Corg Content Research Articles

Petroleum source rocks of the Silurian deposits on the Chernov swell (Timan‑Pechora basin)

Silurian source rocks are among the least studied in the Timan-Pechora basin. This is mainly due to their occurrence at great depths (3.0–4.5 km) and the limited penetration of this stratigraphic interval by wells. Another source of information is the outcrops of the Silurian, which are known in the eastern and northeastern parts of the Timan-Pechora basin. The studied section of the Silurian deposits is exposed on the Padimeityvis River, located on the Chernov swell in the northeastern part of the basin. This article is devoted to the study of Silurian source rocks based on the results of lithological, coal petrographic studies and geochemistry of organic matter. The studied section is composed of carbonate and clay-carbonate deposits formed in shallow-water shelf conditions. Most of the section, composed of microcrystalline and microcrystalline with bioclasts limestones, is characterized by low concentrations of organic matter (Corg is generally less than 0.3 %). Elevated Corg contents (up to 1.16 %) are characteristic of clay-carbonate rock varieties, which make up about 20 % of the section. Sediments with increased concentrations of organic matter were formed in isolated and deepened areas of the bottom of the shallow-water basin as a whole. Assessment of the catagenetic transformation based on Rock-Eval pyrolysis data, coal petrographic studies, and conodont color indices showed that organic matter reached the conditions of the middle-end of the main oil generation zone (gradation MC2‑MC3). The obtained geochemical characteristics (Corg, S2, HI), taking into account a certain level of organic matter maturity, indicate that the Silurian source rocks had an average hydrocarbon potential.

A highly diverse living benthic foraminiferal assemblage in the oxygen deficient zone of the southeastern Arabian Sea

The exchange of seawater between the Arabian Sea and the Bay of Bengal, creates a strong seasonality in the southeastern Arabian Sea, including the oxygen deficient zone (ODZ) at intermediate depth. Here, we assess the effect of this strong seasonality on benthic foraminifera living within ODZ of the southeastern Arabian Sea. We delineate five benthic foraminiferal assemblages characterizing different dissolved oxygen levels. A distinct depth zonation in living benthic foraminiferal species is observed within the southeastern Arabian Sea ODZ. Cassidulina laevigata, Cassidulina carinata and Eponides umbonatus dominate shallow depth, hypersaline, oxygen rich, warm water environment with low organic matter (%Corg) availability. The upper slope intense suboxic zone with moderate %Corg abundance, is characterized by Bolivina seminuda, Hopkinsinella glabra and Eubuliminella exilis. A similar suboxic zone, but with high %Corg concentration on the middle slope, is represented by Rotaliatinopsis semiinvoluta, Hopkinsinella glabra and Epistominella exigua. The lower slope (~ 1000–1500 m) assemblage is dominated by rectilinear species, namely Bulimina arabiensis, Bulimina elegans and Bolivina earlandi and represents a comparatively higher dissolved oxygen environment (1–2 mL/L) with high organic carbon at deeper water depths. Bolivina earlandi, Bulimina aculeata and Globocassidulina subglobosa dominate deep-water benthic foraminifera population, where bottom water is oxygen rich (> 2 mL/L) with plenty of organic matter and the lowest bottom water temperature and salinity. The living benthic foraminiferal abundance as well as diversity increases manifold within the southeastern Arabian Sea ODZ and may be attributed to the strong seasonality. The depth habitat of the dominant living benthic foraminifera has also been reported.

Identifikasi dan Toleransi Kemasaman Mesofauna Indigenous Tanaman Lada untuk Pertumbuhan Bibit Lada (Piper nigrum L.)

