FACTS Northern Ireland - Basis

Aim
MODULE 4 - CROP NUTRIENTS IN PLANTS AND THE FACTORS
INFLUENCING THE AMOUNT OF FERTILISER REQUIRED
To understand the principles of integrated crop nutrient management and the various factors which,
together with fertiliser and organic nutrient application, can be used to satisfy crop requirements.
4.1 Competence
Candidates must be able to estimate the nutrient requirements of a particular crop and appraise a range of
nutrient sources available to clients, prior to constructing nutrient and fertiliser plans and to make fertiliser
recommendations to meet crop requirements and have due regard to the environment.
4.2 Performance Criteria
Candidates must be able to:
• explain the role of all plant nutrients
• calculate typical rates of uptake and removal of nutrients by different crops
• indicate typical symptoms of deficiencies of major and micronutrients
• explain the use of soil analysis as a basis for nutrient recommendations
• interpret the ‘Law of Limiting Factors’
• interpret nutrient response curves and the effect of the "Law of Diminishing Returns"
• use a response curve to calculate an approximate break-even rate for a major nutrient, eg nitrogen in
cereals and explain how economic changes can affect the nutrient recommendations
• distinguish between "economic" and "maximum biological yield"
assess and appraise the effects of crop rotation, farming practices and crop quality specifications on
nutrient availability and requirement
• interpret situations suitable for "maintenance applications" in maintaining soil nutrient reserves and
ensuring effective crop response
• understand and interpret the main units in which advice is given and convert between the different
units giving advice in metric with imperial conversions
4.3 Essential Knowledge and Skills
Candidates must have the ability to:
• explain keywords: locking up, immobilisation, mineralisation, nitrification, de-nitrification, leaching,
volatilisation, uptake
• demonstrate an understanding of how to approach diagnosis of nutrient deficiencies, eg take soil and
plant samples, use pH kits
• demonstrate interpretation of soil and tissue analysis results and their limitations, prior to drawing up
recommendations
• demonstrate an ability to diagnose nutrient disorders in the context of other crop disorders
• convert between metric and imperial units and, where liquids are used, between weight/weight and
weight/volume declaration
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