FACTORS AFFECTING THE ASSIMILATION OF ORGANIC MATTER BY ZOOPLANKTON AND THE QUESTION OF SUPERFLUOUS FEEDING1

Black soil is fertile, abundant with organic matter (OM) and is exceptional for farming. The black soil zone in northeast China is the third-largest black soil zone globally and produces a quarter of China’s commodity grain. However, the soil organic matter (SOM) in this zone is declining, and the quality of cultivated land is falling off rapidly due to overexploitation and unsustainable management practices. To help develop an integrated protection strategy for black soil, this study aimed to identify the primary factors contributing to SOM degradation. The geographic detector, which can detect both linear and nonlinear relationships and the interactions based on spatial heterogeneous patterns, was used to quantitatively analyze the natural and anthropogenic factors affecting SOM concentration in northeast China. In descending order, the nine factors affecting SOM are temperature, gross domestic product (GDP), elevation, population, soil type, precipitation, soil erosion, land use, and geomorphology. The influence of all factors is significant, and the interaction of any two factors enhances their impact. The SOM concentration decreases with increased temperature, population, soil erosion, elevation and terrain undulation. SOM rises with increased precipitation, initially decreases with increasing GDP but then increases, and varies by soil type and land use. Conclusions about detailed impacts are presented in this paper. For example, wind erosion has a more significant effect than water erosion, and irrigated land has a lower SOM content than dry land. Based on the study results, protection measures, including conservation tillage, farmland shelterbelts, cross-slope ridges, terraces, and rainfed farming are recommended. The conversion of high-quality farmland to non-farm uses should be prohibited.

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The prediction of voluntary intake of grazing dairy cows

The Journal of Agricultural Science ◽

10.1017/s0021859600066788 ◽

1986 ◽

Vol 107 (1) ◽

pp. 43-54 ◽

Cited By ~ 23

Author(s):

Lindsey Caird ◽

W. Holmes

Keyword(s):

Organic Matter ◽

Measurement Techniques ◽

Live Weight ◽

Simple Equation ◽

Factors Affecting ◽

Farm Planning ◽

Sward Height ◽

The Mean ◽

Major Factors ◽

Grazing Dairy Cows

SUMMARYInformation on the total organic matter intake, concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY), herbage organic matter digestibility (HOMD), herbage mass, sward height (SHT) or herbage allowance (HAL) measured individually for 357 cows at one of three sites was assembled. Observed intake was compared with intakes predicted by existing intake equations and new prediction equations based on regression models or regression and least-squares constants were developed. Major factors affecting intake were MY, LW, WL, C and HAL or SHT. Although HOMD was correlated with intake, better predictions were obtained when HOMD was omitted. There were differences between sites possibly associated with differences in measurement techniques.The predictive value of some existing equations and new equations were tested against independent sets of data. A simple equation (A) based on MY and LW (Ministry of Agriculture, Fisheries and Food, 1975) gave satisfactory average predictions but the mean square prediction error (MSPE) was high. The equations of Vadiveloo & Holmes (1979) adjusted for bias gave a relatively low MSPE. The preferred new equations for grazing cattle included MY, LW, WL, C and HAL or SHT, and their MSPE were similar to or lower than for indoor equations.The discussion indicates that a simple equation (A) would give adequate predictions for farm planning. The more detailed equations illustrate the inter-relations of animal with sward conditions and concentrate allowances. Predicted intakes may deviate from actual intakes because of short-term changes in body reserves.

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Physio-chemical properties and dynamic of the surface sediment in riparian mangroves along the Tien river, Tien Giang province

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v2i5.777 ◽

2019 ◽

Vol 2 (5) ◽

pp. 50-58

Author(s):

Hung Duc Nguyen ◽

Ngot Van Pham ◽

Duy Van Nguyen

Keyword(s):

Electrical Conductivity ◽

Organic Matter ◽

Surface Sediment ◽

Chemical Properties ◽

Total Sulfur ◽

Mean Sea Level ◽

Factors Affecting ◽

Sediment Samples ◽

Mesohaline Zone ◽

Saturated Extract

This study was conducted to investigate the physio-chemical properties and vertical dynamic of the surface sediment (0–5 cm) in riparian mangroves along the Tien river, Tien Giang province. The distribution of riparian mangroves located from the polyhaline zone (transect S1 and S2) to the mesohaline zone (transect S3 and S4) and the oligohaline zone (transect S5). Three plots (10x10 m) per transect were set based on the elevation of the mangrove floor (cm + mean sea level) and dominant plants. A total of 28 sediment samples were collected in December 2016 and April 2017. Seasonal variation of pH, redox potential (Eh), electrical conductivity of saturated extract (ECse), bulk density, sediment organic matter (SOM) and total sulfur (TS) were measured in accordance with the standard protocols. Seasonal trends of vertical erosion and accumulation were tested by the tracer stick method. The ECse values and TS concentrations were higher in the dry season and in transects closed to the estuary (S1, S2 and S3) but these trends weren’t found for pH, Eh, and SOM. In most of the riparian mangroves along the Tiền river, low elevation (0–50 cm) was one of important factors affecting the Eh and ECse. In the rainy season, major changes in vertical erosion and acumulation have occurred in the transects near the mouth of the river.

