104 AGRICULTURK or" MAINE). 



is the measure of our crops. Plant food then becomes the prob- 

 lem of problems, the chief corner stone, the under-girder of 

 all possible higher agriculture. Indeed, as the volume of our 

 crops is the great determining factor of all industrial life, it 

 would appear that the volume of available plant food is the 

 largest economic factor in the life of nations. It is the prob- 

 lem towards whose solution you must bend every intellectual 

 energy. The expansion of my area of tillage and the increase 

 of crops has rested on six sources of plant food. Time will 

 not permit a discussion of the scientific whys, nor the processes 

 involved, in my method of fertilization. Suffice it to say that 

 it is all a fundamental part of a scientific course of farming. 

 I get plant food for this volume of business from six sources. 

 First, I use muck as a source of nitrogen humus. Before it is 

 used you must think out its relations. From an artificial reser- 

 voir we draw the waters of irrigation as a source of plant food, 

 and as an antidote to drought. Third, I use a fixed system of 

 crop rotation as one of the great conserving forces of soil fer- 

 tility and as one of my chief means of economizing crop pro- 

 duction. 



I use, as you will observe by the following, an eight years' 

 rotation which runs as follows: Corn for silage, treated to six 

 loads of yard manure of ten tons and 750 pounds of fertilizer 

 adapted to this crop; oats and peas, for which I use the previous 

 amount of chemicals or yard manure. Third, clover, using 

 some 700 pounds of chemical fertilizers. Fourth, potatoes, 

 with about ten tons of yard manure plowed under and 1500 

 pounds of chemicals, spread on the surface and harrowed in. 

 Fifth, Hungarian, treated to ten tons of yard manure to the 

 acre. Sixth and seventh, timothy for sale, treated with 700 

 pounds of chemicals to the acre each year. And, eighth, pas- 

 ture also fertilized with chemicals. This .system, you will ob- 

 serve, is one of fertilization of the soil of every acre every 

 year and one of constant increment of soil fertility and increase 

 of crops. 



This, it will be observed, as the third source of plant food, 

 is quite prominent. The fourth source is tillage, which is ma- 

 nuring. Your everlasting grass crop gives only a minimum vol- 

 ume of air through the soil, while tillage opens it up to air 

 circulation. The investigations of men of science in Europe 



