260 AGRICULTURAL CHEMISTRY 



Timothy hay grown on Corn fodder grown on 



manured unmanured manured unmanured 



land. land. land. land. 



Per cent. Per cent. Per cent. Per cent. 

 Crude protein (dry 



matter basis) ... 8.75 6.45 8.85 6.32 



362. Climate. In the early stages of plant growth, the 

 nitrogenous compounds are produced more abundantly 

 than are the non-nitrogenous (Section 351). If the 

 growing season is in any way cut short, the crop has a 

 slightly larger amount of nitrogenous matter than if 

 normal conditions prevail. Any shortening of the grow- 

 ing period or forcing of the crop to maturity lessens the 

 per cent, of dry matter, increases the nitrogenous com- 

 pounds, and decreases the carbohydrates. The composi- 

 tion of grains is influenced by climatic conditions, particu- 

 larly at the time of seed formation when growth is 

 often checked before all of the compounds have been 

 transferred from the leaves to the seeds ; shrunken or 

 immature grain is the result. Such grain contains less 

 starch and more nitrogenous compounds than that which 

 has fully matured. Experiments with potatoes by L,awes 

 and Gilbert show that they too are, to a slight extent, 

 influenced in composition and starch content by climatic 

 conditions ; the longer the growing period, the larger the 

 amount of starch. A short and forcing growing season, 

 together with a fertile soil, has a tendency to produce 

 crops of high nitrogen content. 



363. Stage of flaturity. Since all crops at first pro- 

 duce nitrogenous compounds in larger amounts than at 

 later stages, it follows that early cut crops contain pro- 

 portionally more nitrogen than those cut later. This in- 



