Pengelolaan Lahan Gambut Untuk Pengembangan Kelapa Sawit Di Indonesia

Abstrak.Lahan gambut yang mempunyai sifat mudah rusak, pemanfaatannya harus berpedoman pada upaya pengembangan lahan berkelanjutan dengan konsep pembangunan yang “konstruktif-adaptif”. Pengalihan fungsi lahan gambut untuk keperluan lain berdasarkan kesesuaian dan kemampuan lahan serta penggunaan teknologi yang sesuai harus menjadi dasar dalam pengembangan lahan gambut ke depan. Dengan demikian, pemilihan teknologi dan komoditas yang tepat dan adanya upaya untuk menekan kerusakan lahan hingga sekecil mungkin menjadi sangat penting. Kelapa sawit merupakan salah satu komoditas yang mampu beradaptasi dengan baik pada berbagai jenis lahan, termasuk lahan gambut. Dengan teknologi pengelolaan air yang tepat, disertai peningkatan stabilitas bahan gambut dan serapan CO2 oleh tanaman pada kawasan pengembangan kelapa sawit, maka pemanfaatan lahan gambut akan memberikan faedah yang besar, tidak hanya untuk masa kini tetapi juga untuk masa mendatangAbstract.Peatlands with fragile properties should be used by following the guidance of sustainable land development with land usages concept of “constructive-adaptive” development. Conversion of peatlands for other land usages based on land capability and land suitability as well as the appropriate use of technology should be the basis for their future development. Thus, the selection of suitable technologies and commodities with the attempts to reduce the land damage to the lowest level is very important. Oil palm is one of the agricultural commodities that are able to adapt different types of land, including peatlands. With proper water management and the efforts to increase peat stability and CO2 sequestration in the area of oil palm development, the use of peatlands will provide a great benefit, not only for today but also for the future

Potassium Soil Test Calibration for Corn on Typic Hapludox Cigudeg

Soil testing calibration is a process to provide meaning of soil test value in term of crops response. Research on soil testing calibration for corn has been carried out on Typic Hapludox Cigudeg. The objectives were: 1) to determine critical point of soil test value of K, 2) to determine the application rate of K fertilizer recommendation. The split plot design was used with consisted five rate of K fertilization on three K soil status as the main plots. There were four K soil test methods assessed to determine the critical point value for corn. K availability was classified into three categories namely low, medium, and high class. The results revealed that critical value of four soil testing methods for low, medium, and high respectively were : HCl 25% (<14, 14-29, and >29 mg 100 g-1), NH4OAc pH 7(<84 ppm, 84-220 ppm, and >220 ppm), Morgan (<70 ppm, 70-180 ppm, and >180 ppm), and Mechlich I (<54 ppm, 54-135 ppm, and >135 ppm). K fertilization significantly affected to corn plant height in the low soil K status until the rate of 60 kg K ha-1 (116 kg KCl ha-1). Dry biomass significantly increased due to K fertilization on low, medium as well as high soil K status. K fertilization also improved corn grain production. The ears of corn could not develop without K fertilization. This was an evidence that K nutrient has an important role in enzyme activity and assimilate translocation. Even with low rate of K fertilization, corn has succeeded to form ears and kernels. In the low soil K status, K fertilization sharply increased dry grain, but in the medium soil K status the curve was gentler. Whereas in the high soil K status, K fertilization did not significantly affect the dry grain yield. The recommended application rate of K fertilizationfor corn on Typic Hapludox Cigudeg with low K status was 89 kg K ha-1 and in the medium status was 53 kg K ha-1. Whereas in the high soil K status, no K fertilization was needed

Recommendation of Sustainable Landuse in Border Area East Kalimantan-Malaysia

Development problems of agriculture on border area require handling which more comprehensive and sustainable. Up to now, research results indicate that efforts has been done in handling various problems in agricultural sector, but still partial and is not be able to overcome complex problems. Therefore to overcome various development problems of agriculture on the border area need to be done in holisticaly, covers all aspect i.e. social, economics, ecology, and institution. Sebatik Island is one of state border area between Indonesia and Malaysia, located in Nunukan District, East Kalimantan Province. Up to now, cocoa is still the priority commodity, but its productivity is relatively low. Based on potency and constraint of land resources in Sebatik Island, sustainable recommendations to increase land productivity of cocoa i.e. (1) land and water conservation management, (2) using organic matter, (3) proportional fertilization, (4) using mulch, (5) integrated crop management, (6) integrated crop-livestock system, and (7) improvement of capacity of farmers institutio

