Percentage Of Matter Research Articles

Effects of Harvest Time on the Yield and Forage Value of Winter Forage Crops in Reclaimed Lands of Korea

This research was conducted to select the most suitable winter forage crop varieties for silage in reclaimed land located in the Midwest of Korea by investigating the soil environment, crop growth characteristics, dry weight, and forage value according to growth stage. The slightly alkalescent soil was characterized by a pH of 7.41–7.84, by an electrical conductivity (EC) of 1–2.5 dS/m, and by 440–934 mg/kg of available phosphate. Barley showed the highest chlorophyll content in the heading stage and milk stages, while oats and triticale reached the highest content in the milk and dough stage. In both years, triticale achieved the highest leaf area index (LAI), reaching 4.3–4.8. In addition, triticale showed the highest percentage of dry matter and the highest dry weight in the milk stage. Forage value was the best in the heading stage for all cereal crops; however, its quality decreased as the growth stage proceeded. This study suggests cultivating triticale, which showed high adaptability to reclaimed soil and climatic conditions, as well as good growth and dry weight when harvested between the milk and dough stages. These results indicate that triticale can be cultivated all year round in salty soil and these data can be useful to increase forage production in reclaimed soil.

UV IDENTIFICATION FOR TARFAYAS OIL SHALE AND ASHING AT LOW TEMPERATURE OF Z1 LAYER (MOROCCO)

In order to elucidate our knowledge of oil shale, this work has been initiated. Morocco has large oil shale reserves, the most important deposits of which are in Timahdit, Tarfaya and Tangiers .As oil shale is first-round energy materials that can be used to further valorize these resources, we are interested in the research and development of oil shale-based materials capable of retaining pollutants present in wastewater. In this study, we discuss the role that oil shale can play in inhibiting the infiltration of micro pollutants into the water table. The part of this work presents a bibliographical study on the mineralogy, geochemistry and petro chemistry of oil shale. The use of these materials in the field of environmental protection is discussed. Firstly, an experimental identification work was carried out using the spectroscopic apparatus of our establishment to study the Z1 layer of the Tarfaya deposit in its raw state and in the screen solubilized with chloroform. The Z1 layer has a percentage of organic matter of 12.3% and mineral matter of 29.4% for a heating rate of 21°C/min (A.Attaoui:1999).Then, within the framework of a clean use of the material as an absorbent or depolluting(He.G.Liang et al:2019,S.Gamoudi et al :2019) we carried out the ashing at low temperature of the oil shale, which consists in carrying out combustions on this shale, more precisely on the organic part and not altering the mineral part. In this context, we carried out this incineration on the oil shale of Tarfaya (Z1) at temperatures ranging from ambient to 227°C. The samples were then subjected to HCl acid attacks, and the remaining part was measured and the quantity of the constituents sensitive to this acid attack was evaluated. Pure calcite was taken as a reference and the PH-meter was used to analyses the phenomenon.

Lithofacies characterization and source rock assessment of the lower-middle Miocene Successions in the northern part of Ramadan oil field, central Gulf of Suez, Egypt

Facies of rifting basins reflect different depositional environments from deep to shallow conditions. The present study focuses on subsurface facies characterization and source rock assessment of Kareem and Rudeis rocks in six wells lying in the central Gulf of Suez. The distribution of the lithologic patterns delineated through several constructed facies maps. Porosity cross-plots of Kareem and Rudeis formations to determine the rock minerals and porosity attitudes. Rock–Eval pyrolysis was applied to determine the kerogen type, organic matter richness, percentage, and maturation of the source rocks. The greater depth of the two formations was reflected in the western parts while their stratigraphic thickness increases toward the east and the north directions, with decreasing thickness towards the west direction due to an underlain basin structure of the pre-Miocene. Isolith maps show three deep marine lithologies for the two formations with the anhydrite as a fourth shallow marine lithology in the Kareem Formation only. These lithofacies reflect the turnover from the deep to the shallow depositional environment. The facies change from a main shaly limestone in the Rudeis Formation to calcareous shale in the Kareem formation, indicating transmutation from the lower Miocene deep to the middle Miocene shallow marine environments. The cross-plots reflected the existence of limestone, shale, and anhydrite. Geochemically, both formations are marginally good source rock with a marginally good generation of mixed type II/III and type III. Accordingly, Rudeis and Kareem formations could be good reservoirs rather than being potential source rocks in the central Gulf of Suez.