Rendahnya kesuburan tanah di Bangka menjadi permasalahan utama dalam pola budidaya lada secara menetap. Pemanfaatan mikro dan mesofauna berperan dalam dekomposisi bahan organik, memperbaiki struktur tanah, daur ulang hara dan mengurangi kehilangan hara. Penelitian ini bertujuan mengidentifikasi potensi mesofauna isolasi dibawah tegakan lada dalam memacu pertumbuhan bibit lada. Tahapan awal kegiatan yaitu identifikasi dan analisis kelimpahan mesofauna contoh tanah yang diambil dari Bangka induk dan Bangka Selatan sebagai sentra produksi tanaman lada. Uji potensi toleransi kemasaman mesofauna dengan menumbuhkan bibit lada secara pot sistem pada tingkat kemasaman media yang berbeda. Hasil penelitian menunjukkan mesofauna yang diperoleh jenis Acari dan Collembola dari famili Neanuridae, Isotomidae, Hypogastruridae, Entomobrydae, Sminthuridae, Mesotigmata, Cyphoderidae. Berdasarkan toleransi terhadap pH mesofauna yang teridentifikasi adalah golongan indifferen yang hidup pada kondisi asam dan basa. Mesofauna mampu memperbaiki kesuburan tanah ditunjukkan dengan meningkatnya kandungan C-organik, hara makro P, K, pH tanah dan aerasi tanah. Perbaikan kimia tanah dan porositas tanah akan memacu perkembangan akar dan pertumbuhan bibit lada.

Acid phosphomonoesterase and β-glucosidase activities in volcanic soils under permanent fertilized pastures: distribution profile and microbial effort toward P acquisition

ABSTRACT This work focused on the amounts and distribution of organic C (OC), organic phosphorus (Po), and acid phosphomonoesterase (AcP) and β-glucosidase (βG) activities in volcanic soils, as well as on the effect of inorganic P (Pi) on potential P-acquiring effort. The OC and Po contents are correlated with the active aluminum (Alox) and iron (Feox) and with the stratified gradients of the enzyme activities. The AcP activity does not seem to be suppressed by soil Pi content, showing a positive linear relationship with Pi. High values for the AcP:βG activity ratio are observed, which suggests a high energy allocation (C consumption) to ensure P demand. With the increase of Alox and Feox, the AcP:βG ratios increase and the potential C:P acquisition (ln(βG):ln(AcP)) values decrease. Nevertheless, the average C:P molar ratio of the six soils (115) are below the critical value, above which soils may present low P bioavailability. The results suggest that the effort for P acquisition (AcP:βG) and the potential C:P acquisition are both affected by the size of the Pi pools and by Alox and Feox contents. If Pi retention increases due to high contents of Alox and Feox, energy allocation shifts toward AcP production, in detriment of microbial population and plant nutrition. Considering the OC accumulation in the studied soils, several hypotheses may be considered such as the energy demand toward P acquisition, and the ability of Alox and Feox metal complexes to protect organic molecules to depress βG activity.

Impeded Macrofaunal Colonization and Recovery Following Marine Deposition of Inert and Organically Modified Mine-Tailings

Fine-grained, waste rock (or tailings) produced during mining processes are the main waste product following the extraction of valuable minerals and metals from ores. The proximity of mineral resources to coastal regions in some countries has meant that the organically inert mine tailings are often deposited into the marine environment as a submarine tailings placement or STP. This creates a real environmental challenge since the deposition of tailings at the seafloor can completely smother the benthic environment and reduce benthic biodiversity and alter ecosystem function. A limited number of studies have attempted to quantify the speed of seafloor recovery following tailings disposal and have suggested that one of the main factors limiting seafloor colonisation is the lack of organic matter of the tailings deposited. In this experimental study, we used hydrodynamically unbiased settlement trays within a complete randomised block design to test whether macrofaunal colonisation of mine tailings, and resemblance towards ambient assemblages, is enhanced when tailings become more enriched in organic C (Corg). Our experiment showed that tailings with Corg contents 1% exhibited lower faunal abundance and biomass and different macrofaunal community composition after one year compared to background sediments. Macrofaunal species richness (defined as the total number of different taxa) in the 0% and 0.5% Corg tailings treatments, however, was statistically indistinguishable from ambient intertidal sediments after one year. Furthermore, macrofaunal community structure was more similar to that of the background intertidal sediments after one year, which collectively suggest partial recovery of seafloor biodiversity in tailings with zero to low Corg levels. Nevertheless, macrofaunal abundance and biomass in these treatments remained significantly less than the background community after one year suggesting factors other than the Corg content of tailings may be structuring macrofaunal colonisation and impeding seafloor recovery of tailings deposits. We propose that the non-marine physical structure of the tailings particles, which show great angularity is predominantly responsible for the observed delayed recovery.

