THE VALUE OF FILTER PRESS CAKE AS A FERTILIZER FOR VEGETABLE CROPS. PRELIMINARY TRIALS WITH TOMATOES AND CUCUMBERS

Abstract

Filter press cake, a refuse from sugar mills in Puerto Rico can be used advantageously for fertilizing tomatoes and cucumbers grown in the soil type Coto Clay No. 20. When applied at the rate of 12 tons per acre plus 1,000 pounds of fertilizer 8-10-15 it caused a significant increase in yield of marketable tomatoes amounting to 20.5 per cent over the treatment where chemical fertilizer 8-10-15 had been applied alone at the rate of 1,000 pounds per acre. When 20 tons filter press cake were applied alone and with different complete and incomplete chemical fertilizers, also significant increases in yield of cucumbers were observed. The yield with 20 tons of filter press cake alone was equivalent to the yield obtained with a complete fertilizer having 200 pounds NH₃, 200 pounds P₂O₅and 200 pounds K₂O.  Results seem to indicate that the most profitable treatment would be probably 20 tons filter press cake plus 200 pounds NH₃and 200 pound P₂O₅