Slow- Release Fertilizer Formulation Using Acrylic and Chitosan Coating

The low-efficiency problem in fertilizer application can be overcome by controlling fertilizer solubility, i.e. by rendering the fertilizer to be released gradually; such material is also known as slow-release fertilizer (SRF). This research was aimed to formulate SRF by coating technique using acrylic and chitosan as the coating material, and to evaluate fertilizer resistance to too fast disintegration, and rate of nutrient release method. The results demonstrated that fertilizer formulation containing  N, P, K, Fe, Cu, and Zn with granulation technique yielded 74% of granules with 2-5 mm in diameter. The SRFs (formulated fertilizer with acrylic or chitosan coating) were more resistant to water pounding than non-SRF. Furthermore, shaking test with distilled water or 2% citric acid, or by percolation test with distilled water showed that the SRFs had lower nutrient solubility than the non-SRFs. The results of shaking test also specifically indicated that coating with acrylic made the fertilizer more resistant to the citric acid,suggesting that this coating material would be more suitable in acidic soils. The SRFs formulated with the addition of chitosan during blending of micronutrients prior to mixing with macronutrients, granulation, and final coating exhibited lower nutrient solubility than the SRFs without the pre-coating chitosan addition. [How to Cite: Lili H, G Djajakirana, Darmawan, and CP Munoz. 2015. Slow- Release Fertilizer Formulation Using Acrylic and Chitosan Coating. J Trop Soils 19: 37-45. Doi: 10.5400/jts.2015.20.1.37][Permalink/DOI: www.dx.doi.org/10.5400/jts.2015.20.1.37

The Diversity and Abundance of Springtail (Collembola) on Forests and Smallholder in Jambi

Harapan forests is the first restoration forest in Indonesia, includes several different ecosystems. Different ecosystems have different characteristic to affect the diversity and abundance of Collembola. In the ecosystem, Collembola have an important role in biocontrol, decomposition, soil nutrient distribution, stimulation of soil microbial activity and as an alternative feed for predators. This study was aimed to investigate the diversity and abundance of Collembola in four ecosystems at Harapan forest, i.e. secondary forest, rubber forest, rubber smallholder and oil palm smallholder. To achieve the objective, soil samples were taken at 48 observation points in the four ecosystem. The soil samples were then extracted by Kempson Extractor. The diversity and abundance of Collembola in four ecosystems were categorized as medium to high. The total of individual and population of Collembola in the secondary and rubber forest ecosystems were likely to be higher than in the rubber and oil palm smallholders. This study had also identified four orders, 14 families and 31 genera of Collembola, where Isotomiella and Proisotoma dominated the genus of Collembola in the four ecosystems. [How to Cite: Widrializa, R Widyastuti, DA Santosa and G Djajakirana. 2015. The Diversity and Abundance of Springtail (Collembola) on Forests and Smallholder in Jambi. J Trop Soils 20: 173-180. Doi: 10.5400/jts.2015.20.3.173][Permalink/DOI: www.dx.doi.org/10.5400/jts.2015.20.3.173]&nbsp

Keselarasan Penyediaan Nitrogen dari Pupuk Hijau dan Urea dengan Pertumbuhan Jagung pada Inceptisol Darmaga

Increasing N use efficiency and decreasing N pollution can be achieved by synchronization between supplying pattern of N and crop N demand. Leaching-incubation experiment had been carried out for evaluating supplying pattern of N from 14 treatments of green manure (Flemingia and Gliricidia), urea and their combinations. Only 5 treatments of the split application of Gliricidia, urea and their combinations, and single application of combination of urea and Gliricidia synchronize with corn N uptake model. These five fertilization treatments were further examined in the greenhouse and in the field experiment. The synchronization between supplying pattern of N and corn growth in treatment without leaching was resulted by application of urea at planting followed by Gliricidia at 3 weeks after planting (WAP) and urea at planting and 3 WAP, whereas in treatment with leaching were resulted by split application of Gliricidia at planting and 3 WAP, urea at planting followed by Gliricidia at 3 WAP, and single application of urea and Gliricidia at planting. Urea applied at planting followed by Gliricidia at 3 WAP resulted in the high production of seed dry-weigh with low N inorganic leaching

Changes of Soil Organic Matter Fraction on Ultisols Jasinga by Soil Tillage and Organic Matter Practices