Магнітна сприйнятливість ґрунтів чорноземної зони Лівобережжя України та її інформативність в агрохімічному аспекті

Goal. To study the distribution of values of magnetic susceptibility (MS) of soils of agricultural lands of the chernozem zone of the Left Bank of Ukraine and to evaluate their informativeness for control of organic carbon (Corg) of soils at the regional level. Methods. Methods of soil sampling according to DSTU 4287:2004 were used and the humus content was determined according to DSTU 4289:2004. The standard software product Statistica® was used to establish the statistical indicators, and the results of the research were visualized in the environment of MapInfo and Surfer. Results. 90 samples were taken from the upper soil horizon (0–30 cm) of lands of different types (arable land, pastures, forest), their ratio roughly corresponded to the current structure of agricultural lands. For all samples, the specific MS was determined using a kappa-containing KLY2 according to the Evans method. Conclusions. The degree of relationship between the content of sorghum in the soils of the study area did not allow making unambiguous recommendations for the use of MS by interpolation or extrapolation of values at the regional level. This is due to differences in pedogenesis and soil use. The scattering graph of MS and Corg can identify areas that meet different conditions of soil formation: steppe, meadow, gray forest. They did not find regularities in the spatial distribution of soil MS (except for the growth of values with increasing hydrothermal coefficient) and Corg content.

The quality of soil organic matter, accessed by 13C solid state nuclear magnetic resonance, is just as important as its content concerning pesticide sorption

The global increase of food production has been achieved mainly through the intensive use of inputs such as pesticides. Once released to the soil, sorption (which could be represented by Freundlich solid-water distribution coefficients – KF) and degradation are two governing processes that determine the distribution and persistence of pesticides in the environment. In spite of the huge dataset, the only apparent generalisation is the high correlation between KF and soil organic matter (SOM) content. However, in this work no correlation was observed between KF and organic C content (OC) and so the obtained KOC (KF normalised by OC) spread out in a wide range: 1100 to 11,400 mL g−1 for abamectin; and 30–150 mL g−1 for atrazine, both ranges corroborate with data from literature. These high variabilities indicate that other soil components or SOM quality strongly interfere in the pesticide sorption in addition to SOM content. Seeking to estimate the influence of SOM quality in the abamectin and atrazine KOC values, the humic acids, a fraction of the SOM, was analysed by 13C nuclear magnetic resonance spectroscopy (13C NMR) and Principal Component (PC) Regression. The first PC of 13C NMR spectra presented negative loadings for aliphatic compounds and positive loadings for aryl C, typical of partially oxidised pyrogenic C. Their scores showed strong correlation with the abamectin KOC values (R2 = 0.91, p < 5 10−8) and weaker with atrazine KOC (R2 = 0.63, p < 0.0001), in addition to a smaller standardised slope: 1.01 for abamectin and 0.76 for atrazine. These results could be explained by the higher hydrophobicity of abamectin, being thus more prone to interact with the polycondensed aryl groups from the pyrogenic C. It is also important to highlight that humic acids are useful proxies for understanding the paramount interaction of SOM with pesticides.

Sandy Soil Amended with Clay Soil: Effect of Clay Soil Properties on Soil Respiration, Microbial Biomass, and Water Extractable Organic C

The low organic C (OC) sequestration and low water and nutrient holding capacities of sandy soils can be improved by amendment with clay soils. However, the effect of clay soils may depend on clay soil properties, including cation exchange capacity (CEC) and clay and OC contents. Two experiments were carried out. In the first experiment, sandy soil was mixed with two high clay content soils (Sodosol and Vertosol) at 10% and 40% (w/w). The soil was left unamended or amended with wheat straw, to assess if the effect of clay soil addition was influenced by OC addition. In the second experiment, sandy soil was mixed with two low-clay content soils which differed in CEC without wheat straw amendment. In experiment 1, compared with sandy soil alone, amendment with Sodosol (low OC) reduced cumulative respiration more strongly than addition of Vertosol. Without wheat straw addition, both clay soils increased microbial biomass C (MBC), whereas with wheat straw, they reduced microbial biomass C (MBC) compared with sandy soil alone. Sodosol amendment reduced water-extractable OC (WEOC) without wheat straw but increased it with wheat straw. In experiment 2, only the high CEC clay soil reduced cumulative respiration, MBC and WEOC compared with sandy soil alone. Clay soil addition to sandy soil will result in the greatest OC sequestration if the added soil has high clay but low OC content and its CEC is high.

