One section of Agronomy 354 is being taught F09 semester. See the course homepage: Loynachan. See electronic library.

We have developed specific Web pages to aid you in understanding the 354 material (see table below). In addition, we have identified other Web sites that will give background, add interest, or show practical use of 354 material that are linked in the outline (many other sites are also available and we have just linked a representative few--use search engines to find others). 

DEPARTMENT CHAIR:  Dr. Kendall Lamkey,  2101 Agronomy

PREREQUISITES:   Agron 154 and Biol 101 or 211

A.    COURSE INTRODUCTION
    A1    Getting Acquainted (Chemistry Review) (Periodic Chart)
    A2    Books and References:
    A21        Soil Fertility and Fertilizers , Havlin, Beaton, Tisdale, Nelson, 7th Ed. (Text)     
    A22        References:   Prime reading is in bold in the outline. Several books in the library can be used as further sources of information.  These books will be referred to by their abbreviations in the course outline.  Reading in more than one book can clarify your understanding of the subject.  These are optional readings (unless in bold).

         1.  Soils and Soil Fertility, Troeh and Thompson,  6th Ed., (TT)
         2.  Nature and Properties of Soils, Brady and Weil, 14th  Ed. (B)
         3.  Soil-Plant Relationships, Jeffrey (Je)
         4.  Russell's Soil Conditions & Plant Growth,  Ed. Wild (W)

     A3     Grading and Exams (see your instructor's course homepage.)

For items handed-in late, possible points will be reduced 10% per day M-F late (we expect items to be handed-in on time). If you must miss class, notify the instructor before missing. For those wishing additional experiences in soil fertility laboratory procedures, consider taking Agronomy 354L for 1 credit--meets T 12-3, T 3-6, W 1-4, or R 2-5.

A31   Makeup exams:  If you must miss a regularly scheduled exam, a makeup exam may be given as long as you notify the instructor that you would be absent before the exam.  Makeup exams may be oral exams and must be completed within five class days of the exam that was missed unless there are extenuating circumstances.

     A4  Cell Phones--Please be sure your cell phone is off before coming to class. A cell phone ringing is a rude interruption to your classmates and the instructor.

     A5   Please see the General Catalog concerning ownership of course-related presentations, where specific written permission to sell notes or recordings must be obtained from the presenter.

     A6   If you have a documented disability and anticipate needing accommodations in this course, please make arrangements to meet with me soon. Please request that a Disability Resources staff send a SAAR form verifying the disability and specifying the accommodation needed.    

     A7   The purpose of this course is for the student to gain an understanding of the principles of soil fertility and soil-plant relationships.

     A8   Soil Fertility is an aspect of applied science concerned with the sources and availability of essential nutrients for plant growth with respect both to quantity and quality of the crop produced.  Soil tilth and soil-plant relationships affect availability of nutrients and plant uptake.  To understand these concepts, it is necessary to build on general information about soils, chemistry (chemistry review), crops, and other subjects.  The student is expected  to be familiar with the basic concepts of soils (1) formation and classification,  (2) physical properties, (3) composition, (4) biological processes, and (5) soil and water conservation.  Remember that we will cover principles in this course that are equally applicable if your interests are agronomy, horticulture, forestry, or environmental management.

B.    PLANT GROWTH AND FACTORS AFFECTING IT (Text 1-13)
B1    Principles of Growth (Growth Curves)
B11        Types of response curves
B12        "Law of the minimum", diminishing returns, optimum levels (Law of the Minimum)
B13        Mathematical expressions and concepts--Mitscherlich, Bray
B14        Response curves and economics (Relative Nutrient Requirements)
B2    Crop, Soil, and Climatic Factors (Text 417-434)
B3    Other Factors--pests, diseases, insects, weeds, management (Deficiencies vs. Other) (Plant Disease Diagnostics)

C.    THE ROOT AND ITS ENVIRONMENT (Je 3-17)
C1    Functions--absorption, anchorage, and storage (Roots)
C2    Structure (Plants and Their Structure, I) (Plants and Their Structure, II)
C21        Root hairs--size, composition, and absorption sites (Movie of Root Hair Growing)
C22        Internal cell components--nutrient uptake involvement
C3    Microbial Interactions
C31        Rhizosphere (Rhizosphere)
C32        Nitrogen fixation (The N Cycle and N₂ Fixation)
C33        Mycorrhizae (Mycorrhizae Movies) (Photos)
C4    Growth--response to compaction, wetness, and aeration

D.    SOIL TILTH (W 378-411) (B 266-309)
D1    Definition (National Soil Tilth Laboratory, Ames)
D2    Soil Structure and Mechanical Behavior (Soil Physical Properties) (ISU Soil Management)
D21        Aeration porosity (Aeration)
D22        Pore continuity and length
D23        Ease of root penetration
D3    Formation and Destruction of Soil Structure (Understanding and Managing Soil Compaction)
D4    Cultivation/Minimum Tillage (Iowa Tillage Management)
D41        Seedbed preparation (Prairie Restoration Seedbed Preparation)
D42        Compacted or restricted zones (Garden Compaction)
D43        Moisture ranges for cultivation (Soil Compaction and Drainage) (Soil Compaction--Causes and Consequences)
D44        Adverse effects--crusting, compaction, anaerobic layers, puddled structure
D5    Nature's Plow--the Earthworm (Earthworms and Crop Management) (Earthworm Movie) (Earthworms)

