84 



EFFECT OF PHOSPHATES 



Field Results. The nitrate figures for the samples of soil taken 

 weekly from the slag and untreated plots at Horndon, Martin's 

 Hearne, and Lambourne End are given in Table XLIV and the results 

 are shown graphically in Figs. 19, 20, 21 and 22. 



TABLE XLIV. NITRATE CONTENT OF THE SOILS ON THE BASIC SLAG 

 AND UNTREATED PLOTS DURING 1920 



The curves at all three centres have a general similarity of appear- 

 ance, and they demonstrate that at certain periods during the season 

 there is a much greater accumulation of nitrate in the slag plots 

 than in the untreated. 



Even on the very sour soil at Lambourne End nitrification seems 



