Monday, January 10, 2011

Building Soil in the Desert

Soils in arid lands are usually not very productive. Because they are dry for long periods, many living things that normally work together to form rich soil are lacking. Very often the soils are sandy or of hard clay and only a few kinds of plants adapted to these harsh conditions can survive in them. As a result, agriculture has not been sustainable in these areas like it has in many parts of the world.

Today, however, there are apparent exceptions to this claim. Many desert regions are very productive. The Central Valley of California, for example, is one of the richest agricultural places on earth. Yet surprisingly it gets less than 12 inches of rain a year. In this dry land farmers have been producing abundant harvests for over a century. Even so, I stand by my claim: it just isn’t sustainable – at least at a local level.

In the desert, we have only been able to grow crops by bringing in billions of dollars worth of artificial inputs such as: fertilizers, pesticides, adjuvants, pheromones. I don’t mean to imply that this is a bad thing. The reality is that we would not be able to feed the world in its current condition without using the desert so proficiently. It is true that industrial agriculture is responsible for the loss of vast amounts of productive agricultural lands - especially through erosion and the sterilization of croplands. But this isn’t really an issue so much in desert regions where the rich soil wasn’t present to begin with.

In those deserts that have had the luxury of warm sandy soils, with enough water nearby, modern agriculture has made out quite nicely. In other deserts it’s been more difficult. These areas, though rich in biological diversity, have never been very agronomically productive.

My grandparents (on my father’s side) learned this the hard way. They were both raised in the cold desert of central Utah where sage brush is supreme and where the 5,000 foot elevation makes it cold enough that only one crop a year is possible. They got married at the turn of the 19th Century; and, after living for several years in Emery County, they loaded up their things and moved south to Hanksville, in Wayne County looking for a better life. This is the country east of Capitol Reef National Park and just north of Lake Powell. It is strikingly beautiful in its spare colorful formations but the soil is the soil of arid lands. It is not very productive.

My grandmother had to work very hard just to raise a small vegetable garden. Grandpa Wells would divert water from the local canal (that he helped dig from the Fremont River) to moisten the hard clay soil enough for Grandma to work with a shovel. This was a long hard process but without it, the ground couldn’t be broken and there was not nearly enough rain to grow a crop without it. Grandma and Grandpa had six children (and I don’t know how many grandchildren). Almost all of them had to live somewhere other than Hanksville. To this day the area remains mostly unfarmed.

The question that nobody seems to be asking is whether or not it is even worthwhile to develop a locally sustainable agriculture in places like Hanksville. And by locally sustainable I mean an agriculture that is continuous, year after year, without artificial inputs.

I guess that nobody has asked the question because on the surface it makes no sense whatsoever. How can anybody imagine growing a crop in hard clay or sand without adding fertilizer or other inputs from the world of agribusiness?

My answer is that pursuing agriculture as a business is not a very good idea in many of these desert lands. On the other hand, pursuing agriculture as part of a locally sustainable lifestyle is a real possibility.

The key to making it work all depends upon the soil. Historically, our American agriculture (even in the desert) has been based on using the soil. If a desert region lacked a suitable substrate for growing crops we never bothered with it. Maybe a few cows were left to find a meager sustenance on such land but that was about it. In fact that’s about where things stand today.

But it doesn’t have to be this way. It is possible to build soil, in the desert. Take the silty clay loam of Hanksville as an example. There are abundant minerals in this soil that would greatly enrich a crop, but they just aren’t available. But if a dedicated individual were to put forth the effort of creating compost - and lots of it - over time the hard clay would crumble and become part of a more frangible soil.

You would need to start with a big compost pile using the fallen leaves from local shrubs and trees. Mix these with animal manure and keep it moist, while turning it over occasionally. When this turns to soil, spread it on the garden. Seeds planted in this soft earth will grow. You may not have a lot to start with but keep at it. A drip line for watering would serve well if you have a lot of plants or a frequent hand-watering with a bucket or hose will do. Once the seedlings are on their way, add more leaves (even straw will work) and then place rocks over the leaves around the seedlings to retain moisture. If you keep things moist enough you will soon see signs of earthworms. After a few seasons the worms will work the ground from hard dirt to a rich soil that can be easily cut with a spade. Before too long you will have discovered one of the best kept secrets of these under-utilized lands: deserts can be extremely productive.

Of course local conditions will vary. You may need to bring in earthworms yourself if they don’t occur in your area. You may also have to be creative about finding enough plant material for composting. Then once your garden is thriving you may need to figure out how to keep rabbits or rodents out. But be persistent. Desert agriculture isn’t a well-established science in any form. And locally sustainable desert agriculture is a discipline that hardly even exists. It shouldn’t be this way. With the right care and determination the desert has a lot to offer.

2 comments:

  1. Good article. I know that this was written years ago but the information is as relevant now as ever. I don't see compost as a viable option but there are other methods. Swales and mulch seem to be the key. I am currently experimenting by growing native annuals in swales and using them as mulch.

    ReplyDelete
  2. Very nice to hear. I wish you the best of success.

    ReplyDelete