Soil nutrient levels are reliable for indicating was is available to the plant while the tissue nutrient levels are reliable as an indicator of what is in the plant. Combine both when determining fertilizer programs.

Application of plant nutrients economically at correct time and with right amounts is necessary in a way that nutrients could be taken up by plants efficiently with minimum losses.Application of manures and fertilizers.Application of soil amendments.Inheriting nutrient status of soilFactors inherent in the cultivar, rootstock; genetic make-up, age  of crop, time of sampling; seasonal variation, age of leaves, position of leaves, yield of crop etcPlant analysis has been considered a very promising tool to assess nutritional requirements of plants for cost effective and environment friendly agriculture. Diagnosing nutritional status of bananas through plant analysis not only provides the basis of correct fertilizer requirement of the crop but also guides towards the nutritional requirements of future crops.

To add to the previous two answers, plant nutrient levels are driven by the uptake of nutrients form the soil.  The uptake of some nutrients is somewhat controlled by plant genetics (such as Ca) while other nutrients can be taken up due to luxury consumption (providing that an excess of nutrients is available).  Because of this, sometimes it is difficult to know what is "normal" or "adequate".  Two references that I have used extensively to evaluate norms over the years are:

Jones, J. B. Jr., B. Wolf and H. A. Mills.  1991.  Plant analysis handbook: A practical sampling, preparation , analysis, and interpretation guide.  Micro-Macro Publishing, Inc.  Athens, GA, USA.

Chapman, H. D. 1965.  Diagnostic criteria for plants & soils. University of California, Riverside, CA. 

Both of these references cover a wide range of plants and crops and provide a good guide for interpreting nutrient levels in plant tissues.

There may be more recent publications that have more up to date material but both of these have served me well.

On a local level, it might be helpful to start collecting data along with fertilizer practices and yields to develop a local data base that incorporates soils, climate and seasonal weather patterns.  This information can be very useful when discussing nutrient responses with local growers.

Thank you all for the useful comments and suggestions. I have been collecting data on soils and tissue samples to evaluate nutrient content for last 2 years noting the nutrient management history of the fields but yield have been an issue because before the plants get to mature 20% of the berry have dropped or eaten by birds. Can the soil nutrient levels be used to come up with tissue nutrient standards?

Is the fruit drop due to a suspected nutrient issue?  Do you suspect that that is why the fruit drops?

If you are using standardized sampling methods you should be able to establish nutrient trends that in combination with soil nutrient values, that can begin establishing values that can be useful in interpreting the nutrient status of the crop.  The fruit eaten by birds is highly unlikely to be related to the nutrient status of the crop but the fruit drop may be.  With the data from plant and soil nutrient status, you might be able to get some insights into what the status should be.

Very interesting question and equally informative responses , we have received. 

Infact , in annual crops, soil testing is always considered very reliable ( with  exception of LCC in cereals for N-management) , while in perennial crops, leaf/petiole analysis is the best within certain limitations. In perennial crops, while developing optimum tissue nutrient concentration , we need to first develop leaf sampling technique in terms of size of leaves to be sampled, position of to be sampled leaves on shoots, types of shoots , fruiting or non-fruiting shoots to be tested. Then , leaf anlysis -based data alongside fruit yiled should also be generated to alter subjected to different types of interpretation tools, like boundary line concept, ionomics, compositional analysis, DRIS(Diagnosis and Recommended Integrated  system ) , of which DRIS holds maximum promise and finds wider application , as it offers much better flexibility to growers in decision making. Based on these principles, i am enclosing few PDFs fro further reading...There are many more , can be downloaded from the profile on RG.

Let me flag off a question , whether conventional leaf analysis is effective in addressing the nutrient constraints of  current season crop..?

One latest publication on leaf analyis in apple...interesting one...

Can nutritional status of apple trees be determined by leaf analysis

in early vegetation?

ABSTRACT : In this study, whether the nutritional status of apple trees can be predicted in the early stages of vegetation was determined by leaf analysis. For this purpose, from different districts of Isparta province in Turkey where apples are cultivated extensively, 150 apple orchards were assessed according to the production potential of districts. The leaf samples were collected at six different stages of vegetation from these orchards, and nitrogen, phosphorus, potassium calcium, magnesium, iron, copper, zinc, manganese, and boron (N, P, K, Ca, Mg, Fe, Cu, Zn, Mn and B) amounts were determined. Correlations were examined between the sixth period and the previous periods. The presence of significant correlations was interpreted, as leaf analysis can be used to determine the nutritional status of apples in the early growth period. Consequently, it was determined that leaf analysis can be carried out at any time from the beginning of vegetation for all elements except Fe and Cu. Source ;JOURNAL OF PLANT NUTRITION 2017, VOL. 40, NO. 3, 277–282

http://dx.doi.org/10.1080/01904167.2016.1236951

PDF enclosed fro further reading..

Optimum tissue norms are suppose to vary with crop species, climate and soil. Therefore we always say optimum tissue norms once developed fro a crop need to be fine tuned to suit local conditions.