SELECTIONS FROM THE BOOKSHELF - American Society of Agronomy

15 Pages·2003·0.47 MB·English

SELECTIONS FROM THE BOOKSHELF
Agronomyo f Grassland Systems--C.J. be a valuable reference for all persons in- culture, crop ecology, or weed science,
Simpson and R.L. Ison. Cambridge terested in forage systems planning and but not for use as a primary text. I found
University Press, 32 East 57th Street, those involved in forage research. Al- the chapters on population models (Chap-
NewY ork, NY1 0022. 1987. Illus. 169 though the authors clearly define key ter 3), the regulation of plant populations
p. Handcover $49.50, Paper $16.95. terminology, the reader needs a good (Chapter 4), evolutionary ecology (Chap-
background in the sciences, plant phys- ter 7), and interactions in species mixtures
This book describes current under- iology, plant ecology, animal science, (Chapter 8) to be of greatest interest
standing of how grassland systems work. agronomy, and economics to fully com- the agronomy student. Many agronomy
The overall thrust is an emphasis on sys- prehend the material presented.- undergraduatesw ill likely react negatively
tems concepts and the underlying biolog- GERRYL . POSLER, Dep. of Agron- to the relatively limited numbero f agro-
ical principles. The book is very concisely omy, Kansas State Univ., Manhattan, KS nomic examples cited in the book. Most
written with chapter contents arranged in 66506. examples are drawn from the ecology
a decimal outline system. The authors are literature considering natural ecosystems.
to be commendefdo r the inclusion of the Yet the author has not entirely neglected
many interacting factors involved in the specialized interests of agronomists,
grassland systems. However, the detail as evidenced by his discussion of popu-
for each particular topic is not great, be- lation density and plant yield in Chapter
cause of the manyi nteracting factors that 4 and the consideration of crop mixtures
are considered. and land equivalent ratio in Chapter 8.
Introduction to Plant PopulationE cology,
The eight chapters are arranged in a Nevertheless, one challenge in using this
Second Edition--Jonathan Silvertown.
generally developmental sequence, con- LongmanS cientific and Technical, co- book in an agronomyc ourse will be to get
sidering physiological, ecological, and students to look beyond the specific
published in the USAw ith John Wiley
systems principles. The chapters included examples to consideration of the princi-
& Sons, Inc., 605 Third Ave., New
are ple being discussed.
York, NY1 0158. 1987. Illus. 229 p.
1. An overview Paper $19.95. Because this book considers principles
2. Generation (seed and vegetative) of plant population ecology in a broader
3. Vegetative growth There is little disagreement among context than agriculture, it can broaden
4. Flowering and seed production agronomy educators that knowledge of the perspectives of students. For exam-
5. Mineral nutrition principles of ecology provides an impor- ple, I think the book has considerable
6. Herbage quality and animal intake tant foundation for modern agronomic promise if used as a focus for a seminar
7. Grassland-animal interaction sciences. The emergence of agroecology for seniors or graduate students. To as-
8. Grasslands in farming systems as a subdiscipline within both the ecolo- sess this possibility, I held a series of in-
formal discussions this past spring
At the end of several chapters, after gy and agronomy professional societies
organized around some of the chapters
presenting the concepts and principles, attests to the increased recognition of this
from this book with faculty and gradu-
the authors provide an excellent section point. Jonathan Silvertown defines popu-
ate student colleagues in my department.
regarding implications for management. lation ecology as a specialized branch of
For each session, one seminar participant
Each chapter also contains a few selected ecology concerned with quantifying inter-
was assigned the responsibility as discus-
references recommended for further actions betweens pecies and their environ-
reading. ment within a defined geographical area. sion leader and the other participants read
The authors use a very large number Certainly considerations by agronomists the assigned chapter or chapters from the
book. The primary focus for the ensuing
of tables, figures, graphs, and equations and weed scientists of interspecific com-
discussions was to assist one another to
to effectively highlight and illustrate key petition/interference in crop communities
understand the concepts presented in the
concepts, allowing them to minimize the involves understanding elements of popu-
book and to probe their relevance to agro-
amount of textural material. Three ap- lation ecology. Similarly, understanding
nomic topics of interest to the partici-
pendices are included: derivation of crop plant growth as influenced by
pants. The book was well suited to this
climatic data for calculation of grassland changes in plant density and spatial ar-
purpose, being technical enough to in-
growth; calculating the feed demando f rangement is a plant population ecology
trigue the participants, most of whomh ad
livestock; and investment analysis using kind of concern. Thus, there is muchi n
discounted cash flow. A good index and this second edition of Introduction to limited prior exposure to population ecol-
extensive list of references, many from Plant Population Ecology to interest the ogy course work, yet not being so long
or detailed as to cause them to lose in-
Australia and NewZ ealand, will increase educator in agronomy or weed science.
the usefulness for many readers involved On the whole, the book is detailed and terest.
in research. relatively advanced for an introductory In addition to the chapters noted
This book should be useful as a text for text. Most agronomyte achers will find it above, the book also considers other
a graduate course in forage manage- useful as a reference for undergraduate topics of interest to agronomists such as
ment/forage systems planning. It will also or graduate courses in crop growth and seed dispersal and dormancy, clonal
46 J. Agron. Educ., Vol. 18, no. 1, 1989
growth habit in relation to plant popula- Martyn G. Ford and David W. Salt, portant reference for graduate students
tion establishment and persistence, the Portsmouth Polytechnic, Portsmouth, and provides interesting background
demography of ramets, and the concept addresses "Behaviour of Insecticide De- reading for individuals interested in re-
of the niche. Each of these topic discus- posits and Their Transfer from Plant to search directed toward optimizing pesti-
sions are worthwile reading for agrono- Insect Surfaces." cide delivery to target pests. The many
my students who want to broaden their The chapter on herbicides includes a literature citations are an excellent source
understanding of the natural world as well good review of the physical and chemi- of additional information on the sub-
as enhance their understanding of plant cal properties of the plant cuticle. Factors ject.--PATRICK J. SHEA,Department
growth in communities. affecting pesticide retention and physical of Agronomy, University of Negraska-
The author maintains that the second loss from plant surfaces are discussed. Lincoln, Lincoln, NE 68583.
