bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early acceleration of electrons and protons at the nonrelativistic quasiparallel shocks with different obliquity angles
Authors: Fang Jun , Lu Chun-Yan , Yan Jing-Wen , Yu Huan 
Published: December 2019

Abstract
The early acceleration of protons and electrons in the nonrelativistic collisionless shocks with three obliquities are investigated through 1D particle-in-cell simulations. In the simulations, the charged particles possessing a velocity of 0.2 c flow towards a reflecting boundary, and the shocks with a sonic Mach number of 13.4 and an Alfven Mach number of 16.5 in the downstream shock frame are generated. In these quasi-parallel shocks with the obliquity angles θ = 15°, 30° and 45°, some of the protons and the electrons can be injected into the acceleration processes, and their downstream spectra in the momentum space show a power law tail at a time of

1.89
×

10

5

ω

pe

−
1

, where ω
pe is the electron plasma frequency. Moreover, the charged particles reflected at the shock excite magnetic waves upstream of the shock. The shock drift acceleration is more prominent with a larger obliquity angle for the shocks, but the accelerated particles diffuse parallel to the shock propagation direction more easily to participate in the diffusive shock acceleration. In the early acceleration stage, more energetic protons and electrons appear in the downstream of the shock for θ = 15° compared with the other two obliquities. Moreover, in the upstream region, the spectrum of the accelerated electrons is the hardest for θ
nB = 45° among the three obliquities, whereas the proton spectra for θ
nB = 15° and 45° are similar as a result of the competition of the effectiveness of the shock drift acceleration and the diffusive shock acceleration.
Forecasts of cosmological constraints from HI intensity mapping with FAST, BINGO and SKA-I
Authors: Yohana Elimboto , Li Yi-Chao , Ma Yin-Zhe 
Published: December 2019

Abstract
We forecast the cosmological constraints of the neutral hydrogen (Hi) intensity mapping (IM) technique with radio telescopes by assuming 1-year of observational time. The current and future radio telescopes that we consider here are Five-hundred-meter Aperture Spherical radio Telescope (FAST), Baryon acoustic oscillations In Neutral Gas Observations (BINGO), and Square Kilometre Array phase I (SKA-I) single-dish experiments. We also forecast the combined constraints of the three radio telescopes with Planck. We find that the 1σ errors of (w
0, wa
) for BINGO, FAST and SKA-I with respect to the fiducial values are respectively, (0.9293, 3.5792), (0.4083, 1.5878) and (0.3158, 0.4622). This is equivalent to (56.04%, 55.64%) and (66.02%, 87.09%) improvements in constraining (w
0, wa
) for FAST and SKA-I respectively relative to BINGO. Simulations further show that SKA-I will put more stringent constraints than both FAST and BINGO when each of the experiments is combined with Planck measurements. The 1σ errors for (w
0, wa
), BINGO + Planck, FAST + Planck and SKA-I + Planck covariance matrices are respectively (0.0832, 0.3520), (0.0791, 0.3313) and (0.0678, 0.2679) implying there is an improvement in (w
0, wa
) constraints of (4.93%, 5.88%) for FAST + Planck relative to BINGO + Planck and an improvement of (18.51%, 23.89%) in constraining (w
0, wa
) for SKA-I + Planck relative to BINGO + Planck. We also compared the performance of Planck data plus each single-dish experiment relative to Planck alone, and find that the reduction in (w
0, wa
) 1σ errors for each experiment plus Planck, respectively, imply the (w
0, wa
) constraints improvement of (22.96%, 8.45%), (26.76%, 13.84%) and (37.22%, 30.33%) for BINGO + Planck, FAST + Planck and SKA-I + Planck relative to Planck alone. For the nine cosmological parameters in consideration, we find that there is a trade-off between SKA-I and FAST in constraining cosmological parameters, with each experiment being more superior in constraining a particular set of parameters.
Effect of plant spacing and type of P fertilizer on soil chemical properties and yield of maize on C type swampland South Kalimantan
Authors: Hadiayompamungkas B , Sulistyaningsih E , Utami S N H , Sosiawan H , Yusuf W A 
Published: December 2019