E.      ELEMENTS REQUIRED IN PLANT NUTRITION (Text 298-302) (TT 305-319)
E1    Elements Found in Growing Plants (Nutrients in Crops)
E2    Essential Plant Nutrients(Nutrient Deficiency Key) (Elements Essential for Plant Growth)
E3    Nutrient Functions (Plant Nutrients)
E4    Deficiency Symptoms (Nutrient Deficiency Symptoms--ISU) (Nutreint Deficiency Symptoms--IMC) (Nutreint Deficiencies Field Crops)

F.     SOIL FERTILITY EVALUATION (Text 298-361) Soil Sampling Problem (ISU Soil and Plant Analysis Laboratory)
F1    Hidden Hunger
F2    Biological Tests for Soil Fertility
F21        Factorial-designed experiments
F22        Field tests--research, demonstration, field strips
F3    Plant Tissue Analysis (Sampling for Plant Tissue Analysis) (Apple Production) (Plant Tissue Analysis)
F31        Sap tests (quick tests) (Nitrogen in Potato) (Sap Test in Tomato)
F32        Total analysis (Sampling for Corn Plant Analysis) (Turf Analysis)
F4    Soil Testing (General Guide for Crop Nutrient Recommendations in Iowa) (Soil Testing Kits) (LaMotte)
F41        Correlation and calibration of soil tests
F42        Soil sampling and GPS/GIS (ISU--Take a Good Sample to Help Make Good Decisions) (Soil Sampling for Variable Rate Application)
F43        Interpretation of soil test data (ISU--Interpretating Soil Test Reports)

G.    ION EXCHANGE IN SOILS (Text 14-32)
G1   Introduction of Ion Exchange--soil colloids (quartz, hydrous oxides of iron and aluminum, silicate clay minerals, humus)
G2   Cation Exchange--source of charge, cation exchange capacity (CEC) (B 310-357; TT 136-138, 159-161) (Cation Exchange) (Cation Exchange Capacity)
G3   Anion Exchange, Amphoteric Substances (TT 161-162) (Amphoterism)

H.    SOURCE AND UPTAKE OF NUTRIENTS (Text 32-44)
H1    Sources of Nutrients (Symptoms of Deficiency)
H11        Minerals, soil solution, air (Elements of Minerals)
H12        Availability of plant nutrients--chemical, positional, physiological
H13        Available nutrient pool--soil solution, exchangeable ions, soil solids
H2    Nutrient Delivery to the Root and Uptake (TT 306-311) (Nutrient Delivery in Controlled Environments)
H21        Root elongation, mass flow, diffusion (Fick's Law)
H22        Effect of other nutrients--cation constancy, competition, antagonism

I.      SOIL REACTION (Text 45-55) ( B 358-400; TT 151-158)
I1     Chemistry of Soil pH--acidity and alkalinity (Soil pH) (Soil Quality Indicator: pH)
I11         Acidic cations--H⁺, Al³⁺, others; activity
I12         Basic cations--Ca²⁺ Mg²⁺, Na⁺, K⁺; activity
I2     Colloidal Control of Soil pH (Coffee Pot Analogy)
I21         Percentage base saturation
I22         Resistance to pH change (buffer capacity)
I23         Nature and proportion of soil colloids
I24         Kind and proportion of sorbed ions; lyotropic series (TT 150-151)
I3     Changes in Soil pH
I31         Acid-forming factors--crop removal of bases, leaching, fertilizers, erosion, oxidation of reduced S, acid rain (Acid Rain)
I32         Base-forming factors--salt accumulation, mineral weathering, residue return

J.      PROPERTIES AND MANAGEMENT OF SOILS WITH pH VALUES BELOW NEUTRALITY--ACID SOILS (Text 55-60, 234-243)
J1    Acidic Soils--active acidity, potential acidity, lime requirement (Acid Soils of the Tropics)
J2    Soil pH for Crop Production (Grape Production and Soil pH) (Soil pH and Landscape Plants)
J21         Influence of soil reaction on nutrient availability
J22         Crop response to liming ( TT 165-173)
J23         Effects of lime on soil:  physical, chemical, and biological
J3    Ca and Mg as Plant Nutrients (Soil Calcium:Magnesium Ratios) (TT 269-275)

K.    THE PRACTICE OF LIMING (Text 60-75)
K1    Lime Needs in Iowa and the United States
K2    Liming Materials (B 387-395) (Home/Garden Soil pH Adjustment) (Liming Vineyard Soils)
K3    Limestone Quality and Effectiveness (Iowa Limestone Law) (Liming Materials) (Turf) (Choosing Liming Materials)
K4    Practical Aspects of Liming--rate, method, timing, and frequency of application; over-liming

L.      PROPERTIES AND MANAGEMENT OF SOILS WITH pH VALUES ABOVE NEUTRALITY--ALKALINE SOILS (Text 75-96; Salt-Affected Problem Soils in North Dakota ) (TT 175-181) (Management of Saline/Sodic Soils)
L1    High Lime Soils--identification, pH, management
L2    Saline and Sodic Soils--identification, pH, management, reclamation (B 413-446) (Diagnosing) (US Salinity Lab) (Salt-Affected Soils)
L3    Irrigation water quality (Irrigation Water Quality Criteria)
L4    Acidifying Soils (Soil Acidification) (Gypsum) (B 395-396; TT 173-175)