COMPOSITION OF PLANTS AND FEEDS 383 



the seed, the more vigorous the young plant. The larger seed, of 

 course, contain more reserve material and plant food. 



Selection of seed from individuals of a desired type may affect 

 the composition of the plant. Thus, at the Illinois Station, corn 

 of high and low protein and high and low fat have been produced. 

 By selecting seeds from beets containing high quantities of sugar, 

 the sugar content of the sugar beet has been increased 8 to 10 

 per cent. It is not possible to improve all crops in this way. 



The soil affects the composition of the crops to some extent. 

 Foliage crops grown upon rich soils contain a larger percentage 

 of nitrogen than those grown on soils poor in nitrogen. Leaves 

 and stems are influenced to a greater extent than seed by the soil, 

 because the seed are more constant in composition. Wheat and 

 other grains show material differences in composition when grown 

 upon different soils. Not all plants are affected by the composi- 

 tion of the soil. Lawes and Gilbert found that the use of nitro- 

 genous and mineral manures for twenty years did not affect the 

 nitrogenous content of wheat. 



As the plant contains more nitrogen during early stages of 

 growth, anything which cuts short the growing season will cause 

 the crop to contain slightly more nitrogenous material. If the 

 growth of the plant is checked at the time of seed formation, 

 shrunken or immature seed may result. Such grain contains less 

 starch and more nitrogenous compounds than those fully matured. 

 Plants grown in arid or semi-arid regions may contain a higher 

 percentage of nitrogen than in regions of more abundant rainfall. 

 For instance, the nitrogen content of Texas cottonseed meal 1 is 

 considerably greater in the western or semi-arid part of the state 

 than in the eastern part. 



Hay and Hay Making. Hay is the dried and partly fermented 

 leaves and stems of certain grasses and clovers. Some fermenta- 

 tion is requisite to develop the characteristic flavor and aroma. 

 The method used for hay making depends on the character of the 

 plant and the climate. A succulent plant and a moist climate 

 demands more care than dryer plants and a dry climate. Some 

 1 Texas Bulletin, 70. 



