Table Of ContentSECOND EDITION
Principles of
Field CroD Production
John H. Martin
Formerly Research Agronomist, Agricultural Research Servi
United States Department of Agriculture
Warren H. Leonard
Late Professor of Agronomy, Colorado State University;
and Agronomist, Colorado Agricultural Exp"iment Station
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The Macmillan Company,
NEW YORK
Collier-Macmillan Limited,
LONDON
© Copyright, THE MACMILLAN COMPANY, 1967
All rights reserved. No part of this book may be reproduced
or transmitted in any form or by any means, electronic or
mechanical, including photocopying, recording or by any
information storage and retrieval system, without permission .
in writing from the Publisher.
First Printing
Earlier edition copyright 1949
by The Macmillan Company.
Library of Congress catalog card number: 67-16360
THE MACMILLAN COMPANY, NEW YORK
COLLIER-MACMILLAN CANADA, LTD., TORONTO, ONTARIO
PRINTED IN THE UNITED STATES OF AMERICA
Preface to the First Edition
This book presents some of the facts and fundamental principles
essential to an understanding of field crop production in the United
States. It is designed as a college text for a general course in field crops,
especially for agricultural students who take only one course in crop
production. It also should serve as a reference to those concerned with
crop production. The subject matter probably is more advanced than
that in other general crops books, but if so it should help raise the level
of field crop instruction. The book is longer than can usually be covered
in a one-semester course, but it offers a choice of subject matter to meet
different institutional and local requirements. Some knowledge of botany
and chemistry is desirable but not essential to an understanding of the
material presented. Since the subject matter is of national scope it should
be supplemented with lectures or assigned readings on local varieties
and cropping practices.
The references chosen are among those that seem to be pertinent to
the subjects discussed, but many other references would be as applicable.
It is impossible to cite all the worthwhile published articles. Foreign
references are omitted for the most part because they are not accessible
to, or usable by, large undergradute classes.
The major crops are grouped into chapters in accordance with their
botanical relationships. This should help avoid confusion concerning
crop plant structure and behavior. It is realized fully that the arrange
ment, selection, and presentation of topics and references might be
better. Suggestions for improvement and reorganization of the subject
matter will be very welcome.
J.H.M.
W.H.L.
Preface to the Second Edition
Numerous advances in crop science, new cropping practices, new
machines, improved crop varieties or hybrids, new agricultural chemi
cals, and shifts in the importance of many crops in different regions
necessitated a revision of the first edition that would describe modem
methods of crop production.
Less attention is given to varieties of field crops in this new edition.
These must be treated as a local crops laboratory problem, because
varieties differ from state to state as well as from year to year, especially
with the current rapid adoption of new varieties and hybrids.
ACKNOWLEDGMENTS
The authors are deeply indebted to their associates as well as to
others who have assisted in the preparation of the second edition of this
book. Among those whose help is gratefully acknowledged because they
read portions of the manuscript, or supplied subject material, are: W. K.
J.
Bailey, W. M. Bruce, B. S. Crandall, C. Culbertson, C. Gordon, A. A.
Hansen, C. H. Hanson, M. A. Hein, Paul Henson, H. W. Johnson,
Thomas Kerr, F. A. Loeffel, J. E. McMurtrey, Jr., Walter Scholl, C. S.
Slater, C. E. Steinbauer, Dewey Stewart, I. E. Stokes, and W. J. Zaumeyer.
Unless credited elsewhere, illustrations were provided by the United
States Department of Agriculture.
J.H.M.
W.R.L.
Contents
PART ONE General Principles of Crop Production
1 The Art and Science of Crop Production 3
2 Crop Plants in Relation to Environment 17
3 Botany of Crop Plants 51
4 Crop Improvement 78
5 Tillage Practices 94
6 Fertilizer, Green Manuring, and Rotation
Practices 120
7 Seeds and Seeding 154
8 Harvest of Field Crops 186
9 Handling and Grading Market Grain and Hay 215
10 Pastures and Pasturage 243
11 Weeds and Their Control 272
PART TWO Crops of the Grass Family
12 Indian Com or Maize 291
13 Sorghums 346
Grain Sorghum, Sorgo, Sudangrass, Broomcorn,
Jo hnsongrass
14 Sugarcane 376
15 Wheat 391
16 Rye 449
17 Barley 460
18 Oats 477
19 Rice 495
20 Millets 519
Foxtail Millet, Proso, Pearl Millet, Japanese
Barnyard Millet, Browntop Millet
21 Perennial Forage Grasses 532
Timothy, Smooth Bromegrass, Orchardgrass,
Tall Fescue, Reed Canarygrass, Kentucky Blue-
vii
viii Contents
grass, Other Bluegrasses, Bermudagrass, Red-
top, Crested Wheatgrass, Western Wheatgrass,
Slender Wheatgrass, Other Wheatgrasses, Peren-
nial Ryegrass, Italian Ryegrass, Wildrye Grasses,
Meadow Foxtail, Tall Oatgrass, Blue Grama,
Buffalograss, Native Range Grasses, Carpet-
grass, Napiergrass, Dallisgrass, Other Southern
Grasses
PART THREE Legumes
22 Alfalfa 575
23 Sweetclover 597
24 The True Clovers 610
25 Lespedeza 631
26 Soybeans 643
27 Cowpeas 663
28 Field Beans·. 672
29 Peanuts 689
30 Miscellaneous Legumes 705
Field Peas, Vetches, Velvetbeans, Burclover,
Black Medic, Buttonclover, Kudzu, Crotalaria,
Trefoil, Sesbania, Lupines, Guar, Florida Beg
garweed, Roughpea, Hairy Indigo, Alyceclover,
Crown Vetch, Pigeon Pea, Fenugreek, Sainfoin,
and Seradella
PART FOUR Crops of Other Plant Families
31 Buckwheat 739
32 Flax 747
33 Cotton 762
34 Tobacco 796
35 Sugarbeets 826
36 Potatoes 847
