(a)HumusAnswer
(b) Horizons
(c) Sandy soil
(d)Silt
a. Horizon CAnswer
b. Horizon B
c. Horizon A
d. Horizon C
e. Horizon B
f. Horizon A
g. Horizon C
h. Horizon A
Because rocks get converted to soil by weathering.Answer
Tar roads have very low porosity so to allow rain to run off into gutters, tar roads sloped on either side.Answer
(a)Water holding capacityAnswer
(b)Percolation rate
(c)Lots of humus
(d)Good amount of nutrients
The space between soil particles is filled with air which is used by organisms for their growth.Answer
The percolation rate is the rate (speed) at which water flows through the pores in the soil. The soil having high water holding capacity will have a low population rate and vice versa.Answer
(a)Sandy soil contains large coarse sand particles but loamy soil contains large and fine particles of sand.Answer
(b)Sandy soil has a very little humus while loamy soil contains a lot of humus.
(a)Inappropriate farming techniques such as the deep ploughing of the land two or three times a year to produce annual crops can lead to soil erosion. Answer
(b)Over cultivation of crops and overgrazing by animals can cause the soil to lose its structure and binding capacity, which makes it easier to erode.
Because it is very dense and less porous that does not allow the water to percolate.Answer
The excessive use of chemical fertilizers reduces the fertility of the soil. It makes the soil hard and less porous. It also kill soil organisms which keep the soil fertile.Answer
A cover crop is grown to cover the land after harvesting the main crop. Cover crops prevent soil from being exposed to wind and flowing water, which prevent soil erosion.Answer
The force of wind and water can also be reduced by growing trees and shrubs on the boundaries of the fields. Rows of plants on the boundaries of fields are known as shelter belts.
(a)Sandy soil contains large coarse sand particles while clayey soil contains fine particles made of clay.
(b)Sandy soils have a lot of air spaces between the particles while clayey soil have little air spaces between particles.
(c)Sandy soil is very porous while clayey soil is very dense and less porous.
(d)Sandy soil has little plant nutrients while clayey soil is rich in minerals.