REVIEW OF FERTILIZER TRIALS ON THE PRODUCTION OF SOME SELECTED HORTICULTURAL CROPS (ONIONS, CARROTS, LETTUCE, GREEN PEPPER): 2010-2023

ABSTRACT

Fertilizer plays a crucial role in the production of horticultural crops, examples are onions, carrots, lettuce and green pepper. The use of fertilizer can significantly enhance the growth, the yield and the quality of these crops. Fertilizer provides essential nutrients such as nitrogen, phosphorous and potassium, which are necessary for the growth and development of horticultural crops. These nutrients are critical for photosynthesis, respiration, enzyme activity and the synthesis of proteins, nucleic acids and other organic compounds. The application of fertilizers can improve soil fertility, structure and water holding capacities which are essential for healthy plant growth. The role of fertilizers in crops also helps correct soil deficiencies and imbalances which can lead to poor crop growth and yield. The use of fertilizer can also help to control weeds, pest and diseases which can cause significant losses to crops. This review present the role of fertilizer in the production of onions, carrots, lettuce and green pepper based on recommended rate for these crops by previous trials and study from (2010 – 2023). For onion production in the rainforest zone, it is advisable to apply 80 kg per hectare of NPK 15:15:15 fertilizer. In rainfed lowland areas, carrot cultivation benefits from the application of 20 tons per hectare of compost. Lettuce cultivation in the rainforest zone thrives with the application of 13 tons per hectare of organic manure. For green pepper cultivation in the rainfall zone, it is recommended to apply 150 kg per hectare of NPK 15:15:15 fertilizer. These aim to optimize crop growth and yield while ensuring sustainable agricultural practices within each specific environmental context.