Preparing or Upgrading Your Orchard Site - Growing Organic Orchard Fruits - page 104

Raised beds are useful on poorly drained home orchard sites where you
can create a berm or raised ridge to plant your trees on. Berms are generally
higher and wider than the raised beds used in orchards and gardens. Like-
wise, raised landscape beds perhaps 10 feet or more in diameter can be used
to improve soil drainage. If your native soil has high amounts of clay and silt,
combine it with sand and organic materials to create an amended soil that
will improve drainage and biological activity in the berms or raised beds. Fig-
ure 4.2 ➔ shows two raised bed designs.
Excessive Drainage
Excessive drainage usually occurs on soils high in sand and/or gravel. They
have little water-holding capacity, and without irrigation, plant growth is
sparse. On a small scale, you can improve the water-holding capacity of
droughty soil by amending it with clay or silt soils, peat soils, compost, wood
chips, bark, or similar materials. On a large scale, adding large amounts of
off-site soils or organic amendments is usually prohibitively expensive.
In all cases, tilling under one to several green manure crops before plant-
ing your trees will start the process of building organic matter. After the
trees are established, annual alley crops, such as barley, can be tilled into the
soil. If you use permanent alley cover crops, blow the clippings into the tree
rows during mowing. Increasing soil organic matter concentrations, however,
is a slow process, and you may need 5 to 10 years of careful management
(discussed in chapter9 ➔ ) to achieve significant increases. If you plan to es-
tablish an orchard on a droughty site, ensure that you have ample irrigation
water and install an effective irrigation system before you plant any trees.