Hello everyone,

I am working in Central America and I would like to create a document that could help me to calculate "simply" the nutrients disponibility in the soil of coffee fields. The formula I would use for each nutrient is :

Nutrient disponibility = result of the soil analysis (ppm or mg/kg) x weight of soil (t/ha) / 1000 x nutrient efficiency (%) / 100

I could find some estimation of efficiencies for N (40-50%), P (25-30%), K (50-60%), Ca (80-90%) and Mg (80-90%) for Central America, but I am still searching for S and the micronutrients.

I am aware that this is a simplified formula and that it would be more accurate to take in account the climate datas, thus to have a different formula for each field. Moreover, it depends of the soil analysis (efficiency of K, Ca, Mg depending of the CEC and the ratios for ex). These are the limits of my calculations.

My question would be :

Do you have S and micronutrients efficiency estimates in soil for Central America ?

Thanks for reading