oS 7 



loam had ;i value almost twice as great for feeding purposes as 

 those- grown on the clay. Those in the black land were almost 

 intermediate between the clay and light loam. 



It has been shown that soils with the lack of one <>f the 

 elements of plant food can be wholly barren to a crop. While that 

 is so, any barren s ul, even pure sand in which there is HOIK- of the 

 elements of plant food, c.m be- made fertile by the judicious addition 

 of artificial manures. 



\Ye will now examine the manures ; what they are composed 

 of and how they are made. 



MANTRKS, OR FKRTIUSKRS. 



It is the general practice to divide them into three classes, and 

 this division 1 intend to follow. 



1. Natural or organic manures. This does not include guanos, 

 or those obtained from deposits in the earth, such as mineral phos- 

 phates or other salts. 



2. Artilicial manures. 

 ^. Special manures. 



Natui al or org mic manures are composed of decayed vegetable 

 matter, the refuse from animals or the organic parts of animals and 

 lish. They may even be a mixture of all these. They depend 

 principally on the organic matter they contain to be classed as 

 manures, espec ally that of their ni rogen, which is high. They 

 have a low manurial value as regards their mineral matter. 



i. Farmyard manure, or the excreta of animals with a m xture 

 of vegetable matter such as straw. 



This is considered by a great many farmers to be a typical or 

 complete manure, that is, that it contains all the ingredients neces- 

 sary to the growth of a crop. While this is the case, it is, never- 

 theless, far from being a complete manure, as the ingredients are 

 not in the best proportions. The mineral matter is there in very 

 small quantity, and in a state that a plant cannot easily assimilate, 

 as it is so insoluble. The nitrogen is also very insoluble and 

 slow in its action. It is generally considered that farmyard manure 

 has a very slow action in supplying food to the plant for the lirst 

 year as compared with other manures. A great many experiment- 

 alists and scientists place a very small value on it as a manure. 

 Ville and Leibig attach very little importance to it. Ville says an 

 artificial manure can be made to give better results and at a less 

 cost. Leibig says, if no other manure was used, the soil would 

 become almost barren to some crops. Sir J. B. Lawes says, all 

 labour spent on the dung adds certainly to the cost, but does not 

 add with the same certainty to its value. 



On his Rothamstecl farm he used most of the farmyard manure 

 that was made on the farm, for mangolds. It depends mostly on 

 its nitrogen for its manurial value, in fact it is virtually a nitrogen- 

 ous manure. It contains only about 48 Ibs. of plant food per ton 



