Healthy soil and sustainable growing

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The Nutrition Garden Project


Originally published in The Cultivar (Winter, 1997 issue), Newsletter of
the Center for Agroecology and Sustainable Food Systems at the University
of California at Santa Cruz.

By Jonathan Knight
(C) Copyright 1997

Contact:
Albie Miles
2458 Empire Grade
Santa Cruz, CA 95060 USA
Phone: (408) 421-9755

This past spring (1996), Center volunteer and apprentice program graduate
Albie Miles began growing all his own food. From planting the first
seedlings to laying in the last cover crops, he kept careful records of
what he grew, what he ate, his labor, and his yields. Between April and
October, he restricted his diet almost entirely to food from his "nutrition
garden," which is located on a portion of the raised-bed garden site at the
Center's 25-acre UCSC (University of California, Santa Cruz) Farm. 

The project's goal was to find out what it takes to grow a complete diet
with organic gardening practices that maintain the soil's fertility year
after year. Miles had to plant crops in proportions that provide balanced
nutrients and sufficient calories. The crops also had to produce enough
compostable biomass to eliminate the need for annual amendments from
outside the garden.

Miles, in consultation with apprenticeship instructor John Farrell, sought
answers to questions such as how much work is involved, what to grow, and
what the diet is like. He also tested different varieties of corn,
amaranth, wheat, and dry beans to see which performed the best under
Central Coast conditions. The project did not include exhaustive soil
analyses or carefully controlled experiments - Miles calls it "soft science
at best." Rather, the project was an attempt to implement what others have
recommended. "This is what people are going to encounter if they try
growing all of their own food," he says.

The nutrition garden covered 4,500 square feet, including paths,
propagation area and compost piles, and 2,500 square feet of French
intensive bed space. The main calorie crops were grain corn, grain
amaranth, spring wheat, potatoes, dry beans and winter squash. Miles also
planted onions, sunflowers, an assortment of dark green leafy vegetables
(chard, kale, collards, and broccoli), and successive sowings of carrots,
beets, green onions, and bok choy.

In coming years the nutrition garden will yield valuable information on how
much compost the soil needs annually to stay productive, and what the
long-term average yields for each crop are. The project will be integrated
into the six-month Apprenticeship in Ecological Horticulture, giving
students a chance to experiment with ways to produce a balanced diet and
compost ingredients from a hand-worked garden plot.

Maximimizing Production in a Limited Space

Ecology Action of the Midpeninsula, a non-profit agricultural research
organization, has set forward some guidelines for growing a personal
nutrition garden using Alan Chadwick's French intensive techniques (see
References). This gardening style produces phenomenal yields in double-dug,
raised beds amended with compost. In situations where the soil is lacking
in certain nutrients, organic fertilizers such as bonemeal, cottonseed
meal, or kelp sand may be used to restore nutrient balance, but the
long-term goal of French intensive gardening is to use compost as the main
soil amendment.

In French intensive gardening, seedlings are planted close together so that
the leaves of the mature plants just touch, reducing moisture loss from the
bed and forming a living mulch that keeps weeds down. This tight, or
"intensive," spacing in rich soil generates yields as much as ten times
higher than those produced by conventional agricultural practices.

Following Ecology Action's crop recommendations, Miles planted 2,500 square
feet of beds worked with the French intensive technique, and ended up
several months shy of a full year's supply of food. However, much of the
shortfall was due to a low potato yield, one that was less than half of the
UCSC Farm & Alan Chadwick Garden's average. Furthermore, yields may well
improve after several years of heavy composting.

Table 1 lists yields for the storage crops (grain corn, amaranth, wheat,
potatoes, dry beans, winter squash, and onions). Yields of leafy greens
were measured in cups of steamed vegetables (Table 2). Altogether, 125
square feet of bed space produced 1.6 cups of steamed vegetables a day from
April 10 to October 26. These results represent only a single season -
subsequent cropping seasons will provide data that will be used to
determine average yields. 

entire article continues at
http://www.cityfarmer.org/albie.html