Abstract
Tidal swampland is one of the suboptimal lands need technology to increasethe yield of maize crops and soil quality. This study aimed to determine the effect of plant spacing and types of P fertilizer on the chemical properties of soil and maize yields, was carried out in type C tidal swampland, and arranged in factorial Randomized Completely Block Design (RCBD). The first factor was the plant spacing, consisting of legowo and zigzag planting system. The second factor was the application of P fertilizer types, namely 1000 kg ha−1 RPR, 250 kg ha−1 SP-36, 1000 kg ha−1 Guano Phosphate, and without P. The results showed that the treatments of P fertilizer type could increase the pH value and available P-nutrient content. Total N content at legowo plant spacing was higher than at zigzag spacing. The highest available K content in all treatments was at 60 days after planting. The zig zag spacing is significant in increasing maize yield by 30% compared to legowo spacing. The provision of RPR fertilizer increased maize yield significantly up to 20%. Therefore, the zigzag spacing and the provision of RPR fertilizer are recommended for maize cultivation in type C tidal swamplands.
Examination of mycorrhizal inoculum for improving maize tolerance to water stress in pot culture using zeolite and Andisol
Authors: Cahyani V R , Suryanti  , Setiawan D F , Suntoro  , Minardi S , Purwanto  , Rahayu  
Published: December 2019

Abstract
Arbuscular mycorrhiza (AM) is known as beneficial microsymbiont that capable to support plant growth by increasing nutrient uptake and improving plant tolerance toward diverse adverse conditions, such as water stress. The present study examined single and mixture mycorrhizal inoculum sources for improving maize tolerance to water stress in pot culture using zeolite and Andisol. Pot culture experiment was conducted using a Factorial Completely Randomized Design with three factors: A: Media type (A0: zeolite, A1: Andisol), B: AM Inoculum sources (B0: No inoculum, B1: Inoculum from Andisol, B2: Inoculum from eight soil types), C: Media moisture level (C1: 50%, C2: 70% of field capacity), with three replications. Each pot contained 300 g of media that sterilized using formaldehyde 2%, Maize were grown until maximal vegetative phase (77 days after planting). The results showed that maize growth on Andisol was higher than on zeolite, inoculum from Andisol were resulted in higher effect than a mixture of inoculum from eight soil types. On zeolite media (A0), inoculum B1 showed to improve plant tolerance to water stress at moisture level of C1 as indicated by plant dry weight (PDW) that 38.6% higher than B2 and 31.9% higher than B0, whereas on Andisol (A1), inoculum B1 resulted PDW 13.4% higher than B2 and 38.4% higher than B0. By AM inoculation in pot culture, maize growth on zeolite media at C1 was lower than at C2, whereas maize growth on Andisol at C1 was higher than at C2 conditions.
The application of various types of organic fertilizer and N, P, K combination on soil fertility, growth and yield of black rice
Authors: Yuniarti A , Machfud Y , Damayani M , Solihin E 
Published: December 2019

Abstract
Black Rice is a source of carbohydrates foodstuff that is a local natural wealth of Indonesia. Black Rice contains a lot of aleurone and endosperm which produce anthocyanin (functions as an antioxidant and antidote to free radicals) so that it has dark purple to black colour. Beside, this black rice also contains fewer sugar levels, more fibre and vitamin E. Other advantages of black rice. It can be used as natural medicine or natural functional food ingredients to treat the body from degenerative diseases such as cancer. Potential yield of black rice is around 4–5 t/ha. Fertilizer is one of the most important factors besides land, labour and capital. Balanced fertilisation has an important role to improve agricultural products. In this study, the extent of the role of various types of organic fertilizers (straw compost, cattle manure, chicken manure and sheep manure) and N, P, K fertilizers on soil quality, the growth and yield of black rice were investigated. The experimental design was carried out using a Randomized Block Design (RBD) consisting of 10 treatments with triplicates. The combination of treatment consisted of straw compost, cattle manure, chicken manure, sheep manure and 0-100% N, P, K. The results showed that the combination of various types of organic fertilizers and N, P, K fertilizers had an effect on plant height, number of tillers and black rice yield (dry grain weight). The application of chicken fertilizers which was added with N, P, K fertilizers for one recommendation gave grain weight of 55.40 g/tiller(7,09 ton/ha).
Understanding nutrient cycles as a key to sustainable forest plantation on tropical peatland in Indonesia
Authors: Sumawinata B , Djajakirana G , Suwardi  , Darmawan  
Published: December 2019