edition is a completer evision of the first. Controversial experimental evidence sup-
Althoughs ome similarities are apparent, porting sites of preferential herbicide
I agree that the newe dition is substantial- entry is presented. Quantitative transport
ly different from the first. The bibliog- and the influence of translocation and
raphy is expanded with the addition of metabolismo n pesticide absorption kinet-
manyr eferences published since the first ics are discussed. Reference to unionized
edition. In some cases figures have been phenoxyacetic acid herbicides as nonpolar
added or deleted since the first edition. would probably be considered inappro- Surficial Deposits of the United States--
Most of these changes improved the read- priate by most chemists. The author in- Charles B. Hunt. Van Nostrand Rein-
ability of the book. dicates that particular reference to the hold Publishing Co., 115 Fifth Ave.,
As an agronomist who never experi- influence of formulation and environ- NewY ork, NY1 0003. 1986. Illus. with
enced formal course work in ecology, I mental factors would be made, but dis- map. 189 p. Hardbound $39.95.
found this book a very good introduction cussion of these aspects is limited. Despite
to concepts of importance to agronomists some minor limitations, this chapter pro- This is a book about what we in soils
interested in the growthd ynamicso f plant vides excellent supplemental material to often call Parent materials. To quote
communities. I found some of the figures the existing literature. from the Foreward [sic] section of the
in the book more complex than I would A detailed, in-depth reviewo f the liter- book, "The term sur.ficial deposits refers
have liked and some could have been ature is includedi n the insecticide chapter. to unconsolidated materials that lie on
better interpreted in the text or legend. Effects of wax composition and content, bedrock, or that occur on or near the sur-
The second edition was printed on a and insecticide formulation on surface face of the earth." Thus, we are intro-
coarser paper than the first. I did not like wettability and chemical availability are duced to nine chapters and a U.S. map
it as well and felt that the crispness of the discussed. Mechanismos f insecticide loss (including Alaska and Hawaii) at a scale
text characters and figures was consider- from leaf surfaces and transfer to the in- 1:7 500 000. Data are said to be not avail-
ably less than in the earlier edition. sect are covered in detail. Insecticide able for Alaska and Hawaii.
In summary, I believe that this book transfer by direct impaction, injestion, Chapters are arranged by type of de-
has much to offer agronomyt eachers as and vapor intoxication are also included. posit. Residuum and other residual de-
a background reference for students or High-quality scanning electron micro- posits, including organics, are considered
themselves. With some imagination it graphs show the effects of application in the first two chapters. The remaining
might also find its way into a curriculum volume, humidity, and time on the ap- deposits mayb e considered to be trans-
as a primary text as in the case of the pearance of pesticide deposits. Micro- ported, and as commonly practiced,
specialized seminar that I described graphs also show insecticide distribution transport media and/or landform of de-
above.--STEVE R. SIMMONSD, epart- on an aphid surface following contact. position are used as differentiating criteria
ment of Agronomy and Plant Genetics, Sources of variability in insecticide field for forming classes. Gravity, shore, gla-
University of Minnesota, St. Paul, MN performance, including the impact of cial, and lake deposits are considered in
55108. preferential deposition on adaxial leaf their turn. The discussion of lake deposits
surfaces and insect avoidance behavior centers mainly on the deposits associated
are discussed. A method of computing the with glacial lakes. Glacial landforms are
effective insecticide dose required to pro- briefly mentioned with glacial deposits.
duce a given responsei n the field is cited. The chapter on stream deposits includes
The editor provides an excellent intro- a consideration of past drainageways of
duction with a frank discussion of the present drainage systems. Eolian deposits
Pesticides on Plant Surfaces--Edited by strengths and weaknesses of each chap- are discussed in only 10 pages of text,
Helen J. Cottrell. John Wiley & Sons, ter. She draws a critical conclusion con- covering both loess and eolian sand. A
Inc., 605 Third Ave., New York, NY cerning pesticide activity: while herbicide final chapter covers "miscellaneous
10158. 1987.86 p. Hardcover. $41.95. efficacy is dependent on efficient cuticle deposits," and includes basalt, bedrock,
penetration, absorption, and (except for clinker, and hot springs deposits. Volcan-
Pesticides on Plant Surfaces constitutes contact herbicides) translocation, insec- ic ash is not noted as a separate surficial
Volume1 8 of Critical Reports on Applied ticides generally need to remain on plant deposit.
Chemistry and reviews herbicide and in- surfaces for maximumav ailability. Cau- Perhaps I am somewhat biased in my
secticide behavior on plant surfaces in tion is expressedr egarding generalizations judgment of this book, for texts such as
separate chapters. Chapter 1, by Ralph amongp esticides and their behavior on Thornbury’s Regional Geomorphology of
C. Kirkwood, University of Strathclyde, surfaces of different plant species. A glos- the U.S., and Schultz and Frye’s Loess
Glasgow, concerns "Uptake and Move- sary follows the introduction and is help- and Related Eolian Deposits of the
ment of Herbicides from Plant Surfaces ful to the reader, whom ay be unfamiliar World, as well as R.V. Ruhe’s work with
and the Effects of Formulation and with some of the terminology. loess and Flint’s writings on glacial
Environment upon Them," Chapter 2, by Pesticides on Plant Surfaces is an im- deposits, have been the background of a
J. Agron. Educ., Vol. 18, no. 1, 1989 4"/
lot of myt hinkingo n the subject of sur- Ona positive note, the booki s welli l- ciples of the nitrogenc ycle andi ts move-
ficial andr elatedd epositsf or years. I was lustrated with maps, photographs, and ment to and through the groundwater.
