Dear Alaa

There are many parameters for determining soil fertility including:

CATION EXCHANGE CAPACITY (CEC)- ORGANIC MATTER-Sodium Absorption Ratio-pH-EC.

Check the attached files. I hope this information will help you.

You will find this book a good reference: https://www.cabdirect.org/cabdirect/abstract/19851998321

I believe that there are at least two newer editions of this book. However, any of the editions will provide an excellent background about soil fertility.

I used a newer edition to teach an undergraduate class in soils and fertilizers.

Dear Alaa

There are many parameters for determining soil fertility including:

CATION EXCHANGE CAPACITY (CEC)- ORGANIC MATTER-Sodium Absorption Ratio-pH-EC.

Check the attached files. I hope this information will help you.

I mean if we need to write an equation of soil fertility index such as :

soil fertility index = x1+x2+x3+.....xn

so what are x1,x2,x3

then how can I classify the soil fertility status according to that equation into : good, moderate , marginal ,bad , ... etc

Nutrient index = (NL * 1 + NM * 2 + NH * 3) / NT

Where, NL, NM and NH are number of samples belonging to low, medium and high classes of nutrient status, respectively and NT is total number of samples analyzed.

The values worked out from nutrient index for nitrogen, phosphorus and potassium respectively, should be compared against the nutrient index values 2.33 for high fertility status of area.

Dear D r.Sharma

thank you so much for your answer , but is this a referenced method ? if it is , I would like to ask you kindly to mention the reference .

Dear Alaa

Greetings

Also you can use the following studies:

Regards

Please consult the our paper published in ISSS

Soil fertility evaluation include :

pH , EC , lime , organic matter , CEC

In Indian conditions we have identified 12 soil parameters necessary to analyse in laboratory for development of soil health card. they are: pH, EC, OC, available N, P, K, S, Fe, Mn, Zn, Cu & B. By using these parameters more than 150 million SHC has been issued till date in India for fertilizer recommendation. Other parameters may be analysed depending on limiting factor in your area. You may consult the soil survey maps of your state for identification of land use potentials and limitations.

All the best

Mr.Alaa,interesting discussion.Parker et al.(1951) introduced the nutrient index to obtain a single value for each nutient in order to compare the levels of soil fertility of one area with those of another.The authors have suggested three tier and six tier system.

PI= no.of samples (low) x 1 + no.of samples(medium) x 2 + no. of samples (high) x3 / Total no.of samples

PI=no.of samples (V.L) 0.5 + no.of samples (L) x 1 + no.of sample s (Medium )x 1.5 + no.of sample (Mhigh) x 2 + no.of samples (High) x 2.5 + no.of samples (Vhigh) x 3 / Total no.of samples

Parker FW, Nelson WL ,Winters E and Miles JE(1951)The broad interpretation and application of soil test summaries.Agronomy Journal 43(3)103-112.

Dear Alaa Khallouf,

Please also have a look at this ResearchGate link and PDF attachments.

Article Soil Fertility Index, Soil Evaluation Factor, and Microbial ...

Good luck!

There are many parameters that determine soil fertility. This depends on the soil classification. Generally, evaluated soil fertility depends on several parameters such as texture, organic matter, soil pH, electrical conductivity, total calcium carbonate, total nitrogen, C/N ratio, available phosphorus, available potassium, exchangeable calcium, exchangeable magnesium and available of micronutrients. This is a few of many.