Abstract
Indonesia has around 14 million ha of peatlands which constitutes 7.4% of Indonesia’s land area and very potential to be developed to support national development, especially related to economic strengthening and in enhancing employment opportunities. An expand areas of peatlands in Indonesia are already being utilized for forest plantation of Acacia crassicarpa. To gain clues in understanding how the chemically poor ecosystems can support the plantation, nutrient cycles. The research was carried out in Acacia crassicarpa plantation areas in South Sumatra, Jambi, and Riau, respectively representing shallow, medium, and deep peat. Data collection includes chemical characteristics of the peat, decomposition rate of the litter, fluctuations of the water table, and growth and production of the Acacia crassicarpa. The results show that: a) Acacia crassicarpa growth and production on peatlands much more depend on the nutrient cycles than on the chemical characteristics of the original soil; b) Leaf-fall and the speed of decomposition respectively from the highest to the lowest, are Riau (deep peat), South Sumatra (shallow peat), and Jambi (medium peat); and c) The more leaf-fall produced and the faster the decomposition, the faster is the nutrient cycles and hence the highest is the production of plant biomass.
Relationships between sodium adsorption ratio and water productivity of tomato plants affected by NaCl applications at different growth stages
Authors: Nurlaeny N , Onggo T M , Arifin M , Herdiyantoro D , Setiawan A 
Published: December 2019

Abstract
Under greenhouse condition, tomato plants (Lycopersicon esculentum Mill. cv. Umagna) were planted in the polybags containing a mixture of soil and charcoal husk with a ratio of 2:1 (v:v) and factorial randomized block design was used in this experiment. Four levels of NaCl concentrations (0; 500; 1000 and 2000 mg kg−1, respectively) and three stages of plant growth i.e. vegetative stage (2-4 weeks after transplanting, WAT); generative stage (5-12 WAT) and vegetative until generative stages (2-12 WAT) with three replications. Seedlings of grafted beef tomato cv. Umagna with rootstock of Rampart cultivar at the age of 40 days after transplanting (DAT) were planted in the polybags. Plants were initially watered until the field capacity, then each NaCl concentrations of 200 mL polybag−1 were given at weekly intervals of 2-4 WAT, 300 mL polybag−1 at 5-8 WAT, and 400 mL polybag−1 at 9-12 WAT in combination with freshwater. Application of 2000 mg kg−1 NaCl significantly affected electrical conductivity (EC), water content and organic C, exchangeable Na+, Cl−, Ca2+, Mg2+ and sodium adsorption ratio (SAR) of soil mixed media. The negative correlations between SAR and water productivity (WP) of tomato (r = 0.37-0.89) are caused by NaCl applications at different growth stages
Application of fishpond sediment and water to increase the efficiency of phosphorus fertilization in land integrating agriculture and fishery
Authors: Hartono A , Anwar S , Hazra F , Prasetyo Y S , Putril S M L 
Published: December 2019

Abstract
The utilization of water from Mount Salak by farmers in addition to agriculture activities is also for fishponds that are widely spread among agricultural lands. The phosphate from fishpond sediment and water flowing to the river was supposed contributing to the enriched phosphate in the Jakarta Bay. The use of fishpond sediment and water in agricultural land was expected to decrease the load of phosphate to the river and increase the efficiency of phosphorus (P) fertilization by decreasing P sorption and increasing the release of P. The fishpond sediment with the rates of 0, 2.5%, 5.0%, 7.5% and 10% were combined with fishpond water or distilled water for watering. They were incubated for one month. The experiment was set up in Completely Randomized Design with three replicates. The results showed that fishpond sediment treatments decreased P bonding energies of P sorption and after P desorption and also the rate constant of P sorption. The best treatment in this experiment was the application of 10% of fishpond sediment watered by fishpond water for those determined parameters. The results suggested that application of fishpond sediment and water increased the efficiency of P fertilization in land integrating agriculture and fishery.
The exploration and utilization of functional microorganisms isolated from the tropical peatlands
Authors: Razie F , Saidy A R , Aidawati N 
Published: December 2019