disappointedin the book.I ts descriptions diagrams. A bibliography is provided Trends in nitrate concentrations of
are unimaginativep, ronet o dwello n the withe achc hapter.I t is organizeidn a log- groundwater are presented, and the
obvious, and not inclusive of muchth at ical fashion and contains descriptive potential impacto f the emergingp ractice
mighte xcite a student’s imaginationa nd formation in a very concise form. of chemigationis discussed. Therei s a
lead to further study. Chapterb ibliogra- Howeverw, ith so manyo ther really good short general presentation on the extent
phies leave out somei mportant works booksa vailableo n this subject, I sincerely of contaminationf roml andfills, under-
that I knowa bout, including those men- questiont hat it wouldb e wortht he $39.95 grounds torage tanks, and septic systems
tioned above. cost to a student. It does not appear to in Michigan.T his discussion includes a
Them api s a useful size, but I wonder be a very inclusive reference sourcef or list of contaminantfsr omt hese sources.
whyt here are no data included for Alas- the professional researchero r teacher.- Therei s a general assessmento f the im-
ka and Hawaii; J.C.F. Tedrowa nd J.V. DAVIDT. LEWIS,P rofessor of Agron- pacts of animal waste systemsw ith some
Drewa re amonga number of workers, omy, University of Nebraska.Lincoln, specific case studies and a paper on the
includingU golini, Douglasa, nd Hill, who Lincoln, NE6 8583-0914. impactso f a large-scale hog production
have studied surface deposits there, in- facility. This section concludesw ith a
cluding studies of soils. Their worki s report that comparesn itrate leaching
publishedin soils journalsa s wella s jour- fromf ertilizers to that froml egumes.
nals sucha s Arctic. In addition, several Rural GroundwaterC ontamination-- The third section contains two papers
areas in Alaskah ave soil surveysa vaila- Edited by Frank D’Itri and Lois G. on the use of models, one for decision
ble. This is also true of parts of Hawaii. Wolfson.L ewisP ublishers, Inc., 121 makingin productiona griculture and the
Soil surveysa re excellent sourceso f in- South MainS treet, P.O. Drawer5 19, other as a teaching tool for understand-
formationa bout surficial deposits. Chelsea, MI 48118. 416 p. Hardcover ing the behavioor f pesticidesi n soils. The
The maph as somea reas whoseb ound- $49.95. third andf inal paperi n this sectioni s on
aries and/ord escriptionsa re inconsistent, groundwaterm onitoring including well
either with the text or with other works This book is a collection of papers dfi!ling, samplinge quipments, amplec ol-
in the literature. TheS andhillsb oundary presenteda t the 20-22O ct. 1986c onfer- lection, and water analysis.
of Nebraskai s misplaced according to ence entitled "Rural GroundwateCr on- In Section4 , twoo f the six papersa re
published maps. The Sandhills are tamination: Assessment of Needs, A of a general nature, one on the drinking
described as being in northwestern Strategy for Action," held at the Michi- water standards mandatedb y the Safe
Nebraska. They are in north central gan State University KelloggB iological Drinking Water Act and the other on
Nebraska.M ucho f the loess in the state Station ConferenceC enter. The book is health implications of groundwatecro n-
is said to be "deeplyw eathereldo ess" and well organizedw ith the variousp apersb e- tamination. Bothp apers give a goodi n-
separated fromP eoria Ioess. There are ing assembledin to six logical sections. sight into the difficultiesi n setting drink-
ampled ata fromg eomorphisct udies, well Theses ections are (i) an overviewo f the ing water standards and in assessing the
logs, University of Nebraska-Lincoln situation; (ii) sourcesa ndi mpactso f con- health risks of drinking contaminated
bulletins, and journal articles by many taminants;( iii) assessmenta nd modeling water. The third paper describes and
workers over manyy ears that showt he of contaminantm ovement(;i v) drinking evaluates someo f the methodsu sed to
loess in that region to be Holocen(eB ig- water standards, health consideration, treat contaminatedw ateri n order to meet
nell) overlyingP eoria loess that extends and risk considerations; (v) protective the drinking water standards. A fourth
to a depth that is sometimesn early 30 regulations andr emediala ction; and (vi) papere xplainst he goals ando bjectiveso f
meters.T hel oess is not obviouslyw eath- strategies for protectingg roundwatearn d a national survey of pesticides in well
ered. Loveland( Sangamonl)o ess exists availablel ocal, state, andf ederal assist- water planned by the USEPAfo r 1987
beneathP eoria and Bignell loess through- ance. Although the book does address and 1988, A detailed discussion on risk
out the easternh alf of the state whereth e sources of contaminations uch as land- and benefit determinations for Wiscon-
maps imply shows" Wisconsinianl oess." fills, undergrounsdto rage tanks and sep- sin’s pestiddeu se policy is presentedi n
It is also stated aboutt he Sandhillst hat tic tanks, mostd iscussionc oncernsa gri- the fifth paper.T hef inal paperi n this sec-
the sand fields originated fromT ertiary cultural chemical contamination, pri- tion is on the regulations for well con-
formationsf urther west. This is not con- marilyn itrates. struction, location, and safety in Wis-
sistent with the opinions( published) In the overviews ection, the authors consin.
Conservationa nd SurveyD ivision bulle- stress the importance of agricultural Section5 of this bookc ontainsa n over-
tins on the subject of Pleistocened eposits chemicalsin today’s productions ystems; view of Michigang roundwaterl aw fol-
in Nebraska. it includes somei nteresting information lowed by a discussion on assessing
Ana dditioiaal inconsistencyd elineates on the increasing use of agricultural groundwatepro llution liability including
an area termed "Lake Deposits" in chemicals.T his section notes the concern somec ase histories. At hird paperi n this
SouthwesternM aine.L andr esource maps of the public over the increasingc oncen- section discussedt he appropriatenesso f
speak of this as the "New England tration of these chemicalds etectedi n the havingt he countiest ake the leadershipi n
Coastal Lowland." Published work groundwatera nd poses somec hallenges groundwater protection and manage-
showtsh e area to consist of silts andd ays to research and extension programs. ment.T his section concludesw ith a paper
containingm arinef ossils. Thec onclusion The second section, containing eight on the potential benefits from land use
wast hat this area wasd epressedu ndert he papersa nd approximately1 50 pages, dis- planning and zoning.
weighto f a very late Wisconsiinc e sheet. cusses sources of nitrogen contamination Thef inal section of the book,c ontain-
It failed to reboundas rapidlya s a rising and its impact on groundwateqr uality. ing two papers, addressest he purposeo f
sea encroacheodn the land as the glacier This section contains somer esults from the conferencea ndp resents strategies for
metled.I t is thereforem ariner ather than specific researchs ites anda nimalf eeding protecting groundwatearn d lists sources
lake in origin. operations and covers someg eneral prin- of assistance.
