Kesuburan Tanah, Pertumbuhan dan Produktivitas Tanaman Kelapa Sawit (Elaeis guineensis) pada Tiga Kedalaman Mineral Pirit

Acid sulfidic land is one of the marginal land that has been used for oil palm development.  Low soil acidity (pH) and high content of Al and Fe are limiting factors for oil palm development in this area.  Oil palm yield in this area was very limited and could not reach the standard of oil palm productivity in mineral soils. The objectives of this study were mapping the pyritic depth distribution, and observing the soil fertility on three pyritic depth (40 – 60 cm, 60 - 90 cm, and >90 cm). The results of this study showed that Paya Rambe plantation had varied pyritic depths, between 40-110 cm. The shallow pyritic depth was found along the river to the sea estuary.  Shallow pyritic depth soil has lower soil fertility than the deeper one.  Soil with shallow pyritic layer has high acidity, Fe, S, and Al contents, also contain low macro nutrients (N, P, K, and Mg) availability.  Furthermore, shallow pyritic depth reduced the oil palm growth, nutrients uptake and oil palm productivity.Lahan sulfat masam merupakan salah satu lahan marginal yang digunakan untuk pengembangan kelapa sawit.  Rendahnya pH tanah dan tingginya kadar Al maupun Fe menjadi pembatas pemanfaatan lahan ini.  Produktivitas tanaman yang dikelola pada lahan sulfat masam di kebun Paya Rambe di Aceh Tamiang, belum dapat menyamai produktivitas lahan mineral lainnya.  Untuk itu penelitian dilakukan untuk memetakan sebaran kedalaman mineral pirit, dan pengamatan kesuburan tanah pada tiga kedalaman mineral pirit (40 – 60 cm, 60 – 90 cm, dan >90 cm).  Hasil penelitian menunjukkan bahwa kedalaman pirit di kebun Paya Rambe bervariasi antara 40 – 110 cm, dimana lapisan pirit dangkal dijumpai di sepanjang sungai yang bermuara ke laut.  Tanah dengan pirit dangkal memiliki kesuburan tanah yang lebih rendah dibanding tanah dengan lapisan pirit dalam, yang tercermin dari semakin tingginya kemasaman tanah, Fe, S, dan Al-dd, serta rendahnya kandungan hara makro N total, P, K dan Mg tersedia dengan semakin dangkalnya lapisan pirit.  Lebih lanjut adanya mineral pirit dangkal menyebabkan pertumbuhan tanaman, serapan hara dan produktivitas tanaman yang lebih rendah dibanding pada areal dengan lapisan pirit dalam

Soil Macrofauna as Bioindicator on Aek Loba Palm Oil Plantation Land

Oil palm plantations of PT. Socfin Indonesia (Socfindo) Aek Loba area has been planted with oil palm since 1931, currently has plants from generation I (± 31 years), II (± 47 years), III (± 74 years), and IV (± 86 years) . The difference in the length of time of utilization and management of plantation land in each generation also determines the presence, both species, density, relative density, and the frequency of the presence of soil macrofauna. Soil macrofauna plays a role in maintaining the balance of the soil ecosystem. This research has been conducted at PT. Socfindo Kebun Aek Loba in February 2017- April 2018. This research was conducted to determine the presence of soil macrofauna on oil palm plantation land of PT. Socfin Indonesia (Socfindo) Aek Loba plantation area. Determination of the sampling point is done by the Purposive Random Sampling method, soil macrofauna sampling using the Quadratic and Hand Sorting methods. There are 29 species of soil macrofauna which are grouped into 2 phyla, 3 classes, 11 orders, 21 families, and 27 genera. The highest density value is in the Generation II area of 401.53 ind / m2 and the lowest density value is in the Generation IV area of 101.59 ind / m2. Frequency The presence of soil macrofauna in the four generations consists of 4 species, namely Pontoscolex corethrurus, Geophilus flavus, Vostax apicedentatus, and Solenopsis fugax

