![]() | 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 |
NOTE: For a more detailed description of tillage equipment, see the PC/ICE Traditional Field Crops Manual.
Hand Implements: Digging hoes, shovels, turning forks, and rakes are very effective for smaller areas. By using the double-digging method (described later in this chapter), the subsoil can be loosened too.
Wooden Plow: Designs date back many centuries; they're animal drawn, and some have a metal tip. They do not invert (turn over) the soil or bury crop residues like a moldboard plow but basically make grooves through the soil. Wooden plows penetrate about 15-20 cm deep.
Moldboard Plow: Depending on its size and the condition of the soil, it penetrates 15-25 cm deep and inverts the furrow slice, making it very effective for burying weeds and crop residues. (Bulky residues like maize stalks must be chopped up first.) Both animal- and tractor-drawn models are used. Moldboard plows aren't as well suited to dry soils, as disk plows and don't handle rocky soils as well. They also don't work well in sticky, clayey soils.
Disk Plow: Better suited than the moldboard to hard, clayey, rocky, or sticky ground but won't bury residues as well; however, this is an advantage in drier areas where leaving residues on the surface cuts down wind and water erosion and reduces moisture evaporation. Nearly all disk plows are tractor drawn.
Rototillers (rotovators) are available in self-powered and tractor-drawn models. They thoroughly pulverize the soil and partially bury crop residues. Heavy duty models can be used for a once-over tillage job. However, their power and fuel requirements are high, and they can easily over-pulverize a soil and destroy its beneficial crumb structure.
Disk Harrow: These are available in animal- or tractor-drawn models and are commonly used after plowing to break up clods, control weeds, and smooth the soil before planting. They are also useful for chopping up coarse crop residues before plowing, but heavier models with scalloped (notched) disks are best for this purpose. Disk harrows are expensive and prone to frequent bearing failure unless regularly greased. Large, heavy duty versions called Rome plows, which are drawn behind big tractors, can sometimes substitute for plowing. Disk harrows cut, throw, and loosen the top 8-15 cm of soil but pack down the soil immediately below that. Repeated harrowing, especially when the soil is moist, can cause compaction in the lower topsoil.