LIST OF ILLUSTRATIONS Stripping heads from barley to save straw for fuel or braid. .Frontispiece Relative amounts of dry soil, air and plant food in cubic Chart of relative diameters of grains of sand, clay and 18 40 36 Chart showing structure of fine-grained soil......... 43 Korean rice fields,. Facing page 41 Garden areas near Tsinan, Shantung Province, China, Chart of sandy, loamy and clay soils in Facing page relation to water 90 41 Effect of capillary movement of soil moisture on position of plant food.. 137 ... Chart showing relation of yield of corn to soluble salts 141 143 Facing page 178 Distant view of cornfield showing influence of manure, Facing page 179 Orange groves about Redlands, California,... Facing page 200 Terraced gardens on hill slope, Japan, ...... Tea bushes mulched with straw, rice fields in back ground, Japan,... ·Facing page 201 Facing page 201 Facing page 206 Iris garden and foot-power irrigation near Tokyo, Japanese farm laborers at midday lunch,....Facing page 207 Japanese village with terraced rice paddies in foreground, Rice fields to which green manure is being applied, Facing page 292 Manuring for rice, with canal mud and clover compost, Facing page 292 Village in Shantung, China showing compost stack, Fitting ground for sweet potatoes, in China, Facing page 293 Facing page 293 CHAPTER I PRODUCTIVE CAPACITY OF THE HE management of soils to establish, to increase and to maintain a high productive capacity of fields is one of the oldest and most extensively practiced arts of industrial life. Most barbaric and all civilized peoples have fostered it. No other art or trade engages the attention and absorbs the energies of so many families. With the vast and ever-increasing demands made upon the materials for food, for apparel, for furnishings and for cordage, which are the products of cultivated fields, better soil management must grow more and more important as populations multiply. With the increasing cost and ultimate exhaustion of mineral fuels; with our timber vanishing rapidly before the evergrowing demands for lumber and paper; |