Nutrient Management for Soils and Plants

TPSS 450


Mitiku Habte

Semesters taught:

Spring 2014, Spring 2015, Spring 2016


  1. Gain a better appreciation of the influence of soil biological, chemical and physical properties on the availability of essential nutrients to plants.
  2. Identify soil and nutrient management strategies and practices that maximize crop productivity while maintaining soil and environmental quality

Skills and knowledge to be acquired:

Students will be encouraged to participate in activities that will challenge them to work with others as well as demonstrated independent ability to analyze and synthesize information. Homework, a term paper, laboratory exercises, and a group project are integral components of the course. As students fulfill requirement revolving around these activities they will develop computer skills, quantitative skill and skills in written and verbal communication. At the end of the course, students are expected to be able to integrate and apply the principles of soil biology, chemistry, physics , and plant nutrition in order to manage nutrients for maximal plant productivity without hampering soil and environmental quality.

Computer skills to be acquired:

Students are required to submit all reports and home works in type-written form and this is intended to encourage the use of computers. The group project will involve statistical analysis of the data collected and preparation of graphs that go into the reports students must submit individually. This will help them be familiar with statistical and graphic software packages.


CHEM 161 and TPSS 304, or consent


Soil Fertility and Fertilizers,2005, J. Havlin, J. D. Beaton, S. L. Tisdale, and W. L. Nelson (7th edition) Prentice Hall, New Jersey

Films and videos:

Video and oPoint presentations are used to supplement lectures

Guest Speakers:

El-Swaify - three lectures on soil salinity; C. Evensen - one lecture on fundamentals of nutrient management; N. V. Hue - four lectures on micronutrients; R. Uchida - one lecture on soil testing; H. Valenzuella -one lecture on fertilizers for organic farming; J. Yanagida - one lecture on the economics of fertilizer use; R. Yost - one lecture soil test calibration and correlation

Field Trips:


Course organization:

The lectures cover the following materials:

  • Introduction - Global food security, Yield-limiting factors, Leibig's Law of the minimum,
  • Essential elements in plant nutrition
  • Basic soil-plant
  • Cation exchange, Base saturation, Anion exchange, Buffer capacity, Movement of ions to roots, and ion absorption by plants
  • Soil acidity - Sources of acidity, Factors affecting soil acidity, Buffering mechanisms, Active and potential acidity, Soil reaction correlations, Soil pH for crop production, Lime requirement, Liming materials and benefits of liming.
  • Soil Basicity/Salinity - Sources of basicity, Saline soils, Saline sodic soils, Sodic soils, Quantitative relationships, Effect on plant growth, tolerance to salinity, Managing saline and sodic soils.
  • Bioavailability of Macronutrients and their management
  • Topics considered are: Forms taken up by the plant, Functions, Deficiency symptoms, Miscellaneous accretions, Factors affecting availability, Forms in soil, Transformations in soils, and Sources for crop production
  • Macronutrients to be covered: Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, and Sulfur
  • Bioavailability of Micronutrients
  • Primary focus: Iron, Manganese, Copper, Zinc, Boron, and Molybdenum.
  • Topics considered: Forms absorbed by plants, Deficiency symptoms, Forms in soil, and Factors affecting bioavailability
  • Soil Fertility evaluations: Deficiency symptoms, Plant analysis, Total analysis, Biological tests, Soil tests
  • Fundamentals of nutrient management: Crop characteristics, Soil characteristics, Nutrient placement, General considerations
  • Interactions among nutrients
  • Nutrients and water use
  • Economics of plant nutrient use, Maximum economic yield, Yield level and unit cost of production, Profitable nutrient rate, Residual effects of fertilizers, Animal waste
  • Agricultural productivity and environmental quality
  • General considerations, Soil and crop productivity, Soil quality, Conservation tillage (CT), Rotation versus continuous cropping, Cover-green manure crops, Environmental quality
  • Nutrient management for organic agriculture


Three one-hour exams 300
Term paper 100
Laboratory reports 100
Home work 100
Final exam 200
Oral presentation 20
Total 820