There is no exact method of determining the fertilizer or plant-food needs of the various crops. Certain guides have been established, however, from analyses of the plants and other means, and some of these block formulas are given here for the information of the consultant. The careful grower will make tests of his own (see p. 56), and use formulas only as guides.

Formulas suggested by the Maine Experiment Station.

It is to be borne in mind in using these formulas that they are only suggestive and that different conditions of soil make such different treatment essential that a formula which may prove successful on one farm may not be equally so on another. In no case is it to be expected that fertilizers will take the place of good tillage and care of crops.

Fertilizer Requirements

1 If desired to apply by machinery, it would be necessary to mix with about 200 pounds of some fine dry material, as muck or loam.

1 Rhode Island Sta. Bui. 90. 2 Beets are successfully grown in Maine without salt.

It is of the utmost importance in purchasing materials for these home mixtures to buy only on a guaranty of composition and to insist that the materials shall be of standard high-grade quality.

Specific mixtures for different crops (Agric. Exp. Sta. Geneva, N.Y., 14th Rept.).

In the following tables (pages 64 to 77), Van Slyke gives formulas for various crops as an illustration of the kinds of mixtures that are ordinarily advised. He is convinced, however, that practically all purposes would be satisfactorily served by the use of not more than a half dozen different formulas. We should work toward the more or less independent handling of nitrogen, phosphorus and potassium compounds, using them separately or together as special conditions and the results of observation and experience may suggest. This is possible, of course, only with the student farmer. For the mass of farmers, the formal recipe or the commercial mixture must yet form the basis of fertilizer applications. As a broad statement to guide the careful farmer, Van Slyke suggests the following: —

For leguminous crops, a formula of 1-8-10 (in the order of nitrogen, available phosphoric acid and potash). For cereals, 3-8-5.

For all kinds of garden crops, 4-8-10. For grass and forage crops, 4-6-9. For orchards, 2-5-10. For root-crops, 3-8-7.

The materials that are given for use in the succeeding tables are assumed to have a fairly definite composition, and the calculations are based on the following conditions of composition: —

(1)  Nitrate of soda, 95 to 96 per cent pure, containing 16 per cent of nitrogen.

(2)  Dried blood, containing 10 per cent of nitrogen.

(3)  Sulfate of ammonia, containing 20 per cent of nitrogen.

(4)  Stable manure, containing .5 per cent of nitrogen.

(5)  Bone-meal, containing 20 per cent of total phosphoric acid, one-half being calculated as available during first season on application; also containing 4 per cent of nitrogen.

Whenever bone-meal is used in a mixture, allowance should be made for its nitrogen, and so much less of other forms of nitrogen-materials used.

(6)  Dissolved bone, containing 15 per cent of available phosphoric acid and 3 per cent of nitrogen.

(7)  Dissolved bone-black, containing 15 per cent of available phosphoric acid.

(8) Dissolved rock, containing 12 per cent of available phosphoric acid.

(9) Muriate of potash, 80 per cent pure, containing 50 per cent of potash.

(10)  Sulfate of potash, 90 to 95 per cent pure, containing 50 per cent of potash.

(11)  Kainit, containing 12 to 13 per cent of potash.

(12)  Wood-ashes, containing 5 per cent of potash.

Alfalfa

Apples

Asparagus

Barley

Beans

Beets

Blackberries

Buckwheat

Cabbage

Carrots

Celery

Cauliflower

Same as for cabbage.

Cherries

Clover

Same as for alfalfa.

Corn

For sweet corn, somewhat larger amounts of nitrogen may be applied.

Cucumbers

Currants

Egg-Plant

Flax

Gooseberries Same as currants.

♦ Grapes

Grass for Pastures

Grass for Lawns

As a more specific mixture, we suggest the following: 100 lb. nitrate of soda, 100 lb. bone-meal, 100 lb. acid phosphate (dissolved rock) and 100 lb. muriate of potash an acre.

Grass for Meadows

Hops

Horse Radish

Lettuce

Nursery Stock

Oats

Onions

Parsnips

Peaches

Pears Same as for apples.

Peas Same as for beans.

Plums Same as for cherries.

Potatoes

Pumpkins Same as for cucumbers. Quinces Same as for apples.