Tuber Yield and Physiological Characteristics of Potato Under Irrigation and Fertilizer Application

ABSTRACT The effects of water availability in the soil and fertilizer application often strongly affect crop growth. Tuber dry matter yield and physiological characteristics of potato (Solanum tuberosum L.) were investigated under different irrigation regimes (S1, full irrigation, 100% of water requirement; S2, 75% of water requirement; and S3, 50% of water requirement). Nitrogen treatments were four amounts of urea (N1, providing 100% of N requirement; N2, 66% of N requirement; and N3, 33% of N requirement, and N4, 0 kg N/ha. Drought stress with 50% of the water requirement and limiting nitrogen fertilizer application suppressed the number and weights of tubers per plant. The yield of marketable tubers in S1 and S2 treatments was not significantly different. Treatments N1, N2, and N3 increased the yield of marketable tubers by 37, 33 and 12%, respectively, compared to N4. Drought stress (S3) increased the percentage of dry matter, but nitrogen fertilization did not cause a significant change. Drought stress (S3) increased the amount of soluble sugars in tubers and proline in leaves; however, the amounts of soluble sugars and proline were unchanged by increased nitrogen fertilization. Full irrigation and meeting of nitrogen requirements of potatoes led to high chlorophyll concentrations in leaves. Under drought stress (S3) and increasing nitrogen, the starch content of tubers was suppressed. The amount of nitrate in the tubers was not affected by irrigation treatments, but was raised by increasing nitrogen fertilization. Irrigation of 75% or more combined with fertilizer application of 66%, was an appropriate treatment for potato production.

Influence of the spectral composition of light on the morphogenesis of the epiphytic orchid <i>Cattleya labiata</i> Lindl. cultivated in the greenhouse

This work evaluates the test results of 3 types of LED lamps with different spectral composition of radiation and photon flux of photosynthesis (PPF, μmol/m2/sec): PPG T8I Agro (37), Navigator DSP-FITO (47.5) and DDP06-3×8-004 UHL 4 ‘Home Farm' (100), in the greenhouse culture of the orchid Cattleya labiata Lindl. The parameters of the thickness of annual leaves, the percentage of dry matter and the increase in biomass per unit of leaf surface (μg/cm2) formed over a period of 140 days were used as indicators to assess the degree of influence of the spectral composition of light on the morphogenesis of C. labiata plants. The spectral characteristics of the LED lamp DDP06-3×8-004 UHL 4 ‘Home Farm' with a white glow, intensity PPF 100 are considered as the most favorable for the successful greenhouse cultivation of the orchid Cattleya labiata Lindl. The combination in its spectrum of red and green spectra with their ratio equal to 1.3, and when the ratio of red and blue spectra equal to 3.34, a higher level of dry matter accumulation is observed per unit of leaf surface area white maintaining parameter of the leaf structure characteristic of a given plant species.

A maceration treatment of leucaena foliage improves its nutritional value by reducing mimosine concentration

Giant leucaena produces high dry matter yields but the foliage contains mimosine, a non-protein amino acid that is toxic to animals, especially non-ruminants. Reducing mimosine concentration in foliage following harvesting may allow for greater use of Giant leucaena and mitigate the negative aspects of higher mimosine concentration in some varieties. We evaluated two methods for post-harvest treatment of foliage of a highly productive interspecific hybrid variety ‘KX2’ for reducing mimosine concentration: (i) maceration treatment; and (ii) extraction with 0.1 N HCl. Mimosine as a percentage of leaf dry matter ranged from less than 1% DM to around 3% DM. Although both methods reduced mimosine concentration, extraction by 0.1 N HCl also reduced gross energy, protein and carbohydrate concentrations of leucaena foliage. The maceration treatment, on the other hand, caused little reduction in crude protein and crude fat concentrations but markedly increased the carbohydrate concentration. ADF and NDF concentrations were also reduced as a result of maceration treatment. The estimated gross energy concentration in macerated foliage was not significantly lower than in unprocessed foliage. A suitable mechanical method for post-harvest maceration of leucaena foliage, e.g. a wood-chipping machine, could be used to reduce mimosine concentration in the foliage, making it safer for feeding to livestock and enhancing the feed value, especially for non-ruminants. These methods should be tested by conducting feeding studies to determine the possible benefits in animal performance from feeding macerated foliage.

