VALUE OF ARTIFICIAL MANURES. 33 



importance tb.it you look first to the mechanical improvement of 

 the soil. I have seen in many cases superphosphate entirely fail, 

 for want of a proper pulverisation of the soil. A very striking 

 case was very recently brought under my notice. On the farm 

 attached to the Agricultural College of Cirencester, with which 

 I am connected, I have lately made some experience with dif- 

 ferent manuring matters. On one portion of the soil I used 

 superphosphate : the result was that on this portion I did not get 

 a single hundred weight more produce than on another portion in 

 close proximity where no superphosphate was used at all. Fortu- 

 nately I tried the same experiment on another portion of the 

 farm, and got a very large result. Now, if I had been content 

 with making only one experiment, to what conclusion should I 

 have arrived ? To the following: that on clay soils for it was 

 a clay soil on which I tried the experiment superphosphate 

 was of no use ; and that it was the worst manure I could use, 

 for it hardly gave me any increase. But I should have drawn a 

 wrong conclusion, and you will observe how difficult it is to 

 form a satisfactory conclusion from a single experiment : for, 

 having tried the same experiment on a similar soil, but upon a 

 soil which was taken in hand for several years before the experi- 

 ment was tried, and which, when the manure was applied, was in 

 a high state of mechanical subdivision I obtained three times as 

 much as upon the portion of land where nothing was applied. 

 You will observe, then, how the mechanical condition of the soil 

 influences the efficacy of artificial manures. Some manufacturers 

 of artificial manures are so well aware of the importance of 

 introducing into farming improved agricultural implements, that 

 they sell those implements without any profit, for they know that 

 they can only then expect a large sale of their manures, when the 

 farmer does the best on his part, and that good manures have no 

 chance of any success, if no care is taken to bring the soil in such 

 a mechanical condition that the artificial manures can exercise 

 any beneficial effect. 



In the next place, allow me to observe, that the chemical com- 

 position of the land greatly influences the efficacy of manure. 

 There are some soils in which phosphatic manures manures 

 containing bone material, or phosphate of lime have no effect. 

 Some soils resting on the greensand formation contain sufficient 

 phosphate of lime to meet all the requirements of the growing 

 crops ; hence you cannot feel surprised that bones or superphos- 

 phate produce no effect upon such soils. The fact is, the soil 

 already contains more than sufficient phosphate of lime to meet 

 all the requirements of the plant ; and hence it is that dealers in 

 superphosphate, containing frequently a very small proportion of 

 of bones, can dispose of their inferior description of superphos- 



