a. A. COWTR 121 



In series I the above dressings were tested respectively at the rates 

 of 50 and 100 mgs. N per kilo soil and in series II the last three were 

 compared at 200 and 100 mgs. N per kilo soil. In each series the pots 

 were divided into sets of three, and all received 1 gram dicalcium 

 phosphate and -5 gram potassium sulphate per kilo soil. Controls 

 without nitrogen were included in each series. 



The fertilisers were applied to the soil and the pots filled on 

 6th September. The seed was sown the following day, 10 seeds in the 

 small and 20 in the large pots. The seedlings were subsequently thinned 

 down to 7 in the small pots and It in the large. The pots received 

 measured equal quantities of water. The crop was harvested on the 

 20th December and the yields of dry matter etc. are set out under 

 Table I. 



Barley Exferiments. 



Each pot held 20 kilos soil, and the nitrogenous dressings were as 

 used in the mustard series, viz. 2.5 mgs. N per kilo soil both on the 

 heavy Rothamsted soil and on the light Woburn soil. The latter con- 

 tained practically no calcium carbonate and was slightly acid in 

 reaction. In all cases 1 gram bone ash, and \ gram potassium sulphate 

 were added per kilo of soil. The complete dressings were applied on 

 28th April and the seed sown on 30th April. Five plants were grown in 

 each pot. The crop was harvested on the 18th July and the results 

 are placed under Table II. 



Rye Experiments. 



This series was undertaken to ascertain whether dicyanodiamide 

 exerted a stimulating action on plant growth, when supplied in a 

 sufficiently small amount to be no longer deleterious. Dicyanodiamide 

 was applied at the rate of 12 J mgs. N per kilo soil: it was tested alone 

 and also in conjunction with cyanamide at the rate of 25, 50 and 100 mgs. 

 N per kilo soil. The Rothamsted and Woburn soils were used. 



All the pots received 2 grams superphosphate and i gram potassium 

 sulphate per kilo of soil. The dressings were applied on the 30th 

 October and the seed sown on the 1st November. In one case the di- 

 cyanodiamide alone was also applied in the aqueous solution as a 

 top-dressing in the early stages of growth. The crop was harvested in 

 both sets on the 24th May, and the yields of di'v matter etc. are placed 

 under Table III. 



