300 SCIENCE PROGRESS 



on barley, potatoes, mangolds, and wheat given in Mr. Knox's 

 book, say that " on this inconceivably flimsy foundation state- 

 ments are made that our food supply can be doubled by the 

 use of bacterised peat." Neither Mr. Knox nor myself have 

 ever made any such claim for bacterised peat, for, although we 

 consider its value has been demonstrated for horticulture, we 

 realise that field experiments have been as yet too few to 

 warrant any specific statement or claim regarding its value for 

 agriculture. 



They quote from the report of the field trials with bacterised 

 peat at the Midland and Dairy Institute, which shows that a 

 dressing of 7 cwt. per acre applied to wheat and seeds hay 

 produced no result in either crop. They do not mention that 

 the same report states that similar negative results were also 

 obtained with other manures. Seeds hay plots were treated 

 at the rate of i| cwt. superphosphate, \ cwt. muriate of potash, 

 and 18 lb. of nitrogen in various forms per acre, and " none 

 of the manures gave an appreciable increase in the crop." 

 This does not prove that phosphates, potash, and nitrogen have 

 no manurial value, but rather, as the report points out, " shows 

 that on land in high condition one must exercise judgment in 

 the use of manures." One cannot expect bacterised peat, 

 which is essentially a humus manure, to give results on land 

 already rich in humus. Judgment must be exercised even in 

 the use of bacterised peat. 



The farmer who farms for profit will be duly impressed with 

 the calculations of Profs. Wood and Biffen who, after saying 

 that " the price of bacterised peat appears to be about £10 per 

 ton," assume that it will have to be used in the open fields in 

 the same proportion as in the experiments at Kew, and then 

 give the cost of application as about £1,000 per acre ! 



The Manchester Corporation are now selling bacterised peat 

 at £4 per ton, and experiments with an improved drying and 

 sterilising plant at Entwistle indicate the probability that this 

 price will be reduced eventually to about £2 per ton. 



The suggestion that farmers should use only 5 to 10 cwt. per 

 acre is objected to because it is made " without a shred of 

 evidence to show that such proportions may be expected to 

 produce in his fields results comparable with those obtained 

 by the use of 10 per cent, in a flower-pot." Plenty of evidence 

 on this point has been received since Mr. Knox wrote his book. 