MEDIA ROOT TRAINER MENGANDUNG COCOPEAT DAN GAMBUT MENDUKUNG PERTUMBUHAN DAN KUALITAS AKAR BATANG BAWAH KARET / Root Trainer Media Containing Cocopeat and Peat to Support Growth and Quality of Rubber Rootstock Roots

&lt;p&gt;The physical and chemical properties of the growing medium for &lt;em&gt;root trainer&lt;/em&gt; of rubber are critical to support plant growth. This study aimed to obtain the best medium for growing rootstock rubber seedlings in the &lt;em&gt;root trainer&lt;/em&gt;. Rubber clone PR 300 seeds were germinated for 21 days, then raised in &lt;em&gt;root trainer&lt;/em&gt; pots for five months. The treatments evaluated were a mixture of &lt;em&gt;cocopeat&lt;/em&gt;, Rawapening peat, and manure at different ratios. The experiment was designed in a Randomized Block Design, three replications, 30 plants per replicate, totaling 720 plants. The observed variables were N, P, K, Mg, C-organic content, pH, and cation exchange capacity of &lt;em&gt;cocopeat&lt;/em&gt;, peat, and manure, as well as plant growth (height, stem diameter, wet weight, and dry weight). ANOVA used for analyzing data, followed with the &lt;em&gt;Duncan Multiple Range Test&lt;/em&gt; at 5% level. The results showed that there were three best &lt;em&gt;root trainer&lt;/em&gt; media for PR 300 rubber rootstock seedlings were a mixture of &lt;em&gt;cocopeat&lt;/em&gt; + peat (1:1), &lt;em&gt;cocopeat&lt;/em&gt; + peat + manure (1:2:1), and &lt;em&gt;cocopeat&lt;/em&gt; + peat + manure (2:1:1). The growth and compactness of the roots are outstanding, so the seedlings are easily removed from the &lt;em&gt;root &lt;/em&gt;&lt;em&gt;trainer&lt;/em&gt; pots without significant damage. Based on the initiation and cost, the best &lt;em&gt;root trainer&lt;/em&gt; medium is a mixture of &lt;em&gt;cocopeat&lt;/em&gt; + peat + manure (1: 2:1). It is necessary to study the use of other types of peat soils apart from Rawapening. Also, it needs to be observed further plant growth after inoculation with the stem and after planting in the field.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Keywords &lt;/strong&gt;: Planting medium, Rawapening peat, rubber clone PR 300.&lt;em&gt;&lt;/em&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;&lt;br /&gt;&lt;/em&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Abstrak&lt;br /&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Sifat fisik dan kimia media tanam di dalam wadah &lt;em&gt;root trainer&lt;/em&gt; bibit karet sangat penting untuk mendukung pertumbuhan tanaman. Penelitian ini bertujuan mendapatkan media terbaik untuk pertumbuhan bibit batang bawah karet di dalam &lt;em&gt;root trainer&lt;/em&gt;. Benih klon karet PR 300 dikecambahkan selama 21 hari pada bedeng pengecambahan kemudian dipindah-tanam dan dibesarkan selama 5 bulan dalam pot &lt;em&gt;root trainer&lt;/em&gt;. Perlakuannya yaitu campuran &lt;em&gt;cocopeat&lt;/em&gt;, gambut Rawapening, dan pupuk kandang (pukan) pada berbagai ratio, dan kontrol. Penelitian dirancang secara Acak Kelompok, tiga ulangan, masing-masing 30 tanaman, sehingga totalnya 720 tanaman. Variabel yang diamati yaitu kandungan N, P, K, Mg, C-organik, pH, dan kapasitas tukar kation dari &lt;em&gt;cocopeat&lt;/em&gt;, gambut, dan pupuk kandang, serta pertumbuhan tanaman (tinggi, diameter batang, bobot segar, dan bobot kering). Data dianalisis dengan ANOVA, kemudian &lt;em&gt;Duncan Multiple Range Test&lt;/em&gt; pada taraf 5%. Hasil penelitian menunjukkan bahwa ada tiga macam media &lt;em&gt;root trainer&lt;/em&gt; terbaik untuk bibit batang bawah karet klon PR 300 yaitu campuran &lt;em&gt;cocopeat &lt;/em&gt;+ gambut (1:1), &lt;em&gt;cocopeat &lt;/em&gt;+ gambut + pukan (1:2:1), dan &lt;em&gt;cocopeat &lt;/em&gt;+ gambut + pukan (2:1:1). Pertumbuhan dan kekompakan akar sangat baik sehingga bibit mudah dilepas dari &lt;em&gt;root tainer&lt;/em&gt; tanpa kerusakan berarti. Berdasarkan kepraktisan dan biaya maka media &lt;em&gt;root trainer&lt;/em&gt; terbaik adalah campuran media &lt;em&gt;cocopeat &lt;/em&gt;+ gambut + pukan (1:2:1). Perlu dilakukan kajian mengenai pemanfaatan tanah gambut jenis lainnya selain dari Rawapening. Selain itu, juga perlu diamati lebih lanjut pertumbuhan tanaman setelah diokulasi dengan batang atas maupun setelah ditanam di lapangan.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Kata kunci &lt;/strong&gt;: Gambut Rawapening, klon karet PR 300, media tanam.&lt;/p&gt;

