424 



NATURE 



[December 25, 1919 



there was a plot devoted to the elucidation of the 

 effect of this substance, and although in the gicat 

 inajoritv of cases the phosphate-/)/ t(,5-potash plot has 

 shown more live-weight increase than phosphates 

 alone, it is only in very rare instances that the gain 

 has been a profitable one. Even on thin soil over- 

 Iving chalk, potash has had little action on pasture. 

 There are several rather conspicuous instances of 

 quite moderate dressings of potash doing positive 

 harm. Thus, at CocUle Park, whereas potash gave 

 an appreciable increase in live-weight in the first nine 

 vears, it proved positively and progressively injurious 

 during the next two six-year periods. Even on a 

 "light stonv loam " in Perthshire, Wright found that, 

 although in the first two years potash when added to 

 slag gave a conspicuous return, in the next three 

 vears "the advantage was wholly with the slag-alone 

 plot." The most notable beneficial effect of potash 

 was obtained in Dumfriesshire on a station where the 

 mineral soil was overlaid by lo ft. of peat. There 

 the use of kainit supplying loo lb. of potash per acre 

 at the beginning of the experiment has in seven 

 vears produced 70 per cent, more meat than phosphate 

 (slag) alone, while the financial gain has been im- 

 proved by nearly 50 per cent. 



Potash has had great influence both on the yield 

 and comoosition of the hay on the meadow at 

 Rothamsted, and it would seem that this substance 

 has more effect on a meadow than on a pasture. 

 The reason is probablv to seek in the fact that in a 

 pasture the top layers of the soil are constantly being 

 enriched by the potash brought from the subsoil by 

 plants and returned through their excreta. In any 

 case, pasture plants on clay soil are in possession of 

 abundant supplies of potash, and it is only where 

 pasture occupies sandy, gravelly, or peaty soil that 

 this manurial element need be seriously considered. 



Lime as an addition to superphosphate was tested 

 at the three original manuring-for-mutton experi- 

 ment stations, a total of 30 cwt. per acre being 

 applied in three dressings in nine years. A notice- 

 able effect was produced tit all stations, and at two 

 of them the gain was a profitable one. The effects 

 of lime can be followed for twenty-one years at Cockle 

 Park, where the soil naturally contains 0-59 per cent, 

 of calcium carbonate. During that period an aggre- 

 gate of 54 tons per acre was applied in seven dress- 

 ings, the phosphate to which it was added being 

 superphosphate in the first nine years and basic slag 

 in the next twelve. The area receiving the lime was 

 the same throughout. The action of the lime has 

 proved to be a progressively decreasing one. On the 

 average it produced an annual increase of 22 lb. live- 

 weight in the first nine years, and of 8 lb. in the next 

 six vears, whereas in the concluding six years of the 

 period it has actually caused a reduction in live- 

 weight of 8 lb. per acre per annum. 



The addition to superphosphate of moderate dress- 

 ings of nitrogen in the form of sulphate of ammonia 

 or of nitrate of soda was tried at the three main 

 manuring-for-mutton stations, and at two others. 

 There is no need to go into a detailed discussion of 

 the results. The evidence is overwhelmingly against 

 the use of nitrogen on pastures. It undoubtedly 

 stimulates the vigour of the non-leguminous herbage, 

 but this reacts on the growth of the clovers, with the 

 result that the production of meat is sometimes, as 

 at Cockle Park, actually and substantially reduced. 



.\t the three original stations dissolved bones were 

 also tried, the comoarison being with equal quantities 

 (200 lb. per acre in nine years) of phosphoric acid 

 derived respectively from basic slag and super- 

 phosphate. The dissolved bones supplied in addition 

 from about 10 lb. to 40 lb. of organic nitrogen. All 

 NO. 26x7, VOL. 104] 



manures were applied as to half in the first year, 

 and, as to the other half, at the commencement of 

 the fourth season, the experiment being continued for 

 nine years at Cockle Park and Sevington (Hants) and 

 for eight years at Cransley (Northants). At Cockle 

 Park slag acted substantially better than dissolved 

 bones, though the latter surpassed the effect of super- 

 phosphate ; at Sevington dissolved bones proved 

 inferior to both the other manures; while at Cranslev 

 the position was reversed. But when the cost is con- 

 sidered there is no question of the superior merits of 

 basic slag. This supej-iority is continued and em- 

 phasised at Cockle Park, where the experiments are 

 now at the end of their twenty-third vear. -\ similar 

 result was also obtained in the series of pasture 

 experiments conducted by the Royal Agricultural 

 Society of England already referred to. There dis- 

 solved bones or bone-meal was tried at ten centres, 

 with the result that " in Herefordshire some benefit 

 was observed, but in the other places no real im- 

 provement could be detected as compared with the 

 unmanured part of the field. So far as these inves- 

 tigations gj), therefore, thev indicate that no further 

 experiments need be made with bones on pasture 

 land." 



With these results before us it is needless to pause 

 to consider whether the comparative failure of bones, 

 dissolved or raw, is due to the inferior qualitv of 

 their phosphate or to the fact that they supplv th^yHl 

 land w'ith nitrogen. ^|| 



.A form of pasture improvement which has had. and 

 still has, much support amongst farmers is feeding 

 with cake. The manure applied to the land through 

 cake residues is a "general" manure, supplying 

 nitrogen, phosphates, and potash, of which that which 

 has the highest value attached to it is the nitrogen. 

 .■\t eleven of the stations in England and Scotland 

 reported on in the .Supplement to the Journal of the 

 Board of Agriculture in 191 1, linseed or cotton cake, 

 or a mixture of these cakes, was used for two. four, 

 or five years, and at every one of them the live-weight 

 gain secured was insufficient to pay for the outlay, 

 the debit balance per acre per annum being in one 

 case nearly a pound. In connection with the improve- 

 ment of pasture, however, it is the residual effect of 

 the cake that has most interest. This matter was 

 put to the test at eight of the manuring-for-mutton 

 stations in the following manner. At the three 

 original stations cake was fed all through the season 

 for two vears, and none given for the next four. At 

 five of the other stations cake was fed for two or 

 four vears, and was then suspended for one, two. or 

 three vears. In this way the improvement of the 

 herbage effected during the years when rake was fed 

 had an opportunity of manifesting itself in the form 

 of live-weight increase in the years immediately suc- 

 ceeding, when no cake was given. In every case the 

 residual effect was found to be appreciable, havini; a 

 money value per ton of cake consumed of as much 

 as 4I. 14.'!. at one station, and 3/. ii.s. at another, the 

 average for the three stations where the residues 

 were followed for four years being fully 3/. per ton, 

 a figure which is of the same order as, though some- 

 what higher than, those adopted by Voelcker and 

 Hall in their revised table of 1902. 



.\ method of improvement of poor pasture that 

 deserves notice consists in scattering the seed of a 

 "renovating" mixture over the surface, usually with 

 concurrent harrowing, rolling, and manuring. This 

 procedure was practised in the series of experiments 

 conducted bv the Roval .Agricultural Society of Eng- 

 land, the seed mixture consisting of four natural 

 grasses in addition to white clover and yarrow. In 

 their final report Carruthers and Voelcker stated that 



