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Organic fertilizers have recently been gaining popularity; however, their governance is not completely assessed in developing countries. This study investigated the nutrient composition of so-called organic fertilizers in Vietnam's markets and issues related to their production, and evaluated their potential to contaminate the groundwater. We analyzed the physicochemical properties of 12 domestic and four imported products of the fertilizers, and conducted a cultivation experiment in sandy soil with the fertilizer applied at a rate of 200 mg N kg(-1) soil using an automatic watering apparatus in a greenhouse. We further studied the production of an "organic fertilizer" from coffee by-products. The nutrient content greatly varied among domestic products, whereas they were quite similar among imported products. The product packaging of the collected samples lacked information regarding raw materials. Two thirds of the domestic products contained over 30% of the total N in the inorganic form, implying that the N content dramatically increased in the fertilizers rather than in their supposed raw materials. The stages involved in the production were composting, the addition of extra soil as a bulking agent, and the mixing-in of chemical substances to increase the nutrient content before packing. The remarkably high ratio of inorganic N to total N was attributed to excessive N leaching from soil by the application of domestic fertilizers. These results suggested the need for quality criteria guidelines for organic fertilizers in Vietnam that underline not only nutrient levels, but also the control of raw materials and production process of compost, because they are closely related to nutrient uptake and the leaching loss of nutrients.

DOI： 10.3390/su10072437

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS  

Background and Aims The source of nitrogen plays an important role in salt tolerance of plants. In this study, the effects of NaCl on net uptake, accumulation and transport of ions were investigated in Nerium oleander with ammonium or nitrate as the nitrogen source in order to analyse differences in uptake and cycling of ions within plants.Methods Plants were grown in a greenhouse in hydroponics under different salt treatments (control vs. 100 mM NaCl) with ammonium or nitrate as the nitrogen source, and changes in ion concentration in plants, xylem sap exuded from roots and stems, and phloem sap were determined.Key Results Plant weight, leaf area and photosynthetic rate showed a higher salt tolerance of nitrate-fed plants compared with that of ammonium-fed plants. The total amount of Na(+) transported in the xylem in roots, accumulated in the shoot and retranslocated in the phloem of ammonium-fed plants under salt treatment was 1.8, 1.9 and 2.7 times more, respectively, than that of nitrate-treated plants. However, the amount of Na(+) accumulated in roots in nitrate-fed plants was about 1.5 times higher than that in ammonium-fed plants. Similarly, Cl(-) transport via the xylem to the shoot and its retranslocation via the phloem (Cl(-) cycling) were far greater with ammonium treatment than with nitrate treatment under conditions of salinity. The uptake and accumulation of K(+) in shoots decreased more due to salinity in ammonium-fed plants compared with nitrate-fed plants. In contrast, K(+) cycling in shoots increased due to salinity, with higher rates in the ammonium-treated plants.Conclusions The faster growth of nitrate-fed plants under conditions of salinity was associated with a lower transport and accumulation of Na(+) and Cl(-) in the shoot, whereas in ammonium-fed plants accumulation and cycling of Na(+) and Cl(-) in shoots probably caused harmful effects and reduced growth of plants.

DOI： 10.1093/aob/mcn156

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The effects of different levels of NaCl (0, 50, 100 and 150 mM) on growth, water relations, ions accumulation and nitrogen assimilation in two varieties of Dactylis glomerata, i.e., Hispanica from a semi-arid area and Frontier from a temperate climate, were studied in a greenhouse in hydroponic culture. Salinity induced a significant decrease in the growth of both varieties; however, their responses to NaCl stress were different. Based on weight and photosynthesis, Hispanica was found initially to be more resistant to salinity than Frontier. However, over a longer period of salinity treatments, Frontier displayed higher salt tolerance, especially at 50 mM NaCl concentration. The initial resistance to salinity of Hispanica, compared to Frontier, appeared to be related with a greater decrease in transpiration and water potential due to salinity, while there was no change in relative water content, suggesting better osmotic adjustment. In contrast, Frontier demonstrated more exclusion of Na+ and Cl- from the xylem stream and a higher K+/Na + ratio, leading to a less harmful effect of salinity in the shoot, manifesting itself in better growth of this variety over the longer term. The results support the hypothesis that growth response to salinity has two phases. The first phase of growth reduction is mostly due to water (osmotic) stress, with the drought adapted variety, Hispanica, exhibiting higher tolerance. In the second phase, when toxic effects of accumulated Na+ and Cl - in tissues caused growth retardation, Frontier proved to have the higher resistance to salinity. © 2008 Asian Network for Scientific Information.