Spatial Distribution of Organic Matter and Nitrogen in the Entic Podzols of the Prioksko-Terrasnyi Reserve and Its Relationship with the Structure of Forest Phytocenoses

Estimates of the spatial heterogeneity of the organic matter distribution in forest soils determined by the influence of the species and spatial structure of phytocenoses are relevant for many environmental problems, including the calculation of carbon sinks and modeling of the dynamics of forest ecosystems. We analyzed the data on the organic carbon (Corg) and total nitrogen (Ntot) contents in the O (forest litter) and AY (humus) horizons of Entic Podzols in the Prioksko-Terrasnyi Reserve (54.89° N, 37.56° E). The studied site is located in a coniferous–deciduous forest formed after overgrowing of the cutting area of pine stands. We sampled the O and AY horizons along transects between trees of different species, i.e., near the trunks, under the crown, and in the intercrown space. The contents of Corg and Ntot in the O horizon varied within 17.6–44.9 and 0.84–1.79%, respectively. The ranges for the AY horizon were greater: 0.71–8.5% (Corg) and 0.035–0.33% (Ntot). The relationship between the contents of Corg and Ntot in the O and AY horizons was close to linear (rs = 0.72 and rs = 0.96, respectively). We also obtained similar C : N ratios for the both horizons. The litter thickness and the content of Ntot in the O horizon, as well as the content of Corg in the AY horizon, significantly differed in different parts of the transects (P < 0.05). The differences in the litter thickness and the Corg content in the O horizon under the crowns of different tree species were also significant. In samples from the AY horizon taken in intercrown spaces, the Ntot content correlated with the demand of plant species of the ground cover for soil fertility. The data obtained reflect the influence of specific features of spatial patterns of surface and root litterfall in multispecies communities of mixed forest stands on the spatial variability of Corg and Ntot contents in soil.

PENGARUH DOSIS PUUK KANDANG SAPI TERHADAP PERBAIKAN BEBERAPA SIFAT FISIK, KIMIA DAN BIOLOGI TANAH PADA KONDISI JENUH AIR DAN KAPSITAS LAPANG

Soils are the main media for the growth of crops, the low yield of crops is always related to soil physical, chemical and biological soil conditions. Cattle manure is an organic fertilizer known well before chemical fertilizer. Many types of research on the use of cattle manure to ameliorate physical, chemical and biological soil properties have been conducted, but the optimum rates of cattle manure especially on sandy soil have never been found. This fact may be caused by leaching of organic materials and nutrients to deeper soil layer unreachable by roots. An experiment was conducted in a plastic house using sandy soils from the district of Kubu, Karangasem regency, with the objectives of studying the effects of rates of cattle manure on physical, chemical and biological properties f soils and the effects of inundated and water field capacity of soils on leaching of nutrients in the soils. The experiment was conducted from June until August 2010. The design used was a split-plot design consisted of four rates of cattle manure (0, 10, 20 and 30 t ha-1) as main plots and two water status of soils (inundated and water capacity) as subplots, with three replications. The results of the experiment indicated that cattle manure is able to ameliorate some of the soil physical properties as bulk densities (g cm-3), soil water status (%), soil permeability (cm hour-1) and total soil pores (%), and increased soil pH, C-organic content (%), C/N ratio, NPK and biological properties of soils of low nutrients status of sandy loam brown regosol soils derived from Vulcan intermediary. The results of the experiment also indicated the occurrence of leaching of organic materials and NPK nutrients to 20-40 cm layer. Based on the experiment results it is to suggest to the farmers that the use of cattle manure should be combined with synthetic chemical fertilizer in several applications during growth periods, but this required further researches.

