Factors Affecting P fixation

Question 1

– P is retained to a greater
extent by 1:1 type of silicate clay than
2:1 type of clay

Answer 1

Type of clay

Question 2

– the greater the time the
soil and added P are in contact, the
greater the amount of fixation

Answer 2

Time of reaction

Question 3

– warm climate fixed greater
amount of P than cooler climate. Give
rise to soil with higher content of
hydrous oxide of Fe & Al

Answer 3

Temperature

Question 4

– This is a process by
which exchangeable or soluble potassium
get trapped in the interlayers of 2:1 clay
minerals (vermiculite, illite, montmorillonite
etc).

Answer 4

Potassium fixation

Question 5

– plant residues,animal residues

        water

Answer 5

Organic sources

Question 6

b) inorganic
fertilizers, primary minerals, rain water

Answer 6

Inorganic sources –

Question 7

•In soils they become deficient in oxygen as by flooding, sulfate concentration falls and sulfide level increases. This is due to the increase activity of sulfate reducing bacteria.

Answer 7

Sulfate Reduction

Question 8

Organic matter is an
important secondary source of some of the
trace elements. They seem to held by
complex combinations by the organic
colloids. Each of the micronutrients cations

Answer 8

Organic forms –

Question 9

are organic compounds that
combines with cations, but protecting
these cation from harmful inorganic
reaction. At the same time, the chelated
nutrients can be utilized by growing plants

Answer 9

Chelates