Efektivitas Pupuk Hayati Mikoriza dan Asam Humat dalam Meningkatkan Efisiensi Pemupukan NPK Mg dan Pertumbuhan Bibit Kelapa Sawit Tahap Main Nursery di Tanah Ultisol

Abstract

One of the challenges in oil palm nurseries is limited soil fertility, especially in Ultisol soils which have high acidity and low nutrient availability. To overcome some of the problems in ultisol soils, mycorrhizal biofertilizers and humic acid are used. The purpose of this study was to analyze the effect of the use of mycorrhizal biofertilizers and humic acid on the growth of oil palm plants (Elaeis quineensis Jacq.) in the Main Nursery. The experiment was conducted in the Agricultural Field of the Faculty of Agriculture, University of North Sumatra using a Non Factorial Randomized Design, consisting of Control, Recomended dosage, Mycorrhizal biofertilizer 20 g/polybag, Humic acid 25 g/polybag, ½ Recomended dosage + 20 g mycorrhizal biofertilizer + Humic Acid 25 g/polybag, ¾ Recommended dosage + 20 g mycorrhizal biofertilizer + Humic Acid 25 g/polybag, 1 Recomended dosage + 20 g mycorrhizal biofertilizer + Humic Acid 25 g/polybag. The results showed that the use of mycorrhizal biofertilizers and humic acid had a significant effect on the growth of oil palm seedlings at the main nursery stage through nutrient availability. The treatment of ½ recomended dosage + 20 g mycorrhizal biofertilizer + 25 g humic acid/polybag can increase plant height, number of leaves, stem diameter, and plant wet and dry weights. The ¾ recomended dosage + 20 g mycorrhizal biofertilizer + 25 g humic acid/polybag and ½ recomended dosage + 20 g mycorrhizal biofertilizer + 25 g humic acid/polybag treatments showed high phosphorus uptake efficiency comparable to the recomended dosage treatment. A single treatment of recomended dosage can increase stem diameter, crown wet weight, crown dry weight and plant phosphorus uptake and phosphorus uptake efficiency. Application of mycorrhizal biofertilizer and humic acid can increase root colonization infection, where the highest treatment is found in the treatment of ½ recomended dosage + 20 g mycorrhizal biofertilizer + 25 g humic acid / polybag and ¾ recomended dosage + 20 g mycorrhizal biofertilizer + 25 g humic acid / polybag.