The Wohurn Pot-Culture Experiments, 1910-11-12. 337 



growth. Accordingly, it was decided to grow in 1911 wheat 

 on a plot of land just outside the pot-culture enclosure, in one 

 case using the natural soil and in the other adding magnesia 

 to the soil. A strip of land 36 square feet in extent was taken ; 

 the soil was analysed and gave lime •77 per cent., magnesia •20 

 per cent. The soil was dug up to the depth of 5 in. in 

 November, 1910, and spread out on a cement floor and 

 thoroughly mixed. One half was passed through a \ in. 

 sieve, and then replaced where it had come from. To the 

 other half, after similar sieving, magnesia was, by careful 

 mixing, added in such amount as to raise the percentage of 

 magnesia in the soil to •40 per cent., and the soil was then 

 replaced. Thus there were two plots, side by side, the one 

 having lime "77 per cent, and magnesia •20 per cent., the other 

 lime ^77 per cent, and magnesia "lO per cent. 



Wheat (" Scjuare Head's Master") was sown on December 

 23, 1910. There was no difference between the two plots as 

 to the time of the plant appearing, but soon it was noticed that 

 the plot with magnesia was stronger and darker in colour. So 

 things went on until quite near harvest time, the magnesia 

 plot having markedly the finer crop. Then the whole 

 experiment was ruined for the year, for in a single night 

 the birds came and cleared the lot off ! 



Nothing daunted, we determined to repeat the trial, dug- 

 over the ground, and re-sowed wheat in November, 1911, no 

 more magnesia being added. The same differences as in 1911 

 were again clearly visible ; both plots were excellent, but the 

 magnesia one was decidedly the better. This afforded an 

 object of much interest to the many visiiors to the farm 

 during the summer of 1912, and who could not fail to be 

 impressed by it. A photograph of the two plots was taken, 

 and is reproduced in Plate 11. This photograph, taken shortly 

 before harvest, shows very clearly the superiority of (h), the 

 plot to which magnesia had been added. 



The precaution had been taken, this year, to wire in the 

 crop, and so the harvest results were fortunately obtained 

 without los-". They were : — 



The grain was examined by our valuer. He reported both 

 lots to l)e excellent, but the magnesia lot was the more regular, 

 translucent, and had a beautiful "bloom" on it. He put its 



