THE FARMER'S MAGAZINE. 



351 



Here some preliminary remark must be submitted. 

 In our prior strictures on the wheat and barley experi- 

 mental series, it was shown that the specific virtue 

 claimed by the experiment alists for nitrogenous ma- 

 nures in promoting the growth of these cereals, was in 

 their affording an abnormal supply of nitrogen, which 

 passing through the roots into the organs of the plants, 

 and from the plants into the atmosphere, performed an 

 important, though unexplained, and indeed ununder- 

 stood, function in its transit. But now, in respect of 

 superphosphate of lime, the evidence of its excellence 

 as a turnip manure is based on the alleged fact that 

 although itself little or not at all alimentary in its na- 

 ture, it plays a reactionary part in the soil, ever, in the 

 opinion of the experimentalists, abounding, but in a 

 state of dormant crudity, with all the elements required 

 in turnip vegetation. Through the instrumentality of 

 this decompositive substance those unavailable nutri- 

 ments are converted into activity to a greater or less 

 extent, proportionate (within certain limits) with the 

 quantity of this manurial re-agent employed in the pro- 

 cess. In support of this hypothesis, the experimen- 

 talists have cited no direct evidence, but there seems no 

 reason to deny it. Nay, more : we willingly admit that 

 the agricultural journals contain many experimental in- 

 stances where superphosphate of lime has shown itself 

 unequivocally successful in producing increased crops 

 of turnips, cultivated under the usual conditions of 

 rotation husbandry. But to this admission falls to he 

 added the important qualification, that the books do not 

 record probably as many instances where the manure 

 had no effect ; for it is well known that experimentalists 

 in practical agriculture too often forget that a negative 

 result may be as important as a positive one, and are 

 actuated by a false feeling of shame in not sending what 

 in very inaccurate language is called their failures to 

 the press. But to return to the supposed action of phos- 

 phoric acid, and of superphosphate of lime, in the soil ; 

 what the dormant substances are, which this re-agent 

 more especially attacks, is not surmised by these in- 

 vestigators ; but at any rate, it is beyond all conception 

 that it forms fresh chemical unions with, and imparts 

 nutritive qualities to, all the chemical elements in the 

 soil, carbonaceous, nitrogenous, siliceous, alkaline, cal- 

 careous, ferruginous, chloric, and sulphurous, which in 

 various groups of combination form the crude organic 

 or inorganic components of cultivated land. In other 

 words there are, no doubt, various or many substances 

 in the soil with which phosphoric acid plays no part as 

 a manurial re-agent. 



Let us, then, suppose the very probable case that there 

 are many soils deficient in elements on which phos- 

 phoric acid acts, and which abound in those towards 

 which it is inoperative ; is it not plain that the exhibition 

 of superphosphate of lime, or any other phosphate salt, 

 in such instances would be entirely futile? Thus, to cite a 

 very ai)posite case : — In 1855, Mr. T, D. Acland cropped 

 five experimental plots in one and the same field, on 

 Killerton home farm, with swede turnips, applying no 

 manure of any kind to the ground, which till 1851 had 

 been out on lease, and poorly farmed. It had borne in 



the four years antecedent to 1855, turnips, barley, 

 clover, and wheat in rotation, receiving no manurial 

 treatment with any of these crops save a moderate 

 dressing of guano with the roots. In point of soil, the 

 field was a deep free loam, of very good quality. In 

 the same close were other twenty plots, also in swedes, 

 and these were managed, culturally, like the five un- 

 manured plots, but dressed with superphosphate of lime 

 in various quantities. In 1856, all the plots were in 

 wheat, and in 1857 a second time in swedes, and while 

 the twenty subdivisions, superphosphated in 1856, again 

 were manured with this substance, the unmanured five 

 still continued so. In 1858 the crop again was wheat, 

 and in 1859 mangolds, the unmanurial and manurial 

 treatment being still the same. The following table 

 exhibits the results as respects the turnip produce : 

 Table IV. 



Than this, is it possible to conceive a clearer case of 

 palpable failure of superphosphate of lime as a manure in 

 root husbandry ? Did Mr. Acland, on the strength of 

 this beautiful, btcause simple, apt, and practical series 

 of trials, promulgate a manurial theory against the use 

 of phosphatic manures, and address it to every English 

 farmer, whether tilling soils alike or unlike to the Kil- 

 lerton soil, or enjoying climates similar or dissimilar to 

 that of South Devon ? By no means ; but on the con- 

 trary, we find him in his concise but perspicuous reports 

 modestly speaking of them as if they were mere mites cast 

 by him into the general treasury of agricultural knowledge, 

 without attempting to elevate them as guiding lights 

 in the actual business of husbandry. Contrasted with 

 the Rothamsted trials, the respective characters of the 

 two, considered in their bearing on turnip cultivation, 

 stand thus : In one the investigation was conducted on 

 a soil every way well adapted for the growth of this root : 

 in the other it was not. In one, the trials had a 

 thorough analogy to the prevailing policy of economic 

 farming : the others had none. If the Rothamsted in- 

 stance afforded any evidence in favour of phosphatic 

 manuring, a fortiori, the Killerton experiments bore 

 better testimony of their futility. If the Rothamsted 

 soil be typical of much land throughout England — of 

 which, however, there is no proof — so, doubtless, the 

 staple in which the Acland experiments were performed 

 may be taken as representing in its idiosyncracy a no 

 less prevalent class of soils. 



But although every unprejudiced mind will readily 