48 J. Agron.E duc., Vol. 18, no. 1, 1989
This book is a valuable summaryo f the table form. The final chapter of this sec- The book contains excellent tables and
conference. As such it is not suited as a tion is a report on rural nonpoint pollu- figures and is a good review of the cur-
course textbook, but would have value as tion in the Lake Erie Basin. rent literature. It contains clear explana-
an occasional reference on special topics. Section 2 contains four chapters cover- tions of the different process influenced
It is a good source of information for ing the effect of conservation tillage sys- by conservation tillage systems as well as
knowledgeable scientists working in the tems on soil physical, chemical, and data from specific research sites. The
field and those newlyi nterested in ground- biological processes. The first chapter in summarya nd conclusions by the editors
water contamination. It gives specific ex- this section explains howt he hydrologic is an excellent discussion on the availa-
amples of groundwaterr esearch as well as parameterss uch as porosity, pore-size dis- ble knowledge concerning the effect of
general principles. A unique feature of the tribution, conductivity, and surface conservation tillage on groundwater
book is its discussion of health impacts roughness are affected by tillage. The quality.--WILLIAM L. POWERS, De-
and risk assessments. The book mayb e of second chapter discusses the effects of partment of Agronomy, University of
more interest to the people in Michigan conservation tillage on these hydrologic Nebraska, Lincoln, NE 68583.
and surrounding states because much of parameters and the relative importance of
the research and case histories are from these effects on water quality. Changes
that area. However,m ucho f the informa- in soil chemical and biological properties
tion and principles can be extrapolated to as affected by conservation tillage as well
manyp arts of this nation and the world. as by other managemenat nd climatic fac- SeedProductiono f Agricultural Crops--
--WILLIAM I~. POWERS,D epartment tors are examinedi n the third chapter of A. Fenwick Kelly. LongmanS cientific
of Agronomy, University of Nebraska, this section. The concluding chapter ex- & Technical, copublished in the USA
Lincoln, NE 68583. plains the regional and temporal variabil- with John Wiley & Sons, Inc., 605
ity of the effects of conservation tillage Third Ave., New York, NY 10158.
on biological and chemical soil con- 1988. Illus. 227 p. Hardcover $77.95.
ditions.
Six chapters comprise Section 3. Dis- This book describes the basic require-
Effects of Conservation Tillage on cussions concern the effect of conserva- ments for the production of seed for
GroundwaterQ uality--Edited by T.J. tion tillage systems on the fate and agricultural crops. It combinest he prin-
Logan, J.M. Davidson, J.L. Baker, and transport of pesticides and nitrogen fer- ciples of seed productionw ith all the prac-
M.R. Overcash. Lewis Publishers, Inc., tilizer. The first two chapters address the tical requirements for producing quality
121 South Main Street, P.O. Drawer effect of conservation tillage on pesticide seed for a large number of field and
519, Chelsea, MI 48118. 1987. 292 p. volatilization, degradation, and plant up- fodder crops grown around the world.
Hardcover $39.95. take. The third chapter emphasizes the The 10 chapters in this book are ar-
processes of pesticide loss from surface ranged in two parts. The first part dis-
This book is a collection of papers from runoff and leaching as affected by con- cusses the principles of seed production
the Conservation Tillage Workshops pon- servation tillage, the fourth chapter dis- and contains four chapters covering re-
sored by the U.S. Environmental Pro- cusses the potential for reduced runoff to production of plants, seed quality and
tection Agency held in Chicago, IL, on increase the leaching of pesticides when quality control, principles of seed grow-
10-12 June 1986. The papers are assem- conservation tillage is practiced. ing, and seed marketing and distribution.
bled as chapters in a logical sequence The final two chapters of Section 3 dis- The second part deals with growing seed
within the five sections of the book. The cuss howv olatilization, denitrification, of particular crops and contains six chap-
editorial style is uniform throughout, and nitrification, immobilization, mineraliza- ters discussing cereals, grasses, forage
the train of thought flows easily from tion, surface runoff, and leaching in- legumes, pulse crops, oil-seed crops, and
chapter to chapter and section to section. fluence the loss of nitrogen and nitrogen forage crucifers and fodder beet. Within
The first section is an overviewo f con- management. each of these crop-specific chapters, the
servation tillage systems in the USA. The fourth and final section of the material is arranged systematically, begin-
There are four chapters in this section: the book contains two chapters on what the ning with the species and commonn ames.
first on conservationt illage in general, the editors term "selected topics." The first The classification of cultivars and their
second and third on pest and nitrogen addresses the resource/waste issue of main distinguishing characteristics are
managemenfto r conservation tillage, and manure and the nutrient movementi n a then given, followed by the essential
the fourth on rural nonpoint pollution in manure management system. The second points to observe when growing a seed
the Lake Erie Basin. Chapter 1 compares is an assessment of Great Lakes Tillage crop. These points include isolation re-
conservation and conventional tillage, de- Practices and disucsses "the impacts on quirement, effects of previous cropping,
fines the various types of conservationt il- water quality of accelerated conservation difficult weeds, crop layout, seed crop
lage practices, and discusses the current tillage adoption in the Great Lakes management,c rop inspection, harvesting,
acreages and trends in conservation til- Basin." drying, seed cleaning, and seed treatment.
lage, including a 1985 regional survey of This is a very good book for the per- Wherea ppropriate, there is a short dis-
practices. The second chapter explains the son interested in processes affected by cussion of hybrid cultivars and the specif-
effect of tillage on weeds, insects, and conservation tillage. It could be used as ic problemst hey pose for the seed grower.
