Đang chuẩn bị liên kết để tải về tài liệu:
STORING WATER IN THE SOIL

Không đóng trình duyệt đến khi xuất hiện nút TẢI XUỐNG Tải xuống

The large amount of water required for the production of plant substance is taken from the soil by the roots. Leaves and stems do not absorb appreciable quantities of water. The scanty rainfall of dry-farm districts or the more abundant precipitation of humid regions must, therefore, be made to enter the soil in such a manner as to be readily available as soil-moisture to the roots at the right periods of plant growth. In humid countries, the rain that falls during the growing season is looked upon, and very properly, as the really effective factor in the production of large.