Erianthus germplasm collection in Thailand: genetic structure and phylogenetic aspects of tetraploid and hexaploid accessions

BackgroundThe genus Erianthus, which belongs to the “Saccharum complex”, includes C4 warm-season grasses. Erianthus species are widely distributed throughout Southeast Asia, East Asia and South Asia. Erianthus arundinaceus (Retz.) Jeswiet is highly adaptable to the environment, has a high percentage of dry matter, and is highly productive. Recently, this species has attracted attention as a novel bioenergy crop and as a breeding material for sugarcane improvement. Such interest in E. arundinaceus has accelerated the collection and conservation of its genetic resources, mainly in Asian countries, and also evaluation of morphological, agricultural, and cytogenetic features in germplasm collections. In Thailand, genetic resources of E. arundinaceus have been collected over the past 20 years and their phenotypic traits have been evaluated. However, the genetic differences and relatedness of the germplasms are not fully understood.ResultsA set of 41 primer pairs for nuclear simple sequence repeats (SSRs) developed from E. arundinaceus were used to assess the genetic diversity of 121 Erianthus germplasms collected in Thailand; of these primer pairs, 28 detected a total of 316 alleles. A Bayesian clustering approach with these alleles classified the accessions into four main groups, generally corresponding to the previous classification based on phenotypic analysis. The results of principal coordinate analysis and phylogenetic analysis of the 121 accessions on the basis of the SSR markers showed the same trend as Bayesian clustering, whereas sequence variations of three non-coding regions of chloroplast DNA revealed eight haplotypes among the accessions. The analysis of genetic structure and phylogenetic relationships, however, found some accessions whose classification contradicted the results of previous phenotypic classification.ConclusionsThe molecular approach used in this study characterized the genetic diversity and relatedness of Erianthus germplasms collected across Thailand. This knowledge would allow efficient maintenance and conservation of the genetic resources of this grass and would help to use Erianthus species as breeding materials for development of novel bioenergy crops and sugarcane improvement.

Evaluation of Nutraceutical Properties of Pleurotus ostreatus (Jacq.) P. Kumm (Pleurotaceae)

Recently, consumption of mushroom is on the increase in many developing countries. They serve as food supplements in diets of the people. The present study was conducted to evaluate nutraceutical properties of the oyster mushroom (Pleurotus ostreatus), a widely cultivated mushroom in Nigeria. Properties such as proximate composition, mineral ions and antioxidants contents were analyzed using standard methods. P. ostreatus was found to contain high percentage of crude fibre, moisture content, carbohydrates, crude fat, total ash, crude protein and oil matter. Percentage of mineral ion such as sodium, calcium, potassium, magnesium, phosphorus, iron, copper and zinc were found to be lower in value. Antioxidants such as flavonoid, phenol, lycopene, β Carotene and ascorbic acid in P. ostreatus were found to be high in value. Overall, the percentage content of minerals in P. ostreatus was less than 1%, proximate composition was 33.64% and antioxidants was 66.16%. This showed that P. ostreatus had a high content of antioxidants, moderate amount of proximate composition and low amount of minerals. As P. ostreatus contains low calorific value and very high content of antioxidants, dietary fibres and minerals, it can therefore be said to be potentially good for medicinal purposes especially among the vegetarian consumers

Production of papaya seedlings and initial growth produced in different polyethylene recipients

The objective of this study was to evaluate the vegetative and productive performance of papaya seedlings in response to different volumes of containers. The experiment was conducted in a seedling production nursery at the State University of Mato Grosso (UNEMAT), Campus de Nova Mutum - MT, using a completely randomized design with five replications, in which four sizes of polyethylene bags were tested in the production of seedlings: 10 x 16 cm, 15 x 21 cm, 17 x 27 cm and 20 x 21 The plots were composed of 3 plants. The parameters evaluated at 70 days after sowing were: plant height, stem diameter, number of leaves, root length, green matter mass and percentage of dry weight of the stem, leaves and roots. The container 17 x 27 cm stood out from the other containers, except for the characteristics of the length of the stem, percentage of dry mass of the stem and leaves where it was equivalent to the container 20 x 21 cm and the percentage of dry mass where all containers were equivalent. The experiment showed that the 17 x 27 cm container is the most recommended for the cultivation of papaya seedlings cultivar Sunrise Solo.

