FERTILITY AND PLANT FOOD.

Otago Witness, Issue 2895, 8 September 1909, Page 7

FERTILITY AND PLANT FOOD.

To produce profitable crops and at thesame v ti«ne to maintain and even to -increase the productive capacity of the soil may -rightly* be termed 'good farming." Many farmers are able to do this, and the knowledge of how to do it has been largely acquired through years of experience, during which the oharaoter of the sort, its adaptability for crops, and the methods of its management and manuring have been made the subjects of careful study, without, however, any definite and accurate knowledge concerning manures and their functions in relation to soils and crops.' Soils vary greatly in their capabilities of , - supplying food ' to , crops. _ Different fhgre- ; dients are - deficient in different soils. The way to learn what materials are proper in a ' given case is by observation and 'experiment. The rational method for .determln- "'* ing what ingredients of plant-food' a soil *' '■- faijs to furnish in abundance, and how these lacking materials can be most econo- ' mically supplied, is 'to "put the 'questions to -th* soil with different fertilising \ niaterials and, get » the reply in the crops produced. < -- The chief use of fertilisers is to supply plant-food. It .is good farming to make the -most of the natural resources of the soil- and of the manures produced on the farm, and to depend upon artificial fertilisers only to furnish what more is- needed. It is not* good economy to pay high prices, for materials whioh ihe soil may itself yield, but it is good economy to supply the lacking ones in the cheapest way. The rule in the purchase of costly commeroial fertilisers should be to' select those that supply, in the best forms and at the lowest cost, the plant-fooi whioh the crop needs and the soil fails tc furnish.