Fertilisers for Market Garden Crops,, 463 



and in many cases considerably more. At our farm, a few 

 miles from Tonbridge, it actually costs 8s. per ton, including 

 cartage. Such heavy dressings as have been mentioned are, 

 therefore, very costly. Town dung, moreover, is poor in quality 

 as compared with farmyard dung. Probably its principal 

 practical value consists in the organic matter it contains, 

 which, in the case of light and sandy soils, is a great desideratum 

 in dry weather for the purpose of retaining moisture in the soil ; 

 while in the case of stiff clays — like our own soil — it also tends 

 to prevent baking and to keep the soil open and spongy. It 

 seems probable that, except on extremely light and open soils, 

 the mere mechanical and physical good effects might be obtained 

 by using very much smaller quantities of town dung than are 

 commonly used, while it appears to be clear, from the results of 

 our experiments, that, for most vegetable crops, such dung, 

 regarded merely as an actual source of plant food, is quite 

 inadequate for the purpose of maximum production unless 

 we use very large quantities. Even then the cost of the dung 

 is very much greater than would suffice to produce the same 

 result if a much smaller quantity of dung were used, supplemented 

 by chemical or concentrated fertilisers. 



The concentrated fertilisers we have used are superphosphate 

 — varied occasionally by basic slag — nitrate of soda, and sulphate 

 of potash (or occasionally kainit). To avoid repetition, it may 

 be taken that, in the following pages : — 



"Light Dung" means 12 J tons, or 25 small cart-loads, of 



London dung per acre ; 

 " Heavy Dung" means 25 tons, or 50 small cart-loads, of 



London dung per acre ; 

 " Phosphates means an annual dressing of about 4 to 6 



cwt. of superphosphate (or its equivalent of basic slag) 



per acre ; 



" Potash " means 1 cwt. of sulphate of potash (or 4 cwt of 

 kainit) per acre. 



The nitrogenous manure used throughout has been nitrate of 

 soda. The necessarily large number of our plots has rendered 

 it quite impracticable to complicate our work by any comparison 

 between this and other well-known nitrogenous fertilisers, such 