DOI： 10.3923/ijb.2008.283.289

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Language：Japanese   Publisher：The Japanese Society of Revegetation Technology  

In order to effective utilize the sewage sludge as the fertilizer; we clarified the characteristics of the incineration ashes of sewage sludge. Concentration of cadmium and lead contained in the incineration ashes material decreased dramatically with burnt up at temperature more than 700°C, as result of volatilization. Zinc and cupper contained in ashes of sewage sludge did not decreased after burnt up at temperature of 950°C but were transformed into in-soluble form by incineration treatments. Sequential fraction of heavy metals as affected by application of the incineration ashes material to soil was analyzed. A greenhouse experiment was conducted to compare the effect of application on the growth of grasses species. Application effect of phosphorus contained in the ashes was larger than that contained in the dried sludge cakes.

DOI： 10.7211/jjsrt.33.128

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This study investigates by a direct questionnaire suvery the response of 508 tea farmers to bamboo as an alternative crop in the Eastern Black Sea region of Turkey. It is found that 77.6 per cent of the participants were not satisfied with tea farming and 76.8 per cent of the participants emphasised that they would like to consider growing an alternative crop. However, 49.6 per cent were not aware of the potential of bamboo. After providing some information about bamboo, only 18.3 per cent farmers were willing to try growing bamboo as an alternative crop. © KFRI 2006.

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Language：Japanese   Publisher：The Japanese Society of Revegetation Technology  

DOI： 10.7211/jjsrt.31.198

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DOI： 10.7211/jjsrt.31.167

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DOI： 10.7211/jjsrt.31.194

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DOI： 10.7211/jjsrt.30.235

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DOI： 10.7211/jjsrt.30.336

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The growth of soil improving species planted with grasses was decreased on the weathered granite soil due to inhibiting the phosphorus uptake. The effects of bamboo charcoal addition and phosphorus fertilizer on the growth of soil improving species were investigated under nutrients poor condition. It was recognized that the growth and nodulation of soil improver declined considerably with addition of bamboo charcoal, but increased with phosphorus fertilizer. On the other hand, mix-planted soil improver grew lower when bamboo charcoal and phosphorus were simultaneously applied. These suggest that adsorption of soil phosphorous by bamboo charcoal causes phosphorous deficiency and hide the effect for soil improver when they were mix-planted.

DOI： 10.7211/jjsrt.30.33

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Language：Japanese   Publisher：The Japanese Society of Revegetation Technology  

The effective utilization of the bamboo which was unused organic resources was considered, and heavy metal adsorption ability of the bamboo carbide was compared with it of wooden charcoal and activated carbon. As the result, pH of the bamboo charcoal showed the basicity regardless of the carbonization temperature, and it became clear to have the adsorption ability which bamboo charcoal which mainly contains the potassium is excellent. Then, the practically experiment was carried out on heavy metal adsorption ability in the street dust in utilizing the bamboo charcoal under the planting tree in the roadside as a mulching material. It became clear to be effective in the control of the heavy metal pollution by laying the bamboo charcoal under the planting.

DOI： 10.7211/jjsrt.30.39

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The effect of mixed planting with grasses on growth of soil improving species under the nutrients poor condition was investigated. The amount of nodules and aboveground biomasses of the improving species decreased with increasing the number of mix planted grasses and increased with phosphorus fertilizer. The results suggest that a lack of phosphorus in soil was due to mix planting with grasses and it cause the decline of nodulation and low growth of soil improving species.

DOI： 10.7211/jjsrt.29.33

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Language：Japanese   Publishing type：Research paper (scientific journal)  

The regenerative capacity of bamboo is very high and bamboo has been receiving attention from the viewpoint of effective utilization of resources. Recently, bamboo charcoal has been produced everywhere in Japan, in what has become a bamboo charcoal boom. In this study, the fundamental properties of bamboo charcoal, including humidity control capacity after different carbonizing conditions, were compared with those of wood charcoal. The obtained results are as follows; 1) Ash content is about 4 times greater in bamboo charcoal than in wood charcoal. 2) There is a good correlation, regardless of the wood species, between carbonization temperature and electrical resistance, and it is possible to estimate the carbonization temperature in a traditional charcoal kiln. 3) The pH of wood charcoal changes from acid to alkaline with rising carbonization temperature, but the pH of bamboo charcoal maintained its alkalinity regardless of the carbonization temperature. The quantity of ash and potassium content in bamboo charcoal seems to be related to the pH. 4) The humidity control capacity in the high humidity region of bamboo charcoal is better than that of wood charcoal.

