Essential nutrient for plant growth. Testing for deficiencies and effects on plant growth. Effect on plant diseases.

Describes the results of a long-term field experiment in Sweden. By Artur Granstedt and Lars Kjellenberg.

Comprehensive online book about proper fertilizer uses, soil pH and soil sampling.

Contains details about plant nutrient requirements, recommendations for fertilizer use and best agricultural practices for fertilizer application.

Environmental problems associated with the nitrogen fertilization of field grown vegetables.

A program by PotashCorp to address misconceptions about fertilizers and the role of the fertilizer industry. Detailed description of fertilzer use and production. Many downloads and a quiz.

Papers describing deficiency symptom in crops and field vegetables.

Aims to promote and encourage responsible fertilizer use. Contains many fertilizer fact sheets.

Information on fertilizer use, production and consumption.

Agricultural use and the environmental impact of fertilizer, lime and soil amendments.

Provides publications and educational material.

Information on all aspects of soil fertility and fertilizers.

Educational site for students and teachers about soil and soil biology.

Introduction to the sources of, and the uses of foliar fertilizer.

Technical information and practical experiences about agricultural food production and the use of fertilizers.

Crop information for all US regions and information on soil fertility and fertilizer application.

Application time, forms of fertilizer and methods of application to be considered when applying fertilizer to wheat.

Production and agronomic effectiveness of fertilizers.

Describes the production, distribution and consumption of fertilizers, their intermediates and raw materials

Lectures about soil surveys, soil texture, soil acidity and soil fertility. Information about liming, fertilization and soil testing with particular reference to forestry.

Lectures and Laboratory Units of the Soil Sciences Courses at the University of Minnesota. Influences on soil fertility are explained and simple soil tests are described.

Explains how to detect and combat iron deficiency in plants.

Magnesium/sulphur deficiency symptoms are widespread due to inappropriate nutrient management. This website offers not only details about the origin, properties and production of Kieserite, but also a wide range of information concerning its importance and possibilities of use in agriculture.

Indian Agricultural Resources. Information about manures, organic, inorganic and biofertilizers.

On the deficiencies that may occur in soilless floriculture, and how these can be remedied.

Online programs that simulate the response of crops to fertilization, crop residue incorporation and consider the effects of time, soil type, cultural practice and weather. Downloads available for researchers.

Describes the phosphorus (P)and potassium (K) soil testing and fertilizer recommendation system in Ontario, Canada.

Describes the effective use of this fertilizer. Soil availability, fertilizer characteristics and application.

Institute of the University in Denmark. Features publications and research reports.

The influence of potassium on plant nutrition and soil.

A university lecture describing the physical and chemical effects of liming on different soil types.

Description of tests that allow farmers to adjust nitrogen applications to meet the needs of each specific field.

Measures to improve soils suited to farmers in the third world.

Describes important soil tests and explains how to perform and interpret them.

A series of reports describing the effects of various micronutrients on the growth and health of plants. Pictures of plants with deficiency symptoms.

Simple step by step guide to soil sampling and analysis with explanatory images.

A detailed description from the International Centre for Integrate Mountain Development. Its main focus is on mountain soils and sloped agriculture in th Hindu-Kish region.

Answers questions related to the enhancement and maintenance of soil fertility.

Application recommendations for different fertilizers.

A large collection of information ranging from soil test interpretation to prevention of nutrient deficiencies.

The Ontario Ministry of Agriculture and Food offers a large collection of newsletters and factsheets with topics ranging from soil sampling to fertilizer requierements and micronutrients.

Soil fertility management for forage crops. A introduction from the Penn State University's Agronomy Department.

Gives detailed description of the soil and fertilizer requirements of forage crops during establishment and maintenance. University of Pennsylvania.

Common fertilizers and their characteristics.

Soil fertility practices in Manitoba and general fertilizer use considerations. Details about fertilizers, their characteristics, application rates and usage recommendations. N-fixation, Manure and soil factors are also described.

Describes the different fertilization requirements for direct seeding.

Frequently asked questions about soil fertility, the application of animal wastes, organic and chemical fertilizers. Also features an online discussion forum.

Information about university research with extensive list of publications.

Information with regard to soil pH, fertilizers and lime application.

Research findings and practical technologies that help conserve and improve soil conditions. Applicable to farming, ranching, forestry and gardening.

Gives examples of soil test values and explains their significance.

This site from the Manitoba Agriculture, Food and Rural Initiatives offers advice and information about the management and fertility of soil. Includes erosion, salinity and soil surveys.

Offers a database and search function of a range of articles about fertilizers, micronutrients and fertilizer application.

Information on the relationship between the quality of sugarcane and soil fertility.

A number of bulletins describing soil analysis, soil types and fertiliser application.

A student paper describing soil conditions in forests. Particularly what causes the pH to change and what influences this will have on the ecosystem.

Scientific, technical, environmental, economic and safety aspects of the production, marketing, use and application of fertilizers.

Background information on the role of sulphur in soil fertility, sulphur containing fertilizers and explanation of the results of a soil test.

Information about soil fertility and how it can be improved.