Continuous Application of Farmyard Manure. 97 



of the wheat land, and tabulated results lead to the conclusion 

 that the wheat will eventually maintain a somewhat higher 

 total produce than the barley. This is what might be expected 

 with the autumn-sown crop, with its longer period for root 

 development, and consequent possession of a greater range of 

 soil for the collection of food. 



Farmyard manure, applied yearly for twenty years 

 (Plot 7), gave an average annual produce of more than 48 

 bushels of grain and 28cwt. of straw. The weight per bushel, 

 quantity of grain, and quantity of straw were all considerably 

 higher over the second than over the first ten years. The 

 manure probably supplied from three to four times as much 

 nitrogen as any of the artificial fertilisers, and much more 

 of carbonaceous organic matter, and of every other con- 

 stituent of the crop, than was contained in the produce. 

 It would leave a large residue of nitrogenous, carbonaceous ? 

 and other matters in the soil, which seem to be very slowly 

 available for future crops ; but the large accumulation of 

 organic matter increases the porosity of the soil, and its 

 capacity for the retention of moisture ; and the crops are 

 thereby rendered both less susceptible to injury from excess 

 of rain, and more independent of drought. As without 

 manure, so with farmyard manure, barley compared with 

 wheat yielded, over a series of years, more grain, less straw, 

 but nearly the same quantity of total produce (grain and straw 

 together). This is remarkable when it is considered that the 

 wheat is autumn sown and autumn manured, and the barley 

 spring sown and spring manured. It is interesting to note 

 that during the twenty years, 280 tons of farmyard manure, 

 containing from 80 to 90 tons of dry, solid matter, were 

 applied per acre ; but the produce only amounted to 24f tons 

 of grain and 28^ tons of straw, or in all to only 53 tons ; and 

 the increase over the produce without manure was only 

 about 14J tons of grain and 16J tons of straw, in all 30j tons 

 of total increase, which certainly would contain less than one- 

 third as much dry, solid matter as was supplied in the dung. 



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