When annual crops are grown and planted in the spring, there is a considerable amount of time when the soil is not occupied by living plants. This means that for a large portion of the year there are no living plants to take up nutrients, especially nitrate, that can leach out of the soil. This is especially a problem in the Midwest, where many soils have tile drainage, which accentuates the discharge of high-nitrate water into streams and rivers. In addition to not taking up nutrients, the lack of growing plants means that the soils are wetter and more apt to produce runoff and erosion as well as leaching. Thus, rotations that include perennial forages and winter grains help maintain or enhance the quality of both ground and surface waters. And, while intensive use of cover crops helps water quality in a similar way, cover crops should not be viewed as a substitute for a good rotation of economic crops.
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