MAINTAINING FERTILITY.

New Zealand Herald, Volume LXVIII, Issue 20779, 23 January 1931, Page 18

MAINTAINING FERTILITY.

VALUE OF PHOSPHATES. I'he farmer who would use phosphate without maintaining a scientific soi 1 - building programme and rotation on his land is usually the farmer who expects a "shot in the arm" or some quick "patent medicine" type of cure for his low yields. According to an American writer, who deals with the application of phosphorus to sugar beet crops, phosphate is no cure-all or dope cure for soil. By adding it, to lii.s land the grower is merely reluming in a fairiy high concent ruled form fertility that he or his predecessors took out unduly last, either by unwise cropping (no rotation) or by heavy cropping (11il;11 yields). || appears that iu most farming countries phosphorus is the least plentiful soil clement from the .standpoint of crop production. This is a world-wide condition. Il is almost the first element the deficiency of which has been shown on a universal scale to be responsible for limiting crop yields. Hence it is among the earliest of commercial fertilisers. Hut where it has been used the longest and with best effect, tlieie. too, barnyard manure and the turning under of green growth or crop residues have been practised the longest. Misapprehensions concerning phosphato fertiliser for sugar beets are likely to be advanced bv blind adoption of its use. Farmers who try it and fail to obtain results are apt to condemn it. A soil test for phosphorus deficiency should precede any large purchase of it, and constant testing of fields by demonstration plots would also be advisable.

The emphasis which has horn given to phosphate in sugar-beet-growing localities has served to distract attention from the beneficial effects of its application produced on other crops, apart from the holdover effect for at least two succeeding yours. \Yc know that Income is a high user o[ phosphorus, and spreading phosphate on lucerne fields has produced lioth incmisod yields and heller quality hay. Wheat and small grains in general also show a marked response to phosphate fertiliser if the soil is lacking in phosphorus.