30-10-10 type, actually 24-8-8, can be made up with 10 lbs. ammonium phosphate 16-20-0; 10 lbs. urea 45-0-0; 4 lbs. potassium sulphate 0-0-50, at a cost of about 40 cents a pound; soluble. OD80-65

30-10-10 type, actually, 21-7-7, can be made up with 20 lbs. lawn fertilizer 25-4-5, 6 lbs. ammonium phosphate 16- 12-0; 2 lbs. potassium sulphate 0-0-5-, at a cost of about 30 cents a pound; clay settling out can be discarded. OD80-65; this mix is questionable because indeed a good quantity will settle out; the materials are only sparingly soluble. OWD

30-10-10; 3 lbs. urea, 10 oz. triple-super phos- phate, 5 oz. muriate of potash; use 3 heaping teaspoons to five gals, water; the phosphate will not dissolve completely. A68-331

A ratio of 4-2-1 can be made from ammonium nit- rate, diammonium phosphate and muriate of potash; no proportions given; refer to OD68-10

For fast growth in spring for cymbidiums mix in 450 litres of water, 250g potassium sulphate, 226g nitram (presumably ammonium nitrate) 28g magnesium sulphate (Epsom salts). AU87(2)-15

For late summer spike initiator in cymbidiums: in 450 litres of water put 340g potassium nitrate, 170g mono ammonium phosphate (MAP), plus 42g Urea 46%. AU87(2)-16

For special needs: to 100 gallons of water,- For nitrogen only, add 1 lb. Urea or 2 lbs. Ammonium nitrate; or, 2 lbs. Calcium nitrate; For Nitrogen-plus-Phosphorus: 12 oz. Urea plus 12 oz. Mono-ammonium phosphate; or, 12 oz. Ammonium nitrate plus 12oz. Mono-ammonium phosphate (MAP) plus 8 oz. Potassium chloride, or 8 oz. Ammonium nitrate, plus 8 oz. MAP, plus 8 oz. Potassium chloride; For Nitrogen-and-Potassium, 12oz. Ammonium nitrate, plus 12 oz. Potassium chloride; other formulas. OR79-202

For summer feed for cymbidiums: to 450 litres of water add 225g potassium nitrate, 226g mono-ammonium phosphate (MAP), 113g urea 46%. AU87(2)-15

Formulas based on Craig Hillemann's equations in Orchid advocate, 1979, p.94+ are given in pounds, with costs, for formulas 24-8-8; 21-7-7; 18-6-6; 13.5-13.5-13.5; 12.5-12.5-12.5; 8-8-8 (liquid); 4-20-20; 4-10-10 (liquid) and 2-10-10; all water soluble; refer to OD80-65+

Hudlow formula: 2 lbs. Ammonium nitrate, 1 lb. Potassium nitrate, 8 fluid ounces Phosphoric acid 75% food grade, and 2 oz. optional Water-In; put all in 5 gals, water to make a 15-7-5 fertilizer to be used at the rate of one ounce to one gallon of water; for a low nitrogen feed omit the Ammonium nitrate. 0IE86Jy-10

In five gallons of water put 2.75 pounds Urea, 400c:c phosphoric acid; in another five gallons put 2.75 pounds potassium nitrate; mix the two and feed in a l-to-16 water proportioner, every second watering. OD87-174

Late summer spike initiator for cymbidiums = to 450 litres of water add 226gr. Ammonium phosphate, 226gr. Potassium chloride, plus trace elements. AU87(2)-16

Mathematical formula for preparing fertilizers from bulk components; custom mix your own, with dilution water, for one-tenth normal price. OA79-94+

Summer feed for cymbidiums: to 450 litres of water add 283g ammonium nitrate, 85g di-ammonium phosphate, 198g potassium nitrate AU87(2)-16

Summer feed for cymbidiums: to 450 litres of water add 340g potassium nitrate, 85g nitram (presumably ammonium nitrate), 85g magnesium sulphate. AU87(2)-16