31.
Soil Conservation
Deserves The Highest National Priority
Why should the leaders of countries today commit their government and their people to a national programme of soil conservation?
The answer is that soil takes many years to create, but it can be destroyed in almost no time at all. With the loss of soil goes man’s ability to grow food crops and graze animals, to produce fibre and forests. It is not enough to describe the soil as a country’s greatest source of wealth; it is more than that; it is a country’s life. And in one country after another today, the soil is washing or blowing away.
The answer is that soil takes many years to create, but it can be destroyed in almost no time at all. With the loss of soil goes man’s ability to grow food crops and graze animals, to produce fibre and forests. It is not enough to describe the soil as a country’s greatest source of wealth; it is more than that; it is a country’s life. And in one country after another today, the soil is washing or blowing away.
Soil Is A Complex Mixture
Soil covers most of the land surface of the earth in a thin layer, ranging from a few centimeters to several metres deep. It is composed of rock and mineral particles of many sizes mixed with water, air, and living things, both plant and animal, and their remains.
On our scale of time, soil formation is extremely slow. Where the climate is moist and warm, it takes thousands of years to form just a few centimetres of soil. In cold or dry climates, it takes even longer, or soil may not form at all. While soil is technically a renewable resource, its slow rate of formation makes it practically irreplaceable.
Soil is a dynamic mixture, forever changing as water comes and goes and plants and animals live and die. Wind, water, ice, and gravity move soil particles about, sometimes slowly, sometimes rapidly. But even though a soil changes, the layers of soil stay much the same during one human lifetime unless they are moved or scraped, or ploughed by man.
On our scale of time, soil formation is extremely slow. Where the climate is moist and warm, it takes thousands of years to form just a few centimetres of soil. In cold or dry climates, it takes even longer, or soil may not form at all. While soil is technically a renewable resource, its slow rate of formation makes it practically irreplaceable.
Soil is a dynamic mixture, forever changing as water comes and goes and plants and animals live and die. Wind, water, ice, and gravity move soil particles about, sometimes slowly, sometimes rapidly. But even though a soil changes, the layers of soil stay much the same during one human lifetime unless they are moved or scraped, or ploughed by man.
Soil Teems With Life
It is comprised of countless species that create a dynamic and complex ecosystem and is among the most precious resources to humans.
All soil is full of life, and good soils are teeming with it. Plants and animals help keep the soil fertile. Plant roots tunnel through the soil and break it up, and decaying plants form humus. Burrowing animals mix the soil; the excrete of animals contribute nutrients and improve soil structure.
Besides the soil’s more obvious inhabitants, which include rodents, insects, mites, slugs and snails, spiders, and earthworms, there are countless microscopic residents, some helpful to man and his crops, some harmful.
Good soils seem to hold the greatest populations of bacteria. Almost without exception, bacteria are involved in basic enzyme transformations that make possible the growth of higher plants, including our food crops. From man’s point of view, bacteria may well be the most valuable of the life forms in soil.
Chemical reactions occur in the soil as a result of exchange of positive ions, or cations. More exchanges take place in clay soils than in any other type. These chemical reactions are also essential to plant growth and development and are a good index of soil fertility.
All soil is full of life, and good soils are teeming with it. Plants and animals help keep the soil fertile. Plant roots tunnel through the soil and break it up, and decaying plants form humus. Burrowing animals mix the soil; the excrete of animals contribute nutrients and improve soil structure.
Besides the soil’s more obvious inhabitants, which include rodents, insects, mites, slugs and snails, spiders, and earthworms, there are countless microscopic residents, some helpful to man and his crops, some harmful.
Good soils seem to hold the greatest populations of bacteria. Almost without exception, bacteria are involved in basic enzyme transformations that make possible the growth of higher plants, including our food crops. From man’s point of view, bacteria may well be the most valuable of the life forms in soil.
Chemical reactions occur in the soil as a result of exchange of positive ions, or cations. More exchanges take place in clay soils than in any other type. These chemical reactions are also essential to plant growth and development and are a good index of soil fertility.