In situ organic matters, such as Mucuna sp., Flemingia sp., and plant residues differ in quality (in terms of lignin, cellulose and nutrients contents). Such difference determines soil organic matter content especially labile fraction that could effect on soil properties. The aims of this research were to study: 1) the effects of various sources and quality of organic matters on soil organic fraction, and 2) the relationships between the changes of particulate organic matter and C-microbes (POM and Cmic) and soil quality indicators. The experiments were conducted in greenhouse of the Center for Soil and Agroclimate Research and Development, Bogor, from January to May 2003. The factorial completely randomized design was used with three replications. The first factor was the method of organic matters application: 1) mulch on soil surface and 2) incorporated with soils. The second factor was the sources of organic matters (dosage in equvalent with 2% organic C), i.e: 1) Mucuna sp., 2) Flemingia sp., 3)maize residue, 4) mixture of Mucuna sp., and Flemingia sp., 5) mixture of Flemingia sp. and maize residue, 6) mixture of Mucuna sp. and maize residue, and 7) mixture of Mucuna sp., Flemingia sp., and maize residue. The results showed that on organic matter application with incorporated method, C/N ratio and lignin content of organic matter have positive correlation with organic C, Cmic and Cmic/Corg, but have negative correlation with POMp. The changes of soil qualities caused by short term organic matter application could be seen from the changes of labile fraction of organic matter. When organic matter was incorporated, POMtand POMt/Corg have positive correlation with bulk density, but have negative correlation with RPT, PDC, available K, and total- N. When organic matter was spreaded on the soil surface, Cmic has positive correlation with available P. The changes on labile fraction (Cmic and POMt) was easy to be detected in short period, thus the changes of physical characteristics and the availability of macro nutrients is easy to be predicted

Keselarasan Penyediaan Nitrogen dari Pupuk Hijau dan Urea dengan Pertumbuhan Jagung pada Inceptisol Darmaga

Increasing N use efficiency and decreasing N pollution can be achieved by synchronization between supplying pattern of N and crop N demand. Leaching-incubation experiment had been carried out for evaluating supplying pattern of N from 14 treatments of green manure (Flemingia and Gliricidia), urea and their combinations. Only 5 treatments of the split application of Gliricidia, urea and their combinations, and single application of combination of  urea and Gliricidia synchronize with corn N uptake model. These five fertilization treatments were further examined in the greenhouse and in the field experiment. The synchronization between supplying pattern of N and corn growth in treatment without leaching was resulted by application of urea at planting followed by Gliricidia at 3 weeks after planting (WAP) and urea at planting and 3 WAP, whereas in treatment with leaching were resulted by split application of Gliricidia at planting and 3 WAP, urea at planting followed by Gliricidia at 3 WAP, and single application of urea and Gliricidia at planting. Urea applied at planting followed by Gliricidia at 3 WAP resulted in the high production of seed dry-weigh  with low N inorganic leaching.   Key words: Synchronization, nitrogen, green manure, urea, cor

Fine root chemistry and decomposition in model communities of north-temperate tree species show little response to elevated atmospheric CO 2 and varying soil resource availability

Rising atmospheric [CO 2 ] has the potential to alter soil carbon (C) cycling by increasing the content of recalcitrant constituents in plant litter, thereby decreasing rates of decomposition. Because fine root turnover constitutes a large fraction of annual NPP, changes in fine root decomposition are especially important. These responses will likely be affected by soil resource availability and the life history characteristics of the dominant tree species. We evaluated the effects of elevated atmospheric [CO 2 ] and soil resource availability on the production and chemistry, mycorrhizal colonization, and decomposition of fine roots in an early- and late-successional tree species that are economically and ecologically important in north temperate forests. Open-top chambers were used to expose young trembling aspen ( Populus tremuloides ) and sugar maple ( Acer saccharum ) trees to ambient (36 Pa) and elevated (56 Pa) atmospheric CO 2 . Soil resource availability was composed of two treatments that bracketed the range found in the Upper Lake States, USA. After 2.5 years of growth, sugar maple had greater fine root standing crop due to relatively greater allocation to fine roots (30% of total root biomass) relative to aspen (7% total root biomass). Relative to the low soil resources treatment, aspen fine root biomass increased 76% with increased soil resource availability, but only under elevated [CO 2 ]. Sugar maple fine root biomass increased 26% with increased soil resource availability (relative to the low soil resources treatment), and showed little response to elevated [CO 2 ]. Concentrations of N and soluble phenolics, and C/N ratio in roots were similar for the two species, but aspen had slightly higher lignin and lower condensed tannins contents compared to sugar maple. As predicted by source-sink models of carbon allocation, pooled constituents (C/N ratio, soluble phenolics) increased in response to increased relative carbon availability (elevated [CO 2 ]/low soil resource availability), however, biosynthetically distinct compounds (lignin, starch, condensed tannins) did not always respond as predicted. We found that mycorrhizal colonization of fine roots was not strongly affected by atmospheric [CO 2 ] or soil resource availability, as indicated by root ergosterol contents. Overall, absolute changes in root chemical composition in response to increases in C and soil resource availability were small and had no effect on soil fungal biomass or specific rates of fine root decomposition. We conclude that root contributions to soil carbon cycling will mainly be influenced by fine root production and turnover responses to rising atmospheric [CO 2 ], rather than changes in substrate chemistry.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47710/1/442_2005_Article_191.pd