SOIL AND WATER QUALITY -- Copyright -- PREFACE -- Acknowledgments -- Contents -- Executive Summary -- BASIC CONCEPTS -- Soil Quality -- Pollution Prevention -- Profitability and Productivity -- THE AGENDA -- Enhancing Soil Quality -- Efficient Use of Inputs -- Resisting Erosion and Runoff -- Field and Landscape Buffer Zones -- IMPLEMENTING THE AGENDA -- Problem Areas, Problem Farms -- Problem Areas -- Problem Farms -- Farming Systems -- Better Tools and Information -- Better Management Tools -- Better Information -- New Cropping Systems -- Criteria and Standards -- INFLUENCING PRODUCERS' DECISIONS -- Barriers Imposed by Price and Supply Control -- Soil and Water Quality as Policy Objectives -- Policy Instruments -- Research Applications -- Technical Assistance -- Long-Term Easements -- Nonvoluntary Change -- Rights and Responsibilities -- PART ONE -- 1 Soil and Water Quality: New Problems, New Solutions -- SOIL AND WATER QUALITY PROBLEMS -- Soil Quality -- Water Quality -- Surface Water Quality -- Groundwater Quality -- Environmental Risks -- SEARCH FOR SOLUTIONS -- Factors Influencing Solutions -- State and Local Government Policies -- Characteristics of the Agricultural Sector -- TIME TO MOVE AHEAD -- 2 Opportunities to Improve Soil and Water Quality -- CONSERVING AND ENHANCING SOIL QUALITY -- Defining Soil Quality -- Importance of Soil Quality -- Agricultural Productivity -- Water Quality -- Global Climate -- Soil Policy Goals -- Erosion Control Alone is Not Sufficient -- Soil Degradation as an Environmental Problem -- Measurement of Soil Quality -- National-Level Assessments of Soil Quality -- Assess Currently Available Data -- Soil Management at the Farm Level -- Soil Quality Thresholds -- Soil-Specific Management -- Promise of New Technology -- Better Use of Available Information -- INCREASING INPUT USE EFFICIENCIES.

Mass Balance between Inputs and Outputs -- Increased Input Efficiency -- Improving Nitrogen Management -- Reduction of Residual Nitrogen in the Farming System -- Nitrogen Mass Balances -- Refining Fertilizer Recommendations -- Realistic Yield Goals -- Accounting for All Sources of Nitrogen -- Synchronizing Fertilizer Applications with Crop Needs -- New and Improved Tools -- Improving Phosphorus Management -- Phosphorus Cycle -- Transport Processes -- Phosphorus Mass Balance -- Control Phosphorus Buildup in Soil -- Thresholds for Phosphorus Levels in Soil -- Improving Manure Management -- Nutrient Value of Manures -- Manure Is an Important Source of Water Pollution -- Obstacles to Improving Manure Management -- Livestock Concentration -- Nitrogen and Phosphorus Buildup after Repeated Applications -- High Capital Costs -- Special Emphasis on Manure Management -- Improving Pesticide Management -- Constraints to Making General Recommendations -- Reducing the Total Mass of Pesticides Used -- Pesticide Mass Balance -- Improved Pesticide Use Efficiency -- Integrated Pest Management -- Design Better Pesticides -- Improve Pesticide Application Practices -- Match the Pesticide to Site Conditions -- Alternative Pest Control Technologies -- Improving Irrigation Management -- Disposal of Drainage Water -- Reduction of the Volume of Drainage Water -- New Cropping Systems -- Technical Constraints to Input Management -- Economic Constraints to Input Management -- Managing Cropping Systems -- INCREASING RESISTANCE TO EROSION AND RUNOFF -- Time Lag of Sediment Load Reductions -- Protecting Stream Channels -- Resistance to Episodic Damage -- Conservation Tillage and Residue Management -- Develop New Cropping Systems -- Probability Analysis -- CREATING FIELD AND LANDSCAPE BUFFER ZONES -- Creating Managed Buffer Zones -- Protection of Existing Natural Vegetation.

Balance Needed -- 3 A Systems Approach to Soil and Water Quality Management -- LINKAGES AMONG OBJECTIVES -- LINKAGES AMONG PROGRAMS -- ADVANTAGES OF FARMING SYSTEMS APPROACH -- Variability -- Targeting -- Integration -- Win-Win Opportunities -- Adaptability -- FARMING SYSTEM AS UNIT OF ANALYSIS AND MANAGEMENT -- Integrated Farming System Plans -- Rigorous Planning Standards -- Soil Quality -- Input Use Efficiency -- Resistance to Erosion and Runoff -- Buffer Zones -- Need for Performance Standards -- Use of Models -- Purposes, Advantages, and Limitations of Modeling -- Models of Nonpoint Source Pollution -- On-Farm Record Keeping -- Developing Capacity at the Local Level -- Public-Sector -- Private-Sector -- TARGETING PROBLEM AREAS AND FARMS -- Soil and Water Quality Monitoring -- Soil Quality -- Water Quality -- Monitoring Production Practices -- Problem Farms -- Monitoring Progress -- Refine Strategies to Change Producer Behavior -- Regional and National Data Collection -- IMPLEMENTING A SYSTEMS APPROACH -- Limited Funding -- New Sources of Funds -- 4 Policies to Protect Soil and Water Quality -- ENVIRONMENTAL AND AGRICULTURAL POLICY -- A Brief History -- Incremental Redesigning of Agricultural Policy -- Incentives are Perverse -- Incremental Reform -- Increasing Planting Flexibility -- Nonincremental Reform of Agricultural Policy -- Limitations of Commodity Program Reform -- Effects of Program Elimination -- Environmental Policies for Environmental Goals -- FACTORS AFFECTING PRODUCERS' DECISIONS -- CONTINUUM OF POLICIES -- Research and Development -- Understanding Producers -- Technical Innovation -- Technical and Financial Assistance -- New Approaches -- Potential for Change -- Market-Based Incentives -- Facilitating Changes in Land Use -- Long-Term Easement Program -- Advantages of Easements -- Implementing an Easement Program.

Need for Nonvoluntary Approaches -- State and Local Legislation -- Evaluating the Role for Regulation -- Implications of the Structure of Agriculture for Regulation -- Clarifying Landowner Responsibilities and Rights -- Advantages of Defining Rights and Responsibilities -- Implementation -- PART TWO -- INTRODUCTION Soil, Water, and Farming Systems -- 5 Monitoring and Managing Soil Quality -- DEFINING SOIL QUALITY -- IMPORTANCE OF SOIL QUALITY -- Soil Quality and Agricultural Productivity -- Effect of Soil Degradation on Productivity -- Effect of Soil Degradation on Costs of Production -- Sustaining Soil Quality Is Essential to Improving Agricultural Productivity -- Soil Management -- Soil Quality and Water Quality -- Direct Effects -- Indirect Effects -- Soil Quality and Water Quality Are Linked -- Soil Quality and the Global Climate -- Soil Quality as a Long-Term Goal of Soil Management -- National Assessments of Soil Resources -- Soil Quality and Soil Conservation -- Soil Quality and Sustainability -- IMPORTANCE OF MONITORING CHANGES IN SOIL QUALITY -- Indicators of Soil Quality -- Minimum Data Set -- Nutrient Availability -- Organic Carbon -- Labile Carbon -- Texture -- Water-Holding Capacity -- Structure -- Rooting Depth -- Acidity and Alkalinity -- Pedotransfer Functions -- Quantifying Soil Quality -- Indicators of Productivity -- Indicators of Water Regulation -- Indicators of Buffering Capacity -- Temporal and Spatial Variabilities -- Temporal Variability -- Spatial Variability -- EXTENT OF DEGRADATION OF U.S. SOILS -- Physical Degradation -- Erosion -- Erosion Estimates -- Effect of Erosion on Soil Quality -- Compaction -- Surface Soil Compaction -- Subsoil Compaction -- Alleviation of Subsoil Compaction -- Corn Yield Response to Subsoil Compaction -- Chemical Degradation -- Salinization -- Acidification -- Biological Degradation.

Organic Matter Content -- Carbon from Biomass -- Soil Fauna Activity and Diversity -- Effects of Biological Degradation -- 6 Nitrogen in the Soil-Crop System -- THE NITROGEN CYCLE -- Mineralization -- Nitrification -- Immobilization -- Denitrification -- Interactive Processes -- NITROGEN MASS BALANCE -- Nitrogen Inputs -- Nitrogen in Fertilizers -- Nitrogen Fixed by Legumes -- Nitrogen in Animal Manure -- Nitrogen in Crop Residue -- Other Nitrogen Inputs -- Nitrogen in Rainfall -- Nitrogen in Irrigation Water -- Soil Nitrogen and Mineralization -- Nitrogen Outputs -- Nitrogen in Crops and Residues -- Nitrogen Balance -- Losses to the Environment -- Losses to the Atmosphere -- Losses to Surface Water and Groundwater -- OPPORTUNITIES TO REDUCE NITROGEN LOSSES -- Accounting for Nitrogen from All Sources -- Regional Nutrient Balances -- Farm Nitrogen Balances -- Improving Nitrogen Management -- Soil Testing -- Improving Estimates of Crop Nitrogen Needs -- Economically Optimum Rate of Nitrogen Application -- More Refined Models Needed -- Determining Realistic Yield Goals -- Synchronizing Applications with Crop Needs -- New Tools for Nitrogen Management -- Obstacles to Better Nitrogen Management -- Economic Obstacles -- Seasonal Obstacles -- Cropping Systems as a Nitrogen Management Tool -- 7 Phosphorus in the Soil-Crop System -- THE PROBLEM OF PHOSPHORUS DELIVERY TO SURFACE WATERS -- SOURCES OF PHOSPHORUS -- Point Sources -- Agricultural Sources of Phosphorus -- Forms and Bioavailability of Phosphorus -- Soluble Phosphorus -- Particulate Phosphorus -- Total Phosphorus -- PHOSPHORUS IN THE SOIL-CROP SYSTEM -- The Phosphorus Cycle -- Mass Balance -- Phosphorus Inputs -- Phosphorus Outputs -- Phosphorus Buildup in Soils -- TRANSPORT PROCESSES -- Leaching and Subsurface Flow -- Surface Flow -- Soluble Phosphorus Losses.

Sediment and Sediment-Bound Phosphorus Losses.