THE MANURING OK MARK KT-OARDKN CHOI'S. 



The Potash includes : — 



Potash soluble in dilute (1 per cent.) citric acid solution (probably 



readily " available " potash) 0-004 



The Phosphoric Acid includes: — 



Phosphoric Acid soluble in dilute (1 per c<:iit.) citric acid solution 



(probably readily "available " phosphoric acid) . . . 0*005 



It will be soon that the soil is naturally poor in li mo ; and tin; quantity 

 of phosphoric acid soluble; in dilute citric acid solution clearly indicates 

 the natural need of the field for phosphatic manure, and the proportion 

 of soluble potash is sufficiently low to indicate also the need for potassic 

 manure, and to account for the very marked effect produced by potash 

 salts on some of our crops, especially on those plots on which no dung 

 has been used. It will also be seen that tlx; stock of organic nitrogen 

 derived from the residues of previous crops is also very low, as is also the 

 proportion of total organic matter; the soil is therefore also very well 

 adapted for experiments involving an inquiry into the comparative value 

 of nitrogenous manure for various crops. 



A portion of this field which in the autumn of had been sown 



with wheat, was ploughed up during the winter and well dug, to prepare 

 it as far as possible for the first season's trials. After the first season- 

 that is to say, at the close of 1891 -being poor in lime, it was limed at 

 the rate of 2J, tons of lime per acre, and this treatment was repeated a 

 year later. 



Gknkkajj Plan of thh Kxphmmhnth. 



The initiation of these experiments, as has boon already mentioned, 

 was due to the wish to ascertain how far and under what conditions 

 nitrate of soda could be used to advantage in market gardening. It was 

 clear, however, that experiments properly directed to the elucidation of 

 this problem could not fail to be of value in answering other and wider 

 questions, and it at once became our purpose to so arrange our trials as 

 to render the information derivable from them as wide as possible. The 

 general plan of the experiments is directly designed to obtain answers to 

 the following questions : — 



Is it more economical, in the case of any particular market-garden crop, 

 to use lighter heavy dressings of purchased dung (stable manure) ? 



How far can. purchased dung, with due regard to economy, be 

 partially replaced by simple chemical fertilisers V 



Assuming nitrate of soda to be the nitrogenous fertiliser employed, 

 what quantity is it most economical to use, in conjunction with 

 phosphates and with or without potash, in partial replacement of 

 dung ? 



Is it possible economically to dispense with dung altogether and to 

 get as good a result simply by using chemical fertilisers ? 



It is not, be it clearly understood, intended to question the utility 

 and high value of dung produced by animals on the farm and enriched 

 by the consumption of purchased feeding stuffs. The production of such 



