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most soils, even those that are very poor, usually contain an 

 abundant supply of plant food, though sometimes other elements 

 are lacking or are present only in those forms that plants can not 



use. 



To increase fertility we must improve texture and add plant 

 food and humus. Tillage may do much to improve texture, but 

 tillage alone w^ill not sufifice. We must add humus. In doing so 

 we add plant food, and make the soil more permeable to air and 

 water. 



INCREASING THE STOCK OF HUMUS. 



There are three general methods of supplying humus to the soil. 

 The first and best is the addition of stable manure. When pro- 

 perly managed it adds large quantities of both plant food and 

 humus. But manure is not always available. When such is the 

 case, the best thing to do is to make it available. Raise more for- 

 age, keep more stock, and make more manure. But this takes time 

 and capital so that other means are sometimes necessary. When 

 stable manure is not to be had, we may plant crops for the pur- 

 pose of turning them under, thus adding large quantities of humus 

 at comparatively little cost. Ploughing under green crops is 

 called green manuring. Under certain conditions this is an 

 excellent practice. 



STABLE MANURE. 

 Properly handled, stable manure is by all means the best remedy 

 for poverty of the soil. Very few farmers handle manure so as to 

 get even as much as half the possible value from it. There is 

 probably no greater waste in the world than in connection with 

 the handling of manure by the farmer. Five-eights of the plant 

 food in manure is found in the the liquid part of it. This is usually 

 all lost. Not only is this the case, but the solids are heaped beside 

 the stable, frequently under the eaves, where rains wash away 

 much of their value. Fermentation in these manure heaps also 

 sets free much of the nitrogen to escape into the air. 



GREEN MANURES. 



The practice of ploughing under green crops as manures is not 

 very general, and we do not know as much as we should like to 

 know of the value of this method. Some crops do not thrive when 

 sown on land into which a green crop has recently been ploughed. 

 This is particularly true of those crops that like a solid seed bed, 

 or which are sensitive to acids. When a heavy green crop is 

 ploughed under, it goes through a fermentation not unlike that 

 which occurs in a barrel of kraut, resulting in the formation of a 

 considerable amount of acid. 



Alfalfa is particularly sensitive to acids, and it also requires a 

 compact seed bed. It is unwise, therefore, to green manure the 

 land just before sowing with alfalfa. 



Generally speaking, when it is desirable to plough in a green 

 crop before fall-sown crops, it should be done a month or six 