plant pathogens and discusses the timing a textbook for a special topics course on The book is well written and easy to
and placement of herbicides, insecticides, conservation tillage, but for most classes follow. The author uses an adequate
and fungicides. Chapter 3 on nitrogen would be better used as an additional numbero f figures, formulas, graphs, ta-
management contains an explanation of reference for students and instructors. It bles, and equations to illustrate the
the various conservation tillage systems describes each conservation tillage system material presented in this book. An ex-
and implements, including their effect on and the implements used and their poten- tensive list of references, mainlyi nterna-
nitrogen use efficiency. Current state and tial effect on the fate and transport of fer- tional, will increase the usefulness for
regional recommendations are listed in tilizers and pesticides. researchers and technicians involved in
J. Agron. Educ., Vol. 18, no. 1, 1989 49
seed production. The five-page index is may be replaced by new estimates of 30 ~1 diversity is surprising and frightening.
rather limited in its listings. to 50 million species. Because the vast The world was apparently losing about
This book should be useful as a text for majority of these species are insects and one species per day in the 1970s, and this
undergraduate and graduate courses in mostl ive in tropical forests, it is possible rate is estimated to be one species per
seed production of field and fodder crops. that as many as 8007o or more of the hour in the 1980s. It is possible that by
It will be a very good reference for crop planet’s species are threatened by the cur- the end of the current century we will
breeders, administrators and extension rent destruction of this unique biological have lost between2 0 and 50070o f all spe-
workers involved in seed production, habitat. cies. P.R. Ehrlich contends that "today’s
those involved in developing seed produc- The immediate relevance of Biodiver- trends of habitat destruction and modifi-
tion in developing countries, and the prac- sity is more apparent to some in our cation.., are an infallible recipe for bio-
tical seed producer in any country. Some profession. Plant breeders clearly need ac- logical impoverishment." In conclusion,
basic knowledgeo f plant science and field cess to genetic variability if we are to E. O. Wilsons tates that our decisions will
production is necessary to fully com- maintain the productivity of hybrids and come down to a matter of ethics. Our
prehend the material presented.- varieties of current major crop species. "drive toward perpetual expansion.., is
KENNETHH . BARNETT, Department The genes for insect and disease resist- basic to the humans pirit. But to sustain
of Agronomy, University of Nebraska, ance, for drought tolerance, and for it we need the most delicate, knowing
Lincoln, NE 68583-0914. adaptation to future cropping systems stewardship of the living world that can
often can be found in the centers of origin be devised. "
of these crops. But many habitats for Biodiversity is a book that should be
both crop and animal species are disap- read by every agronomist. At the very
Biodiversity--Edited by E.O. Wilson. pearing, thus removingf orever the source least, it should be available as a reference
National AcademyP ress, 2101 Consti- of greater genetic diversity for future crop in our agricultural libraries and brought
tution Ave., NW, Washington, DC improvement. Even with the potentials of to the attention of every new generation
20418. 1988. $19.50 paper, $32.50 induced mutations and biotechnology, of undergraduate and graduate students
cloth. centers of origin and germplasmc ollec- in our field.--CHARLES A. FRANCIS,
tions remain the most efficient route to Agronomy Department, University of
"If humanity survives to look back on introducing needed variability into our Nebraska, Lincoln, NE 68583.
the 20th century, future historians will crop breeding programs. This source
regard the mass extinctions of plant and clearly is threatened.
animal species, nowu nder way, as the de- Yet why should we care? This loss of
velopment with the most lasting conse- diversity would appear to only affect Morphologyo f the Rice Plant (Software
quences for us. This volume summarizes plant breeders, and surely science can be Program)--lnternational Rice Research
under one cover the manyf aces of the ex- used to create new variability any time we Institute, Manila, Philippines. Distrib-
tinction crisis: whethera nd howf ast it is need it! Such reasoning ignores both the uted by Agribookstore, 1611 North
happening, why it makes a difference, greater economic cost of finding new Kent St., Arlington, VA2 2209. 1989.
and whether we can reverse or avoid it." diversity comparedt o preserving what we $35.00.
This quote from the review by Dr. J.M. nowh ave and the cost of losing an invalu-
Diamond of UCLAc learly outlines the able habitat which is part of the larger This interactive courseware uses inte-
vital relevance and timely nature of the ecosystem. Several authors discuss our grated text and excellent graphics to teach
book, Biodiversity. current narrow focus on applications of the different parts of the rice plant and
Fifty-seven short papers in this volume technology and how this domination ap- the terms associated with them. The
were presented to the National Forumo n proach can spell disaster in the long run. courseware begins with seed structure,
BioDiversity in September 1986 and have Wed epend on an extremely narrow range and then proceeds sequentially to illus-
been edited for publication by the emi- of crop and animal species for all our trate the structures that occur in rice ger-
nent biologist E.O. Wilson of Harvard food--this may not always be possible. mination, emergence, and growth and
University. A clearly written and up-to- Newu ses of exotic plants are being dis- development using self-paced learning
date collection by many of the world’s covered each year--cures for cancer, and active learner participation. Each sec-
best knownc ontemporary scientists, Bio- AIDS, and the commonc old may well be tion provides immediate feedback and
diversity is must reading for anyone seri- sitting today in a tropical forest canopy reinforcement for the plant parts learned
ously concerned about the long-term waiting to be found. It is extremely risky in that section. This courseware requires
survival of our humans pecies as well as to our owns urvival to destroy this re- a computer with 256 K memory, color
the preservation of a livable habitat for source. graphics adapter, color monitor, and
most of the rest of today’s life forms. There is a broader lesson for agrono- DOS2 .0 or later.
