1909.] Summary of Agricultural Experiments. 311 



amount of apportioned tithe renteharge at the present time 

 to ^3,711,498. The actual value, however, fluctuates, being 

 determined from year to year by the septennial averages of 

 the price of grain. At the present value it now amounts to 

 ^2,595,154, or about 70 per cent, of the apportioned amount. 

 The septennial average, as calculated under the provisions 

 of the Corn Returns Act, 1882, shows that the value of ^100 

 of tithe renteharge for the year 1909 is £6g iSs. 5j<2. 



SUMMARY OF AGRICULTURAL EXPERIMENTS. 

 Experiments with Root Crops {continued). 



Manuring of Mangolds on Black Fenland (Camb. Univ., Dept. of 

 Agric, Farmers' Bull. No. 6). — This experiment, in conjunction with 

 other experiments in manuring peaty soils, was carried out in 1898-9 

 on different types of fenland at three centres in the Isle of Ely and 

 Huntingdonshire. These black peaty soils contain sometimes as much 

 as 1 2 per cent, of nitrogen and | per cent, of potash. Though analyses 

 do not suggest a deficiency of phosphates, yet in practice phosphatic 

 manures are found to increase the yield of crops, and superphosphate 

 gives better results than other phosphates. The object of this experi- 

 ment was to find out how much superphosphate could be profitably 

 employed, and whether an addition of nitrogen or potash to the 

 superphosphate would increase the profits. 



The largest yield (22 tons 6 cwt.) was produced by 3 cwt. super- 

 phosphate, 2 cwt. nitrate of soda, and 1 cwt. muriate of potash. 

 Valuing the mangolds at js. per ton, the profit over the unmanured 

 plot was 39s. Without the potash the yield was 21 tons 18 cwt., and 

 owing to the smaller cost of manure the profit was increased to 

 45s. 6cl. The greatest profit (585. 6d.) was made with 6 cwt. super- 

 phosphate alone, a yield of 21 tons 13 cwt. being obtained in this case. 

 The results suggest that for mangolds on black soils, a heavy dressing of 

 superphosphate at sowing, with a top dressing of nitrate of soda after 

 singling, will generally be the most profitable system of manuring. 

 The addition of common salt proved harmful at each of the centres. 



Manuring of Swedes (Rothamsted Expt. Stat., Ann. Report, 1908). — 

 Swedes were sown after the failure of mangolds on land on which no 

 swedes had been grown since 1870, and the results of the different 

 systems of manuring are given. 



Manuring of Swedes (Harper-Adams Agric. Coll., Field Expts., 1908). 

 — Experiments were carried out at three centres in Staffordshire on 

 behalf of the County Education Committee. One experiment was in- 

 tended to test the relative values of sulphate of ammonia, calcium 

 cyanamide, and nitrate of soda as a source of nitrogen to the swede 

 crop, the same amount of nitrogen being applied in each case, in 

 addition to 4 cwt. steamed bones, 3 cwt. superphosphate, and 2 cwt. 

 kainit. Nitrate of soda gave the heaviest yield, while sulphate of 

 ammonia gave a slightly better return than calcium cyanamide. 



