Improving Soil 287
Animal manure
Animal manures provide all the nutrients plants need, and over time improve
soil texture, soil structure, and soil fertility. Chemical fertilizers, on the other
hand, give crops only 2 or 3 nutrients and do not improve the soil.
Some care must be taken with manure. Using too much manure will cause
too many nutrients to build up in the soil and can pollute waterways. Fresh
manure also carries germs that can cause illness. Do not put fresh manure
near drainage ditches or waterways. Always wash your hands and your
clothing well after handling manure.
Fertilizing with human waste
Human urine can be turned into fertilizer, and human feces when properly
treated can add organic matter to the soil. But human waste carries harmful
germs and causes illness if it is not properly handled. (To learn how to safely
use human waste to improve crop yields, see Chapter 7.)
Compost
Compost is a natural fertilizer made of food scraps, crop
waste, weeds, and animal manure. Adding compost to
the soil is a way of adding crop nutrients back to the
earth. It would take a lot of work to make enough
compost for a large field, so compost is most
often used on smaller plots. (To make
compost, see pages 400 to 403.)
Soil
Compost
Compost can be used in many ways:
• Add a shovel full of compost in the bottom of
planting holes before planting fruit trees.
• Mix a handful of compost with soil in
planting holes when you plant seeds.
• Spread a layer of compost on top of your soil
before turning it.
• While plants are growing, make a circle of
compost around the plant stem. For a tree,
make the circle where the edge of the tree’s
shade falls in the middle of the day. Cover it
with a little soil. It will slowly feed the plant
as water carries nutrients to the roots.
A Community Guide to Environmental Health 2012