37 Sweetpotatoes 881
38 Miscellaneous Forage Crops 895
Jerusalem Artichoke, Root and Leaf Crops, and
Pumpkin and Squash
39 Miscellaneous Industries Crops 908
Hops, Mint, Dill, Wormseed, Wormwood,
Mustard, Sesame, Safflower, Castorbean, Perilla,
Sunflower, Guayule, Hemp, Ramie, Kenaf,
Sansevieria, Taro, Teasel, Chicory, Pyrethrttm,
Belladonna, Henbane, Ginseng, Goldenseal, and
Poppy
CONTENTS
PART FIVE Appendix
Table A-I Seeding; Seed and Plant Characteristics 961
A-2 The Percentage Composition of Crop Products 976
A-3 Conversion Tables 986
A-4 Trade Names of Seed Treatment Chemicals 989
GLOSSARY 990
INDEX 1007
PART ONE
General Principles
()f Crop Production
1
CHAPTER
The Art and Science
of Crop Production
CROP PRODUCTION AS AN ART
Primitive man lived on wild game, leaves, roots, seeds, berries, and
fruits.15 As the population increased, the food supply was not always
<1
suffiCiently stable or plentiful to supply his needs. Crop production began
when domestication of plants became essential to supplement natural
supplies. The art of crap production is older than civilization, and its
essential features have remained almost unchanged since the dawn of
history. These features include (1) gathering and preserving the seed of
the desired crop plants, (2) destroying other kinds of vegetation growing
on the land, (3) stirring the soil to form a seedbed, (4) planting the
seed when the season and weather are right as shown by past experience,
( 5) destroying weeds, (6) protecting the crop from natural enemies,
and (7) gathering, processing, and storing the products.
Farm machines merely speed the hand of man in doing these things
or enable him to do the work better.
According to the story of the Creation, man originally was expected
to subsist solely upon horticultural' and animal foods. Only after he had
tasted the fruit of the Tree of Knowledge did he consume field-crop
products. Adam was banished from the Garden of Eden with the follow
ing warning: "Thorns also and thistles shall it bring forth to thee; and
thou shalt eat the herb of the field. In the sweat of thy face shalt thou eat
bread." It seems that the next grower of field crops clashed with a sheep
herder and was driven to still poorer lands with these words: "When
thou tillest the ground, it shall not henceforth yield unto thee her
strength." With this burden the problems of the crop grower have con
tinued through the ages. Today in the United States 97 per cent of the
cropped land is devoted to field crops.
The early husbandman cultivated a limited number of crops, the
cereals being among the first to be grown in most parts of the world. The
same crop often was produced continuously on a field until low yields
" Superscript numbers indicate numbered references at the end of chapters.
3
4 General Pl'inciples of Crop Production
necessitated a shift to new land. This temporary abandonment of seem
ingly partly worn-out land has been almost universal in the history of
agriculture. This is still common in parts of Africa, but it is also a highly
effective practice in growing tobacco in southern Maryland. A modifica
tion of this practice was the introduction of bare fallow every two or
three years. The primitive husbandman removed by hand the destructive
insects in his fields, and appeased the gods or practiced mystic rites to
drive away the evil spirits he believed to be the cause of plant diseases.
With advanCing civilization materials such as sulfur, brine, ashes, white
wash, soap, and vinegar were applied to plants to suppress diseases or
insects.
Romans of the 1st century A.D. intertilled many crops with iron hand
knives. Intertillage was practiced on almost all crops grown by American
Indians.4 Intertillage with animal power was advocated in England in the
17th century.
The value of lime, marl, manures, and green manures for the mainte
nance of soil productivity was recognized 2,000 years ago. Boob on
agriculture written by the Romans (Pliny, Varro, and Columella) of
about the 1st century A.D. describe the growing of common crops includ
ing wheat, barley, clover, and alfalfa by procedures very similar to those
in use today except that more of the work was done by hand and the
farm implements then used were crude.5 However, in the experimental
nursery plots of present-day agronomists, as well as in thousands of home
gardens and on the small farms of many lands, one sees crops being
grown and harvested by hand methods almost identical with those
followed by the slaves in the Nile Valley in the time of the pharaohs
6,000 years ago.
The old art of crop production still predominates in farm practice
throughout the world. Plant pathologists and entomologists have found
ways to control plant diseases and insect pests more effectively. Chemists
and agronomists have found supplements for the manure and ashes
formerly used for fertil~zers. Rotations perhaps are slightly improved.
Many new crop varieties have been introduced.
Improved cultural methods doubtless followed observations made by
primitive farmers. They found better crops in spots where manure, ashes,
or broken limestone had been dropped, or where weeds were not allowed
to grow, or where the soil was dark, deep, or well watered, or where one
crop followed certain other crops. Observations or empirical trials quickly
revealed roughly the most favorable time, place, and manner of planting
and cultivating various crops. These ideas were handed down through
the generations. Observation, the only means of acquiring new knowl~
edge until the 19th century, continued to enrich the fund of crop lore.
Eventually, the exchange of ideas, observations, and experiences, through
agricultural societies and rural papers and magazines, spread the knowl
edge of crops.
