Page:Popular Science Monthly Volume 73.djvu/407

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HE rotation of crops or the order in which crops are grown upon the same land during a period of years is of such moment to the successful development of our agriculture, and consequently of our national welfare that it must receive consideration. The farm value of our farm products has increased rapidly in the last few years, having risen from $4,717,000,000 in 1899 to $7,412,000,000 in 1907. The figures indicate an increase in value for 1907 of 50 per cent, over 1899. This remarkable growth in the value of farm products is largely due to an increase in the area tilled. Now that the best land is settled, it is essential to increase the productivity of an acre, and as the rotation of crops is one means of securing this result its usage must extend. The use of manure and fertilizers have been recommended and proved to be of value in the eastern states for increasing crop yields. The value of plant breeding and the development of plants which are capable of giving heavier yields and products of better quality has been recognized; and the productions of many workers have added millions of dollars annually to our national welfare. It is safe to say that anything that benefits the farmer and increases his ability to produce wealth is of distinct value to the nation and of direct interest to the world.

A study of the rotation of crops used at any particular period in the history of a nation is of value as a guide to the status of agriculture. Agriculture had its birth in the ages of antiquity, when some mother conceived the idea that she might save herself and her child from famine by growing or affording protection to some of the plants which furnished food. From this time on and for a long time the requirements of the people were scanty, and the crops grown were so few that no rotation could be carried on. Evidence shows that the neolithic people of Europe had the rudiments of agriculture, that they grew cereals, had cattle and were conversant with the arts of weaving, spinning and pottery-making. Among other places, they inhabited the hills of Britain and Ireland, where terraces made by them on the hillsides in Wiltshire and even as far north as the Cheviot Hills and the Grampian Mountains of Scotland are still visible. These races practised irrigation and a system of agriculture something like that now in vogue on the hills of parts of China and among the Coorgs, a hill