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

What are primary mediators, Primary mediators are those, which are produced...

Primary mediators are those, which are produced before degranulation. These primary mediators are stored in granules. Some of the primary mediators are histamine, heparin, protease

Explain the dietary fibre and colon cancer, Explain the Dietary fibre and c...

Explain the Dietary fibre and colon cancer? The relationship between colorectal cancer and dietary fibre remains complex. Although a cause-and-effect relationship between fibre

Determine some common micronutrient deficiencies, Determine some Common Mic...

Determine some Common Micronutrient Deficiencies? Vitamin A deficiency Iron deficiency anaemia Iodine deficiency disorders Zinc deficiency

A brief history of heart surgery, A brief history of heart surgery : The d...

A brief history of heart surgery : The dawn of Paediatric cardiac surgery was on August 26, 1938 when Robert, Gross, at the boston Children's Hospital, ligated ductus arteriosus

Explain catalyzed and non-catalyzed reactions, Is there a difference betwee...

Is there a difference between the initial and the final energy levels in catalyzed and non-catalyzed reactions? The catalysis does not alter the energetic state of reagents and

What are the homologous chromosomes, Q. What are the homologous chromosomes...

Q. What are the homologous chromosomes? Which are the human cells that do not have homologous chromosomes? Chromosomes contain genes genetic information in the form of nucleoti

Hirudinea - feeding and digestion in annelids, Hirudinea - Feeding and Dige...

Hirudinea - Feeding and Digestion in Annelids Hirudinea involves free living and ectoparasitic leeches. Leeches are blood suckers. The digestive system contains a preoral cham

Changes in chromosome number, Aneuploidy : One or inore chron~osomes of a n...

Aneuploidy : One or inore chron~osomes of a normal set nlay bc lacking or present in excess. The term riullison~y refers to absence of both the chromosomes of a pair. Monosomy, tri

Create a dichotomous key for ant, Create a dichotomous key the following or...

Create a dichotomous key the following organisms, ant, butterfly, fly, beetle, grass hopper, wasp, ladybug, roach and dragonfly.

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