 | Soils, Crops and Fertilizer Use |
 |  | About this manual |
| | Acknowledgements |
|  | Chapter 1: Down to earth - Some Important Soil Basics |
| | What is soil, anyway? |
| | Why do soils vary so much? |
| | Topsoil vs. subsoil |
| | The mineral side of soil: sand, silt, and clay |
| | Distinguishing "tropical" soils from "temperate" soils |
| | Organic matter - a soil's best friend |
| | The role of soil microorganisms |
| | Chapter 2: Trouble-shooting soil physical problems |
| | Getting to know the soils in your area |
| | Soil color |
| | Soil texture |
| | Soil tilth |
| | Soil water-holding capacity |
| | Soil drainage |
| | Soil depth |
| | Soil slope |
| | Chapter 3: Basic soil conservation practices |
| | Rainfall erosion |
| | Wind erosion |
| | Chapter 4: Seedbed preparation |
| | The what and why of tillage |
| | Common tillage equipment |
| | The abuses of tillage and how to avoid them |
| | Making the right seedbed for the crop, soil, and climate |
| | How deep should land be tilled? |
| | How fine a seedbed? |
| | Some handy seedbed skills for intensive vegetable production |
| | Chapter 5: Watering vegetables: When? How Often? How Much? |
| | It pays to use water wisely |
| | Some common watering mistakes and their effects |
| | Factors influencing plant water needs |
| | Ok, so get to the point! how much water do plants need and how often? |
| | Some methods for improving water use efficiency |
| | Chapter 6: Soil fertility and plant nutrition simplified |
| | Let's Make a Deal |
| | How plants grow |
| | Available vs. unavailable forms of mineral nutrients |
| | Soil negative charge and nutrient holding ability |
| | Soil pH and how it affects crops growth |
| | Important facts on the plant nutrients |
| | Chapter 7: Evaluating a soil's fertility |
| | Soil testing |
| | Plant tissue testing |
| | Fertilizer trials |
| | Using visual "hunger signs" |
| | Chapter 8: Using organic fertilizers and soil conditioners |
| | What are organic fertilizers? |
| | Organic vs. chemical fertilizers: which are best? |
| | Some examples of successful farming using organic fertilizers |
| | How to use organic fertilizers and soil conditioners |
| | Chapter 9: Using chemical fertilizers |
| | What are chemical fertilizers? |
| | Are chemical fertilizers appropriate for limited-resource farmers? |
| | An introduction to chemical fertilizers |
| | Common chemical fertilizers and their characteristics |
| | The effect of fertilizers on soil pH |
| | Fertilizer salt index and "burn" potential |
| | Basic application principles for N, P, and K |
| | Fertilizer application methods explained and compared |
| | Troubleshooting faulty fertilizer practices |
| | Getting the most out of fertilizer use: crop management as an integrated system |
| | Understanding fertilizer math |
| | Chapter 10: Fertilizer guidelines for specific crops |
| | Cereals |
| | Pulses (grain legumes) |
| | Root crops |
| | Vegetables |
| | Tropical fruit crops |
| | Tropical pastures |
| | Chapter 11: Liming soils |
| | The purpose of liming |
| | When is liming needed? |
| | How to measure soil pH |
| | How to calculate the actual amount of lime needed |
| | How and when to lime |
| | Don't overlime! |
| | Chapter 12: Salinity and alkalinity problems |
| | How salinity and alkalinity harm crop growth |
| | Lab diagnosis of salinity and alkalinity |
| | Appendixes |
| | Appendix A: Useful measurements and conversions |
| | Appendix B: How to determine soil moisture content |
| | Appendix C: Spacing guide for contour ditches and other erosion barriers* |
| | Appendix D: Composition of common chemical fertilizers |
| | Appendix E: Hunger signs in common crops |
| | Appendix F: Legumes for green manuring and cover-cropping in tropical and subtropical regions |
| | Appendix G: Some sources of technical support |
| | Appendix H: A bibliography of useful references |
Chapter 7: Evaluating a soil's fertility
Deciding how much and what kind of fertilizer a farmer needs for her crops is a twostage process:
1. The soil's present fertility level should be evaluated, ideally by soil testing.
2. Once the soil's present state of fertility is known, the most appropriate kinds and amounts of fertilizers can be determined, considering the following factors:
• Type of crop
• Feasible yield goal as determined by:
•• Yield-limiting factors such as available moisture, soil characteristics, weather, pests, and diseases.
•• Farmer management level
•• Available capital for needed inputs
• Expected cost/return based on likely yield and market value (more difficult to predict with vegetable crops than field crops).
In this chapter, we'll focus on stage 1 and cover the following methods of evaluating a soil's fertility:
• Soil testing
• Plant tissue testing
• Fertilizer trials
• Spotting visual "hunger signs"
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