Increasing the quality of a soil—enhancing it as a habitat for plant roots and beneficial organisms—takes a lot of thought and action over many years. Of course, there are things that can be done right off—plant a cover crop this fall or just make a New Year’s resolution not to work soils that really aren’t ready in the spring (and then stick with it). Other changes take more time. You need to study carefully before drastically changing crop rotations, for example. How will the new crops be marketed, and are the necessary labor and machinery available?
All actions taken to improve soil health should contribute to one or more of the following: (a) growing healthy plants, (b) stressing pests, and (c) increasing beneficial organisms. First, various practices to build up and maintain high levels of soil organic matter are key. Second, developing and maintaining the best possible soil physical condition often require other types of practices, in addition to those that directly impact soil organic matter. Paying better attention to soil tilth and compaction is more important than ever, because of the use of very heavy field machinery. Last, although good organic matter management goes a long way toward providing good plant nutrition in an environmentally sound way, good nutrient management involves additional practices. In this chapter we’ll focus on issues of organic matter management.
Because organic matter is lost from the soil through decay, washing, and leaching,and because large amounts are required every year for crop production, the necessity of maintaining the active organic-matter content of the soil, to say nothing of the desirability of increasing it on many depleted soils, is a difficult problem.
—A.F. Gustafson, 1941
Table of Contents
- About the Authors
- Preface
- Introduction
- Healthy Soils
- Organic Matter: What It Is and Why It's So Important
- Amount of Organic Matter in Soils
- The Living Soil
- Soil Particles, Water, and Air
- Soil Degradation: Erosion, Compaction, and Contamination
- Nutrient Cycles and Flows
- Soil Health, Plant Health, and Pests
- Managing for High Quality Soils: Organic Matter, Soil Physical Condition, Nutrient Availability
- Cover Crops
- Crop Rotations
- Animal Manures for Increasing Organic Matter and Supplying Nutrients
- Making and Using Composts
- Reducing Erosion and Runoff
- Preventing and Lessening Compaction
- Reducing Tillage
- Managing Water: Irrigation and Drainage
- Nutrient Management: An Introduction
- Management of Nitrogen and Phosphorus
- Other Fertility Issues: Nutrients, CEC, Acidity, and Alkalinity
- Getting the Most From Routine Soil Tests
- Taking Soil Samples
- Accuracy of Recommendations Based on Soil Tests
- Sources of Confusion About Soil Tests
- Soil Testing for Nitrogen
- Soil Testing for P
- Testing Soils for Organic Matter
- Interpreting Soil Test Results
- Adjusting a Soil Test Recommendation
- Making Adjustments to Fertilizer Application Rates
- Managing Field Nutrient Variability
- The Basic Cation Saturation Ratio System
- Summary and Sources
- How Good Are Your Soils? Field and Laboratory Evaluation of Soil Health
- Putting It All Together
- Glossary
- Resources