VARIATIONS IN COMPOSITION 139 



older grass, and is consequently more nourishing. The 

 same comparison may be made between young clover 

 and that which is allowed to mature for hay. Fodder 

 crops should be cut for hay immediately full bloom is 

 reached ; after this point the quality of the hay will 

 considerably deteriorate. 



While fodder crops deteriorate towards maturity, 

 from the conversion of soluble carbohydrates into fibre, 

 crops such as potatoes and mangel improve, the carbo- 

 hydrates produced in their case being respectively 

 starch and sugar, both of them substances of great 

 feeding value. 



The influence of high manuriiig on the composition 

 of green crops and roots is generally considerable. A 

 luxuriant crop will always contain more water than 

 one in less active growth. Very large mangels may 

 contain only 6 — 8 per cent, of dry matter, while in 

 quite small roots the proportion may be as high as 

 14 per cent. Luxuriance also retards maturity. A 

 heavily manured mangel will contain, at the same 

 date, a smaller proportion of sugar than a similar 

 mangel grown on poorer soil. Liberal nitrogenous 

 manuring, while greatly increasing the bulk of the 

 crop, will thus at the same time diminish the pro- 

 portion of carbohydrates, and increase the proportion 

 of nitrogen, ash constituents, and water present. In 

 highly manured crops a smaller proportion of the 

 nitrogen will exist as albuminoids than in crops less 

 heavily manured and more mature. Thus, in a crop 

 of mangels of 18 tons per acre, manured with farm- 

 yard manure only, the albuminoid nitrogen amounted 

 to 38 per cent, of the total nitrogen ; while in a crop 

 of 28 tons, manured with nitrate of soda and super- 



