The principles of crop nutrition do not vary from crop to crop. All crops need the same essential elements. The difference between crops is that they need those essential elements in different ratios, different amounts, and at different times. Even the same crop has changing needs.
When we talk about nutritional balance, we must keep in mind which balance it is that we are seeking.
The same crop will have different balances depending on its stage of growth, stage of crop development, and production targets and parameters..
It is not uncommon to see growers changing their feeding patterns with the above in view. Integrated Nutrition Management (the technique) gives us a tool that allows us to quantify those changing needs and thus base our programs on actual calculated figures rather than guesses and assumptions.
Various factors are involved in determining crop yields and quality. They include area, type of soil, irrigation practices, disease control, weed management, pest management, variety, rootstock, etc...
Nutrition is often overlooked as a quality-seeking tool probably because traditional practices have not been able to address those quality issues.
Historically, soil and tissue analyses have mainly attempted to diagnose deficiencies, and at best solve those deficiencies by using corrective applications. Quality in itself was rarely addressed.
From a practical point of view, analytical data are however as good as the practical recommendations that come out of them. Those recommendations, in turn, are dictated by the standards of judgement.
The traditional methods relied heavily on the so-called Critical Levels (or Critical Ranges) of minerals. The Critical Levels are crop specific. They are determined by comparing yields of a specific crop, having all other variables fixed, and varying only the levels of the mineral the Critical Level of which is to be determined.
The limitations of this approach are many:
Last but not least, Critical Levels in Australia cover the whole continent (ie not area specific) and they are not available for all minerals.
INM is a totally new approach to fertilization. It is based on a 3-fold approach:
A. Identifying Targets:
B. Drawing Practical Recommendations:
INM believes that to reach certain quality targets, it is not enough to solve nutrient deficiencies and to even attain the proper balance.
Some deficiencies may have no bearing on yields and/or quality. Others may even be favourable to produce a certain flavour quality. Sufficiencies of a certain mineral, on the other hand, may not be good enough to produce the quality target sought.
Nitrogen nutrition is typical. Good crop quality is invariably associated with Nitrogen stress towards maturity. Inducing N-stress can improve quality. This is often done deliberately.
In a similar but reversed manner, certain mineral levels have to be pushed way beyond sufficiency levels in order to reach certain quality targets (such as colour, shelf-life, solid content etc...).
INM acknowledges that quality criteria demanded by the market do not necessarily have to match the physiological need of the plant as revealed by traditional yield-based approach of interpreting the analysis data. The technique therefore interprets the data from the specific vantagepoint that has the economic impact.
Given a set of analytical figures, INM will give different interpretations depending on the target, stage of growth, or both.
The recommendations produced by INM are based on those interpretations.
The recommendations include base-feeding, fertigation, and foliar feeding. They are simple to follow and implement, and extremely explicit and specific to the actual target.
C. The Cure:
In brief, INM does not stop at furnishing balanced nutrition to crops. It goes further to suggest selective feeding for the purpose of seeking specific crop targets as set by the grower.
INM is a technique which uses nutrition as a horticultural tool just like pruning, training, shading, lighting, heating, etc... . It is a technique which allows the grower to have better control on the growing conditions of his crop.
FERT-CAL is a very high analysis fertigation calcium product that is based on an organic acid chelate base. It is a straight calcium product and does not contain any other essential element and thus its application will only favour calcium balance. It is ideal for situations where foliar calcium applications are not enough and/or when they cannot be done due to weather or other conditions.