Effect of ph or nutrient availability, Biology

Assignment Help:

Effect of pH or Nutrient Availability

One of the greatest influence of pH on plant growth is through its effect on the nutrient availability. When base saturation is less than 100 per cent, an increase in pH is associated with an increase in the amount of calcium and magnesium in the soil solution, because calcium and magnesium are usually the dominant exchangeable bases. Many studies have shown that plant growth is promoted with increase in percentage of calcium in plants, which in turn is governed by the increasing pH or percentage base saturation. The general relationship between pH and availability of calcium and magnesium and other nutrients is shown in figure below.

1727_realation to soli ph.jpg

Availability of molybdenum increases at higher pH (see figure above). At low pH, molybdenum forms insoluble compounds with iron and is rendered unavailable. Under these conditions, plants like cauliflower, clover and citrus will suffer from molybdenum deficiency but will show better perfonnance when soil pH is increased. Potassium availability is usually good in alkaline soils that reflect the limiting leaching and removal of exchangeable potassium. The availability or solubility of some plant nutrients decreases at higher pH. Iron and manganese which are generally deficient in calcareous soils are two good examples. Phosphorus and boron also tend to be unavairable in acid soils. On the other hand copper and zinc have reduced availabiliry in both highly acidic and alkaline soils. The overall nutrient availability is good at close to pH 6.5.

Another aspeq of soil chemistry not indicated in the figure above is that at extremes of pH, the balance among nutrients becomes unfavourable, and certain nutrients become excessively soluble as to be toxic. For example, at low pH Al, Fe, Mn, Zn and Cu are excessively released to become toxic. The H and OH ions themselves are directly injurious below pH 4 or above 9.

 


Related Discussions:- Effect of ph or nutrient availability

Cells, List structures found in unicellular organisms that are an adaptatio...

List structures found in unicellular organisms that are an adaptation to their free-living life and are not usually found in the cells of multicellular organisms.

What is the significance of rhynchocoel, What is the significance of Rhynch...

What is the significance of Rhynchocoel? The unique body cavity of the Nemertean worms, which comprise the retractable proboscis. There is some debate on whether this is a true

Floral induction, Floral Induction The transformation of vegetative ap...

Floral Induction The transformation of vegetative apex into a floral apex is a multifactor and multistep phenomenon. Despite researches on flowering carried out during the las

Plant cell wall react when it is placed in hypotonic medium, How does the p...

How does the plant cell wall react when it is placed under hypotonic medium? Ans) The plant cell wall (the covering of the cell outside to the cell membrane) is made of cellulos

Protozoa, which symbiotic protozoa present in digestive tract of termites?

which symbiotic protozoa present in digestive tract of termites?

What is the indication of chronic pulmonary thromboembolism, Chronic Pulmon...

Chronic Pulmonary Thromboembolism :  The operation recommended is pulmonary thrombo endarterectomy. Indication :  The main indication for surgery is when patients with chroni

HUMAN SKELETON, What are the main components of the human skeleton?

What are the main components of the human skeleton?

How is the cerebrum anatomically divided, Q. How is the cerebrum anatomical...

Q. How is the cerebrum anatomically divided? The cerebrum is divided into two cerebral hemispheres, the left and the right. Each hemisphere is made of four cerebral lobes: pari

Placenta, PLACENTA - A common tissue of foetus & mother (uterus) which ...

PLACENTA - A common tissue of foetus & mother (uterus) which is physical, physiological & endocrinal connection is known as placenta. FUNCTIO N - To provide nutrients

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd