Agriculture Reference
In-Depth Information
orchard floor management program, and integrate them with your other
practices.
Living Mulches
Living mulches provide all of the advantages of the organic mulches de-
scribed above, and they eliminate some of the disadvantages. Perhaps the
greatest advantage of living mulches is that you produce them on-site in the
alleyways between your trees or grow them as in-row cover crops. As part
of routine alley mowing operations, the clippings can be blown into the fruit
crop rows, where they serve as mulches. You avoid the expenses of purchas-
ing and transporting the materials, and you greatly reduce labor costs asso-
ciated with applying the mulches. You also eliminate concerns about pesti-
cide residues and avoid problems with your organic certification organiza-
tion.
By tailoring the alley crop, you can fine-tune how much nitrogen is avail-
able to your orchard crops. If nitrogen is too abundant, shift to grasses and
other non-nitrogen-fixing alley crops. If more nitrogen is needed, increase
the amounts of alfalfa, clovers, and other legumes in the alley crop mix. Both
annual and perennial alley crops can be used effectively as living mulches.
Much work has been conducted on living mulches recently, and they
show great promise for organic fruit growers. In Washington State trials, al-
falfa proved especially valuable as an alley cover crop and source of mulch,
providing good weed control in the fruit crop rows and adding nitrogen to
both the alleyways and crop rows. In one orchard, an innovative fruit grower
installed a front-mounted mower on his tractor and had a mechanical cul-
tivator and brush rake behind. This arrangement allowed the grower to mow
the alfalfa crop and move the clippings into and out of the tree rows, as well
as to cultivate in the tree rows.
Living mulches are not without their disadvantages. You must still grow
and maintain the cover crop, which must grow tall and dense enough to
provide adequate amounts of mulch. You will need a mower capable of cut-
ting the tall alley crops and blowing the clippings into the crop rows. The
