Years before there was talk of locavores and 100-mile-diets and omnivore’s dilemmas, I came upon Gary Nabhan’s book Coming Home to Eat, a personal account of his experiences striving to solely eat food produced in his home bioregion of the US-Mexican borderlands in southern Arizona. His observations as renowned desert ecologist and ethno-botanist redefined how I thought about food and sustainability and accompanied me on my own sustainable food explorations for years after.
I get the feeling that his latest book, Growing Food in a Hotter, Drier Land: Lessons from Desert Farmers on Adapting to Climate Uncertainty (Chelsea Green, 2013), may be another companion for us in our adventures on the farm. While Growing Food is as practical as its title suggests, it is permeated by Nabhan’s respect for the insights of cultures deeply connected to the land, and his belief that communities connected to their bioregion are the most resilient in the face of environmental change.
While predictions suggest that the coming decades hold much that is new climatically, Nabhan highlights that many living cultures have weathered such changes before, continuing to survive and thrive in the world’s arid lands. As an ecologist, Nabhan is careful to point out that deserts have their own integrity as ecosystems, and while climate change predictions suggest a hotter and drier climate for many regions of the world, it is unwise to simply imagine that our existing landscapes will shift towards arid ecosystems as we know them. Rather, the idea of the ‘desert’ in this book acts as inspiration for developing food production strategies that respond to the uniqueness of individual bioregions.
Each chapter in Growing Food draws inspiration from a traditional arid-lands food production strategy, supported by both contemporary scientific context and reflections on Nabhan’s own experiences among the cultures of the arid lands of the Americas, Middle East, Asia and North Africa. Supported by practical advice and analysis of each strategy’s effectiveness, Nabhan examines rainwater and nutrient harvesting strategies, lo-fi irrigation, reducing heat stress, increasing soil organic content and moisture retention capacity, terracing, inter-cropping, fruit and nut tree guilds and cultivating landscapes that support pollinators. Perhaps a reflection of his scientific background, part of the practicality of Growing Food comes not just with the advice on constructing and cultivating, but also on documenting and measuring the effectiveness of different strategies as a step towards designing locally-adapted, climate-resilient food systems.
Throughout, Nabhan highlights that small-scale, collaborative, community-based approaches are typically more effective than broadscale, corporate solutions. As an example, he compares the approach by biotechnology giants to spend millions of dollars and up to 15 years to develop individual genetically-modified “climate-ready” crops, while community-based seed banks and exchanges continue to actively maintain a vast variety of locally-adapted seeds at little cost. Indeed, “for the cost of producing a single GMO, a dozen or more regional, tribal or community-based seed exchanges could probably grow and offer 5,000 to 10,000 annual seed-stocks per year to farmers and gardeners in the communities they serve.”
As we continue to refine our designs for the farm, a couple of insights in particular stood out. In his discussion on fruit and nut tree guilds, Nabhan observes how climate-change predictions suggest substantial reductions in the chill hours required for blossoming and fruit set in many fruit trees. He asserts that many temperate fruit trees require from 750-1,750 hours of cool (0-7 degrees Celsius) temperatures to produce an adequate crop, however studies have already shown a loss of up to 160 chill hours in some fruit-growing regions, with further loss of 500 hours by the end of this century. Other studies are more dire, with the chill hour “safety zone” predicted to decrease by up to 75 percent by mid-century and 90-100 percent by 2100. In short, he suggests, orchards need to be planned to ensure their optimum temperature needs are still being met in 15-30 years. To support this Nabhan supplies a delectable list of fruit tree varieties with chill hour requirements as low as 100-150 hours. (Thrillingly to me, another of his lists shares some 13 different varieties of prickly pear (Opuntia ficus-indica), each with differently coloured, sized and shaped fruit.)
After a hostile South Australian summer for bees, also concerning was Nabhan’s observation of how changing temperatures are already pushing plant flowering and pollinator activity out of sync, resulting in the potential decline of both. The strategy here is to plant for pollinators, providing forage at multiple times in an effort to maintain a critical mass of pollinators for when food crops flower. As honeybees have faced decline worldwide, the value of, and the need to cultivate habitat for, native pollinators is also gaining importance. (Bee Friendly: A planting guide for European honeybees and Australian native pollinators is an excellent Australian resource to support this.)
With Growing Food in a Hotter, Drier Land, Gary Paul Nabhan has assembled an insightful and grounded collection of inspiration and ideas for cultivating resilient food systems into an uncertain future. Despite the daunting climate context, his practicality and experience offer not despair, but a sense of possibility.