Score cards and laboratory tests have been developed to help farmers assess their soils, using scales to rate the health of soils.
In the field, you can evaluate the presence of earthworms, severity of erosion, ease of tillage, soil structure and color, extent of compaction, water infiltration rate, and drainage status. Then you rate crops growing on the soils by such characteristics as their general appearance, growth rates, root health, degree of resistance to drought, and yield. It’s a good idea for all farmers to fill out such a score card for every major field or soil type on their farms every few years, or, alternatively, to send in soil to a lab that offers soil health analyses. But even without doing that, you probably already know what a real y high-quality and healthy soil—one that would consistently produce good yields of high-quality crops with minimal negative environmental impact—would be like. You can read more on evaluating soil health in chapter 22.
every farm. Appropriate organic matter management is,
Later in the book we will return to these and other
therefore, the foundation for high-quality soil and a more
practices for developing and maintaining healthy soils.
sustainable and thriving agriculture. It is for this reason
that so much space is devoted to organic matter in this
A lARgER VIEW
book. However, we cannot forget other critical aspects
In this book we discuss the ecological management of
of management—such as trying to lessen compaction by
soils. And although the same basic principles discussed
heavy field equipment and good nutrient management.
here apply to all soils around the world, the problems
Although the details of how best to create high-qual-
may differ in specifics and intensity and different mixes
ity soils differ from farm to farm and even field to field,
of solutions may be needed on any particular farm or
the general approaches are the same—for example:
in any ecological zone. It is estimated that close to half
• Implement a number of practices that add organic
the people in the world are deficient in nutrients and
materials to the soil.
vitamins and that half the premature deaths that occur
• Add diverse sources of organic materials to the soil.
globally are associated with malnutrition. Part of the
• Minimize losses of native soil organic matter.
problem is the low amount of nutrient-rich foods such
• Provide plenty of soil cover—cover crops and/or
as vegetables and fruits in diets. When grains form too
surface residue—to protect the soil from raindrops
large a part of the diet, even if people obtain sufficient
and temperature extremes.
calories and some protein, the lack of other nutrients
• Minimize tillage and other soil disturbances.
results in health problems. Although iron, selenium,
• Whenever traveling on the soil with field equipment,
cobalt, and iodine deficiencies in humans are rare in
use practices that help develop and maintain good
the U.S., they may occur in developing countries whose
soil structure.
soils are depleted and nutrient poor. It frequently is
• Manage soil fertility status to maintain optimal pH
an easier and healthier solution to get these nutrients
levels for your crops and a sufficient supply of nutri-
into people’s diets by increasing plant content through
ents for plants without resulting in water pollution.
adding these essential elements to the soil (or through
• In arid regions, reduce the amount of sodium or salt
irrigation water for iodine) rather than to try to provide
in the soil.
everyone with supplements. Enhancing soil health—in
7
Building SoilS for Better CropS: SuStainaBle Soil ManageMent