PREDICTION DES BESOINS EN ENGRAIS N, P ET K DES LEGUMES CULTIVES EN SOL MINERAL: POIS ET HARICOTS

Abstract

Recommendations of N, P and K fertilization presently made for vegetable production in Quebec need to be verified through local field studies. To this end field trials were made on 11 soils located in the Montreal, Nicolet and Quebec-Portneuf areas, through the year 1978–1980. Fertilization increased green pea yields in seven trials out of 16; most of these increases were caused by phosphorus applications. Similar results were obtained with snap beans, except that this crop tended to require a somewhat greater quantity of applied N. Fertilizer requirements of these crops were obtained by fitting Mitscherlich or polynomial equations to field data. Accordingly 15–30 kg N/ha seem to be required by green peas and snap beans, respectively, to obtain optimum yields. Modification of present soil test norms is suggested for phosphorus and potassium fertilization. For these crops the suggested rates are 20, 40 and over 60 kg P/ha for soils with high, moderate or low levels of available P and the minimum rate of 20 kg K/ha for every level of K except for the low level which would require about 40 kg K/ha for green peas.