It is found that nearly all cultivated soils of Japan are acid to litmus, and this they are inclined to attribute to the presence of acid hydro-aluminum silicates.

The Island Empire of Japan stretches along the Asiatic coast through more than twenty-nine degrees of latitude from the southern extremity of Formosa northward to the middle of Saghalin, some 2300 statute miles; or from the latitude of middle Cuba to that of north Newfoundland and Winnipeg; but the total land area is only 175,428 square miles, and less than that of the three states of Wisconsin, Iowa and Minnesota.  Of this total land area only 23,698 square miles are at present cultivated; 7151 square miles in the three main islands are weed and pasture land.  Less than fourteen per cent of the entire land area is at present under cultivation.

If all lands having a slope of less than fifteen degrees may be tilled, there yet remain in the four main islands, 15,400 square miles to bring under cultivation, which is an addition of 65.4 per cent to the land already cultivated.

In 1907 there were in the Empire some 5,814,362 households of farmers tilling 15,201,969 acres and feeding 3,522,877 additional households, or 51,742,398 people.  This is an average of 3.4 people to the acre of cultivated land, each farmer’s household tilling an average of 2.6 acres.

The lands yet to be reclaimed are being put under cultivation rapidly, the amount improved in 1907 being 64,448 acres.  If the new lands to be reclaimed can be made as productive as those now in use there should be opportunity for an increase in population to the extent of about 35,000,000 without changing the present ratio of 3.4 people to the acre of cultivated land.

While the remaining lands to be reclaimed are not as inherently productive as those now in use, improvements in management will more than compensate for this, and the Empire is certain to quite double its present maintenance capacity and provide for at least a hundred million people with many more comforts of home and more satisfaction for the common people than they now enjoy.

Since 1872 there has been an increase in the population of Japan amounting to an annual average of about 1.1 per cent, and if this rate is maintained the one hundred million mark would be passed in less than sixty years.  It appears probable however that the increased acreage put under cultivation and pasturage combined, will more than keep pace with the population up to this limit, while the improvement in methods and crops will readily permit a second like increment to her population, bringing that for the present Empire up to 150 millions.  Against this view, perhaps, is the fact that the rice crop of the twenty years ending in 1906 is only thirty-three per cent greater than the crop of 1838.