SPATIAL DISTRIBUTION OF THE WESTERN JADWAL SOILS PROPERTIES AND SUITABILITY EVALUATION FOR WHEAT CROP CULTIVATION BY GEOMATICS TECHNOLOGY

The study area was chosen in the district of the western Jadwal in Karbala governorate - Iraq, which is located between E44o05'10'' to E44o13'03'' and N32o38'30'' to N32o27'40'', as 100 locations were identified for the depth of 0-30 cm by auger hole sampling method samples were obtained from each site, and kept laboratory measurements. The results of the study showed that the dominant soil texture is medium clay and silt are the predominant separates in the soil. As for the salinity of the soil represented by electrical conductivity, it was low of the dissolution the salts and the land use for cultivation besides the presence of a drainage network a percentage of the organic matter is good. As for assessing the suitability of the land for cultivation, Results showed the use of the standard addition method of land evaluation for the wheat crop by Sys,1993 is better and more accurate than the standard multiplication method for the wheat crop that was also suggested by Sys, 1980, where the very suitable class S1 and the suitable S2 were the predominant cultivars of the addition method, while the non- suitable class N and the least suitable S5 were classes when the methods of multiplication were used.

Evaluation of improved cassava genotypes for yield and related traits for a better breeding strategy under different agroecologies in Nigeria

This study aimed at determining shoot and root characteristics of cassava as affected by root yield and the influence of soil moisture on vegetative growth and yield. Thirty cassava genotypes were evaluated for morphological and physiological characterization in three locations in Nigeria: Ibadan, Mokwa and Zaria. Randomized complete block design was used with four replicates. Studies on the pasting properties of the genotypes were also carried out. Data were collected on plant height, stem girth, stay-green ability, garri and fresh root weight. Genotypes differed significantly (P < 0.05) across and within locations for shoot and root characteristics. Across locations, genotype 011663 had the highest plant height (132.4 cm); 30572 had the largest stem girth (8.6 cm); and 010040 was the best stay-green (2.2). Genotype 011086 had the highest number of roots per plot (95.7), 950289 had the highest fresh root yield (24.3 t/ha), and 990554 had the highest percentage of dry matter (35.2). Trends in root yields across locations were Ibadan (28.9 t/ha), Mokwa (20.3 t/ha), and Zaria (8 t/ha). Five genotypes IITA-TMS-IBA950289, 010034, 990554, 011807, and 980581 had negligible interactions with the environment and so have broad adaptation and are considered stable; and two clones 011807 and 950166 were found to be the best for pasting properties. Breeding strategies that consider root size, total root number, harvest index, dry matter, with applications for household foods and industrial uses, will be an effective and efficient way to select genotypes for high yield.

Macrofauna community patterns in a Chiloe Island channel used intensely for aquaculture: the ecological status of its benthic environment

BackgroundIt is known that aquaculture may produce negative environmental effects on marine ecosystems. Southern Chile is one of the most important salmon and mussel-producing areas in the world. Here we assess the ecological status of benthic communities near farming centers in Caucahue Channel, Chiloe, which has been used intensely for salmon and mussel production for 30 years.MethodsThe macrofauna, sediments and water column were characterized at distances of 5 to 100 m from three salmon and three mussel-producing centers. Information was also obtained from reference sites 500 to 3000 m from these aquaculture farms. The macrofauna and environmental conditions during winter were analyzed using uni- and multivariate analysis and the AZTI Marine Biotic Index (AMBI) as an indicator of benthic community condition.Results(i) There is a high degree of spatial dissimilarity in macrofauna and environmental variables among sampling sites and types of environments (far from or near farming centers) and between the northern and southern areas of the channel; (ii) sediment structure (mean grain size and percentage of total organic matter) correlated with the observed dissimilarities in macrofauna communities; and (iii) the level of perturbation according to AMBI was heterogeneous, with sites in the undisturbed/normal range to moderately disturbed/polluted.ConclusionsWe found a high spatial dissimilarity in benthic macrofauna and environmental variables among sampling sites, environmental types and between the northern and southern areas of the channel. AMBI and multivariate community-environment analysis are useful tools to define the level of perturbation of a geographic area at different spatial scales, using all the ecological information from each sample and replicates.

