| A | B |
|---|
| soil formation | the mixing of rock and organic matter to form soil |
| soil components | the different parts of the soil |
| pores | spaces in the soil between soil particles |
| nutrients | substances that plants and animals need to get from the soil to remain healthy and growing |
| humus | decomposed remains of plants and animals |
| inorganic matter | soil that has come from the breakdown of rocks |
| organic matter | soil that has come from living things |
| weathering | when rocks are broken down into particles that make soil |
| organisms | living things |
| soil organisms | living things in the soil |
| sand | large soil particles from 0.02 to 2mm in diameter |
| silt | medium sized soil particles from 0.002 to 0.02mm in diameter |
| clay | small soil particeles less tjan 0.002mm in diameter |
| soil texture | the amount of sand silt and clay in the soil |
| loam | soil that has a reasonable mixture of particles sizes |
| parent material | the rock layer from which a soil has developed |
| micro organisms | livings things only seen through a microscope |
| legumes | plants in the pea family |
| mycelium | fungus with a network of interwoven threads |
| mycorrhiza | a mycelium that grows around the root so it can obtain more nutrients |
| cultivate | plough or harrow soil to form a seedbed |
| tilth | the structure of the soil after cultivation |
| aerate | increase the amount of air in |
| casts | worm poos |
| soil erosion | soil that is carried away by wind water or landslide |
| leaching | loss of nutrients as they get washed down through the soil |
| nodules | nitrogen fixing bacteria on the roots of some plants |
| acidic soil | soil with a pH less than 7.0 |
| alkaline soil | soil with a pH more than 7.0 |
| neutral soil | soil with a pH of 7.0 |
| soil acidity | the pH level of the soil |
| lime | crushed limestone rock used to increase pH |
| soil structure | how soil particles and organic matter group in the soil |
| flocculate | bring clay particles together into larger clusters called flocks |
| pH 5.8 to 6.6 | the best soil acidity range for plant growth |
| aggregate | a group of soil particles and organic matter than cling together |
| granules | small aggregates up to 5mm in diameter |
| crumbs | medium sized aggregates 5 to 20mm in diameter |
| clods | large aggregates 20 to 50mm in diameter |
| topsoil | the topmost layer of the soil |
| subsoil | the lower soil layer |
