Soil conservation measures mainly aim at protecting topsoil which is rich in humus and nutrients making it fertile to grow plants.

The water holding capacity is the highest in clayey soil

For planting paddy (rice), clayey soil that is rich in organic matter and have a good water retaining capacity is ideal

No, it is because different types of soil has different absorbing capacity of water.

Percolation rate of water is highest in the sandy soil, while the lowest in the clayey soil.

The rotting dead matter in the soil is called humus.

Clayey soil and loamy soil are rich in humus and are suitable for growing plants like wheat and gram.

(a) It is because these substances pollute the soil. They also kill the organisms living in the soil.
(b) Substances which pollute the soil are a number of waste products, chemicals, pesticides, polythene bags and plastics.
(c) Alertness, responsibility and ecofriendly nature

No, it is not a good practice to remove grass and small plants growing in an open, unused field because the plants cover the soil surface. Their roots bind the soil particles, holding and adhering them in place. It helps in preventing the topsoil from being washed off during heavy rain, floods and winds. In this way, soil erosion is prevented and topsoil layer is preserved for growing more plants.

The man digging a pit could dig with ease initially because of th~\presence of topsoil and subsoil (mainly comprising of humus and nutrients). But as he digs deeper, he finds it difficult to dig beyond a depth of 5 feet as lower layers are made up of small partially weathered rocks with cracks, crevices and with bedrock which make it hard to dig.

Soil in field A is sandy soil while in field B soil is clayey soil which has low percolation rate and water-logging is seen. Since, paddy requires lot of standing water, therefore it is grown in field B.

Given, amount of water = 960 mL
Time taken to percolate = 120 min
The rate of percolation will be
= \(\frac { amount\quad of\quad water(in\quad ml) }{ Percolationtime(inmin) } =\frac { 960ml }{ 120min } =8mL/min\)
Percolation rate = 8 mL/min

Raw soil differs from baked soil. The raw soil is white or dull blackish coloured soil. It contains water and air in it and can be moulded.
Baked soil is the heated raw soil which lost its water molecule due to heating and becomes red. Once the soil gets heated, it cannot be moulded into other form. Clay soil is used for making matkas, toys, pots, etc. The soil is kneaded along with horse dung to make best quality of raw clay soil. This kneaded soil is then placed on the wheel and appropriate shape is given. The final shape of the material is given with hands. The pots and matkas are then kept for drying for three days. These items are baked at high temperature after drying in air and then coloured.

Ans. Yes, soil erosion does not occur easily where the land is covered by vegetation (trees and other plants). It occurs easily in those areas of land which are not covered by vegetation (trees and other plants) or have very little vegetation. If there is vegetation on land,
(i) then the roots of vegetation growing in the soil bind the particles of topsoil firmly. Due to this, the blowing wind and flowing rainwater are not able to carry away topsoil and hence soil erosion does not occur.
(ii) then much of the falling rain hits the trees and plants before it hits the soil. In this way, the cover of vegetation softens the effect of heavy rains on the soil