Environmental factors structuring the assemblage of aquatic insects in an epigean and hypogean stretch of a Neotropical karst stream

The aim of the present study was to identify which variables structure the assemblage of aquatic insects in the subterranean environment, because knowledge about how subterranean communities are structured in rivers with hypogean sections is still emerging. In addition to identifying whether the hypogean assemblage is structured in the same way as the epigean assemblage, we sought to identify whether the environmental restrictions caused by the subterranean habitat resulted in reduced species richness and abundance compared with the epigean habitat. We sampled a 345-m stretch of a stream in Brazil and collected aquatic insects from both the epigean and hypogean environments. In the stream stretch investigated, there was a positive relationship between richness and the percentage of immersion, fine substrate and organic matter, and a negative relationship between richness and conductivity. We also verified differences between the epigean and hypogean environments regarding composition. The variables that best explained the overall assemblage structure included the epigean–hypogean environment and the percentage of coarse and fine substrate. Given the differences between these environments, we emphasise the need for management actions in karst regions that consider the discontinuity of these regions’ river communities to conserve all components of diversity.

ДОННЫЕ ОТЛОЖЕНИЯ ПРИПЛОТИННОГО ПЛЕСА КУЙБЫШЕВСКОГО ВОДОХРАНИЛИЩА (ПО ДАННЫМ ЭКСПЕДИЦИОННЫХ ИССЛЕДОВАНИЙ 2020 г.)

The composition of bottom sediments and the patterns of their spatial distribution are determined by external (type of underlying surface of the catchment area, anthropogenic development, intensity of soil erosion) and internal (water regime, intensity of water exchange, morphometry of the basin) factors. As a result of the expedition studies of the IEVB RAS in the autumn period from September 14 to October 3, 2020, samples of bottom sediments were collected at 21 stations near of Kuibyshev reservoir dam in a 10-centimeter layer. Based on the results of the granulometric analysis and assessment of the organic matter content in the bottom sediment samples, integral granulometric curves were constructed and the spatial distribution of different characteristics of the bottom sediments was analyzed such as the percentage of organic matter in the samples, the interquartile range and the median value of the bottom sediment size at the studied sampling points. The analysis showed that the largest differences in the percentage of particles in the samples of the studied stations (over 60%) are accounted for by particles with a size of about 0,1 mm. Sampling stations located closer to the right bank are characterized by a smaller size of the bottom sediment soil than stations near the left bank. This is due to the fine-grained erosion products of the catchment area is characterized by a relatively uniform granulometric composition of bottom sediments, also mainly by dusty-sand fractions. More uniform in size soil is observed along the right bank – fine products of erosion of sandstones and dolomites of the right bank. The larger interquartile range characterizes the samples taken along the longitudinal profile of the reservoir dam reach and near the left bank in the shallow water zone. In this area of the water area, which is genetically composed of sands and mineral silts, due to the favorable temperature regime and the peculiarities of the circulation of water masses, intensive organic sedimentation processes occur. On average, for the dam reach the content of organic matter in the bottom sediments is 1,1%, which is in good agreement with the data of other researchers.

Recent trends in mountain lake primary production: evaluating the response to fish stocking relative to regional environmental stressors