ANALISIS KEBERLANJUTAN USAHATANI HORTIKULTURA SAYURAN PADA LAHAN BERLERENG DI HULU DAS JENEBERANG, SULAWESI SELATAN

This study aimed to analyse the sustainability of vegetables horticultural farming on sloping land in the upstream Jeneberang watershed based on the index evaluation and the status of sustainability by Rap-farm method using Multidimensional Scaling (MDS).Results of ordination technique analysis Rap-farm method of MDS showed that index of vegetables horticultural farming sustainability ranged from 32.19-62.53. Dimension of ecological, economical, institutional, and technological included into sustainable enough category, while social dimension, included into less sustainable category in vegetables horticultural farming systems.Results of leverage Rap-farm analysis showed that from 43 attributes that were analyzed, there were 23 sensitive attributes that affected into the sustainability of vegetables horticultural farming systems in the upstream of Jeneberang watershed. &nbsp

Pengaruh Pemberian Sulfur dan Blotong terhadap Pertumbuhan dan Hasil Bawang Merah pada Tanah Inseptisol

Penelitian ini bertujuan mengetahui pengaruh sulfur dan blotong terhadap pertumbuhan dan hasil bawang merah di tanah inseptisol. Penelitian dilaksanakan di rumah kaca Kebun Percobaan Jeneponto pada bulan Januari sampai April 2000 dengan rancangan acak lengkap pola faktorial dua faktor dengan empat ulangan. Faktor pertama adalah sulfur yang terdiri atas enam taraf dan blotong sebagai faktor kedua yang terdiri atas tiga taraf. Hasil penelitian menunjukkan bahwa bobot kering tanaman umur satu bulan, bobot umbi saat panen, bobot umbi kering eskip, dan kelas umbi dipengaruhi secara nyata oleh sulfur, blotong, dan interaksinya. Sedangkan susut bobot umbi tidak dipengaruhi oleh sulfur, blotong, dan interaksinya. Pemberian 40 ppm sulfur dan 75 g/pot blotong menghasilkan umbi kering eskip dengan bobot tertinggi

Loss of Soil Organic Matter, Lignocellulose and Microbial Population in Oil Palm Plantations Located at Different Slopes

Loss of soil organic matter can be caused by erosion triggered by soil compaction and high rainfall. The aims of  the study were to determine (1) the loss of soil organic matter, lignocellulose, and soil microbial population due to erosion and (2) the contribution of organic matter from oil palm fronds. In the current study, the erosion plots were built on the accessible inter-row (gawangan hidup) and inaccessible inter-row (gawangan mati) of oil palm plantations located at the slope of 6-10% and >10%. Soil organic matter, lignin, cellulose, and hemicellulose contents and total soil microbial populations were measured in the sediments collected from the erosion plots. The results showed that the loss of organic matter was higher in the accessible inter-row than that in the inaccessible inter-row. The addition of lignin, cellulose, and hemicellulose from oil palm fronds into the soil are 2.06 Mg ha-1 yr-1, 1.13 Mg ha-1 yr-1 and 1.02 Mg ha-1 yr-1, respectively. Total bacterial population in the sediments taken from the accessible inter-row was higher than that from the inaccessible inter-row, while the total fungal population in the sediments from the inaccessible inter-row was higher than that from the accessible inter-row. 

Estimation of the Potential Carbon Emission From Acrotelmic and Catotelmic Peats

Agricultural development on peatland in Indonesia has been constrained by the presence of environment issues in relation to the release of greenhouse gases (GHGs) particularly carbon dioxide (CO2) and methane (CH4) to the atmosphere. This study was aimed to predict the potential carbon emission based on carbon stocks in acrotelmic and catotelmic peats with the reference of groundwater level of peatland.  The results showed that groundwater levels have played an important  role  in  carbon  release, which  has  close  relationship  with  water  regime  of  the upper  layer  of  peats  that influenced by oxidative and reductive conditions of the land.  From the layer that having groundwater level fluctuations during the period from rainy to dry season (acrotelmic peat), the emissions were mostly dominated by CO2 release, while from permanent reductive-layer (catotelmic peat) was not detected.  The decrease of groundwater level from -49.6 to -109 cm has clearly influenced carbon emission.  From each decreasing 1.0 cm groundwater level, CO2 emission measured during the period of February - October 2013 was calculated to yield about 0.37 Mg ha-1 yr-1.Keywords: Acrotelmic and catotelmic peat, carbon emission, groundwater level [How to Cite: Siti N, S Sabiham, B Nugroho and Di Nursyamsi. 2014. Estimation of the Potential Carbon Emission from Acrotelmic and Catotelmic Peats. J Trop Soils 19(2): 91-99. Doi: 10.5400/jts.2014.19.2.91]  [Permalink/DOI: www.dx.doi.org/10.5400/jts.2014.19.2.91] &nbsp

