How does your garden grow?

A simple mixture of organic waste, such as chicken manure, and zeolite, a porous volcanic rock, has been developed into a powerful fertiliser which can also reclaim desert or contaminated land. This is a whole new approach to plant nutrition - Peter Leggo Food and biofuel crops could be grown and maintained in many places where it wasn't previously possible, such as deserts, landfills and former mining sites, thanks to an inexpensive, non-chemical soil additive. The additive, a simple mixture of organic waste, such as chicken manure, and zeolite, a porous volcanic rock, could be used to support agriculture in both the developed and developing world, while avoiding the serious environmental consequences associated with the overuse of chemical fertilisers. The mixture permits a controlled release of nutrients, the regulation of water, and an ideal environment for growing crops. Researchers from the University of Cambridge have demonstrated that with the addition of the biofertiliser, biofuel crops can be successfully grown and - more importantly, sustained - even on coal waste highly contaminated with metal residues. Using coal waste from the site of a former colliery in Nottinghamshire as a substrate, the researchers grew rapeseed, flax, sugar beet and maize, with different additives: manure, zeolite, lime, or biofertiliser, as well as coal waste alone and regular garden soil. Plants grown in the coal waste with added biofertiliser achieved nearly twice the weight and yield of those grown in garden soil or in coal waste with added manure, and more than twice the weight and yield of those grown in coal waste with added zeolite.