5S0 



THE GARDEN AND FIELD. 



May. 1914 



but by putting the toxic soil-sub- 

 stances out of action. 



— Later Views. — 



From the point of view of im- 

 mediate practice the newer hypo- 

 thesis is not important ; but from 

 that of the ultimate practice of 

 manurintr no less than from the 

 point of view of scientific horti- 

 culture it is of very great import- 

 an»:e indee<i. Hence the investiga- 

 tions carried out by Mr. A. D. 

 Hall and his colleagues at Roth- 

 amsted, and published recently by 

 the Royal Society, are particular- 

 ly opportune. 



The net result of these investiga- 

 tions is to vindicate the older 

 \-iew, and to show that the revo- 

 lutionarv toxic hypothesis is with- 

 out foundation. The conclusions 

 reached by Mr. Hall, which are of 

 greatest interest, are, first, that 

 the Rothamsted plots, which are 

 to-day producing poor crops ow- 

 ing to the fact that essential foods 

 — ^now potash, now phosphoric acid 

 —have been withheld during the 

 past 60 years, yield good crops 

 when their particular deficiencies 

 are made good. Thus a phos- 

 phorus. starved soil gives a normal 

 good crop when phosphatic man- 

 ures are added to it and similarly 

 a potash starved soil recovers its 

 fertility when its defect of potash 

 is made good. 



Second, although ithe soil of 

 such plots has carried continuous- 

 ly for past 60 years crops of 

 one -'.ivi only — wheat in som.e 

 cases, barley in others-— water ex- 

 tracts from "the soil are found to 

 have no toxic action whatever on 

 the roots of similar or different 

 plants. 



Hence the toxic theory oi soil- 

 fertilitv mav be dismissed, or at 

 most re'i-arded as of very limited 

 applicability. 



Third, the Whitney-Cameron hy- 

 I)Othesis that all soils contain 

 enoujfh j)otash and phosphates for 

 plant-feedin'r t)urj)o.ses is .shown to 

 lie improbable. For Hall demon- 

 strates that, as we might expect 

 on the old \ iew, the feeding value 

 of a soil-extract increases within 

 the wide limits with its concentra- 

 tion. That is to say, a solution 

 which contains more potash or 

 phosphates products '>igger crops 

 than one which contains le.ss of the 

 substances. Naturally, there is a 

 lim.it to this law that concentra- 

 tion increases crop, and, as we all 

 know, an excess of solul)le fertilizer 

 m rt'sult in no crop at all. The 

 role, therefore, of the artificial fer- 



tilizer is to bring the " soil solu- 

 tion " up to the maximum benefi- 

 cent concentration, and we may 

 still hold the common sense view 

 that fertilizers used as supplements 

 to dung e.xert their beneficial ef- 

 fects by reason of the plentiful 

 supplies of specific foods which 

 th»y put at the disposal of the 

 jjlant. — Gardeners' Chronicle. 



♦ 



Soil Treatment. 



There is no simple way in which 

 a soil can be tested for .its con- 

 tent of the three most essential 

 elements of fertility. It is pos- 

 sible, of course, to have the soil 

 analysed and find out what its 

 content of these plant foods is. 

 But the trouble is that the chem- 

 ist cannot differentiate between 

 the available and unavailable 

 forms of these elements. A chem- 

 ical analysis ol almost any rea- 

 sonably good agricultural soil will 

 reveal the presence of sufficient 

 quantities of these plant foods to 

 produce maximum crops for many 

 vears, and this fact has given rise 

 to the theory which has been seri- 

 ouslv held, even by scientists, that 

 all that was needed to make a 

 soU fertile for an indefimte period 

 is to till it sufTiciently well to as- 

 sist nature in the unlocking of 

 the inert plant food whicb it con- 

 tai and reducing it to forms and 

 con, lations that will be avail- 

 able • r the use of growing plants. 

 But ihe difficulty with the applica- 

 tion of this theory is the fact that 

 the mechanical condition of the 

 soil is a m'ost important factor in 

 soil fertility as well of its actual 

 content of plant food. 



The soil must have an adequate 

 supph' of vegetable matter in the 

 form of humus to grow good crops, 

 and it is most important that the 

 farmer recognize this fact, else the 

 application of available plant food 

 in the form of expensive fertilizers 

 will not give him the results which 

 he expects, to say nothing of re- 

 leasing sufTicient plant food by 

 thorough tillage to grow maxi- 

 mum crops. An abundant supply 

 of humus in the soil aids in the 

 natural drainage of fine-grained 

 soils, and holds the moisture in 

 more open, coarse-grained soils, 

 givinjT it up as needed for the fer- 

 tilitv in the soils and also for the 

 work of the beneficial soil bacteria 

 which aid in making available the 

 fcrtilitv stored in the soil in an 

 unavailable form. 



For these reasons, the most im- 

 portant thing for the average far- 



mer to determine with regard to 

 his soil is whether it is in a good 

 mechanical condition, and if it is 

 not to ]mt it in that condition. 

 Vegetable matter may be added 

 to it in the form of stable manure, 

 which will at the same time add 

 available plant food for the grow- 

 ing of crops. As much manure 

 should therefore be made as pos- 

 sible, and every oimce of this 

 valuable agent in maintaining soil 

 fertilitv should be carefidly saved 

 and apjilied to the soil as soon as 

 practicable after it is mdde. But 

 this Avill not supply the veget- 

 able matter needed bv the soil on 

 able matter needed by the soil 

 on the average farm, so green 

 manure crops must be grown. 

 The le<Tumeis are of course, best for 

 this purpose, but even a non-le- 

 guminous crop will prove beneficial 

 in the suprilying of needed humus 

 to a soil that has become so de. 

 pleted in this necessary substance 

 as to make the main crop a fre- 

 quent failure. 



Ha^ing secured a good mechani- 

 cal condition of the soil the ques- 

 tion of just what available plant 

 foods it will '^ay to supply and in 

 what quantities for the different 

 crops grown can best be deter- 

 mined bv putting the question di- 

 rectly to the soil itself, by trying 

 out different forms of coimbinations 

 and quantities of these plant foods 

 on difTerent parts of the field and 

 comparing the results secured 

 with a check plot or strip in the 

 field on which no fertilizer was 

 used. In the making of experi- 

 ments of this kind, however, re- 

 sults should not be judged by gene- 

 ral appearances alone, as the eye 

 cannot measure the results with 

 suflicient accuracy in many cases 

 to determine whether the invest- 

 ment was a profitable one or not. 

 There is yet a great deal to be 

 learned about soil fertility, but in 

 a general way we know that it 

 pays to use supplementary fer- 

 tilizers, and it remains for the in- 

 dividual farmer to make an indivi- 

 dual solution of the problem so 

 far as the details are concerned. — 

 Michigan Farmer. 



• 



A certain millionaire did not ap- 

 prove of foreign mis.sions. One 

 vSimday at church, when the col- 

 lection was being taken for these 

 missions, the collection approached 

 the millionaire and held out the 

 collection bag. 



The millionaire shook his head. 

 " I never give to missions," he 

 whispered. 



"Then take something out of the 

 bae, sir," whispered the collector. 

 " The money is for the heathen," 



