BioCycle October 2016
We are in need of a new revolution in how food is grown. A growing population in combination with climate change has put heavy pressure on our current system. The last time this happened (about 50 years ago) we had the Green Revolution to save the day. Major improvements in crop breeding and the use of synthetic fertilizers and pesticides resulted in enormous yield gains in farms across Asia, Europe and the Americas. Norm Borlaug won a Nobel Peace Prize for his role as the “father” of this revolution.
In the U.S. in particular, we have this green stuff down. But we need to get even more out of our soil and food systems. In other words, we need a new revolution. My question is what color is it going to be this time? A recent op-ed piece in the New York Times by Jason Lusk, a professor from Oklahoma State University, suggested that making the green even greener was the way to go. Lusk talked about the changing face of agriculture: Fewer farms and fewer people farming them. In contrast with 1900, when 40 percent of the U.S. population lived on farms, now only 1 percent do. (Photo essay on industrial agricultural in the NY Times)
With this shift we have seen a change in what farms look like. From 1940-1980, the number of farms fell by 50 percent and the size of those remaining tripled. This is not just for field corn and wheat; it is also true for lettuce and tomatoes. The median tomato farm covers 620 football fields. The median lettuce farm is a whopping 1,373 football fields. That is Caesar salad for everybody plus the ragu.
We have also seen a change in how farms are farmed. Say goodbye to the horse and plow. The main reason farms have been able to grow in size is the availability of a range of sophisticated types of equipment. Precision agriculture can provide detailed yield maps of fields, real time moisture and nutrient readings. This level of efficiency has reduced water use, soil erosion and greenhouse gas emissions for each unit of food produced. This is factory farming.
Lusk thinks this is OK. He does say there is room for improvement and notes new industry initiatives that are focusing on soil health. While he mentions the increasing use of legumes to fix nitrogen nowhere does he mention manures or composts as part of the solution. Lusk sees what I’ll call lime green as a way to avoid Soylent Green (a 1973 science fiction movie depicting a future suffering from pollution, overpopulation, depleted resources, poverty, dying oceans, and year-round humidity due to the greenhouse effect).
More Brown Than Green
I’ve recently read two books that have a different take on what we need for the next revolution in growing food. Both are heavier on the brown than the green. The Emergent Agriculture by Gary Kleppel and the Third Plate by Dan Barber argue that recognizing the complexity of the soil-plant ecosystem is the key to success for the next revolution. They both bring farms down in size and equipment, but scale up in terms of crop combinations and rotations. They both make the case that feeding the soils is critical to both the success of the crop as well as the value of the crop. Crops grown in richer soils have richer flavors (important to Barber, a chef) and are richer in micronutrients.
Kleppel’s and Barber’s approaches echo those of the potato farmer I wrote about last year (see “Transpoosion,” December 2015). They fall into the same paradigm as Wes Jackson, creator of the Land Institute. Dr. Jackson views complex perennials as a critical component of a solution. Ecological intensification — or encouraging and building on naturally occurring plant communities — is the term Jackson uses. Both Kleppel and Barber agree with this and add a few farm animals into the mix. The animals provide the manure that enriches the soil and allows it to support more complex planting system. Both authors live in New York State and provide examples of small-scale farms (less than 1,000 football fields) that are integrated into their communities. The farms grow apples, carrots and beets, but the authors also include examples of small grain growers, with Barber describing a local mill coming back to life to mill the wheat.
I am puzzled about how this model translates into practice in a new green revolution. I don’t think that compost and biosolids from cities can provide a real solution for more than a very small sliver of the land that we need to farm. We just don’t make the volume that would be needed. I have seen how the biosolids from many of the cities in Washington State have improved the soils and subsequently the yields and diversity of what can be planted on the dryland wheat fields in the state. So have the crop insurance folks — biosolids in the region are now considered as part of the Natural Resources Conservation Service toolbox. But if you go back to Lusk in Oklahoma, there aren’t enough biosolids there to scratch the surface. With 3.9 million people and about 30 kg of biosolids per person per year, that comes out to about 115,000 tons. At 5 tons per hectare, that is enough to cover about 23,000 hectares or 58,000 football fields (42 lettuce farms).
If you take a look at agriculture in Oklahoma, you’ll find that they don’t grow much lettuce. They do farm more than their share of football fields however, with a total of 13.8 million hectares in cultivation. The biggest commodity crop grown in the state is winter wheat, with a total of 1.5 million hectares harvested in 2015, according to the Oklahoma Department of Agriculture. As of 2010, about 84 percent of that acreage was fertilized with synthetic fertilizers (www.knoema.com).
Oklahoma residents may not generate a lot of biosolids, but a lot of cows are raised in the state — about 2 million head. Cows make humans look like complete wimps in terms of manure production. Each one produces about 1 dry ton of manure each year, therefore Oklahoma cows produce the equivalent of 67 million people. Now that is enough to cover some wheat ground — about 1.3 tons/hectare/year. This isn’t quite enough for the full crop but certainly enough to bring that synthetic fertilizer percentage way down.
What Lusk has left out of his “lime green” revolution is this animal waste. If we are going to grow enough grain to support the number of animals that we use, we need to make use of their manures. Appropriate use of animal manure is just a first step towards the brown revolution that is described by Kleppel and Barber. But it is a critical step. And it may be the first part of a marriage between the high tech approach to growing food and a way of farming that can sustain our soils and satisfy our appetites.
Sally Brown is a Research Associate Professor at the University of Washington in Seattle and a member of BioCycle’s Editorial Board.