158 



MISSOURI AGRICULTURAL REPORT. 



come which causes the water to move downward, whether by capil- 

 larity or by percolation, these partly emptied granules will draw the 

 water with the plant food which it may carry back into themselves and 

 thus hold both the moisture and the other nourishing elements up nearer 

 to the surface where they will be more efficient. And so it is that a 

 strongly granulated soil may profitably be more highly fertilized than 

 one which is not and so maintained at a higher stage of productive 

 power. To illustrate, when a solution carrying potash was allowed to 

 percolate very rapidly through the four poor and the four good soils, to 

 which reference has already been made, the soils which were most 

 highly granulated and which possessed the highest productive capacity 

 were able to absorb from the solution and retain within their granules 

 at the rate of 1,736 pounds of potash per acre of the surface foot, 

 while the four poor soils, less strongly granulated and possessing less 

 internal surface, were able to take from the solution at the rate of only 

 893 pounds per acre. 



In proof of .the greater power of highly granulated* soils to hold 

 back against leaching the plant food elements, the same 8 soils were 

 treated with the same amounts of the same kinds of stable manure, and 

 then, after an interval of six months, they were all leached in the same 

 manner and with the same amounts of pure water, to see how much of 

 the plant food elements would be retained. The results obtained are 

 given in the next table. 



Amounts of manure applied. 



Potasli In manure 



Potash retained— 



Four good soils 



Four poor soils 



200 tons per acre. 

 870 pounds per acre. 



663 pounds per acre. 

 448 pounds per acre. 



The table shows how different was the power of the two groups 

 of soil to hold back against leaching the potash which had been carried 

 to them in the stable manure. It will be clear also that when the roots 

 of crops spread themselves out over these differently charged soil 

 granules, which are filled with and surrounded by moisture carrying 

 the plant food, they are under the very best conditions to obtain and 

 utilize it. 



In order that there may be established a strong and deep granula- 

 tion of the soil, the first essential condition is ample under drainage, 

 and it is most fortunate that, in the great majority of fields, natural 

 conditions abundantly secure this. The most universal condition, re- 

 quiring attention on all soils, except in the very limited highly organic 

 types, is a deep and abundant incorporation of organic matter in the 