From the introductory chapter by mists: the value of biological diversity This courseware is excellent for teach-
editor E.O. Wilson, the book moves within a field and in cropping systems. ing the various parts of the rice plant. It
quickly through statements on the mag- We currently drive our crops toward requires no previous knowledge of plant
nitude of the problem of diversity disap- genetic uniformity and are forced by eco- science to understand the plant parts
pearance to how we as a species depend nomics or habit to pursue a monoculture taught. The graphics and sound effects
on genetic variation. Emphasis through- strategy in designing farming systems. allow the user to have fun and learn at
out is on the tropical forests, which oc- The folly of this paradigm is clearly the samet ime. This courseware could also
cupy only 7070 of the land surface, but are shownb etween the lines of the book Bio- be used in introductory courses in U.S.
estimated to contain at least 50°70 of all diversity, where benefits of genetic diver- schools to teach the different parts and
species. This may be a gross underesti- sity are described from a biological, an growth of grass plants in general.-
mate; based on recent research by T.L. ecological, and an economic point of KENNETHH . BARNETT, Department
Erwin and others, the original calcula- view. of Agronomy, University of Nebraska,
tions of 1.5 to 5 million species on earth The rate of disa0vearance of biologi- Lincoln, NE 68583-0914.
50 J. Agron. Educ., Vol. 18, no. 1, 1989
STUDENT ESSAYS
The following three articles are the winninge ssays from the subject most appropriate for the Journal of Agro-
the 1988 American Society of AgronomyS tudent Essay nomic Education. The JAE Editorial Board agreed to
Contest. These were formerly published in Crops and publish the essays here with the understanding that the
Soils Magazine and last year upon termination of the students’ advisors or other departmental faculty would
magazine they were published in the Journal of Produc- be asked to make editorial corrections. In fact all our
tion Agriculture. It was proposed at the 1988 Annual professional journals have the proofreading and editori-
Meeting of ASAth at these essays really reflect student al assistance of secretaries, colleagues, peer reviewers, and
research and Writing achievements and hence ate part of staff editors at ASAH eadquarters.
First Place
Nitrates in our groundwater: Canthey be prevented?
Reece A. Dewell
p
IEOPLEa lways say that there is nothing better than
GETTING TO THE GROUNDWATER
drinking an ice cold glass of water after complet-
ing a strenuous task. However,r ecent studies have led
Twom ain factors, rainfall and the soil’s nitrate con-
to concern over the amounts of nitrates found in ground
tent, determine the amount of nitrates reaching the
and surface water supplies. The main reason for concern
groundwaters upply. Other factors, such as soil, climate,
on this topic is best understood from the fact that 50°70
type of crop, and nitrogen management, may also play
of the United States’ drinking water comesf rom ground-
important roles in the process. With this information, one
water supplies. This information, found in a paper by
woulde xpect different areas of the nation to have differ-
Gyles W. Randall, University of Minnesotas oil scientist,
ent levels of groundwater contamination.
stressed that in rural areas, this percentage increases to
Nitrates present in the soil, usually due to an excess
85070. Pregnant womena nd children less than 6 months
amount of nitrogen fertilizer applied, are picked up by
old are in the most danger of becomingi ll, but as nitrate
penetrating water molecules and thus begin leaching from
levels increase, the potential danger to others becomes
the soil. The rate and amount of leaching depends heav-
a definite possibility. Thus, national attention has been
ily on a soil’s texture and structure. Sandy soils usually
focused on the problemw ith somes tates passing individu-
give way to larger volumes and faster leaching rates,
al laws.
whereas clay soils react in a different way.
Nitrates are nitrogen products, so nitrogen fertilizers
play a large role in the production of the contaminants.
IDEAS TO REDUCE POLLUTION
From the time nitrogen was discovered to promote plant
growth and production, farmers have been using nitro-
In a September 26, 1987 Wallaces Farmer article by
gen fertilizers to help increase crop yields. Now,a fter
Jeff Young, Larry Bundy, a University of Wisconsin soil
manyy ears of this practice, it has been discovered that
scientist stated that there are managemenot ptions that
someo f the applied nitrogen, in the form of nitrates in
will produce high yields, and at the same time limit con-
groundwater, could end up being dangerous unless some-
tamination of groundwaters. According to him, the first
thing is done to prevent the major crisis that could result.
step to be taken is to decide howm uchn itrogen fertilizer
should be applied by considering a realistic yield goal of
Department of Agronomy, Turner Hall, 1102 South.Goodwin Avenue,
no more than 10 to 20070 above a field’s average. This
Urbana, IL 61801.
will decrease the amount of excess nitrogen in the soil
Published in J. Agron. Educ. 18:51-52 (1989). that will not be used by the plants.
J. Agron. Educ., Vol. 18, no. 1, 1989 51
15 -
14 -
13 -
z 12- r n I
011 -
i 1 0 -
9-
%dl-la Fig. 2. Nitrate concentrations can be determined by adding alpha-
napthylamine to various solutions. As shown above, higher nitrate
concentrations result in darker shades. From left to right, concen-
trations range from 0 (pure water) up to 10 parts per million.
01
example of one of these areas. Increasing nitrate concen-
61 72 74 A- 4
trations in three counties, as shown in Fig. 1, show why
YEARS
IZZI BUFFALO =HALL 0M ERRICK people are becoming concerned.
Fig. 1. Changes in groundwater N03-N levels in the Central Platte Iowa is also taking steps to control contaminants in
Nebraska NRD. their groundwater. Iowa’s Groundwater Protection Act
went into effect July 1, 1987, and calls for the spending
Organic matter content of the soil should also be con- of $64.5 million over five years to prevent groundwater
sidered, since nitrates are released from the organic mat- contamination. Randy Killorn, an Extension Agronomist
ter. If manure and legume credits are not taken into at Iowa State University, says this law is based on two
consideration, excess fertilization over crop use could oc- findings:
cur. Additional considerations should deal with apply-
1. “Any detectable quantity of a synthetic organic
ing the nitrogen in the spring instead of the fall to allow
compound in groundwater is unnatural and un-
maximum uptake by the crops and less loss by leaching
desirable
in late fall or early spring.
2. “Decontamination (of groundwater) is difficult and
expensive to accomplish. Therefore, preventing con-
tamination of groundwater is of paramount im-
RULES AND REGULATIONS
portance.”
