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Rh in part by underflow and capillary rise to the soil from which it was collected, or be applied directly for irrigation by pumping. In this province the rains may often be heavy but the total fall for the year is small, being little more than twenty-four inches, hence there is the greatest need for its conservation, and this is carefully practiced.

Fig. 60.—Treadling of fields for drainage, conservation of rainfall and of fertility, in the Shantung province. Trenches are two feet wide on the bottom, six or eight feet wide at the top, and two and a half to three feet deep.