C-Organik Tanah dan Perhitungan Kebutuhan Pupuk Perkebunan Kelapa Sawit Rakyat di Kabupaten Labuhan Batu

Abstract

Smallholder oil palm plantations in Labuhan Batu Regency have an important role in the regional economy. However, to achieve optimal results, good soil management is required. One of the important factors in soil management is the status of C-organic and macro nutrient balance that affects soil fertility and the need for appropriate fertilization. This study aims to analyze the C-organic status of smallholder oil palm plantations in Labuhan Batu district and calculate the fertilizer needs of oil palm farmers in Labuhan Batu based on soil macro nutrient status data. The method used in this research is the survey method by means of field observation, soil sampling, soil sample analysis, and soil macro nutrient status data field observation, soil sampling, sample analysis in the laboratory. Sampling in the field using purposive sampling technique. Parameters observed include pH, C-organic, N- total, available P, and K-total, Mg and Ca. The data obtained were tested using simple regression and correlation methods. The results showed that soil C-organic values varied from 1.04% in Lingga Tiga and Pulo Padang villages to 3.86% in Pangkatan village, which had the highest C-organic content. Soil nitrogen (N) levels in the various villages ranged from moderate (S) to high (T), with values varying from 0.3% to 0.59%. Meanwhile, phosphorus (P) levels in most villages were at a moderate level (S), with values ranging from 15.72 ppm to 19.34 ppm. Soil potassium (K) levels varied from low (R) to very high (ST). Calcium (Ca) levels in the soils of all villages were at a low level (R), with values ranging from 1.95 me/100g to 2.73 me/100g. Magnesium (Mg) levels in the soils were mostly at very low (SR) to low (R) levels, with values ranging from 0.25 me/100g to 0.42 me/100g. Fertilizer doses on various samples of oil palm plantations in Labuhan Batu District, it is known that there are variations in fertilizer doses between each village. Pangkatan village showed higher use of Urea, TSP and MOP fertilizers compared to other villages. Tebing Lingga Lama and Kampung Padang villages tend to use lower amounts of fertilizer. The use of dolomite, which tends to be uniform across villages, serves to improve soil pH.