KANDUNGAN C-ORGANIK TANAH DAN TOTAL NITROGEN PADA TANAH VERTISOL YANG TELAH DIBAKAR DAN TIDAK DIBAKAR

The use of fire in agriculture land preparation may result in the change of various soil properties. Therefore, a study was conducted in the village of Oeteta, Kupang to determine soil total organic-C and total nitrogen of burned and unburned Vertisols. Randomized complete block design with two factors was applied. The first factor was burning treatment with two levels: burned and unburned. The second factor was soil depth with three levels: 0-10cm, 11-20cm and 21-30cm; all together made up 54 experimental units. Results showed that in all depths there was no significant difference in total soil organic-C between burned and unburned soils. However total soil organic-C contents in both burning treatments were considered high. Similarly, the was also no significant difference in total soil nitrogen between burned and unburned plots. Total soil N was considered in high and medium levels for burned and unburned soil respectively. In summary, burning does not affect soil total organic-C contents but reduces soil total N contents.

PENGARUH DOSIS PUPUK KASCING DAN NITROGEN TERHADAP PERTUMBUHAN DAN HASIL TANAMAN SELADA (LACTVCA SATIVA L.) VAR GEORGIA

The low of growth and yield of lettuce is quite often caused by the low of soil fertility, especially nitrogen and C-organic content. Poor soil physical properties also contribute to the cause of low yield of lettuce. Improved soil physical and chemical properties by adding casting fertilizers and nitrogen are expected to be able to increase the yields of lettuce. The field experiment was conducted in Candikuning village, district of Baturiti, Tabanan regency, from October 2005 to January 2006. The objective of the experiment was to study the effect of casting fertilizer and nitrogen rates on the growth and yields of lettuce. A randomized complete block design was used in this experiment and two treatment factors were imposed. Those two treatment factors were rates of casting fertilizers (i.e. 0, 10, 20 and 30 t ha"1 ) and rates of N (i.e. 0, 92, 138 and 184 kg N ha"1), which were arranged factorially and repeated three times. Results of the experiment indicated that interaction between casting fertilizer and nitrogen rates did not significantly affect the yields of lettuce. The rates of N only significantly affected several growth variables and the oven-dry weight of heads plant-1. Increased rates of N from 0 to 92 kg N ha-1 significantly resulted in the oven-dry weight of heads of 2.798 g plant-1 which was 13.9% higher than that of 0 kg N ha-1. Rates of casting fertilizer significantly affected head diameter and the oven-dry weight of heads plant"1 and ha-1. Increased rates of casting fertilizer from 0 to 10 t ha-1 gave the oven-dry weight of heads as much as 0.232 t ha"1 or 9.43% higher than the weight given by the rate of 0 t ha-1. The effects of rates of casting fertilizer and N were only significant on several soil physical properties. The relationship between rates of casting fertilizer and yields of lettuce was quadratic (Y = 0.21135 + 0.0032 X - 0.001 X2 ; R2 = 0.981). The optimum rate of casting fertilizer was 16.0 t ha-1 with the maximum oven-dry weight of heads of 0.237 t ha-1, meanwhile, the optimum rate of N had not obtained in this experiment.

Use of Brassica juncea and Dactylis glomerata for the phytostabilization of mine soils amended with compost or biochar

Phytostabilization of mine soils contaminated by potentially toxic elements (PTEs) requires plants tolerant to PTE toxicity and to the poor soil physico-chemical characteristics of these areas. A pot experiment was carried out to assess the phytostabilization potential of Brassica juncea and Dactylis glomerata in mine soils amended with compost and biochar. Furthermore, the Environmental Risk of the soils and the effects of the phytostabilization process on the microbiological population size and activity in the soils were also determined. According to the Ecological Risk Index (ERI) the soils studied presented “very high risk” and As, Cd and Pb were the target elements for phytostabilization. Both amendments improved soil conditions (e.g., increasing total-N and total organic-C concentrations) and contributed to PTE (Cd, Pb and Zn) immobilization in the soil. Compost showed a more marked effect on soil microbial biomass and nutrients release in soil, which led to higher B. juncea and D. glomerata biomass in compost treated soils. Biochar treatment showed a positive effect only on D. glomerata growth, despite it provoked strong PTE immobilization in both soils. The addition of both amendments resulted in an overall reduction of PTE concentration in the plants compared to the control treatment. In addition, both plant species showed higher accumulation of PTE in the roots than in the shoots (transfer factor<1) independently of the treatment received. Therefore, they can be considered as good candidates for the phytostabilization of PTE contaminated mine soils in combination with organic amendments like biochar and compost.

