Manual of agriculture for secondary schools; studies in soils and crop production

Front matter

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Preface

Theoughout the country to-day many schools of secondary grade are expressing a desire to add to their present curricula of studies courses of instruction in agriculture ; but they are in doubt as to the character and extent of the work which would be possible or advisable for them to olfer in this subject.

While a considerable number of elementary books in agriculture has been written in recent years, few, if any, of them were prepared for high school grades, and do not assume to compare in the character of matter presented or in their thoroughness of the treatment of the subject with texts in the other sciences taught in high schools.

Agriculture is now recognized as embracing so large a field, with so many different divisions and special interests, that no single book within the proper bounds of a high school text could pretend to compass the whole subject. The work should be presented in separate courses which may be taken by classes either in the order of their natural sequence, or a selection can be made of those courses most directly related to the particular agricultural interests of the communities where the schools are situated.

There are many excellent books on the various topics included in each department of agriculture, and a great wealth of agricultural information has been published in bulletin form. All of this is available matter for reference and should be of much value to teachers and students in their work ; but as yet there are no texts in agriculture that have been prepared to meet the special needs of high school courses. There is no question, however, but viii PREFACE

that the urgent demand for such texts will call forth in the near future many good books, and in the meantime much may be done with the material now at hand in making a beginning in the work of secondary school agriculture.

The purpose of this Manual is to outline a course of study in agriculture, covering at least one year's work, which shall be of high school grade, and shall offer training in sciences comparable to that furnished by the other science courses in good high schools.

The writer believes that all of the work in agriculture taught in our high schools should be of such character that it will appeal to the practical farmer as real agriculture, possible of application to actual conditions and closely related to the affairs of the homes and the farms of the community. In addition to this it should possess such educational value, both in its content and in its opportunities for training in scientific methods and habits, as to justify its place in the curriculum of any good high school.

The work as outlined in this course is confined to studies in soils and crop production. Since the growing of crops is the basis of all farming operations and every form of agriculture is intimately associated with the cultivation of the soil, it seems best to make this work the foundation for the courses in agriculture to be taught in high schools.

Then, following this, a study of the breeds and types of the most important farm animals and something of the laws of breeding and improvement of stock, a study of methods of feeding, the principles of nutrition and a comparison of the nutrient values of the different foodstuffs produced and used on the farm, the symptoms, causes, treatment, and prevention of the more common ailments of domestic animals, the composition and care of milk and the testing of milk for butter fat, a study of the more common insect pests and plant diseases with the proper treatment for each, and the preparation of the different insecticides and fungi-

PREFACE ix

cides, — such topics as these might be selected as material for the work of a second course.

The plan of work suggested in this Manual includes recitations following the reading and discussion of the portions of texts and bulletins treating each topic as it is taken up combined with exercises in the laboratory and supplemented wherever possible with pot-culture work and field experiments.

Many of the laboratory exercises are the same that are used in the courses in agricultural colleges, for it is believed that the work in high school agriculture should hold the same relation to college agriculture as exists in the case of the other high school sciences, — botany, zoology, physics, chemistry, and in mathematics and languages, — with the expectation that many high schools will be able to do work in agriculture for which college credits can be allowed.

In Part I, Exercise 1 is borrowed from Soil Physics Laboratory Guide by Professors Stevenson and Schaub of Iowa State College. Exercises 2 to 20 inclusive are taken from Laboratory Manvxd for Soil Physics by Professor J. G. Mosier of the University of Illinois. In a few instances they have been shghtly altered to adapt them to the purposes of the book.

In Part II, page 52, acknowledgment is made to Dr. C. G. Hopkins and Professor J. H. Pettit of the University of Illinois for material used.

In the work with corn the author has drawn very freely from the admirable circular. Studies of Corn and Its Uses, prepared by Professor Fred H. Rankin of the University of Illinois.

Part I. Studies About Soils Page

I. Physical Composition of the Soil ... 1 Exercise 1. Examination of Soil Particles with Microscope ....... 2

II. Moisture Relations of Soils .... 3

Exercise 2. Determination of Total Moisture in Samples of Field Soils ..... 4

II. Different Forms of Soil Moisture ... 6 Exercise 3. Determination of Capillary Moisture

in Field Soils 8

T. Soil Temperature and its Control . . .9 Exercise 4. Effect of Drainage on Soil Temperature 10

V. Influence and Control of Color of Soils . 10

Exercise 5. Effect of Color of Soil on Temperature 1 1

71. Effect of Lime on Heavy Soils . . .12

Exercise 6. Determination of the Effects of Lime

on Plastic Soils . . . . . .13

Exercise 7. Weight of Soils . . . .14

Exercise 8. Determination of the Apparent Specific Gravity of Surface Soil under Field Conditions 15

Exercise 9. Determination of the Weight of Soil per Acre-foot . . . . . . .15

Exercise 10. Determination of Specific Gravity of Soils. Volumetric Method .... 16 xii CONTENTS

VII. Questions concerning the Weight of Soils

VIII. Porosity of Soils

Exercise 11. Determination of Porosity — First Method

IX. The Organic Matter in Soils

Exercise 12. Determination by Ignition of the Loss of Organic Matter by Cropping

X. The Water-retaining Power of Soils .

Exercise 13. Power of Soils to retain Water

XI. Effect of Compacting the Soil

Exercise 14. Power of Compact Soils to retain Water

XII. How Organic Matter in Soils affects their Water-holding Power Exercise 15. Effect of Organic Matter on Reten tion of Water .....

XIII. Capillary Movement of Soil Moisture

Exercise 16. A Study of the Capillary Action of Soils

XIV. A Common Mistake in Applying Manure

Exercise 17. Effect of Organic Matter on Rise of Water in Soils

XV. The Farmer's Control of Soil Moisture

Exercise 18. Effect of Soil Mulches on Evapora tion of Water from Soils

XVI. Mulches of Various Materials

Exercise 19. Effect of Artificial Mulches upon Evaporation of Water from Soils .

CONTENTS XIU

PAGE

XVII. Impeovement of Heavy Soils by Use of Farm

Manure 35

Exercise 20. The Effect of Organic Matter on Baking of Clay Soils 37