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Language：Japanese   Publisher：The Japanese Society of Revegetation Technology  

DOI： 10.7211/jjsrt.29.231

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DOI： 10.7211/jjsrt.29.297

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Changes in biological nitrogen fixation activity (C2H2-reduction activity; ARA) and organic composition of leaf litter with decomposition were measured with the wire-netting cage method at evergreen broad-leaved secondary forest. Ilex chinensis and Cinnamomum camphora were chosen as the investigated species. The result indicated that the change of weight loss and ARA of leaf litter with decomposition were different in species. ARA of the leaf litter was not closely related to C/N ratio. Higher ARA was recorded in I. chinensis at early stage of decomposition in which water soluble fraction and benzene-ethanol soluble fraction were mostly remained. Compared with I. chinensis, ARA of C. camphora leaf litter was smaller but slightly increased with decomposition. We estimate that the amount of nitrogen fixed in leaf litter of both species was 0.521 kg·ha-1·yr-1, and most of them might be fixed on leaf litter of I. chinensis in this site.

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Language：Japanese   Publisher：The Japanese Society of Revegetation Technology  

DOI： 10.7211/jjsrt.28.306

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DOI： 10.7211/jjsrt.28.139

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Topsoil samples derived from a granite parent material were taken from a 9 years old burned forest and incubated at different moisture contents. The soil is bare and its ash bed was already depleted by runoff. A close relationship was found between the factors of soil water content, nitrogen (N) mineralization rate and CO_2 release resulting from the activities of soil microorganisms. The samples incubated at relatively high initial moisture content had a high mineralization rate. After the increase of soil moisture content to 70% of its MWHC (Maximum Water Holding Capacity), the rate of increase was higher in samples with low initial moisture content. In other terms, the dryer the soil samples were, the higher was their N mineralization rate after being moistened at the same final level. The peak recorded in the rate of nitrogen mineralization during the first 3 days after the increase of soil moisture content was followed by a gradual decrease. The increase of soil moisture content had more effect on N mineralization in the case it happened 7 days after the beginning of the incubation than 14 days later. As far as carbon dioxide was concerned, the drier the soil samples were, the higher were their CO_2 release after a sudden accretion of their initial water content adjusted to a final 70% MWHC. Instead of decreasing in the same way N mineralization did, the amount of CO_2 released from soil augmented, suggesting a regain in soil microbial activity which may have led to N immobilization.

DOI： 10.7211/jjsrt.26.280

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DOI： 10.7211/jjsrt.25.627

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The effects of ammonium and nitrate as the nitrogen source on concentration of NO_3^--N, NH_4^+-N, amino acids, protein, carbohydrates and site of nitrogen assimilation were studied in Nerium oleander L. under NaCl salinity. Plants were grown in semi automatic sand culture system in the green house. We distinguished different distribution of carbohydrates and amino acids by nitrogen source under salinity. Ammonium and amino acids concentration increased in roots of ammonium treatment by salinity whereas protein concentration decreased. The level of carbohydrates decreased in leaves and increased in roots by salinity in ammonium treatment. No significant change in level of amino acids and carbohydrates was observed in nitrate treatment due to salt stress. Based on concentration of NO_3^--N, NH_4^+-N in xylem sap, glutamine synthetase and nitrate reductase activity, nitrogen assimilation was mostly done in roots and leaves in ammonium and nitrate treatments respectively. The lower tolerance of ammonium fed plants than nitrate is mostly related to higher diversion of carbohydrates from structure production to roots for ammonium detoxification and osmotic adjustment in ammonium fed plants under salinity.

DOI： 10.7211/jjsrt.24.22

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Other Link： https://jlc.jst.go.jp/DN/JALC/00056010862?from=CiNii

Language：English   Publisher：The Japanese Society of Revegetation Technology  

The effect of ammonium and nitrate as nitrogen source on growth, water relation and ions concentration were studied in Nerium oleander L. under NaCl salinity. Plants were grown in semi automatic sand culture system in the greenhouse. It was revealed that salt tolerance of Nerium plants was significantly increased when supplemented with nitrate as sole nitrogen source than that of ammonium. Total dry weight, leaf area and number were reduced more drastically in ammonium than nitrate treated plants. A higher level of Na^+ and Cl^- was observed in leaves and branches in ammonium treated plants under salinity whereas these ions were accumulated in roots in nitrate. Additionally, salinity induced more decrease in K^+/Na^+ selectivity and K^+ concentration in leaves and branches of ammonium fed plants. Osmotic adjustment was done faster in nitrate treatment and leaves succulence ratio as weight per leaf area did not decrease due to salinity. Decrease in photosynthetic rate was almost similar in both nitrogen treatments under salinity. Our result indicates that nitrate fed plant reduced the level of stress by reducing concentration of Na^+ and Cl^- in leaves. In contrast, sequestration and counterbalance of high concentration of Na^+ and Cl^- in leaves of ammonium fed plants is highly energy required process and diverted the energy from plant production.