Water Management and Soil Fertility Status at A Reclaimed Tidal Lowland of Telang Jaya Village, South Sumatra, Indonesia

&lt;p&gt;Tidal lowland has a great prospect due to its vast area to support the improvement of national food security and the development of agribusiness system. Based on these potentials, it is necessary to study water management the physical dan chemical characteristics of soil on tidal land at Telang Jaya, South Sumatra. The aim of the study is to develop micro water management in the field level for rice cultivation, and to evaluate the soil fertility in relation to the rice production. The soil properties can be used to determine the level of soil fertility and the land management problem at the area. Research method was done by experimental research in combination with survey and monitoring. Rice was cultivated in tertiary block and the ground water table fluctuation was record in daily bases. Soil samples were taken from 0-20 cm depth (the root depth for common food crops) and then analyzed at the laboratory. The result had showed that the soil fertility status at Telang Jaya was low to moderate. The limiting factors of soil fertility found in this study were consisted of low nitrogent content, low C-organic content and acid soil condition (low bases and pH). Ground water taken at February to March was maintained on 10 to (-10) cm related to the soil surface. It was sufficient for crop water requirement. Water management objective for second rice was mainaly for control drainage during the intial stage, and retain rainfall water. Pumping irrigation was required during Elnina climatic condition at generative phase. By proper water management system rice production could achive 5 ton/ha.&lt;/p&gt;

Effect of Application of Urea Fertilizer and Goat Manure on Some Chemical Properties of Soil and Yield of Mustard Plant

This study was aimed to elucidate the effect of the application of urea fertilizer and goat manure on some soil chemical properties and yield of green mustard plant ( Bressicca j uncea L). This study was conducted with a randomized block design consisting of two factors. The first factor was the application of goat manure (K) consisting of three levels, i.e. (K1) 1 t goat manure ha -1 , (K2) 1.5 t goat manure ha -1 , and (K3) 2 t goat manure ha -1 . The second factor was the application of urea fertilizer consisting of two dose levels, i.e. (U1 75 kg) urea fertilizer ha -1 , and (U2) 100 kg urea fertilizer ha -1 . The measured parameters were soil organic-C content, soil total N content, and fresh weight of the green mustard plant. Results of the study showed that the combination of 2 t goat manure ha -1 and 100 kg urea fertilizer ha -1 was the best treatment that significantly affected soil organic-C content, soil total N, soil C/N ratio, and yield of fresh weight of the mustard green plant.

Effect of Application of Rice Husk Ash and Rice Straw Compost on Chemical Properties of an Ultisol Soil under Sweet Corn

This study aimed to determine the effect of rice straw compost and rice husk ash on some chemical properties of an Ultisol soil under sweet corn plant. This study was conducted at the Labuhan Batu Rantau Prapat University Campus Land and the PT. Socfindo Laboratory. The design used in this study was a randomized factorial design consisting of two factors with two replications. The first factor was the application of rice husk ash with four dose levels (g 5 kg -1 of soil), i.e. P0 (0), P1 (10), P2 (20), and P3 (30). The second factor was the application of rice straw compost with four dose levels (g 5 kg -1 of soil), i.e. J0 (0), J1 (25), and J2 (50), J3 (75). Results of this study indicated that the application of rice straw compost significantly increased soil organic-C and available P contents, as well as plant height, plant dry weight, N and P uptake by the plant. The treatments, however, did not significantly increase soil pH and total-N content. The application of rice husk ash significantly increased soil organic-C content and N uptake by the plant, but it did not significantly increase pH, available P content, and total N content of the soil.

