BARNYARD MANURE 135 



But all the later years have shown that phosphorus was 

 most needed and potash least needed. 



BARNYARD MANURE 



139. Importance of Manure. Over half a century ago 

 a French scientist declared that one of the most important 

 lessons for the farmer to learn was how to. produce good 

 barnyard manure and to use it rationally; that the funda- 

 mental question was and would remain the manure ques- 

 tion. The older our farm lands become, the more truth 

 we see in his statement. In many parts of America the 

 manure is thrown away. In regions where thousands of 

 dollars are spent for fertilizers, a half of the value of 

 manure is usually lost before it is applied to the land. 



Figured at the price that the plant-food in manure 

 would cost in fertilizers, the amount produced in the 

 United States is worth $2,353,000,000 1 per year. The value 

 of the corn crop in 1908 was about two-thirds this 

 amount, $1,601,000,000. 



140. Value of Manure. The value of manure is often 

 figured on the basis of what the nitrogen, phosphoric 

 acid and potash would cost if purchased in commercial 

 fertilizers. The plant-food in manure is less soluble than 

 that in fertilizers ; on the other hand, this method does 

 not give any value to the humus, which is a very important 

 part of the manure. Field trials usually show that this 

 is a fair method of comparison with fertilizers, particu- 

 larly when the lasting effects are considered. Truck- 

 growers in New Jersey, who buy both manure and ferti- 



^armers' Bulletin Nu. 192, p. 5 



