Crops. 187 



quiring a warm climate and abundance of water, hence it is 

 usually grown under irrigation. When so grown it yields two 

 crops and requires liberal manuring. Since nitrification is sup- 

 pressed on rice land, nitrates are very effective with this crop. 

 Composted manures are used for the crop in China and Japan. 



Rice grain is extremely low in ash, fiber and fat, and contains 

 but about 7.4 per cent of protein. It is essentially a carbohyd- 

 rate food, nearly 80 per cent of it being starch. The rice of 

 commerce is a product of a milling process which removes the 

 outer husk from the grain and yields as by-products, rice polish 

 and rice bran. The former is fine and floury and much richer 

 than the grain in ash, protein and fat, while the latter is a coarse 

 material high in percentages of ash and fiber. The two by- 

 products are usually mixed and sold as rice-meal, or rice-feed. 

 Like wheat, and in contrast to most of the other grains, rice car- 

 ries a large share of its phosphorus compounds in the outer 

 coatings, which makes possible a considerable recovery of phos- 

 phoric acid with the manure produced from rice feeds. 



Leguminous seeds differ chiefly from the seeds of cereals by 

 a higher content of protein and a correspondingly lower content 

 of carbohydrates. This does not involve, as already pointed out, 

 a heavy demand upon the soil supplies of nitrogen. Protein 

 formation in these crops, however, places a considerable tax upon 

 the ash constituents of the soil. In some cases the carbohydate 

 material of these grains has been found to consist chiefly of 

 galactans, a class of compounds already discussed under the 

 4 * poly-saccharides " of the plant. Liberal supplies of phosphoric 

 acid, lime and potash are required for these crops. A number of 

 legumes produce seed which form a considerable bulk of the total 

 crop. This is true of the soy-bean, horse-bean and cowpea. The 

 several varieties of the true bean and the pea are the only seeds, 

 however, of much commercial importance. The soy-bean and 

 peanut seeds are distinguished by high percentages of fat, 

 amounting to about 17 and 45 per cent in the grains, respectively. 



