AP BIOLOGY

Detailed explanation-1: -Add home-made garden compost, bagged compost or well-rotted manure. As a rule, add a minimum 5cm layer of organic matter over the surface before digging or forking it in. These organic fertilisers are more beneficial to soil bacteria than inorganic compounds.

Detailed explanation-2: -Parent material, Soil texture, Slope gradient, Vegetation cover, Rainfall, Land use intensity, Previous land use type, and Terraces (presence of), Water storage capacity. Average soil depth for each soil mapping unit.

Detailed explanation-3: -Soil depth can greatly influence the types of plants that can grow in them. Deeper soils generally can provide more water and nutrients to plants than more shallow soils. Furthermore, most plants rely on soil for mechanical support and this is especially true for tall woody plants (e.g., shrubs, trees).

Detailed explanation-4: -The effective depth of a soil for plant growth is the vertical distance into the soil from the surface to a layer that essentially stops the downward growth of plant roots. The barrier layer may be rock, sand, gravel, heavy clay, or a cemented layer (e.g. caliche).