191 1.] Summary of agricultural Experiments. 329 



Composition of Sawdust (Roy. Agric. Coll., Cirencester, Scientific 

 Bulletin, No. 2, 1910). — The use of sawdust as litter, and, consequently, 

 as a constituent of manure, makes its composition, as regards nitrogen 

 and ash constituents, of interest to agriculturists. The sawdust of the 

 wood of various trees, obtained from sawpits, was examined at the 

 College. The water in the sawdust, as received, varied from 6 to 

 13 per cent. In the dry matter the nitrogen varied from 0*14 per cent, 

 to 0*30 per cent., and the mineral matter from 0*25 per cent, to 1*38 per 

 cent. Assuming the presence of 10 per cent, of moisture, the mean 

 result is 0*2 per cent, of nitrogen in the sawdust. 



Manuring of Potatoes (Univ. Coll. of N. Wales, Bangor, Agric. Dept., 

 Bui. 8, 19 10). — This experiment has been carried out for the last three 

 years, at six centres each year. Taking the average for the three years, 

 the average crop of marketable potatoes from the unmanured plot has 

 been 4 tons 2§ cwt. Ten tons of farmyard manure per acre have pro- 

 duced an increase of 2 tons 19 cwt., and 20 tons of farmyard manure 

 have given an increase of 4 tons 2 cwt. There is little doubt that the 

 extra ten tons could be used with more effect elsewhere. The highest 

 yield (9 tons 10^ cwt. per acre) has been obtained from 10 tons of farm- 

 yard manure supplemented by a complete dressing of artificials, viz., 

 202 lb. sulphate of ammonia, 524 lb. superphosphate, and 164 lb. 

 sulphate of potash per acre. These artificials cost £2 12s. per acre, and 

 increased the yield by 2 tons 9 cwt. per acre, so that the extra quantity of 

 marketable potatoes was obtained at a cost of a little more than £1 per 

 ton. Professor Winter states that, looking at the experiment as a whole, 

 it is clear that 20 tons of farmyard manure per acre cannot be economically 

 applied, although 10 tons per acre is not enough to produce a full crop 

 of potatoes. The returns on the plots where the smaller amount of farm- 

 yard manure, along with an incomplete dressing of artificials, was used 

 were relatively satisfactory. The plots that received the complete dress- 

 ing of artificials in addition to 10 tons farmyard manure gave the best 

 result. 



Manuring of Permanent Grass Land (Roy. Agric. Coll., Cirencester, 

 Scientific Bulletin, No. 2, 19 10). — This experiment has been carried out 

 on the same land for over twenty years. A summary of the results from 

 the beginning was given in the Journal for August, 19 to, p. 399. The 

 soil varies considerably in depth and texture, and in the amount of car- 

 bonate of lime contained in it. 



In 19 10 the unmanured plot gave over 25 cwt., a crop that has been \ 

 exceeded in only two previous years. Two plots with 12 tons of farm- 

 ; yard manure annually gave an average increase over this of 18J cwt. 

 1 he artificials were applied in the following quantities per acre : — Nitrate 

 of soda, 2\ cwt. ; sulphate of ammonia, 2 cwt. ; superphosphate, 5 cwt. ; 

 \ kainit, 5 cwt. ; and with these quantities a yield of over 2\ tons, or about 

 20 cwt. more than from the unmanured plot was obtained from various 

 combinations. Ten cwt. of basic slag alone improved the quality of the 

 herbage, but had little effect on the quantity. 



A preliminary botanical examination of the growth in the field has 

 been made. On the unmanured plot, and on the plots receiving kainit 

 ilone and nitrate of soda alone, the number of flowering species found 

 R as about 30 ; with kainit and superphosphate the number was reduced 

 to 22; and with kainit, superphosphate and nitrate of soda, to 16. 



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