NATURE 



THURSDAY, SEPTEMBER i6, 1915. 



AGRICULTURAL TEACHING IN AMERICAN 

 SCHOOLS. 



The Essentials of Agriculture. By H. J. Waters. 

 Pp. x + 455 + xxxvi. (Boston and London: 

 Ginn and Co., 1915.) Price 1.25 dollars. 



PRESIDENT WATERS tells us in his preface 

 that the American people have decided that 

 the public schools shall teach pupils "to think 

 and to do," and shall give a training- intimately 

 related to the life the student expects to lead. 

 As a necessary consequence agriculture figures 

 largely in American schools, and we are told that 

 wherever it is well taught it has proved to be a 

 source of strength — whether the institution is a 

 one-teacher country school, a high school, a col- 

 lege, or a university. The most successful method 

 is to make the teaching local, taking the whole 

 neighbourhood as the laboratory, and drawing 

 abundantly on the local farms, gardens, orchards, 

 and lanes, and the recognised local experts for the 

 apparatus and materials required. 



The teacher who embarks on such a course soon 

 runs up against considerable difficulties, because 

 none of the simple cases described in the popular 

 book ever seem to occur in his own district ; and, 

 on the other hand, the problems in his district 

 appear to be tantalisingly ignored by the book. 

 It is indispensable, therefore, that the teacher's 

 library shall contain only books by men of wide 

 experience, and for this reason a special welcome 

 is sure to be given to President Waters's book, 

 for few men can claim to possess the necessary 

 qualifications in greater degree. 



The opening chapters set out briefly the prin- 

 ciples on which the " new agriculture " rests. 

 Under American conditions, where one or two men 

 with modern machinery work a large farm, the 

 man-yield is high though the acre-yield is low. 

 Under European — including British — conditions 

 the acre-yield is high, but the man-yield is low. 

 What is wanted is a combination of the two. 

 President Waters, therefore, proceeds to set out 

 the conditions necessary for an increase in the 

 acre-yield. 



First of all, better plants and animals are needed. 

 An account is given of the way in which improve- 

 ments have already been effected in the common 

 erops and live-stock, and the underlying •prin- 

 ciples are clearly set out. The author next dis- 

 cusses how plants feed and grow, and deals not 

 only with plant food in the conventional sense but 

 a&o with the water relationships of the crop, a 

 subject to which American investigators have 

 NO. 2394, VOL. 96] 



rightly paid considerable attention. This is 

 followed by a section on soils, and emphasis is 

 laid at the outset on the need for adopting a con- 

 servative policy. " We may be wasteful and care- 

 less of everything else," says the author, quoting 

 William Brown, "but the land belongs to the 

 Ages. We are trustees holding this land . . . 

 and the happiness, the comfort, and the very exist- 

 ence of our children's children, and the millions 

 who will follow, is dependent upon the conscien- 

 tious, far-seeing wisdom with which we discharge 

 this solemn trust." This high line is adopted by 

 many of the most distinguished teachers of the 

 United States, and is the key-note of much of the 

 development work of recent years. The author 

 follows Cyril Hopkins in working out his illustra- 

 tions, and gives actual figures to show what quan- 

 tities of nitrogen, phosphorus, potassium, etc., 

 must be present in the soil in order to give a full 

 crop. In Dr. Hopkins's experience the method 

 works satisfactorily, although it has been the sub- 

 ject of much criticism. The quantities of these 

 materials present in any ordinary soil are far in 

 excess of the requirements of the crop, and it is 

 necessary to assume that they are mostly in com- 

 binations unavailable for the plant, but that they 

 become available at a certain rate per annum : 

 2 per cent, of the nitrogen, i per cent, of the 

 phosphorus, and 0*25 per cent, of the potassium, 

 being the rates quoted here. Naturally, a com- 

 parison can only be set up between soils of similar 

 types under similar climatic conditions, but the 

 actual procedure is much like the one that answers 

 very well in this country, although based on a 

 different principle. 



The author next passes on to manures, and has 

 much to say about the losses and wastage to 

 which farm-yard manure is often subject. It is 

 estimated that the amount produced in the United 

 States each year is worth more than two billions 

 of dollars, i.e., more than the entire wheat or 

 corn crop, and that nearly one-half is wasted. 

 We ourselves are in no better case ; the illustra- 

 tions given by the author could be paralleled in 

 this country. Fortunately the matter is being 

 seriously taken in hand at Rothamsted and other 

 experimental stations. 



Individual crops and animals are then described, 

 and the book closes with chapters on the business 

 aspects of farming, and on mechanical power for 

 farmers. 



The book brings home vividly to the reader the 

 enormous part played by the experiment stations 

 in the development of American agriculture. The 

 advances made during the last forty years would 

 appear incredible if they were not accomplished 



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