In place of nitrate of soda, a similar quantity of sulphate of ammonia may be used.
Instead of superphosphate, the following may be advantageously employed: phosphatic guano, or mixtures of basic slag and superphosphate, or bone meal and superphosphate; or basic slag may be applied alone on land deficient in lime.
Four pounds of kainit may also take the place of one pound of sulphate of potash in the suggested mixtures mentioned below.
Where dung is recommended, twenty to twenty-five loads per acre is meant; larger quantities are frequently applied, but these are uneconomical and much less efficient than more moderate amounts supplemented with artificial fertilisers.
All the manures should be worked into the soil before sowing or planting out, except the nitrate of soda, which is best applied separately to the growing plants, preferably in small doses at intervals of two to four weeks.
In all cases the quantities of artificials named are intended for use on one square rod or pole of ground.
PEAS AND BEANS.—These leguminous plants are able to obtain all the nitrogen they need from the air. They should, however, be amply supplied with potash and phosphates, a good dressing being:—
2-3/4 to 3-1/2 lb. superphosphate
3/4 lb. sulphate of potash
DWARF BEANS are sometimes benefited by the addition of 1/2-lb. to 1 lb. of nitrate of soda.
ASPARAGUS.