ANALISIS FINANSIAL DAN EKONOMI TANAMAN SELA JAGUNG DAN KEDELAI PADA TANAMAN KELAPA SAWIT BELUM MENGHASILKAN

Maize and soybean can be planted for intercropping on immature oil palm, however its  financial and economycal aspects have not been widely studied. This study was aimed to analyze the financial and economic aspects of intercropping of maize and soybean on immature oil palm, level of land use efficiency, and comparison of efficiency between monolculture and intercropping system.  The study located in Sorolangun Experimental Station, District of Sorolangun, Jambi. Methods used in the study were farming business analysis, Revenue Cost Ratio (RCR), Return on Investments (ROI), Land Equivalent Ratio (LER), and Land Equivalent Optimize Ratio (LOER). The results showed that maize had a profit level of Rp 9,676,564/ha/growing season, RCR 1.76; ROI 188.28% (three growing seasons per year), while soybean had a profit level of Rp 4,059,352/ha/growing season, RCR 1.51 and ROI 75.22% (three growing seasons per year). Based on these results,  intercropping of maize and soybean on immature oil palm are economically and financially feasible. For the land use efficiency, corn LER value for corn and soybean was 0.95 and 0.85, respectively, showing that yield of maize and soybean from intercropping system (effective land area of ​​7,200 m2 per ha of oil palm area) was 95% and 85% when compared to monoculture system. The LOER value of corn and soybeans per ha was 1.32 and 1.18, respectively, which showed that corn and soybeans growing on intercropping system with immature oil palm were more efficient than monoculture system at the same size of  land. Based on those comparative analysis of economic values, financial, and land use efficiency, corn was a better alternative crop for intercorpping on immature oil palm than soybean.Jagung dan kedelai secara teknis dapat dijadikan tanaman sela pada areal tanaman belum menghasilkan (TBM) kelapa sawit, namun aspek finansial ekonomi tumpangsari ini belum banyak dikaji. Penelitian ini bertujuan untuk mengkaji analisis finansial dan ekonomi  jagung dan kedelai sebagai tanaman sela pada TBM kelapa sawit, mengetahui tingkat efisiensi penggunaan lahan, dan mengkaji komparasi efisiensi tanaman monokultur kelapa sawit dan kombinasi usaha tani tanaman sela jagung dan kedelai pada TBM kelapa sawit. Penelitian dilakukan di Kebun Percobaan Sorolangun, Kabupaten Sorolangun, Jambi. Metode penelitian yang digunakan meliputi analisis usaha tani, Revenue Cost Ratio (RCR), Return on Investment (ROI), Land Equivalent Ratio (LER), dan Land Equivalent Optimize Ratio (LOER). Hasil penelitian menunjukan bahwa jagung memiliki tingkat keuntungan sebesar Rp 9.676.564,-/ha/musim tanam, RCR 1,76; ROI 188,28% (tiga musim tanam per tahun), sedangkan kedelai memiliki tingkat keuntungan sebesar Rp 4.059.352,-/ha/musim tanam, RCR 1,51 dan ROI 75,22% (tiga musim tanam per tahun). Dengan demikian secara ekonomi dan finansial tanaman sela jagung dan kedelai layak diusahakan. Dari aspek efisiensi penggunaan lahan, nilai LER jagung dan kedelai sebesar 0,95 dan 0,85 yang menunjukan bahwa penanaman jagung dan kedelai (luas lahan efektif 7.200 m2 per ha sawit) memiliki produktivitas 95% dan 85% jika dibandingkan dengan tanaman monokultur. Namun nilai LOER jagung dan kedelai per ha sebesar 1,32 dan 1,18 yang menunjukan bahwa jagung dan kedelai sebagai  tanaman sela pada TBM kelapa sawit lebih efisien dibanding sistem tanam monokultur pada luasan yang sama. Berdasarkan analisis komparasi nilai ekonomi, finansial, dan efisiensi penggunaan lahan tersebut,  jagung memberikan hasil yang lebih sebagai tanaman sela pada TBM kelapa sawit dibandingkan dengan kedelai