USE OF FERTILISERS.

New Zealand Herald, Volume LXVI, Issue 20241, 29 April 1929, Page 18

USE OF FERTILISERS.

THE VALUE OF, LIME,

OPINIONS OF AN EXPERT. ■Sir John Russell, of the Rothanistcd Experimental Station, lecturing to fanners on the Science of Manures, said that manures only represented ono side of crop management, and unless all other requisites were attended to they could not yield the maximum results. Liming was one of the precautions that had to be taken into account. The easiest way of increasing crops was to use nitrogenous manures, but tho difficulty was that if they went too far the plants were liable to become diseased. Phosphate manures increased the growth of roots, aided cereals to tiller, and mado ripening earlier. They were also very beneficial on grazing lands Of tho three more common phosphafic manures, superphosphate should be used for arable land, basic slag for grass, and bones might be used according to price.

In regard to tho potassic manures, muriate of potash, he said, was cheaper, and for all practical purposes gave equally as good results as sulphate of potash. By diagram illustration ho showed that good crop yields could be kept up for a few years with artificial manures, but eventually they went down below the yield of farm-yard manure. It would be interesting, therefore, to try to discover something—whatever that something was —in farm-yard manure, which kept up the yield- Farm-yard manure helped the moisture supply of the soil, and so enabled plants to go through drought better, while it also helped excess of water to get away, and facilitated plant roots in travelling in the soil in search of food and water.

Another point was the apparent feeding effect on the plant, which they could not produce by any known artificial substance. What that something was, ho sail., was one of the unsolved problems of the present time. The immediate practical thinj for the farmer was to recognise the value of farm-yard manure, and make the best use of it.