Growth performance and biomass production of Eleusine indica and Rorippa sylvestris on heavy metal contaminated soil after biochar application

Heavy metal contamination was an environmental and human health problem all over the world. Cadmium is the most hazardous heavy metals due to its high mobility and toxicity at low concentrations. Lead (Pb) also belongs to the hazard element caused by its prolonged persistence in the soil. This study aimed to develop the remediation techniques on polluted land, i.e. a combination of biochar and indigenous plant. The biochar was produced by slow pyrolysis method. This experiment was conducted at the farmland at Sumber Brantas, Malang, East Java. We used rice husk and tobacco waste biochar, and Eleusine indica (L.) Gaertn and Rorippa sylvestris (L.) Bess. as remediator plants. The results showed that rice husk biochar had a significant effect on pH value and potassium content (p = 0.0001; p=0.0004). On the contrary, the soil nitrogen content, soil organic-C content, and soil cation exchange capacity applied with tobacco waste biochar application were higher than that applied with rice husk biochar (p = 0.03; p=0.00001; p = 0.00001). The improvement of soil characteristics increased the growth of Eleusine indica and Rorippa sylvestris as indicated by the plant height and biomass. The addition of biochar could promote the growth of remediator plant and enhanced the accumulation of Pb and Cd in the plants. Mixtures of rice husk biochar and tobacco waste biochar caused Eleusine indica more effectively absorbed heavy metals than Rorippa sylvestris on all types of biochar treatments; Eleusine indica absorbed Pb and Cd higher than Rorippa sylvestris as shown by Pb and Cd contents in the soil.

Plasticity, Mineralogy, and WRB Classification of Some Typical Clay Soils along the Two Major Rivers in Croatia

Quantification of soil plasticity is usually based on Atterberg limits or indices, which are then used for engineering and agricultural purposes on clay soils. Because these limits/indices are seldom analyzed during routine soil surveys, they are sometimes estimated from available soil properties using pedotransfer functions (PTFs). Main aim of this study was to test if two robust PTFs, previously created by other authors for other soils/areas, may be used for predicting plasticity of typical clay soils on fluvial deposits in Croatia. We analyzed mineralogy, plasticity, and related physicochemical properties of four representative soil profiles along Sava and Drava, two longest Croatian rivers. Particle size distribution patterns pointed to more uniform sedimentation along Sava, compared to Drava. Also, more clay was found within Sava profiles. Soil texture was finer farther away from the sources of both rivers. Soil cation exchange capacity (CEC) was almost fully positively correlated to clay content. On the other hand, Corg content showed no correlation to CEC. This is attributed to the significant presence of smectite across all studied soils. Clay was recognized as the main factor influencing soil plasticity. When compared to the measured values, the predicted values of plasticity index and liquid limit were heavily underestimated. Hence, region-specific PTFs should be developed for more accurate prediction of plasticity in these soils. According to the WRB-2015, the soils were classified as Eutric Reductigleyic Stagnic Gleysols (Clayic, Humic, Protovertic). Because soils were not dry during field description, shrink-swell cracks were not prominent, and therefore soils were not classified as Vertisols. We suggest that field criteria for classification of Vertisols should not depend on actual soil moisture. Instead, plastic limits/indices could be used.

Temporal trends of organic carbon accumulation in seagrass meadows from the northern Mexican Caribbean

Carbon sequestration in seagrass meadows mitigates the currently rising CO2 atmospheric levels, as these ecosystems are highly productive and preserve sediment organic carbon over long periods. Five 210Pb dated sediment cores, collected from seagrass meadows dominated by Thalassia testudinum in the northern Mexican Caribbean touristic corridor Cancun-Riviera Maya, were used to establish temporal trends of organic carbon (Corg) content, burial rates and stock variation over the past 100 years. Corg contents (0.17–1.94%) and burial rates (2.0–252 g m−2 yr−1) were generally within the lower end range reported for seagrass meadow sediments worldwide. Corg stock gradually increased over the past decades, associated with increasing sediment accumulation, possibly caused by inland erosion promoted by agricultural and forestry activities and, in the recent decades, by a rapid increase of urban development due to a fast growth of the tourist industry and population, likely causing fertilization of coastal waters. Seagrass meadow sediments in the northern Mexican Caribbean coastline showed long-term Corg storage and preservation, since ~ 40 to ~ 100 years depending on the core, which emphasizes the need to protect these ecosystems against impacts of global change, and their incorporation into climate change mitigation strategies should be considered.