A History of Agriculture in India v1.c8.s1.t2: Action of Animals
A History of Agriculture in India v1.c8.s1.t2
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Action of Animals
v1.c8.s1.t2.1
The larger rodents, like rats, squirrels and rabbits, burrow into the ground and thus large quantities of partially decomposed rocks are exposed to the agencies of weathering. Earthworms and ants also help to decompose and disintegrate the rocks. They carry down vegetable matter, which on decomposition helps to break down the minerals. Earthworms pass large quantities of soil through their bodies. This passage of soil through their bodies amounts to more than 22 tonnes of soil per hectare. This process greatly helps to mix the soil with the subsoil. Worm-casts are particularly useful to the farmer, as they help to loosen and perforate the soil to facilitate the penetration of roots, water and air. These worms also drag down leaves, pieces of straw, etc., into their holes, thus incorporating organic matter into the soil, and making heavy soils lighter and light soils heavier.
v1.c8.s1.t2.2
As the soil particles become smaller, their water-holding capacity increases, as each soil particle is surrounded by a film of capillary water. This water is very effective in the decomposition of the soil particles. Hydration, oxidation and carbonation work simultaneously. These decomposition processes are always accompanied with increases in bulk and these tend to disrupt the rock and further assist to disintegrate it.