2005). With the exception of C, H, and O, which plants obtain from air and water, plants derive the remaining 14 elements from the soil or through fertilizers, manures, and amendments (Parikh ...

Soil is a mixture of tiny particles of rock, dead plants and animals, air and water. Different soils have different properties depending on their composition. Sandy soil is pale coloured and has ...

When European-American settlers first began ploughing in Iowa, they found the weather and local geology had combined this organic mulch with sand and silt to form a nutrient-rich type of soil ...