Abstract
The utilization of peatlands may decline the ecological functions of peatlands as carbon sink, water storage and biodiversity source. Therefore, different scientific approaches are required to increase peat productivity and inhibit decline in the ecological functions of peatlands. This article is aimed to provide information on researches that have been carried out in tropical peats in the South Kalimantan Province. The exploration and the potential utilization of microbes was reviewed from several studies conducted in the Desa Landasan Ulin Utara (LaURa), Kota Banjarbaru, South Kalimantan Province. Peat research carried out in the Desa LaURa during the dry season after peat fires in 2015 showed that microbial SRBM (mixture of N fixing, solubilizing P and cellulolytic microorganisms) from the modified recharge bio-pore system was able to improve the growth of roots, stems, and leaves, nutrient uptake, and increase production and biomass of soybean. In another research in 2018, the use of commercial biofertilizers containing Azotobacter sp and Lactobacillus sp applied to the LaURa peats significantly increased the total N and pH of peats but did not accelerate the decomposition of peat materials. In subsequent study on the exploration of nitrogen fixing microorganisms from the LaURa peats (sapric peats) which amounted to 10375-10500 cells g−1, the total N-fixing microbial population was correlated positively to the pH and EC of peats, and correlated negatively to the contents of peat organic C. Combining the results, the total N2 fixing microbial (NFM) population was significantly affected by organic C and peat EC (total NFM population = -154.052 + 33.126 pH + 607.117 EC, R2 = 51.63%). Results obtained from these studies demonstrated that the functional microbes of peatlands are able to maintain ecological functions of the peats.
The opportunity of direct seeding to mitigate greenhouse gas emission from paddy rice field
Authors: Susilawati H L , Setyanto P , Kartikawati R , Sutriadi M T 
Published: December 2019

Abstract
Direct seeded rice (DSR) is one of the options to reduce CH4 emission because it uses less water during initial cropping but it sometimes has side effects such as increasing N2O emissions. The trade-off N2O and CH4 production in rice soils makes a real challenge to reduce the gas production. Nonetheless, few studies have observed the effect of DSR to GHG emission. This study aims to investigate the option of agriculture strategy used to reduce GHG emission without any yield loss through DSR. The study was conducted during rainy season at experimental field of Indonesian Agricultural Environment Research Institute (IAERI), Central Java, Indonesia. We compared the emission of CH4 and N2O, yield and yield components that affected by DSR and TPR practices. Total CH4 emission in TPR was from 352 kg ha−1 season−1 and, it ranged from 187 kg ha−1 season−1 in the DSR. The CH4 emissions were 47% lower for DSR than for TPR during a rice growing season. No significant differences were observed among crop establishments on N2O emissions. GWP were reduced by 46.4% under DSR compare to TPR. Crop-establishment did not influence grain yield, indicating the potential of DSR as alternative methods of establishing lowland rice with low GHG emissions.
Amelioration of Ultisols in West Java Indonesia with microparticle of steel slag
Authors: Devnita R , Hudaya R , Rosana M F , Sandrawati A , Hazarika H 
Published: December 2019

Abstract
Researchs used steel slag as ameliorant had proven that it can improve some soil chemical characteristics. The objective of this reasearch was to investigate the influence of microparticle of steel slag in improving some soil chemical characteristics of Ultisols. The treatments were arrange in Completely Randomized Designed (CRD) with ten treatments: control (without steel slag), steel slag in coarse particle (mesh), and 1-9% (in weight percentage) of microparticle of steel slag. The soil and the treatments were repeated three times and incubated for four months and then be analyzed the change of soil characteristics due to the amelioration after 1, 2, 3 and 4 months of incubation period. The result showed that amelioration of Ultisols with microparticle of steel slag improved several soil characteristics like increased pH, CEC, available P, and exchangeable basic cations like Ca, Mg, K and Na. The treatments did not decrease the P-fixation, however they increased available P.
Soil properties, growth and spears yield quality of five asparagus cultivars grown in tropical soil affected by NaCl applications
Authors: Nurlaeny N , Onggo T M , Arifin M , Setiawan A , Herdiyantoro D , Putra R M 
Published: December 2019

