, and a few decades of farming with soluble NPK fertilizers, have left them impoverished. Today, despite the greatest care, each year large tracts of land are lost to salt and wind erosion. Shelterbelts of trees are indispensable allies in an effort to reverse this loss of farmland, and to anchor a regeneration of the soil. Significant forest cover can eventually stabilize the local climate, too. The Western Australia chapter of Men of the Trees is dedicated to this task.