The soil is enriched of dissolved ions and inorganic salts because of

(1) Raining

(2) Leaching

(3) Weathering

(4) Erosion

Which of the following is not true about soil?
P. Soil not only supplies minerals but also harbours nitrogen fixing bacteria and other microbes
Q. It holds water
R. It supplies air to the roots
S. It acts as a matrix that stabilises the plant
T. It is a source of photosynthate
U. It is positively geotropic without any exception

1. S, T and U
2. T and U
3. S and U
4. R and T

Which of the following micronutrients does not form components of fertiliser?

Nitrogen:
Find the incorrect one.
1. Plants compete with microbes for it.
2. It is a limiting nutrient for both natural and agricultural ecosystem
3. Nitrogen has triple covalent bonds
4. Nitrogen fixation is conversion of nitrogen into nitrate

In nature, ……….. and ……….. provide enough energy to convert Nitrogen to nitrogen oxides (NO, NO₂, N₂O).

Decomposition of organic nitrogen of dead plants and animals into ammonia is called

Which of the type of fixation leads to fixation of atmospheric nitrogen to ammonia?

Electrical nitrogen fixation leads to

Ammonia is first oxidized to nitrite by the bacteria except

Consider the following statements:
Regarding plant mineral nutrition -
I. The deficiency symptoms of nitrogen, potassium and magnesium are visible first in senescent leaves.
II. Manganese inhibits calcium translocation in shoot apex.
III. Lack or low level of N, K, S, Mo causes an inhibition of cell division.
Which of the above statements are true?
1. I and II only           2. I and III only
3. II and III only         4. I, II, and III