| A | B |
|---|
| Soil fertility | soil's ability to support plant growth |
| How much of the world's food comes from the land? | 90% |
| weathering | breakdown of rocks, natural processes |
| organic fertilizers | plant animal waste compost, manure |
| inorganic fertilizer | chemical formulation of nutrients |
| transpiration | loss of water by plants |
| stomata | plant pores |
| infiltrate | soils ability to allow water to soak in |
| water holding capacity | ability of soil to hold water |
| evaporative water loss | liquid to gas on soils surface |
| ph 7 | neutral |
| 1-6 | acidic |
| 8-16 | basic |
| hydroponics | culture plants without soil |
| sand | individual rock particles: 2mm-0.05mm |
| silt | finer particles 0.05-0.002 |
| clay | microscopic |
| loam | 40%sand, 40%silt, 20%clay |
| humus | residue of partly decomposed orgainc matter |
| composting | The process of letting orgainc waste decompose presence of air |
| topsoil | clumpy loose humus rich soil |
| subsoil | densly packed lacks humus and soil organisms |
| soil profile | reveals the layering of soil |
| nematode | small worm |
| splash erosion | compaction of soil that results rain hits bare soil |
| sheet erosion | even layer soil removed runoff |
| erosion | process of soil and humus carried away by water or wind |
