Essential chemical elements absorbed from the soil in the form of inorganic ions.
the layer of soil on the surface
A distinct layer of soil, such as topsoil.
a rich soil consisting of a mixture of sand and clay and decaying organic materials
partially decomposed organic matter
A process in which positively charged minerals are made available to a plant when hydrogen ions in the soil displace mineral ions from the clay particles.
chemicals that promote plant growth esp. N, P and K
a way of supplying water to an area of land
condition in which the earth's surface is worn away by the action of water and wind
nitrogen fixing bacteria
bacteria that can use nitrogen in soil to make nitrogen compounds
the assimilation of atmospheric nitrogen by soil bacteria and its release for plant use on the death of the bacteria
an enzyme of nitrogen-fixing microorganisms that catalyzes the conversion of nitrogen to ammonia
bumps on the roots of certain plants that house nitrogen-fixing bacteria
form when Rhizobium are contained within vesicles in the root cell
symbiotic bacterium that lives in nodules on roots of specific legumes and fixes nitrogen gas from the air into a form of nitrogen plants require
mutualistic partnerships between fungi and the roots of certain plants
mychorrhizae with a dense sheath or mantle of mycelium over the root surface
mychorrhizae with no sheath that extend a fine fungal hyphae into the soil
plants such as mosses, lichens, and orchids, that grow on other plants but do not take nutrients from them