A dressing of stable manure two or three inches thick all over the plot or at the rate of from three to five hundred pounds to a plot twenty by twenty feet is about the right quantity to use when the ground is dug or plowed.
Sheep manure is perhaps the next in importance of the organic manures and is more concentrated than barn-yard or stable manure. It can be applied at the rate of forty pounds to four hundred square feet. It is better to spread it over the surface immediately after the ground has been broken up, and thoroughly mix it with the surface soil by means of a rake or harrow.
Hen manure is still more concentrated and should be used in the same way, or as a top-dressing after the crops have started their growth. Twenty pounds to four hundred square feet is a suitable amount to apply. To facilitate its distribution it should be mixed with dry earth and kept in a dry place for a few weeks before it is desired to apply it.
Of the so-called chemical fertilizers, those that are sold by seedsmen as “complete” fertilizers are the best for the amateur to buy. These at the present time are usually made up in the proportion of 5 per cent. nitrogen, 8 per cent. phosphorus, and 1 per cent. potash. Use twelve pounds to four hundred square feet.
All of the preceding are “complete” fertilizers containing nitrogen, phosphorus, and potash in varying proportions. If they are used in combination the quantities must be reduced.
Bone meal is a fertilizer which contains phosphorus and nitrogen. In some of its forms it is rather slow acting and sometimes does not become fully available for the use of the crop until the year succeeding its application. Use twelve pounds to four hundred square feet.
Nitrate of soda is the quickest-acting fertilizer that we have and is very valuable for stimulating the growth of plants early in the spring, when the nitrogen content of the soil is usually low. It is especially suitable for those crops that are grown for their leaves, such as spinach, lettuce, and cabbage. Great care must be exercised in the use of this fertilizer, as an overdose will injure or kill the plants. As it is very soluble, it should not be applied until the plants are up and ready to use it, otherwise much of it will be washed out of the soil and wasted. It should be sprinkled on the surface of the soil, first crushing the lumps, and then mixed in with a hoe or cultivator. An ounce to each square yard, applied at intervals of about three weeks, until the crops have a good start, is the right proportion to use. It is impossible to lay too much emphasis on the necessity for care in the use of this fertilizer. It must not be allowed to come in contact with the leaves of the crop, or it will cause them to burn and turn brown. Generally speaking, it is not a good fertilizer to use on root or fruit crops, although it can be used to good advantage in helping young plants of tomato, cucumber, muskmelon, etc., to get a start just after they have been planted out. Its use later in the season is likely to result in the production of leaves at the expense of fruit.
Wood ashes contain potash and lime. This fertilizer is a valuable dressing for heavy, clayey soils, as it improves their physical condition. It is good for root crops, such as beets, carrots, radishes, etc. Use twenty pounds to four hundred square feet.
It is best to apply all concentrated fertilizers as surface dressings, and then harrow or rake them into the soil, rather than to plow or dig them under.
If it so happens that the soil is not very fertile and there is only a limited quantity of fertilizer available, it is a good plan, instead of spreading it all over the plot, to apply it only in close proximity to the hills or drills in which the plants are growing.