Sia ME, Doyle RM, Moser KA. 2020. Recent trends in mountain lake primary production: evaluating the response to fish stocking relative to regional environmental stressors. Lake Reserv Manage. XX:XXX–XXX. Although mountain lakes are often remote, they are impacted by a myriad of stressors, including species introductions, atmospheric fertilization, and climate change. These stressors have the potential to increase primary production, which can threaten mountain lakes by decreasing water quality, reducing species richness, and lowering dissolved oxygen concentrations. The relative importance of these stressors as drivers of production is not well understood. We therefore investigated the importance of fish stocking, relative to other stressors, as a driver of primary production in mountain lakes. Our research focused on Uinta Mountain lakes, which, like many lakes in the western United States, were stocked with salmonid fish in the 1950s. In 2 stocked lakes and one unstocked lake, we reconstructed a record of ∼300 yr of primary production from lake sediments using changes in percentage of organic matter and spectrally inferred concentrations of chlorophyll a and its derivatives. With long-term trends in primary production, we determined that all 3 study lakes, including the unstocked lake, show unprecedented increases in primary production beginning in the 1950s. We attribute recent increases in primary production mainly to atmospheric deposition of nitrogen and climate warming, but do not rule out future impacts of fish stocking. Our article demonstrates how breakpoint analysis can be used to identify the most serious threats to mountain lakes, even if those lakes are impacted by multiple stressors or stressors originating from distant places.

Effect of Sulfur Levels and Number of Cuttings on Characteristics and the Yield of Barley (Hordeum vulgaire L)

Objective: Barley Hordeum vulgaire L is an important grain crop, and is grown in large areas all over the world. The experiment aims to study the effect of different levels of fertilizer from agricultural sulfur (0, 1500, 3000, and 4500 kg) S / H, and the number of cuttings (without cut, one cut, and cut twice) on the yield and quality of green forage and grain yield for barley crop Iba 99.&#x0D; Material and Methods: In this experiment, randomized whole section design was used in the arrangement of splinter panels - splinter with three replicates, sulfur levels for the secondary plates and the number of cuttings in the sub-plot plates.&#x0D; Results: The addition of agricultural sulfur at the level (4500 kg S / H) resulted in a significant increase in the following characteristics: - plant height, number of tillers / m2, number of spikes / m2 and grain yield. Whereas the sulfur level (3000 kg S / E) resulted in a significant increase in the two green forage yields and the number of grains / spike when added and for the first and second seasons in succession.&#x0D; Conclusion: Sulfur has significant effect on plant height and a significant effect of interference between sulfur levels and the number of leaves and number of tillers /m2, but it has no effect on the percentage of protein matter in green forage. The increase on sulfur has a significant effect on spike and gave the highest rate (509.4 spike / m2), and increase the protein level in grain to the highest rate 16.95.

Effect of Sulfur Levels and Number of Cuttings on Characteristics and the Yield of Barley (Hordeum vulgaire L)

Objective: Barley Hordeum vulgaire L is an important grain crop, and is grown in large areas all over the world. The experiment aims to study the effect of different levels of fertilizer from agricultural sulfur (0, 1500, 3000, and 4500 kg) S / H, and the number of cuttings (without cut, one cut, and cut twice) on the yield and quality of green forage and grain yield for barley crop Iba 99.&#x0D; Material and Methods: In this experiment, randomized whole section design was used in the arrangement of splinter panels - splinter with three replicates, sulfur levels for the secondary plates and the number of cuttings in the sub-plot plates.&#x0D; Results: The addition of agricultural sulfur at the level (4500 kg S / H) resulted in a significant increase in the following characteristics: - plant height, number of tillers / m2, number of spikes / m2 and grain yield. Whereas the sulfur level (3000 kg S / E) resulted in a significant increase in the two green forage yields and the number of grains / spike when added and for the first and second seasons in succession.&#x0D; Conclusion: Sulfur has significant effect on plant height and a significant effect of interference between sulfur levels and the number of leaves and number of tillers /m2, but it has no effect on the percentage of protein matter in green forage. The increase on sulfur has a significant effect on spike and gave the highest rate (509.4 spike / m2), and increase the protein level in grain to the highest rate 16.95.

Land-Cover Patterns and Hydrogeomorphology of Tributaries: Are These Important Stressors for the Water Quality of Reservoirs in the Mediterranean Region?