As a result of the growing danger of nitrate pollution There are several general provisions of this law. First,
in the groundwater, federal legislation and some individu- the amount of information collected on groundwater
al states are presenting and enforcing certain rules and quality will increase greatly. More testing similar to Fig.
regulations to control this problem. Since convening in 2 will be done and new tests developed. Research centers
January 1987, at least 10 bills relating to control of have been established at the University of Iowa to deter-
groundwater contaminants have been introduced into the mine the impact on human health and at Iowa State
100th congress in hopes of getting federal legislation University to determine better practices to use in order
passed. The main problem now is the difference in polit- to get maximum farm profit as well as reduce ground-
ical opinions of how much the federal legislation should water pollution.
become involved. There are many provisions specifically related to pesti-
Meanwhile, some states have passed their own legisla- cides and fertilizers. For example, fertilizer salesmen are
tion dealing with groundwater nitrates. According to required to purchase licenses and pay inspection fees.
Gary W. Hergert, an Associate Professor of Agronomy Pesticide applicators are required to pass a state exam
at the University of Nebraska West Central Research and to become a certified applicator and must do so every
Extension Center, two important bills related to ground- year. Licenses must also be purchased by anyone selling
water quality have been passed and implemented in pesticides. Dealers are even required to report the amount
Nebraska as of January 1, 1987. One bill, the Nebraska of fertilizers and pesticides sold in the state each year.
Chemigation Act, requires any irrigator or applicator to With these state regulations, and the pending federal
use specified safety equipment on any irrigation device legislation, giant steps are being taken to control this
used to inject chemicals into irrigation water. It also re- growing problem. However, cooperation and involve-
quires the applicator to go through training and take a ment are needed by many more people to completely con-
test in order to become certified. The second bill, the trol this dangerous situation. Hopefully, in the near
Groundwater Nitrate Bill, provides for establishment of future, nitrates in the groundwater will be justs one more
special groundwater protection areas where nitrate levels problem overcome and a memory in the pages of history
are too high. The Central Platte Nebraska NRD, is an books.
52 J. Agron. Educ., Vol. 18, no. 1, 1989
Second Place
A future of integrated weed control
Janet Marth
F
ROM the beginning of crop cultivation, weeds have This suppresses the weeds due to lack of sunlight (Fig.
been a factor in yield loss. Modern chemical weed 3). Physical control involves cultivation, which has been
control as we know it today developed right after World popular in the past for between the row weed control.
War 11. Throughout the last forty years, herbicides have However, in this age of conservation tillage programs,
evolved rapidly to become the major method of weed this method is being discarded. These two control
control. However, research on environmental effects of methods are not major weed control methods in them-
herbicides has developed more slowly. Due to residues selves, but they are important in combinations with other
found on food and in groundwater, herbicides have been control measures.
closely scrutinized in the last few years by the Environ- One of these other methods is biological weed control.
mental Protection Agency and the public. Even though Biological control includes use of insects as well as plant
chemicals are effective and economical for controlling pathogens. In the past, biological control has not been
weeds in many cases, the known environmental hazards important due to high cost, inavailability, and lack of sig-
are a major concern. As a result, research on integrated nificant research. This method has been overshadowed
systems and alternatives to chemicals for controlling by the rapid evolution of chemical control. Research on
weeds has excellerated in the last few years. biological control has increased in the 1980s. One exam-
Integrated pest management is becoming well known ple is the research being done with rust fungi on Canada
for economically and safely controlling insects, but for thistle at Montana State University and on cocklebur at
weeds this approach has not received as much emphasis. North Carolina State University. The fungi produce telio-
An integrated weed control program will include all avail- spores (Fig. 4), which under heavy infection cause stunt-
able methods in a comprehensive, economical, and en- ing of cocklebur. In the research on Canada thistle, a
vironmentally safe management program. Each program spore releasing device was designed to spread rust patho-
will be different for the many weed problems, tillage gens in the field. This device could be utilized with other
systems, soil types, crops and climates found in the United fungi as weed control agents. The research with these
States. These programs will include physical, cultural, fungi is continuing and hopefully will yield an effective
biological, and chemical weed control methods with the and economical control measure for weeds.
most important component being crop scouting. An example of insects controlling weeds is a seed head
A scouting program allows for economical and effec- fly (Tephritidae) on thistles. The fly lays eggs on the
tive treatment choices that are specific for the individual flower head and develop into larvae that feed on the seed
weed problems in each field. Scouting for weeds involves head. Unfortunately, weather conditions and growth
early season scouting and weed mapping. Figure 1 illus- stage of the thistles must be perfect in order for the fly
trates early season scouting conducted within two weeks to lay eggs. As research continues, these factors could
after crop emergence to evaluate performance of preplant be overcome. The future is promising for biological con-
and preemergence herbicides, identify weed species, and trol finding its place in integrated weed management
determine the severity of infestations. Weed mapping is systems.
done towards the beginning and end of the growing
season. These maps help to provide information on the
location of problem weed infestations and help to moni-
tor the changes in infestations from year to year. The
early weed map facilitates planning for weed control
measures in season. The late season weed map helps to
evaluate the effectiveness of the applied weed control
measures (Fig. 2).
Physical and cultural weed control methods are parts
of an integrated program, which producers have been per-
forming for many years without realizing it. Cultural
practices such as proper row spacing and plant popula-
tion in soybeans will allow them to canopy over the row.
Department of Agronomy, Turner Hall, 1102 South Goodwin Avenue,
Urbana, IL 61801.
Fig. 1. Scouting for weeds is important in determining species and in-
Published in J. Agron. Educ. 1853-55 (1989). tensity (photo by W.S. Curran).
J. Agron. Educ., Vol. 18, no. 1, 1989 53
Table 1. Estimated cost of full-season weed control in soybeans
Late Season Weed Map grown on clay soil (Mississippi, 1980).