The Role of Iron Oxide in the Characteristics of the Highly Weathered Soil

Iron oxide is generaly found in the clay mineral composition of highly weathered soil (low activity clay soil) like Oxisols. There is limited information about the role of iron oxide in Oxisols, on the other hand the information is very important when we want to make use of the Oxisols. This study was done to investigate the role of iron oxide in the soilcharacteristic especially CEC, pHo, available water, plasticity index, soil color and maximum phosphate absorption. Soil samples were taken based on Soil Survey Staffs (1991), from different kinds of highly weathered soil i e: Typic Hapludox, Plinthic Hapludox and Anionic Acrudox, each sample was taken from two locations. At each location sample was taken from three different site : upper, middle and lower slope. Chemical analysis was done to determin the level of Fe.d, Fe.o, Fe.p, CEC (NH4OAc 1 M), pHo, available water, atterberg index and maximum phosphate absorption, and soil characteristics that useful for soil classification. Data were analyzed using matrix correlation test, simple and multiple regression. Principle Component Analysis was used to solve when multicolinearity problem happen. Results show that the Anionic Acrudox has the highest content of Fe.d and Fe.o, varied from 12.03 – 12.27% and1.01 – 1.12% . Followed by Typic Hapludox varied from 9.52 – 10.57% and 0.31 – 0.46% respectively for Fe.d and Fe.o. The level of Fe.d and Fe.o for Plinthic Hapludox varied from 6.31 – 9.40% and 0.09 – 0.17%. The higher the iron oxide content the lower the cation exchange capasity and the higher of the pHo. Multi regression analysis results between CEC and some soil characteristics shows that Fe.d and Fe.o can indicate thehighest variability namely 35.8%. While correlation between pHo and Fe.o shows the highest correlation and highly significant (r² = 0.65).Iron oxide has highly effect on available water and plasticity index, the higher the iron oxide content, the higher is the available water and the lower the plastisity index. The higher the iron oxide content the higher is intensity of red color of the soil. And the higher the iron oxide content, the higher is the maximum phosphate absorption; this condition is disadvantageus for plants, because the phosphate is not available for plants

Dominant Soil Characteristics That Effect on Available K at Smectitic Soils

Research aimed to study dominant soil characteristics that effect on available K of smectitic soils were conducted in Laboratory of Research and Soil Test, Indonesian Soil Research Institute. The soil characteristics that has been analised were soil texture (pipette), organic-C (Kjeldahl), and CEC (NH4OAc); mineralogical analyses of clay fraction (X-Ray Diffraction); K fractionation: soil soluble-K (0.0002 M CaCl2), exchangeable-K (NH4OAc), and total-K (HNO3+HClO4); and potassium sorption. The results showed that the content of soil soluble, exchangeable, non-exchangeable, and total-K was in order of Vertisols > Alfisols > Inceptisols. The percentage of soil K fraction of the soils, however, was in order of soluble-K < exchangeable-K < non-exchangeable-K. Although the soils had high content in total K but most of them were in nonexchangeable form, thus they were not available for plant growth. Soil K buffering capacity and maximum sorption were in order of Vertisols > Alfisols > Inceptisols. The bond energy constant of Vertisols, however, was similar with that of Alfisols but it was about twice with that of Inceptisols. Soil clay, organic-C, and CEC affected the availability of soil K significantly (P > 0.95). Smectite contributed significantly (P > 0.95) to soil negative charge so that it held an important role in controlling soil K buffering capacity and maximum sorption. To increase the efficiency of K fertilizer, plant species that can produce organic acid exudated from roots in high quantity can be developed in smectitic soils. The use of Na, NH4, and Fe cations need also to be considered for K management in the soils as well