Balanced Fertilization Strategy for Semi-Temperate Vegetables In The Highlands, Philippines

Abstract

On station and on farm experiments in the highlands were conducted to come up with a balanced fertilization strategy for selected semi-temperate veg­etables. Cabbage, broccoli, carrots, bell pepper, and potato which are the major crops grown in the highlands were subjected to 24 fertilizer combinations. Ten best treatments were selected from initial experiments for verification and evalu­ation. Three trials for cabbage, broccoli, and potato while two trials for carrots and bell pepper were done.

On station results on cabbage showed that application rate of 250-100-100 kg NP2O5K2O/ha + 7 tons/ha chicken manure significantly produced the heaviest with bigger and more compact cabbage heads. Similar results were noted from on farm trial. Marketable tuber yield of potato was highest with the application of 140-140-140 kg NP205K20/ha + 5 t/ha formulated organic fertilizer + Boron. For broccoli, fertilizer rate of 240-60-60 kg NP205K20/ha + 5 tons/ha formu­lated compost + Boron produced the heaviest yield and biggest curds. Reducing the recommended rate by 25% with chicken manure and Boron supplementation gave comparable yields. Bell pepper produced the heaviest at a fertilizer rate of 100-200-100 kg NP205K20/ha + Boron. Application of the recommended rate of 100-200-100 kg NP205,K20/ha+ 5 tons/ha formulated organic fertilizer + Boron gave comparable yield. On carrots, the heaviest yield was noted from application of 90-170-90 kg NPK/ha + Boron though it did not differ significantly from other treated plants. Higher return on investments was realized in most treatments with reduced fertilizer application.

The effects of the treatments on soil properties differ from each area planted with the test crop. An improvement in soil organic matter was noted in most treatments involving organic fertilizer application. While a general decrease in soil pH were noted from those treated with higher rate of inorganic fertilizers. Results indicated that combined application of organic-inorganic fertilizer proved to be more effective in terms of crop responses and on soil properties.