Tag: biology

• When a plant's soil pH increases the plant's ability to absorb certain nutrients is disrupted.
• A pH of 6.0 to 7.0 (slightly acidic to neutral) range is most suitable for the best growth of plants. 
  
• A most economical and effective method to control the pH of the soil is the addition of $CaCO _3$ because it increases the pH level of acidic soil, thus reducing the acidity and increasing the alkalinity of the soil.
  
• Hence the most economical and effective method to control the pH of the soil is $CaCO _3$.
• So, the correct answer is '$CaCO _3$'.

• The water holding capacity of a soil is a very important agronomical  characteristic. 
• small particles have a much larger surface area than the larger sand particles.
  
• large surface area of particle allows the soil to hold a greater quantity of water. so , option A is correct.
  

Edaphic factor is an abiotic factor relating to the physical or chemical composition of the soil found in a particular area. For example, very alkaline soil may be an edaphic factor limiting the variety of plants growing in a region.

Azotobacter is a well-known free-living nitrogen-fixing bacterium found in soil. Rhizobium is also a nitrogen fixer, but it is symbiotic (living in root nodules), while Nitrobacter is involved in nitrification, not nitrogen fixation.

Oxalophytes are the plants that grow in acidic soil that maintained at pH 5.5 as this enables the plant to absorb nutrients required for the growth.

A good soil is that which allows the water to percolate slowly into groundwater. These soils can remove pollutants and they promote the growth of healthy vegetation, which in turn reduces soil erosion. 

Soil pH is in the range of 6 to 7 for most plants but some prefer acid or alkaline conditions. At this pH soil organic matter and structure is very good. A lot of micro-organisms, that support plant growth can live in the soil at this pH.

Plants and animals aid in the development of a soil through the addition of organic matter. Fungi and bacteria decompose this organic matter into a semi-soluble chemical substance, known as humus. Larger soil organisms, like earthworms, beetles, and termites, vertically redistribute this humus within the mineral matter found beneath the surface of a soil. Humus is the biochemical substance, that makes the upper layers of the soil become dark. It is coloured as dark brown to black. 

Soil pH is important because it influences several soil factors affecting plant growth, such as :

Loam is considered ideal for gardening and agricultural uses, because it retains nutrients well and retains water, while still allowing excess water to drain away.