Shall we not now seek to learn which of the natural resources of our land will never be replaced if we squander them? Let us also learn which may be made good again by Nature, if we are willing to wait long enough, as well as to assist her in her slow work.
Each year the growing plants take certain substances from the soil. It is necessary for us to put back like substances if we would keep up the fertility of the soil. If we are neglectful of this law, or allow water to wash the soil away until only the bare rocks remain, poverty will be our lot for many years.
Nature will, however, if we give her a chance, renew the soil. The rocks will crumble and, by and by, seeds will sprout and tiny plants obtain a foothold. But it may take a whole lifetime, or hundreds of years, even, for a new and fertile soil to come again.
During the early years of placer mining in California thousands of acres of rich lands in the foothills were destroyed. Only boulders were left. Now fifty years have passed and a new soil is being formed, but it will be a long time yet before it will be as good as it was in the first place.
Upon the Western prairies only grain has been raised for so many years that in many places the soil will scarcely grow a crop worth gathering. Many farmers have never thought of this, but the wise ones understand that they must frequently add plant food to the soil to replace that taken by crops. They understand also that it is a good thing to change the crops grown upon any particular field from year to year, since different plants take different substances from the soil.
H. W. Fairbanks
The miner in his search for gold ruins the beautiful valley, leaving it a mass of boulders.
Water goes through a ceaseless round. It rises from the sea and lakes to form the clouds, falls as rain or snow, and then flows back down the slopes to the sea. Although we have learned that we cannot change the quantity of rain that falls in any place, we can influence the way in which it runs back to the sea. This in turn affects the lives of people. We can store water in reservoirs, and by building canals have it to use on the land during the summer. We can also keep it from flowing back to the sea as rapidly as it otherwise would, by leaving uninjured the covering of vegetation which has been spread over the mountain slopes. The water will run from bare rocks and bare soil much more quickly than it will from soil that is covered with leaf mold and held by plant roots. Do you not see, then, that we have almost as much control over water and its distribution as though we could increase or decrease the rainfall?
What about the forests? If we cut them down, will they ever come back? All through the eastern part of our country and in the mountains of the West are lands once forested which have been cleared and turned into farms. Many of these farms, when abandoned, have in a few years been covered with a growth of young trees. The scattering trees that had been left in the vicinity of the clearings furnished the seed. The winds and the birds carried the seed to the open fields and so the forests began again.