Abstract
To cultivate asparagus (Asparagus officinalis L.) in the tropics is constrained by high temperature and humidity that are potentially stimulating the development of soil-borne diseases. The research was aimed to observe the NaCl applications effects on properties of soil physicochemical, growth and spears yield quality of asparagus in the tropical medium elevation (730 meters above sea levels). The experiment used Split-Plot Design with three levels of NaCl concentrations (1, 2 and 3 g L−1, respectively) as the main plot and five asparagus cultivars (Atlas F1, de Paoli F1, Jing Green F1, San Knight F1 and Jaleo) as the subplot with three repetitions. No interaction was found between NaCl applications and asparagus cultivars at 12 weeks after planting. NaCl concentrations significantly increased soil electrical conductivity (2.14 -2.68dS m−1); levels of soil Na+ (1.77-2.34 cmol kg−1) and Cl- (25.02 -27.79 mg kg−1), but decreased the levels of Ca2+ and Mg2+, respectively by 1.23 and 1.44 cmol kg−1. Higher spears number and weight of asparagus were produced by cultivars of Jaleo (54.3% and 66.4%, respectively) and Atlas F1 (50.9% and 62.6%, respectively). The conclusion shows that Jaleo and Atlas F1 can adapt to the tropical medium environment due to their genetic traits.
Effect of arbuscular mycorrhizal fungi and different composition of growing medium on growth and production of potato seed cultivars Medians in Inceptisols Jatinangor
Authors: Nurbaity A , Hamdani J S , Rahayu R P 
Published: December 2019

Abstract
Arbuscular mycorrhiza fungi (AMF) has been known can increase the productivity of many crops including potatoes. Growing medium is also vital for the growth of potatoes, especially in medium-high land. Good combination of AMF and growing medium is expected to improve the physical and biological soil properties and increase growth and seed production. An experiment aimed to evaluate the effect of AMF and different media composition on growth and yield of potato seeds G2 cultivars Medians in medium land has carried out at Jatinangor, Indonesia. The experiment used randomized block design with treatments: growing medium (soil + compost (2: 1), soil + compost + cocopeat (2:1:1), and soil + compost + charcoal husk (2: 1: 1); and AMF (without and with AMF). Results showed that there was interaction effect between AMF and composition of growing medium on percentage of stolon formed into tuber and weight of potato tubers per plant. Treatment of medium soil + compost + cocopeat (2:1:1) and the addition of AMF increased the percentage stolon formed into tubers as high as 84%, and potato tuber weight to 328 g plant. Growing medium consisted of soil + compost + cocopeat (2:1:1) increased plant height, plant dry weight, shoot root ratio, and number of potato tubers. This finding showed that AMF application combined with proper growing medium increased the the production of potato seeds.
A critical contribution on understanding the mechanism and implication of peat irreversible drying
Authors: Wardani I K , Suwardi  , Darmawan  , Sumawinata B 
Published: December 2019

Abstract
The term irreversible drying is known as a condition when peat soil material is dry and cannot be re-wet after an intensive drying. This condition is a result of peat soil hydrophobicity that occurs when a contact angle between peat soil particles and water is greater than 90° and is always understood to be associated with water content. However, in South Kalimantan, there was a phenomenon of irreversible drying but soil water content was still around field capacity and there was a visible coating substance on the particle surface. The purposes of this study were 1) to clarify the cause of irreversible drying in this location and 2) to show a possible effect of rock phosphate addition on the hydrophobicity’s disappearance. A hydrophobic peat soil sample was taken from the location that is cultivated for oil palm. Field observation was conducted on the peat soil that had been amended by rock phosphate. The peat soil hydrophobicity was identified by the Water Drop Penetration Time method and the surface coating substance was observed using SEM-EDS. The WDPT result shows that the peat soil was in hydrophobic condition, but the water content was still around field capacity. The results from SEM-EDS indicate that the coating substance was found as sulfate salts. The rock phosphate that had been added in the field shows a positive effect on the disappearance of the peat irreversible drying. However, the mechanism of soil properties change due to rock phosphate cannot be confirmed yet and need further investigation.
On the development of measurement procedure of particle density for peat material
Authors: Faoziah N , Iskandar  , Djajakirana G , Darmawan  , Sumawinata B 
Published: December 2019

Abstract
Value of particle density of tropical peat materials commonly is considered to be 1.4 g/cm3. This value was based on the measurementusing a pycnometer. However, this value would not be correct for tropical peat that has coarse material that could plug the narrow opening of the pycnometer. Hence, the use of pycnometer to measure particle density of tropical peat material has a possibility to get false values because the coarse material will inhibit the measurement process. Therefore, we are proposing the use of a three phases meter to measure particle density of tropical peat materials. The particle density value obtained by using three phases meter was around 1.8 g/cm3. The value was higher than pycnometer result due to the three phases meter could ensure the measurement of all size tropical peat material.