French wine and minerals

Requirements are calculated in “units” (or kilograms). Example: 50 units of an “x” can be made per 100kg of fertilizer containing 50% of this element, or per 500kg of fertilizer containing 10%.  Quantities are expressed in grams in the case of oligo-elements, whose needs are much smaller.
Approximate annual requirements

For one hectare of ‘average’ vines:
20 to 70 “pounds” of nitrogen;
10 to 20 “pounds” of phosphoric acid (P2O5); 
30 to 80 “pounds” of potash (K2O);
60 to 120 “pounds” of calcium (CaO);
The four elements above are called principal components or major.  10 to 25 “pounds” of magnesia (MgO), an element called “secondary”;

The items below are called “trace elements”. Their average requirements are:
400 to 600 grams of iron (Fe);
80 to 150 grams of boron (B);
80 to 160 grams of manganese (Mn);
60 to 115 grams of copper (Cu);
100 to 200 grams of zinc (Zn);
1 to 2 grams of molybdenum (Mo).
Time and method of intake
Often in different regions, the minerals were made immediately after harvest to encourage the establishment of food reserves before the leaves fell.  In the northernmost regions, the harvest is later and leaf drop is earlier.

Fertilizer applications are rather late in winter.  In some regions, such as Champagne, dates of fertilizer applications are set by the prefecture, after consultation with professional organizations. These measures are taken to limit losses.
User input: They are buried directly using a special drill, equipped with a ploughshare incorporator, called “locator”.  This technique is intended to bring the fertilizer area explored by the roots, to concentrate and also to limit competition from weeds.  Given the quantity (required) being relatively low, trace elements are made on the ground under the same conditions as the major elements in season by foliar.  In all cases, we must ensure that they remain comparable.
Form and formulation
Nitrogen: Nitrogen organic (natural or synthetic (urea)), ammonium nitrate (ammonium nitrate 33%), ammonium sulphate 21%, ammonium phosphate, etc.
Phosphates: according to soil pH, addition of phosphates or finely ground, superphosphate of lime, phospal phosphate, ammonia. This product is advisable in calcareous soils, as it will be longer taken up by the plant.
Potassium: chloride and sulfate are the two most used. Another form, patenkali brings together magnesia.
Calcium: reserved for acid soil and decalcified. The fineness of the product to use is a function of soil acidity.
Magnesia: magnesium sulphate and patenkali provide a form of “MgO” long assimilated.
Trace elements can be made as chloride, sulfate, nitrate, chelate, or in organometallic form.  We must ensure their bioavailability over time.