11 



limited only by what leaves a profit from the first and subsequent 

 crops. 



The physical qualities of the soil naturally are of the greatest 

 importance for the action of fertilisers, and so much is certain that 

 the more favorable the conditions of growth are as regards these 

 and moisture, the greater may also be the quantity of commercial 

 manures suitable for the particular crop wth a view of obtaining 

 the largest crop and net profit. In some cases, even in our climate, 

 losses of plant food may occur where the soil cannot absorb it, or the 

 permeability to water is very great in sandy and gravelly soils 

 resting upon a percolating subsoil, and there* it is advisable to use 

 manures that slowly decompose, as farmyard dung, green manuring, 

 blood manure, or fertilisers like bonemeal and Thomas phosphate. 

 Where 'the water sinks too quickly even these might be given in 

 smaller doses from time to time, so as not to lose plant food. In 

 naked fallow there is comparatively more danger of losing it in such 

 soils after heavy rains, but they are better not fallowed. 



I find that last year, up to May 31, 219,000 tons of the Star Brand 

 alone of Thomas phosphate, irrespective of other brands and super- 

 phosphates, were used for agricultural purposes in Germany, as against 

 138,000 tons in the same period of the previous year. There was 

 -altogether a yearly consumption of 300,000 tons of phosphoric acid 

 in one form' or another. In Europe in 1899, 1,800,000 tons of 

 Thomas phosphate and 975,000 tons of superphosphates were used, 

 against 107,688 tons of potash in the form of 80 per cent, muriate of 

 potash, 90 per cent, sulphate of potash, and of sylvinit and kainit. 

 Although the sale of potash for agricultural purposes was constantly 

 increasing, the quantity used in 1895 having been seventeen times 

 greater than in 1880, Professor Dr. Wagner has last year clearly shown 

 that the proportion of three of phosphoric acid to one of potash is 

 for very large districts in Germany (and probably also here) entirely 

 wrong. If the highest returns are expected, considerably larger 

 quantities of potash are necessary. He thinks that 200 Ib. of phos- 

 phoric acid require 268 Ib. of potash, instead of as present only 66 Ib. 

 of potash. If the larger quantity of potash is not given the supply 

 of it in the soil is drawn upon, so long as it lasts. Under any 

 circumstances, "it exists chiefly in insoluble compounds in the soil," 

 as stated by Professor Wright, of Glasgow, and the plants may find 

 only a thousandth part of 1 per cent, soluble, where we find 3 per 

 cent, or 4 per cent, in the soil. They have, therefore, to search 

 for it, and cannot consume it quickly and easily enough in pro- 

 portion to the phosphoric acid and nitrogen supplied. It is also 

 not quite correct to say that only sandy and moor land require 

 potash, and that clay and strong loam contain a sufficient supply. 

 Tt is the exception, not the rule. Professor Wright and C. M. 

 Aikman say in "Potash Manuring: Its Value to British Agricul- 

 ture" : "In whatever form the potash is absorbed it has been, at any 

 rate, proved beyond doubt to be an absolutely necessary ingredient 

 -for the growth of all crops." Frequently, however, the wrong 

 ^potash manure is being used for clayey soils, for kainit contains too 



