November 22, 1900] 



NATURE 



85 



happened on the farm of a neighbour, it may be that their 

 own practice is not all that could be desired. When once 

 this spirit of inquiry has been roused, a long step for- 

 ward has been made. But farmers will give attention to 

 work that is going on in their own neighbourhood, under 

 conditions with which they are familiar, when they would 

 not concern themselves with results obtained on a station 

 that they had never seen. For this reason, local experi- 

 ments and demonstrations would be justified, even if 

 they were no more than a repetition of work conducted 

 elsewhere. 



Some curious results have, from time to time, been got 

 with potash, and at no place has this been more con- 

 spicuously the case than at the Northumberland Demon- 

 stration Farm of Cockle Park. Speaking generally, and 

 taking the average of several seasons, one finds that, in 

 the North of England, the addition of 3 or 4 cwt. of 

 kainit per acre to a nitrogenous-phosphatic artificial 

 dressing increases the turnip or swede crop by about 

 30 cwt. per acre. Such a return is moderately profitable, 

 but not sufficiently so to make it a matter of the first im- 

 portance, whether north-country farmers use potash for 

 their turnips or not. But not so at Cockle Park, where 

 the arable land is a light loam overlying millstone grit. 

 At that station, potash has proved to be absolutely indis- 

 pensable in the growth of root crops, so much so, in fact, 

 that, without the support of potash, other manurial 

 elements have practically no effect. The figures for 

 turnips — in terms of an acre — for three years are as 

 follows : — 



During two of the seasons the crop was actually in- 

 jured by the use of nitrogen (in the form of sulphate of 

 ammonia) and phosphoric acid (in the form of super- 

 phosphate of lime) unsupported by potash. Similar re- 

 sults have been got by at least one foreign investigator 

 by means of water-cultures, and it would be interesting 

 to have an explanation of this curious phenomenon. 

 But, without any explanation, the many hundreds of 

 farmers who have seen these demonstrations have at once 

 perceived that, on land of this character, large expendi- 

 ture on manures may be absolutely profitless ; and they 

 have gone home with the determination to experiment on 

 their own land, in order to ascertain whether their system 

 of manuring is as rational as it might be. 



To show how unsafe it is to apply, generally, results 

 obtained with one class of plant, attention may be 

 directed to some experiments begun in 1897 on a perma- 

 nent meadow, situated within a few hundred yards of the 

 three fields in which the turnip experiments were con- 

 ducted. The soil of this meadow is somewhat more 

 argillaceous than that of the arable land, but from the 

 appearance of the soil, and in view of the results referred 

 to above, one would not expect that the herbage growing 

 upon it would be absolutely independent of artificial 

 supplies of potash. And yet four years' results have 

 shown that not only does potash fail to increase the 

 yield, but that, when used unsupported by phosphate, it 

 does positive harm. The figures are as follows, the 

 sulphate of potash, which was applied each year, supply- 

 ing 50 lbs. of potash per acre : — 



NO. 1 62 I. VOL. 63] 



Treatment. 



Unmanured ... 

 Potash only .. 



Sulphate of ammonia .. 



plus potash 



Phosphate 



plus potash 



Ammonia and phosphate 



,, ,, plus potash 



1900 

 Cwt. 



Total 



Cwt. 



89i 

 76 



26i 122^ 



22}|I06| 



27 io7i 

 26i!io9| 



I 



304,133^ 

 3oi i29i 



V^ithout any exception, the potash has invariably reduced 

 the yield {a) when used alone, and {b) when added to a 

 nitrogenous manure. This depressing influence is more 

 pronounced in the last two than in the first two years, a 

 result doubtless due to the accumulation of potash in the 

 soil. When used along with phosphate, the potash 

 slightly increased the yield in the first two years, 

 whereas it has reduced it in the last two. Finally, when 

 added to both nitrogen and phosphate, the action of the 

 potash has either been harmful, or, at the best, negative. 



These results not only come out in weighing the crops, 

 but they are precisely what one would anticipate from 

 the general appearance of the plants. In the case of 

 turnips, the plants that have received no potash are of an 

 unhealthy green colour. The leaves are shrivelled and 

 puckered, and covered by large yellow blotches. In the 

 case of the meadow plots that have received potash, 

 without phosphates, \.\i& herbage is pale, almost brownish- 

 green in colour. In other parts of the country this 

 poisonous influence of potash on the mixed herbage of 

 meadows has been observed, Mr. Wood, for instance, 

 having recorded several cases in the east of England. 

 It is evidently a subject of some scientific interest, and 

 worthy of further investigation. 



In the past, the agricultural experiments and demon- 

 strations conducted by the local colleges and other 

 institutions subsidised by the Board of Agriculture h ive 

 been chiefly concerned with the manuring of land, though 

 a considerable amount of work has, in the aggregate, 

 been done in the direction of {a) testing new varieties of 

 plants ; {b) dealing with insect and fungoid injuries, 

 and the eradication of weeds, notably charlock ; {c) the 

 rearing and feeding of stock ; {d) dairying ; (<?) cider 

 manufacture. The initiation of such work has, with few 

 exceptions, been left entirely in the hands of the stafif at 

 the various centres, and while much is to be said in favour 

 of this system, there is a good deal to be urged against 

 it. More particularly it is apparent that the lack of any 

 central control, or, it may be, the want of opportunities 

 for consultation among the workers, has engendered a' 

 certain amount of unnecessary confusion, which could 

 easily have been avoided with advantage to every one. 

 While one worker uses 50 lbs. of phosphoric acid, 

 another, perhaps, uses 65 lbs., while a third may use 

 3 cwt. of some phosphate without regard to its contents of 

 phosphoric acid. This means all-round waste of energy, 

 and renders definite comparison of the results impossible. 



By voluntary association, one special four-course rota- 

 tion experiment is being carried out by the Durham 

 College of Science, the Yorkshire College, Cambridge 

 University, the South-Eastern Agricultural College and 

 Nottingham University College. The present season 

 will see the close of this experiment at three of the 

 centres, and the results are likely to be much more valu- 

 able than if the work had been entirely uncoordinated. 

 Major Craigie, in his report, directs special attention to 

 this experiment, as also to the fact that the Board has 



