Sunday, August 26, 2018

Toward sustainable farming, part 1: Perennial grain crops


This is part one of a two-part posting on changes needed to make North America’s farming systems more sustainable and productive in the future. Both posts are inspired by a visit I paid earlier this summer to the Land Institute in Salina, Kansas.

Established decade ago by farmer/scientist/agrarian philosopher Wes Jackson, the Institute seeks to transform the way we farm, especially the way we grow grains. One of its key missions is to develop perennial plant substitutes of our main grain crops. They’ve had some notable success on the crop development side, now their task is to fit these new plants to harvesting and distribution systems. If the Institute is successful, the resulting benefits would be revolutionary for agriculture, for biodiversity, for watershed health, for controlling climate change.

We already derive many of our foods from perennial plants: tree fruits, nuts, asparagus being common examples. But most of the common seeds and grains we consume – wheat, corn, barley, soybeans, canola – are annual plants grown in monoculture (i.e. large fields containing only one plant species). Monocultures of annual plants are not natural, and it takes a great deal of technology to impose them on the natural landscape. To plant a field of grain, you start by plowing up the needed space to denude it of existing vegetation, creating a blank slate of exposed soil. Once exposed to the elements, the light organic matter and clay particles in the soil that your grain plant will need to draw upon for nutrients are easily eroded by wind and rain. To replace lost nutrients and further boost the soil’s productivity, you pound into it nitrogen fertilizer – typically by spraying the field with ammonia – and will likely add some phosphorus and maybe potash, too. These latter two fertilizers are obtained from mines in distant places; the nitrogen fertilizer is made in a factory that uses a lot of natural gas in the process. Not all of this fertilizer stays on your land; some of it runs off into local waterways, fertilizing algae growth and altering the temperature and chemistry of the water, to the detriment of native species.

Once you’ve fertilized, you are ready to plant your seeds, which may or may not be genetically modified (increasingly they are) to resist the herbicide you’re going to spray on your field to keep the “weeds” (i.e. all other species of plant that might naturally grow there) from outcompeting your young crop plants. If you farm in a dry area – e.g. virtually all of western North America – you will want to irrigate your crop in early summer when it is forming its seed head. If you’re lucky, a river passes your farm and you have a legal right to draw water from it, or you are situated over an underground aquifer from which you can pump irrigation water. Your crops benefit from the added water, but an adverse byproduct is that you mobilize salts that naturally occur in the soil, which accumulate near the surface when that added water evaporates in the sun. Crop plants typically don’t tolerate salt, and so over time heavily irrigated soils become less productive. Once you start to irrigate, you can’t go back to rainfed-only and expect your fields to be as productive as they once were.

Once your crops have matured and the seeds have cured, you’re ready to harvest, which is done by driving heavy equipment across the fields, burning considerable amounts of fossil fuels and compacting the soil, which you will have to undo by plowing next time you plant. There are techniques called ‘no till’, which means to plant without plowing by drilling your seeds into the ground, but to compensate for the lack of mechanical weed killing done by the plow, no-till methods typically use extra treatments of chemical herbicides to keep the weeds down. Not good for waterways, not good for native plants and the insects they support.

If all of the above sounds unnatural, wasteful of resources, hard on the soil, damaging to the health of the natural environment, and not sustainable for the long term, that because it is. Large scale, industrial monoculture crop farming produces tremendous volumes of grains, but it is more like a mining operation than the idealic red-barned family farm non-farmers are encouraged to imagine.

Wes Jackson and the Land Institute want us to switch to perennial grain and seed crops that, once planted, mostly look after themselves for years on end. Unlike annuals, perennial plants develop extensive root systems that allow them to draw moisture and nutrients from deep in the soil, meaning they don’t typically require irrigation, and need only occasional fertilization. They have less trouble competing with the weeds – many of which are themselves annuals – because they are established, expansive, and shade out the smaller plants. The long term operating costs for the farmer are much lower, since s/he purchases less seed, fertilizer, and herbicide, and no longer needs expensive plowing equipment or gas to fuel it. Each summer the farmer harvests the ripened seeds and that is pretty much it. When the plants get old and become less productive, the farmer replaces them individually on an as-needed basis. The farmer may occasionally go into the crop to manually remove shrubs and trees that push up within it, bit it’s generally ok if other plants grow up within the crop; it’s not intended to be a complete monoculture. This means the field is more likely to host a range of insects and smaller animals, especially since they’re not being killed off by chemical sprays. The soil and local waterways will be healthier for it as well.

 
Image comparing root development of annual wheat vs perennial wheat, from the Land Institute

If perennial crops are so great, why aren’t we already growing them on a large scale? For many of the same reasons why we aren’t all driving electric cars or why our major cities tend to have lousy public transportation. It isn’t because the technology doesn’t exist, but because we are so heavily invested in our current systems that it’s economically and socially difficult to make the switch. A lot of very large and powerful companies make a lot of money off our current agricultural system, selling seeds and chemicals each year to farmers, and manufacturing all that equipment farmers use to grow annual grains. Our post-farm food production systems are geared to the specific varieties of food crops we currently produce, and rely on their uniformity to produce our packaged breads and ramen noodles. Skeptics will argue that per acre grain yields are lower for perennial crops, which is true at the moment, but that gap is rapidly shrinking. However, if your metric of performance is yield per input costs instead of yield per acre, perennial crops win hands down. That translates into better incomes for farmers and allowing them more ability to innovate in other parts of the farm operation, such as getting into polyculture (which I will talk about in my next blog posting).

Experimental wheatgrass in greenhouses at the Land Institute.

It’s not surprising that the greatest uptake of the Land Institute’s methods has so far been in China – where food demand and agricultural damage to available cropland are both soaring – and in Africa, where farmers are not yet widely tied into industrial farming practices. It’s time for North Americans (and other developed countries) to take a harder look at crop perennialization. Too many public research dollars are being used to study how to squeeze more productivity out of annual crops, to the benefit of the agri-business companies. Do not believe them when they claim their goal is to better feed a growing global population of hungry mouths; if that were true, we’d be spending our research dollars in very different ways than we currently do.

It’s a shame that the leading institute for research on crop pernnialization is a small farm on the outskirts of Salina that leans heavily on interns, volunteers, and private donations to do its work. If I were running a government research program (unlikely to ever happen) or a billionaire philanthropist looking for ways to change the world for the better (even more unlikely), I’d be investing heavily in crop perennialization research – not just on the plants themselves, but on how to facilitate the changes in the wider food production system needed to make it happen.

In my next posting, I’ll talk about Wes Jackson’s concept of “nature as measure” and the need for a return to polyculture farms.


.