Four streams in the Guadiana watershed were followed up to assess hydrogeomorphological and physicochemical characteristics, and to analyze its correlation with land use/land cover (LULC), analyzing their possible influence in reservoir water quality and possible influence in the reservoir water quality. The highest amounts of organic descriptors and nutrients were quantified in streams with the major percentage of olive groves and vineyards and urban land cover classes. Streams more influenced by agro-silvo-pastoral class presented better water quality, as this type of LULC acts as a buffer of the contamination runoff. The results highlighted that the hydrogeomorphology of the streams may influence the transfer of pollutants loads to reservoirs. Hence, in intermittent streams characterized by coarse particles in the sediment, high amounts of pollutants are accumulated when the flow ceases, and are further transported to the reservoirs when the flow retakes. On the contrary, streams with sediments characterized by a great percentage of fine particles and organic matter do not induce so much stress in reservoirs, since these allow the adsorption of nutrients and trace elements, without their transfer to reservoirs.

Changes in physico-chemical properties of paddy soil due to water and fertilizer management

Soil physico-chemical properties are an important phenomenon for sustainable crop production and maintenance of optimum soil health. Hence, a laboratory measurement was conducted with soil samples of three years long experimental field of the Department of Soil Science, Bangladesh Agricultural University, Mymensingh to assess the changes in five selected soil physico-chemical properties viz. soil texture, bulk density, soil pH, total nitrogen and organic matter. The experiment was laid out in a split plot design with two water regimes (continuous flooding and alternate wetting &amp; drying) in the main plots and five fertilizer treatments (N0 - control, N1- 140 kg N/ha as PU, N2- 104 kg N/ha as USG (2× 1.8 g/ 4 hills), N3 - 5 t CD + PU @ 140 kg N /ha on IPNS basis and N4- 5 t CD + USG (2× 1.8 g/ 4 hills @ 104 kg N/ha)) in the subplots under rice-rice cropping pattern with three replications. After three years, soil samples were collected at 0-5 and 5-10 cm soil depths for measuring bulk density and at 0-10 cm depth for other soil properties and analyzed. Results found that % sand, % silt, % clay, bulk density and soil pH was not changed significantly compared to initial status. Percentage of total nitrogen and organic matter was significantly affected by irrigation and fertilization. Total nitrogen (%) was higher in AWD whereas organic matter (%) was higher in CF practice. The highest total nitrogen (%) and organic matter (%) was found in N4 treatment in which USG was applied in combination with cowdung as organic manure. It can be suggested that N4 treatment was formed good combination for sustaining chemical properties of soil. Further long- term experimentation will be needed to know the changes in soil properties for sustainable crop production and improving soil health.&#x0D; Asian Australas. J. Biosci. Biotechnol. 2020, 5 (2), 65-71

Propiedades físicas y químicas del suelo urbano del Bosque San Juan de Aragón, Ciudad de México

Ante la falta de estudios sobre suelos urbanos en México, en el presente trabajo se evaluaron ocho propiedades físicas y químicas empleadas por el Indicador Condición de Suelo del FIA (Programa Nacional de Inventario y Análisis Forestal, de Estados Unidos), para determinar la calidad de los suelos y su papel en el desarrollo de las especies arbóreas del Bosque de San Juan de Aragón. Las propiedades evaluadas y analizadas en términos horizontales y verticales, fueron: pH, conductividad eléctrica, contenido de sales, textura, densidad aparente, y porcentajes de materia orgánica, carbono orgánico y espacio poroso. Se colectaron 96 muestras de suelo sobre 28 sitios de muestreo de 0.1 ha, a tres profundidades, 0-5, 5-10 y 10‑15 cm. El pH promedio del suelo fue 7.2; conductividad eléctrica, 0.51 dS m-1; densidad aparente, 1.02 g cm-3; espacio poroso, 61.84%; sales disueltas totales, 327.20 mg L-1; materia orgánica, 3.6% y carbono orgánico, 2.63%, así como una clase textural franca. Los suelos del área de estudio presentaron variabilidad vertical para densidad aparente, espacio poroso, contenido de materia orgánica, carbono orgánico, conductividad eléctrica y sales solubles, y fueron relativamente homogéneos en sentido horizontal. Con excepción de la materia orgánica, el resto de las propiedades presentaron valores aceptables para el buen desarrollo de las diferentes especies arbóreas presentes en el bosque e identif icadas en estudios previos. La medición de las propiedades evaluadas, permitió obtener un panorama real sobre la capacidad de este suelo urbano para funcionar como soporte adecuado en el desarrollo de especies leñosas.