Farmer: D. Johnson Crop: Corn Township: Rockville
1980 Cost ($/ha)
Scout: J.L. Marth Year: 1986 County: Ford
Acres: 50 Operation Equipment Labor Materials Total
Disk (6.4 m); broadcast and
nrIrr I--, incorporate 1.12 kg tri-
fluralidha 9.14 1.38 15.57 26.09
Plant; apply 0.45 kg metri-
buzidha (50cm band on
lOOem row spacing) 0 0 7.39 7.39
Cultivate 7.68 1.61 0 9.29
Postdirect 0.11 kg 2.4-DB +
0.25 kg linurodha (50em
band on 100-cm row spacing) 5.09 1.38 6.23 12.70
Cultivate 5.14 1.06 0 6.20
Cultivate; postdirect 0.67 kg
dinoseblha (50em band on
lOOem row spacings) 7.51 1.38 3.53 12.42
Total 34.56 6.81 32.72 74.09
trol that they offer. Many weed problems cannot be con-
trolled without chemicals; however, as stated earlier,
residues have been found in food and groundwater. As
a result, chemicals should only be applied in combina-
tions with other available methods, instead of routinely
treating every acre. Presently, other methods such as
Be--+
biological controls are limited. This makes scouting, as
1-Scattered 2-Slight 3-Moderate &Severe well as proper chemical application and disposal, espe-
cially crucial.
Fig. 2. Actual weed map, which indicates weed species in the field and
severity of the infestations. (The hempdogbane are found on a rise Chemicals like other technologies are evolving rapidly
and the smartweed in the lowest area of the field.) through research. For example, the herbicide Classic
developed by DuPont comes in a six inch tall container
The last component of an integrated weed control pro-
and treats an acre with ounces instead of quarts or gal-
gram is chemical weed control. The current amount of
lons of product. This has far reaching economic impli-
chemicals used in a field for weed control is phenomenal.
cations for storage and transport of agricultural
These chemicals can be costly, but they work quickly and
chemicals. One drawback is that chemicals like Classic
help prevent yield losses. Table 1 shows the estimated cost
tend to be as expensive or more expensive than other
of full season weed control in soybeans as stated by the
chemicals in big containers. As chemicals are researched,
Mississippi Department of Agriculture. Much of the cost
many experts agree, including Illinois extension expert
is due to chemicals and their application. Chemicals were
Don Kuhlman, that agricultural chemicals will be per-
applied four different times and overlap in the weed con-
fected for safety with components that occur naturally
in plant organisms.
Looking at the past and present to predict the future
Fig. 4. Teliospores produced by different species of rust fungi which
Fig. 3. Cultural practices of proper population and row spacing allow infect weeds such as Canada thistle and cocklebur (photo by D.G.
for soybeans to canopy over the rows (photo by W.S. Curran). White).
54 J. Agron. Educ., Vol. 18, no. 1, 1989
is not always accurate; however, the recent trends just chemical for specific weeds at the proper rate, is becom-
discussed lead to several conclusions about the future of ing more widespread. The main reason is to reduce chem-
weed control. As chemical costs increase and more dis- ical costs. Herbicides will not disappear as other weed
coveries are madea bout the extent of chemical toxicities control methods are developed, but will more likely be
to humans and the environment, development of inte- an integral part of a complete integrated weed manage-
grated methods will increase and become available to ment program. For now though, chemicals will continue
more producers. Scouting, in order to use the proper to be the economical weed control method of choice.
Third Place
Genetic exchange may improve wheat cultivars
Lisa McMurphy
T
rlE need to improvec ertain aspects of wheat quality the numbers also range from one through seven and are
and production efficiency is ever prevalent in the followed by the letter R, for rye.
minds of farmers and researchers. Along with increas-
ing awareness of and concern about environmental MANIPULATION TECHNIQUES
hazards comest he need for better wayso f protecting crop
plants against pests and diseases. Methodso f controlling Hybrids between wheat and rye in which the entire
pest infestations without the use of expensive, hazardous, genomeo f rye is added to wheat can he made. However,
or environmentally dangerous chemicals or costly tillage the addition of the whole rye genome produces some
procedures are sought by agricultural researchers and reproductive disorders. Because of this, the most effec-
heralded by environmentalists and farmers alike. tive way of introducing genes from rye into wheat seems
Wheat breeders are becoming increasingly enthusias- to be the establishment of chromosomea ddition, substi-
tic about the prospect of breeding plants with natural tution, and translocation lines.
defense mechanisms against pathogens. In fact, many Addition lines, in which single pairs of rye chromo-
new wheat cultivars carrying resistance to greenhug, leaf somes are added to wheat, are not directly useful in wheat
rust, and other pests are nowa vailable to the farmer. The breeding because of chromosomei nstability. However,
source of someo f these resistances is genetic material that they are important for researching the genetic potential
has been transferred from rye into wheat. In addition to of the added chromosome,a nd they form useful materi-
pest resistance, manyo ther desirable agronomic charac- al for initiating chromosomseu bstitution and transloca-
teristics such as increased yield, efficient nutrient use, and tion lines.
high lysine content can be, and have been, incorporated A substitution line is produced by adding a rye chrom-
into wheat from rye. osome pair to a wheat plant deficient for the wheat
chromosomet hat is to be replaced. In other words, a
THE BASIS OF GENETIC EXCHANGE specific rye chromosompea ir is substituted for a specific
An explanation of the genetic composition of wheat
and rye is in order. Wheatc arries 21 chromosompe airs,
seven from each of the three genomes: A, B, and D. Rye
1R
contains seven chromosompe airs, all of which have been
determined to have some homoeologous relationship to
chromosomeso f wheat. In other words, certain chromo-
somes of rye are able to take the place of certain other
chromosomes of wheat.
Individual chromosomes are identified by a number
followed by a letter. In wheat, the numbers range from
one through seven, and a letter denotes the genomet o
which the chromosomeb elongs, A, B, or D. For instance, 1B 1B ~-’
3B is chromosomen umbert hree of the B genome. In rye, 1R
Fig. 1. This computer schematic shows the arrangemento f chromo-
Department of Agronomy, Oklahoma State Univ., Stillwater, OK some bands, often referred to as the chromosome" fingerprint,"
74078-0507. whichr esearchers use to identify specific chromosomesT. he chromo-
somes shown arc 1B of wheat, the 1B/IR translocated chromosome,
Published in J. Agron. Educ. 18:55-56 0989). and IR of rye.
J. Agron. Educ., Vol. 18, no. 1, 1989 55