46 A PRACTICAL TREATISE 



g-ent farmers, that dung should not be laid upon the land until 

 it has underg-one such a change as may be sufficient to destroy 

 the seeds and insects which it may contain. This, however, 

 cannot be effected except by a putrid fermentation, which, 

 under common farm management, cannot be completed until 

 the heap be decomposed and cool ; for otherwise, the operations 

 of cartage, spreading, and ploughing in the manure, while in 

 a state of heat, would dissipate the gaseous matter, and thus 

 occasion the loss of that in which its nutritive powers are 

 partly supposed to consist. 



Produce of Strmo and Dung. — The quantity of straw 

 grown per acre depends upon such a variety of circumstances 

 touching soil and cultivation, season, and kind of crop, that it 

 is quite impossible to form any precise calculation on the 

 subject. Estimates have however been made of the average 

 weight of different sorts produced by the various species of 

 grain, from which a general idea of their gross amount may 

 be formed. Although it is clear that nothing like accuracy 

 can be expected on that point, yet it is in the power of every 

 farmer to form a tolerably exact notion of the weight of all the 

 straw actually grown upon his own land ; and coupling this 

 wdth the number of his live-stock and the nature of their food, 

 he will probably be able to make out such a rough calculation 

 of the gross quantity of farm -yard manure as may not be far 

 from the truth. Such an account may indeed appear at first 

 sight to be more curious than useful ; but crops depend in a 

 great measure on yard-dung, and their rotation must be regu- 

 lated, on most soils, by its amount ; it is therefore important to 

 ascertain, as nearly as possible, the quantity on which a man 

 who is dependent upon its production alone, without purchased 

 manure, can rely, before he lays his plan for the ensuing year. 

 The following are some of the estimates alluded to: — 



31 cwt. or 3472 lbs. . .. wheat .... 160sf. or 3520 lbs. 

 25 " 2810 . . *. beans and pease 130 " 2660 

 25 " 2800 . . . oats .... 130 " 2860 

 20 " 2240 . . . barley ... 100 " 2200 



Rye, about 3 loads of 36 trusses each, or 3888 lbs. 



The yield of different years varies the proportion which all 

 grain and pulse bear to the straw; but the average of wheat is 

 about 12 bushels to the load, which, according to the practice 

 in most parts of England, consists of 36 trusses of 361bs. each, 

 and weigns llcwt. 2qrs. 81bs. ; but according to the above 

 statement, the whole average of the kingdom is supposed to 

 be about 1} ton per statute acre. 



