yoS Summary of Agricultural Experiments, [dec, 



the same way there are four series of plots under experiment on a four-course 

 rotation, each of which bears a different crop in any one year. These plots 

 are sub-divided and treated on 10 different systems of manuring. Each of the 

 large plots may be regarded, therefore, as a farm on which ten different systems 

 of manuring are being tested, or the same section on each of the four plots 

 may be taken together to represent a farm on one definite system of 

 ■manuring. The results are given for 1906 and to some extent for previous 

 years. The most successful results in 1906 were obtained from the four 

 plots representing a complete rotation, which received the following manurial 

 treatment : 10 tons farmyard manure to wheat, 1 cwt. nitrate of soda and 

 5 cwts. superphosphate to roots, i\ cwts. superphosphate to barley, and 

 2i cwts. superphosphate to clover ; these plots yielded an average profit of 

 y/s. per acre. Another set which yielded much the same result (36.?. per 

 acre) received 10 tons farmyard manure to roots, 1 cwt. nitrate of soda to 

 wheat, and 5 cwts. superphosphate to clover. 



MISCELLANEOUS MANURIAL EXPERIMENTS. 



Sewage Sludge {Royal Commission on Sewage Disposal, Appe?idix VIII. 

 to Fifth Report).— The experiments carried out under the supervision of the 

 Board of Agriculture, on behalf of the Royal Commission on Sewage 

 Disposal are described on p. 690 of the present issue. 



Sewage Sludge {Univ. Coll. of North Wales, Bangor, Agric. Dept., 

 Bull. VIII., 1907). — This experiment was one of the series mentioned above. 

 The sludges applied failed to produce any appreciable effect. 



Green Manuring journal Roy. Agric. Soc, Vol. 68, 1907). — Experi- 

 ments in green manuring have been carried on for a number of years at 

 Woburn, and tares ploughed in have always given a subsequent corn crop 

 inferior to that obtained when mustard has been ploughed in. This 

 result is entirely opposed to theoretical considerations, as tares are a 

 leguminous crop and add twice as much nitrogen to the soil as does 

 mustard. The very interesting question was thus raised as to what was the 

 cause of the apparent disappearance, or at least the non-working, of the 

 nitrogen. Investigations at the Woburn Pot-culture Station have now shown 

 it to be due to the alteration produced in the physical condition of the soil. 

 When tares are grown the soil is left in a light and very open condition, and 

 there is a much more rapid loss of moisture than when mustard is grown. 

 The soil being left in a less consolidated condition and requiring more 

 moisture to be supplied to it, is, in the case of light sandy land, such as 

 that of Woburn, in a much less suitable condition for the subsequent growth 

 of a wheat crop than it is after green manuring with mustard. 



Pot Culture' Experiments {Journal Roy. Agric. Soc, Vol. 68, 1907). — A 

 short summary of the experiments in 1906-7 is given. The relations of lime 

 .and magnesia in soils have been studied, and most interesting results have 

 been obtained, both as regards the quality of the corn (both wheat and barley) 

 and the nature of the root growth. It is found generally that as the relative 

 proportions of lime and magnesia in a soil approach nearer and nearer to the 

 ratio 1 : 1 so the wheat gram tends to become more and more glutinous or 

 " hard," in other words to show more " strength." Inquiries have also been 

 pursued with regard to the " acid " condition obtained in Stackyard Field as 

 the result of the continued application of salts of ammonia to a soil naturally 

 poor in lime. The influence of salts of lithium is being investigated. 

 Chloride and sulphide of manganese have been shown to have a beneficial 

 -effect on the oat crop, when given in quantities not exceeding 1 cwt. per acre. 



