ABSTRACT
Phosphate, for the purpose of calculating unexhausted manurial values, is further divided into soluble and insoluble, and this is invariably shown on the bag.
Some intensive farmers use a great deal of nitrogen and there are cases of as much as 400 units of nitrogen per acre (1,000 units per ha) being used by dairy farmers, at average intervals of three weeks during the growing season. Similarly, some intensive and specialist cereal growers apply three or possibly four top dressings of nitrogen at three-weekly intervals in the spring — often 170 units and more. Nitrogen is rarely applied in the winter as rainwater leaches (washes)
it out of the soil. It is always wise to have the soil tested for phosphate and potash levels. Basic slag, when obtainable is very good for grassland and is generally applied at the rate of 0.5 tonne per acre (1.25 tonnes per ha). It encourages clovers, which in turn improves the fertility by naturally fixing nitrogen.
