Kajian Respon Morfofisiologi dan Produksi Kelapa Sawit dengan Teknik Pemotongan akar

Abstract

Oil palm is an important plantation commodity in Indonesia due to its high economic value. However, increasing oil palm productivity is challenging because of its limited land area, so physiological practices are needed to increase productivity. One of the factors affecting oil palm productivity is interaction between roots and nutrients. Nutrient uptake by oil palms is influenced by the characteristics of the root system, including morphology, growth rate, and chemical reactions with soil and water. Attempts to increase oil palm productivity include root cutting techniques. This technique has been applied in crop cultivation, but its application to oil palm still requires more studies. Besides root cutting, organic matter applications such as litter and oil palm empty fruit bunches (TKKS) can play an important role in improving soil physical conditions. This improvement in soil quality through organic matter can support better root growth, especially in dense soil structures. In addition, plant age also affects its physiological and productivity responses to root cutting and organic matter application. Research consisted of four parts: 1) Assessment of morphophysiological and production responses of oil palm to root cutting; 2) Sentinel-2 based estimation system of nutrient status levels, NDVI values, fertilization recommendations; 3) Effects of root cutting on organic carbon stock availability; and 4) Effect of different types of fertilizers on productivity of oil palm after root cutting. First experiment. Analysis of the results showed that root cutting at a certain depth and intensity had a significant impact on oil palm growth and yield. Root cutting at a depth of 20 cm with 50% intensity had a significant effect on plant height. Yield analysis showed that root cutting at a depth of 10 cm and 20 cm with 50% and 75% intensity had better results in terms of number of bunches, weight, and yield components compared to the control. Overall, the results provide insight that regulating root cutting at the right level and intensity can be an effective strategy to improve oil palm growth and yield. Second experiment. The results of this experiment showed that the differences in N and P concentrations between treatments were not significant, but there were significant variations in K concentrations. Root cutting tended to decrease N and P content, and increase K content to maintain plant turgor pressure. Satellite image analysis showed that root cutting did not significantly change NDVI values, but indicated stable nutrient availability. The correlation between NDVI and nutrient content showed a strong positive relationship, indicating root regeneration after cutting. Third experiment. The results analysis showed significant variation in soil carbon stock content between treatments, ranging from 14.42 to 16.69 tons ha-1 year-1. This highlights the complexity of the interaction between root cutting and soil organic carbon availability, which can affect nutrient cycle and land productivity. Optimal plant growth after root cutting occurred over a 3-month period, with optimal soil carbon content occurring at 20 cm depth and 75% cutting intensity. This indicates that root cutting with certain parameters can have a significant impact on soil fertility and organic carbon availability in a relatively short period of time. Fourth experiment. Experimental results showed the effect of fertilizer type on oil palm plants at several plant ages after root cutting indicated morphological and production responses that were not significantly different at each plant age. Significant plant morphological responses that were only influenced by plant age were stem circumference, primary root distribution, 8th month bunch weight, NDVI value, soil K nutrient content, root N and P content. Fertilizer application at each plant age resulted in the highest bunch weight in the potassium fertilizer treatment at the age of 12 years followed by the leaf litter fertilizer treatment at the age of 16 years. Generally, the fertilizer treatments at each plant age did not show significant results after root cutting, but the highest increase in bunch weight compared to the control was found in the leaf litter fertilizer treatment at palm age 16 years.