DOI： 10.7211/jjsrt.23.237

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Language：English   Publisher：The Japanese Society of Revegetation Technology  

The effect of four levels of salinity (0,50,100 and 150mM NaCl) on growth, Na^+ accumulation and nitrogen assimilation in three grasses "Lolium multiflorum, Lolium perenne and Festuca arundinacea" was studied. We report a differential response of Lolium and Festuca species to NaCl salinity where Festuca was found to be more resistant than Lolium species. NaCl induced more reduction in dry weight and photosynthetic rate in Lolium species than F. arundinacea. The Na^+ and Cl^- level in plants increased with the increase in salinity. Shoots of Lolium species accumulated high level of Na^+ and Cl^-. However, high concentration of Na^+ was not observed in shoots of F. arundinacea. Also, the decrease in K^+/Na^+ ratios were more severe in Lolium species than F. arundinacea. The total-N and NO_3^--N concentration decreased drastically in Lolium species due to salinity. However, such an effect was observed only at 150mM NaCl in F. arundinacea. The NH_4^+-N concentration was increased in all species under salinity. The results indicate that Na^+ exclusion probably rescued the Festuca plant from severe stress while in the Lolium species such a resistance mechanism was not established. Our results suggested that there exists potential to utilize Festuca in pasture land management in saline areas.

DOI： 10.7211/jjsrt.23.161

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Language：English   Publisher：Japanese Society of Soil Science and Plant Nutrition  

DOI： 10.20710/dohikouen.44.0_218_2

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The vertical movement of soil water and major ions in topsoil of secondary forests were investgated by using D2O and 15NH4Cl as tracers of water and nutrient elements, respectively. Undisturbed soil columns were collected with cylinders made of vinyl chloride pipe in different stands. The rain solution was dropped uniformly on the column by using the artificial rainfall equipment in twice. The artificial rainfall was continued for 10 h at constant intensity of 4 mm/h. At the second time of rainfall, the tracer solution labeled with D2O and 15NH4Cl applied on the column. The concentrations of Cl-, Mg2+, and Ca2+ increased with the D2O discharge and only small quantity of 15NH4+-N moved to the lower horizon on the Brown forest soil columns. The downward velocity of the D2O-tagged water agreed approximately with that of Mg2+ and Ca2+. But large amount of the 15NH4+-N was discharged with the D20-tagged water on the column that was collected in the forest floor removal stand. In spit of heavy water discharging, the concentration of Cl- in discharged soil solution did not increase obviously in Andosol column because of the effect of anion absorption into the soil.

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Publisher：THE JAPANESE FORESTRY SOCIETY  

DOI： 10.11519/jjfs1953.75.3_225

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Language：Japanese   Publisher：日本緑化工学会  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：日本緑化工学会  

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Language：English   Publisher：Japanese Forestry Society  

The recovery of aboveground biomass and nutrients in sprout shoots was studied for two years after clear cutting in the Sanbe Forest of Shimane University. Although the number of sprout shoots decreased in the second year, the mean diameter and length of shoots in the second year increased to about twice of those of the first year. The weight of the nonphotosynthetic organs and leaves in the second year also increased to l.5〜1.8,and 1.1〜1.7 times, respectively, of those of the first year. The increases in weights tended to differ depending on the species. The nutrient concentrations of nitrogen, phosphorus, and potassium in both leaves and shoots were greater in the first year than in the second. Calcium and magnesium concentrations in the leaves and shoots increased from the first to the second years. The amounts of nutrient elements that were accumulated in the sprout shoots on four experimental plots were 18〜33 for nitrogen 1.l〜2.1 for phosphorus, 12〜26 for potassium, 3.2〜6.3 for magnesium, and 14〜25 kg/ha for calcium. These amounts corresponded to about lO% of the nutrient accumulation in a deciduous broadleaved forest before clear cutting.

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Other Link： http://agriknowledge.affrc.go.jp/RN/2010411986

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Language：Japanese   Publisher：THE JAPANESE FORESTRY SOCIETY  

DOI： 10.11519/jfsc.118.0.707.0

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DOI： 10.11519/jfsc.117.0.322.0

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Authorship：Last author,　Corresponding author   Language：English   Publisher：Japanese Society of Soil Science and Plant Nutrition  

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Type：Seminar, workshop

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Type：Certification seminar

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Author：Myself 

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