Our dry farmed/No-till soil management

Our last post began a discussion of how we manage soil moisture and fertility. To summarize, our orchard is mostly dependent upon winter rainfall rather than summer irrigation since water is very scarce in these hills. This area was historically "dry farmed." And according to the gospel of dry farming, that meant cultivating the soil as soon as it was dry enough to work in the spring. The object was to plow under all winter weeds so most of the winter/spring rainfall was preserved for the orchards instead of going into weed growth. To "seal in" the moisture, the ground was cultivated repeatedly as weeds re-emerged, leaving a fine "dust mulch." Unfortunately the result of bare, finely cultivated soil is erosion of top soil, death of soil building organisms, and continual loss of fertility.

So our challenge with dry farming is how to save the maximum rainfall moisture for our main crop (orchard trees), while also preserving and improving soil fertility. Our solution has been to simply mimic nature's soil building process, with some enhancements. Some years back I began planting a cover crop in the fall, one that adds maximum organic matter and nutrients to the soil, rather than just letting native weeds grow. I also stopped tilling every spring, opting instead to just mow near the end of the rainy season. The result has been a real slowdown in erosion and a big increase in fertility, all with no apparent sacrifice in soil moisture.

Now instead of a finely powdered soil devoid of life, we have the rich porous soil pictured here, protected from sun and wind by cover crop residue, full of decaying roots that microbes turn into fertilizer, and permeated with earthworm holes that allow air and water to enter. Instead of winter rain runoff looking like chocolate milk, very little rain runs off since it is slowed by dense cover crop and easily soaks into the sponge-like soil. In short, our soil is now capturing and holding more moisture and building more fertility. Our annual soil test lab results show high to very high nutrient levels and steadily increasing organic matter content, all without any inputs other than compost and natural mineral amendments.

Because soil biological activity is nature's fertilizer factory and all soil life requires moisture, we use what meager well water we have to do some minimal drip irrigation through the dry summer season. Call it "dry farming plus." By putting a mound of compost under each drip irrigation emitter, we create small zones where earthworms and microbes flourish. These function as feeding stations for the trees, providing a small but steady supply of nutrients and trace minerals.

A mass of fine feeder roots forms under each mound, absorbing nutrients along with a bit of water. The amount of water is only a tiny fraction of what irrigated orchards get, but our big juicy fruit, deep green leaves, and rampant tree growth speak for themselves. Clearly the trees are getting plenty of what they need. Because they have never been irrigated, the root systems have grown deep to survive the dry summers. And while they will look a bit stressed during low rainfall years, the high soil nutrition gives them the strength to cope until the fall rains start again.

What really drives our passion for the orchard is fruit flavor. We are gratified to hear customers frequently comment, "that was the best I ever tasted," or "I haven't tasted fruit like that since I worked on my grandparents' farm." Producing such exceptional fruit with minimal water and without synthetic chemicals just feels right.

Our June/July harvest limps to an end

The last of our first-crop figs and Santa Rosa plums are picked, and we're ready to get on to other work. Harvesting is usually satisfying, seeing the literal fruits of our labors lined up handsomely in boxes. But this year was a challenge, with the late June rain causing heavy losses and defects due to splitting and mold. But one of the things we value most about rural living is a close connection to nature. And with that comes the frequent reminder that nature is in charge. So we are challenged to learn more about the interaction of weather and tree crops, to have realistic expectations, and to accept a bad year now and then. Not such a bad deal.

On the plus side, the long and wet rainy season is a big boost for our dry farmed trees, which depend upon rainfall moisture left in the soil to last them through the summer. Traditionally, "dry farming" means growing a crop with little or no irrigation beyond rainfall, then conserving that rain moisture by maintaining a finely-cultivated soil surface to act as a dirt mulch. The hills around us were always dry farmed since orchards were first planted in the mid-late 1800's, simply because water is very scarce here.

Unfortunately, the downside of thorough tillage is soil depletion. Bare, loose soil loses fertility through erosion by wind and runoff. Plus, plowing and turning the soil interfere with nature's topsoil building process. Soil is improved when the right plants cover its surface, protecting it from sun and wind; cover crops grow, die, decompose and cycle nutrients on to the next season's plantings.

For many years I followed the traditional dry-farming tilling methods because I was told that was necessary to maintain adequate soil moisture. And after all that's the way it had always been done in these dry hills. But several years ago I began to worry that I was losing too much fertility and decided to take a chance and stop tilling altogether. By going to a "no-till" system of growing a Winter cover crop, I now mow rather than till in the Spring, so the orchard floor is always covered with plant matter. Our best topsoil no longer migrates downhill with each pass of the disc or heavy rainstorm, and though the cover crop uses up some soil moisture, the improvement in soil quality and fertility more than make up the difference. More on this topic next time.

A refreshing summer salad

With hot weather finally here we think of flavorful salads. And with figs and grapefruit on hand we consulted our friend Google and came up with this recipe for Grapefruit & Fig salad

The juicy tart grapefruit pairs well with the sweet fig slices, and the mildly spicy dressing ties it all together. The recipe calls for mango juice, but we juiced the last of our apricots and used that. Pineapple would work well too. And a few nuts would be a fun addition, we're thinking toasted pecans. Enjoy.

Santa Rosa Plums

The good news/bad news saga continues now with the plum crop. We have been able to provide some tasty plums to our commercial clients in the Bay Area. But since the plum crop was light, just like the apricots, we didn't get the yield we normally expect. The rain also affected the earliest Santa Rosa plums, causing some of the cracking and spoilage that we had in the cots. As always, though, our Santa Rosas have great flavor. The tangy purple skin surrounds juicy flesh that tastes sweet, bold and complex.

That being said, there are a few culls available for canners and bakers to enjoy. Give us a call if you are interested in them.

Last year we recommended a Santa Rosa Plum Compote recipe that is found on the web at epicurious.com. Here it is again:
Santa Rosa Plum Compote

This year we tried a recipe for Santa Rosa Plum Galette from Mary Jo Thoresen, famous pastry chef at Chez Panisse. Her recipe and detailed instructions can be found online at this link:
http://www.jojorestaurant.com/news/chronicle6-2000.html

A slice of this dessert topped with the best vanilla ice cream you can find is an incredible combination of flavor and texture, combining tart and sweet to perfection.

We are all indebted to Luther Burbank for cultivating this superb plum. In California, Arbor Day is celebrated on March 7, the date on which he was born in 1849. Now is a good time to make a plum galette, freeze it unbaked, bag it in a plastic bag with all air removed and place it in your freezer. On March 7, 2012, pull it out and bake it.

In addition to the Santa Rosa culls, we have Texas Pink Grapefruit available and a small supply of first crop Black Mission figs. Our phone is 707-448-4792.