Jackie Clark, age 13, of Shreveport,.La., for her question:

WHEN DID CONSERVATION EFFORTS START IN AMERICA?

Conservation is the use of natural resources in ways that do not destroy, damage or waste them. Natural resources that are necessary for all life on earth include air, soil, water, plants, animals and minerals. True conservation started in America around the beginning of the 20th Century.

Soil is one of the most important of all natural resources. Food crops, feed for livestock, trees for fuel, buildings and furniture and all plants are supported by the soil. Soil erosion started to became a serious problem in America during the early colonial days.

Most of the early colonists had lived in areas where the rains fell gently. In the North American climate, however, rain storms often brought violent downpours. Farmers in the colonies did not know how to conserve the soil in the new climate.

It didn't take farmers long to discover that the best soil was being carried away by water erosion. Sometimes all topsoil was washed away until only red clay was left. By 1775, many rivers in the colonies had become black with mud.

Farmers were soon abandoning the used up land and moving to new sites.

It was not until President Abraham Lincoln's time that the government established the Department of Agriculture to improve soil and farming methods and increase food production.

As the 20th Century started, the federal government began to provide money for programs of conservation. Also, citizens formed societies to help save natural resources.

But it wasn't until about 1930 that the real causes of soil erosion were understood. Soil scientist Hugh Bennett, backed by the government, headed a government sponsored soil conservation program.

And in 1935, Congress passed the Soil Conservation Act which recognized the harmful effects of erosion and created the Soil Conservation Service. This group helped people plan the use of the land so the soil would not be damaged.

The Soil Conversation Service, an agency of the U.S. Department of Agriculture, works with people who own or use the land. Most of these people are farmers or ranchers. Some are people who build houses and roads or plan communities.

The Soil Conservation Service helps these people plan the use of land so the soil will not be damaged. More than 3,000 soil conservation districts have been formed. Through these districts people carry out soil and water conservation programs in their own communities.

Here are some of the ways farmers prevent erosion and improve the soil's fertility: contour farming, or plowing and planting across the slopes and around the hills; contour strip cropping, or planting contour strips side by side with strips of grass or clover; terracing of steep slopes; rotating crops; building ponds to store water; cover cropping to protect soil from wind erosion; planting trees on steep slopes and as windbreaks; improving rangeland; fertilizing to replace natural chemicals removed through crop growing.