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Schematic of photosynthesis in plants. The carbohydrates produced are stored in or used by the plant. Composite image showing the global distribution of photosynthesis, including both oceanic phytoplankton and terrestrial vegetation. Dark red and blue-green indicate regions of high photosynthetic activity in the ocean and on land, respectively.
Humus has a characteristic black or dark brown color and is an accumulation of organic carbon.Besides the three major soil horizons of (A) surface/topsoil, (B) subsoil, and (C) substratum, some soils have an organic horizon (O) on the very surface.
Topsoil is composed of mineral particles and organic matter and usually extends to a depth of 5-10 inches (13–25 cm). Together these make a substrate capable of holding water and air which encourages biological activity. There are generally a high concentration of roots in topsoil since this is where plants obtain most of their vital nutrients.
Wilting point describes the dry limit for growing plants. During growing season, soil moisture is unaffected by functional groups or specie richness. [63] Available water capacity is the amount of water held in a soil profile available to plants. As water content drops, plants have to work against increasing forces of adhesion and sorptivity to ...
Soil biology plays a vital role in determining many soil characteristics. The decomposition of organic matter by soil organisms has an immense influence on soil fertility, plant growth, soil structure, and carbon storage. As a relatively new science, much remains unknown about soil biology and its effect on soil ecosystems.
The dry matter consists mainly of carbon, oxygen, and hydrogen. Although these three elements make up about 92% of the dry weight of the organic matter in the soil, other elements present are essential for the nutrition of plants, including nitrogen, phosphorus, potassium, sulfur, calcium, magnesium, and many micronutrients. [1]
The choice of growing media and components to the media help support plant life. Within a greenhouse environment, growers may choose to grow their plants in an aquaponic system where there is no soil used. Growers within a greenhouse setting will often opt for a soilless mix which does not include any actual components of naturally occurring soil.
A leaf (pl.: leaves) is a principal appendage of the stem of a vascular plant, [1] usually borne laterally above ground and specialized for photosynthesis.Leaves are collectively called foliage, as in "autumn foliage", [2] [3] while the leaves, stem, flower, and fruit collectively form the shoot system. [4]