356 



STATE BOARD OF AGRICULTURE. 



abundance of crops without the application of any form of fertilizing 

 materials but later they become less productive and the farmer makes 

 use of farm manure and other materials produced on the farm in order 

 to overcome this condition. Still later materials must be purchased 

 from outside sources if the farm is to continue in its productivity. It Is 

 now considered that many new soils also will profitablj^ respond to ap- 

 plications of lime or other materials. 



The chief object in view when fertilizers are used is to increase the 

 yield of crops at a maximum profit or in other words to increase the 

 labor income on the farm and it should also be the aim to maintain the 

 fertility of the soil at the some time. There are less acres of land, 

 horse and man hours required to raise a given amount of produce on 

 good land than on land of average fertility or less. This is exemplified 

 by the figures in table 7. 



Table 7. — Hours of human labor and hor.se labor and acres of land required to produce the same 

 amount of cro])s on average land and land properly drained, limed and fertilized. 



TIlis may be carried fartlier by showing that tlie returns for labor are 

 alToctcd by croj) yields. Dr. J I. Falconer of Oliio State University 

 recently rei)orted results of studies made in 1918 of G7 farms in a com- 

 munity in iluron county, Ohio. He reported that these farms lie on the 

 same soil type. They were divided into three groups according to their 

 yields as shown in table 8. 



Table 8. — Effect of crop yields on labor income. 



The labor income is greatly affected by crop yields or the fertility 

 relationships of the soil. It is good business practice to produce yields 

 of crops considerably above the average of the state. 



There are several principles involved in the use of commercial fertilizers 

 that should be considered. Application of fertilizers to soils when the 

 formation of available plant-food from vegetable and mineral matter is 

 slow are frequently desirable. If the spring growth of fall sown grain 



