Pertumbuhan dan Kadar Hara Tanaman Kopi Arabika (Coffea Arabica L.) Akibat Perlakuan Bahan Organik dan Pupuk Mikro

Abstract

This study aimed to evaluate the effects of organic fertilizers (Tithonia diversifolia compost, chicken manure, rice husk biochar, humic acid, and fulvic acid) and micronutrients (B, Cu, and Zn) on the growth and nutrient content of Arabica coffee plants under unproductive conditions in North Tapanuli Regency. A factorial Randomized Complete Block Design (RCBD) was applied with 24 treatment combinations and 3 replications, resulting in 72 experimental units. The observed parameters included vegetative growth (plant stem diameter and leaf area) and soil micronutrient levels (B, Cu, and Zn). The results showed that soil amendments significantly affected stem diameter at 3-5 months after application (MAP), with rice husk biochar and humic acid providing the greatest improvement. Cu application was the most effective micronutrient, increasing stem diameter by 30.23% at 4 MAP compared to the control. Furthermore, Tithonia diversifolia compost significantly increased soil Cu and Zn levels, while rice husk biochar enhanced B content. The interaction of rice husk biochar and boron micronutrient fertilizer produced the most favorable synergistic effect, resulting in the highest soil boron concentration and improved soil fertility conditions, which positively influenced the vegetative growth of Arabica coffee.