INM - Nutritional Assessment Report (NAR)

NUTRITIONAL ASSESSMENT REPORT (NAR):

NAR is a crop nutrition diagnostic technique that is exclusive to INM Pty. Ltd., its agents, and its distributors. It is the epitome of a series of improvements in diagnostic skills.
Crop tissue analytical data are as good as their interpretation. No matter how properly a sample has been collected, how thoroughly it has been washed, and how accurately it has been analysed, not unless the analysis figures are properly interpreted, they become totally useless.

COMMONLY USED SYSTEMS OF INTERPRETATION:

There are 2 main systems of interpreting plant tissue analytical data. The traditional one is based on the so-called “critical level” approach. This system interprets data by taking into consideration one mineral at a time. It totally ignores nutritional balances and interactions. Its criteria are extremely specific to particular geographical parameters and specific timing for sampling.

The other, less commonly used systems are based on mineral balance. The concept was introduced in the early 1970’s, and many such systems were developed. Whilst those systems take into account nutritional balances, their major fault is that they invariably ignore the absolute levels of minerals. They fail to see the difference between nutritional balance at low absolute levels of minerals and that at high absolute levels of minerals. If for argument sake the ratio of phosphorus to nitrogen in a particular crop is 1:10, then in such systems, it would not make any difference if the levels of phosphorus and nitrogen were 0.1 and 1 or 0.3 and 3. Another great flaw in such systems is that they invariably suggest unrealistic target levels for certain minerals. If a certain crop, for example, has an extremely high level of a certain mineral, such systems of interpretation will then suggest that all other minerals will need to be unrealistically high in order to match it. In some such instances, such systems could suggest nitrogen levels as high as 7-8.

PROBLEMS OF THE CRITICAL LEVEL APPROACH:

• It fails to take into account mineral interactions.
  
• Its criteria and standards are specific to a certain area at a time.
  
• It is restricted to a specific period for sample collection.
  
• Its standards are yield-based.

PROBLEMS OF THE BALANCE APPROACH:

• It disregards the absolute levels of minerals.
• To achieve nutritional balance, it invariably suggests unrealistic target levels for minerals. For example, if a certain mineral happens to have a very high level, this system of interpretation would then expect all other minerals to also have extremely high levels in order to match it.
• It fails to distinguish between the physiological needs of plants as opposed to marketing needs and targets.
• It is yield-based.
• It cannot cater for different stages of growth.
• Its predictions cannot cater for specific quality targets.
  

PHYSIOLOGICAL NEEDS VS. MARKET EXPECTATIONS:

Both commonly used systems of interpretation fail to distinguish between physiological needs of crops and market expectations. In practical terms, a proper nutritional diagnosis has to be based on economic grounds, and not on growing happy plants per se.

It is very important to note that both over mentioned systems have criteria and standards, which are yield-based. Whilst so much emphasis is being increasingly put on quality issues, the above systems are unable to interpret analytical data from quality perspectives.

NAR:

The Nutritional Assessment Report (NAR) is a very advanced diagnostic skill. The advantages of the NAR are many. They include the following:

• It takes into consideration both, the absolute levels of minerals as well as their relative levels to each other (i.e. balance).
• It suggests feasible and achievable target levels for minerals.
• It clearly distinguishes between a physiological deficiency and one that can have market implications.
• It caters for different stages of growth in the crop.
• Its recommendations are based only on issues, which are directly related to the grower’s targets.
• It uses a flexible spectrum of standards which can be yield-based, but they can also be specific quality-specific based.
• It is able to interpret leaf tissue data even if the levels of one or two minerals are not available.