MANURES 



"But sweet vicissitudes of rest and toil 

 Make easy labor, and renew the soil. 

 Yet sprinkle sordid ashes all around, 

 And load withfatt'ning dung thy fallow ground." 



— Virgil. 



MANURE is any substance added to the soil with a view of rendering 

 it more fertile. Vegetable growths, all kinds of animal matter 

 and many inorganic substances contain plant food, either in the form of 

 elements or compounds. 



To simplify the study of this very important subject, we will classify 

 manures as follows: 



Barnyard or farm manures. 



Green manures. 



Commercial fertilizers. 



In order that we may have a comprehensive knowledge of farm 

 manures from a plant food standpoint, several things should be con- 

 sidered. 



The various feeds contain different amounts of the principal elements 

 of fertility. Likewise the amount of plant food contained in excrements 

 from live-stock varies greatly for different animals. The age and habits 

 of animals affect the different amounts of the essential elements to be 

 found in manure of the same class. For instance, a young growing 

 animal will consume and retain more of the nitrogen and phosphorous 

 in feed eaten than one which has attained its growth and a working 

 animal requires more than an idle one. Hence, it is impossible to give 

 the exact amount of nitrogen, phosphorous and potash in a ton of mixed 

 barnyard manures without making a specific analysis. 



The figures given, however, are based upon chemical analyses made by 

 many of our most learned chemists and represent very closely the plant food 

 value of mixed barnyard manures and the excreta from different ani- 

 mals. All manures contain a percentage of all plant food elements, but 

 we will deal only with the important ones — nitrogen, phosphorous 

 and potash. Such elements as iron, alumina, silica, magnesia, sulphur, 

 lime and soda exist in most soils so abundantly that it is not necessary 

 to consider any of them excepting lime which will be discussed later. 



We will first give the number of pounds of nitrogen, phosphoric acid 

 and potash in a ton of the most commonly used stock feed ; and, subse- 

 quently, the pounds of the same elements in dung and urine from various 

 farm animals, also the pounds contained in mixed yard manures and in 

 litter or bedding. 



If the reader will keep in mind the amount of plant food contained in 

 a ton of manure and will note the requirements of crops which will 

 appear in a subsequent table, he will have a guide to direct him in his 

 efforts to supply his soil with the necessary elements. 