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Wastewater modification processes assessment in a stabilization reservoir

Water Science & Technology ◽

10.2166/wst.2008.203 ◽

2008 ◽

Vol 57 (7) ◽

pp. 1037-1045 ◽

Cited By ~ 2

Author(s):

G. Mannina ◽

G. Mancini ◽

M. Torregrossa ◽

G. Viviani

Keyword(s):

Organic Matter ◽

Performance Optimization ◽

Flow Reactor ◽

Batch Reactor ◽

Mechanistic Model ◽

Resource Planning ◽

Treated Wastewater ◽

State Variables ◽

Factors Affecting ◽

Effluent Quality

A semi-empirical mechanistic model able to simulate the dynamics of a stabilization reservoir was developed incorporating both settling of particulate components and chemical/biological processes. Several factors affecting the reservoir effluent quality were taken into account: hydraulics and hydrology, solar radiation, atmospheric reaeration, algae, zooplankton, organic matter, pathogen bacteria, and sediment-water interaction. The model quantifies the specific influence of each factor on effluent quality, evaluating the correlation between the different considered factors. State variables included in the model were: algae, dissolved oxygen, organic matter, zooplankton and indicator bacteria. The model was transferred into a computational code in order to provide a useful and versatile tool for water resource planning management issues. The model was verified by comparing simulated results with full-scale data collected from a small reservoir (Sicily, IT) filled with partially treated wastewater. The reservoir has a volume of 11,000 m3, a maximum depth of 6.3 m and a mean depth of about 5 m. The monitoring period lasted four months during which the reservoir operated in different hydraulics conditions: as a standard batch reactor and as a continuous flow reactor. The model was able to reproduce the behaviour of the principal simulated parameters thus representing a potential tool for the management and performance optimization of these peculiar storage/treatment systems.

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Transport characterizations of natural organic matter in ion-exchange membrane for water treatment

Water Science & Technology Water Supply ◽

10.2166/ws.2002.0202 ◽

2002 ◽

Vol 2 (5-6) ◽

pp. 445-450 ◽

Cited By ~ 2

Author(s):

D.H. Kim ◽

S.-H. Moon ◽

J. Cho

Keyword(s):

Organic Matter ◽

Ionic Strength ◽

Ion Exchange ◽

Natural Organic Matter ◽

Membrane Surface ◽

Factors Affecting ◽

Organic Fouling ◽

Adsorbed Mass ◽

Pass Through ◽

Exchange Membrane

A series of adsorption experiments were performed to investigate the factors affecting the transport of natural organic matter (NOM) in an ion-exchange (IX) membrane. In this study, the structure of the NOM was hypothesized to be an important factor in terms of the organic fouling of IX membrane. It was found that the adsorbed mass of hydrophobic NOM constituent on the membrane surface was higher than that of either the hydrophilic or transphilic NOM constituent. NOM adsorption was seriously affected by the apparent charge of the NOM. As the apparent charge increased, NOM adsorption also significantly increased. Moreover, the molecular mass of the hydrophobic NOM acids was too high to enable them to pass through the IX membrane, and this caused an accumulated adsorption of solutes on the membrane surface, i.e. NOM fouling. In addition, both pH and ionic strength affected NOM adsorption on the surface of the IX membrane. Lower NOM adsorption resulted from a lower pH and a higher ionic strength.

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Factors affecting soil organic matter conservation in Mediterranean hillside winter cereals-legumes cropping systems

Italian Journal of Agronomy ◽

10.4081/ija.2012.e38 ◽

2012 ◽

Vol 7 (3) ◽

pp. 38 ◽

Cited By ~ 5

Author(s):

Elisa Marraccini ◽

Marta Debolini ◽

Claudia Di Bene ◽

Hélène Rapey ◽

Enrico Bonari

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Cropping Systems ◽

Factors Affecting ◽

Winter Cereals

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Surface coating effects on the sorption and dissolution of ZnO nanoparticles in soil

Environmental Science Nano ◽

10.1039/c9en00348g ◽

2019 ◽

Vol 6 (8) ◽

pp. 2495-2507 ◽

Cited By ~ 6

Author(s):

Zeinah Elhaj Baddar ◽

Chris J. Matocha ◽

Jason M. Unrine

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Soil Ph ◽

Zno Nanoparticles ◽

Surface Coating ◽

Factors Affecting ◽

Soil P

Soil pH and dissolved organic matter (DOM) content are among the most important factors affecting the bioavailability of Zn and the binding and dissolution of ZnO nanoparticles (NPs).

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The carbon cycle and carbon dioxide over Phanerozoic time: the role of land plants

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1998.0192 ◽

1998 ◽

Vol 353 (1365) ◽

pp. 75-82 ◽

Cited By ~ 164

Author(s):

Robert A. Berner

Keyword(s):

Organic Matter ◽

Carbon Cycle ◽

Vascular Plants ◽

Global Climate ◽

Carbon Isotopic Composition ◽

Field Studies ◽

Accelerated Weathering ◽

Fossil Plants ◽

Factors Affecting ◽

Carbon Isotopic

A model (GEOCARB) of the long–term, or multimillion year, carbon cycle has been constructed which includes quantitative treatment of (1) uptake of atmospheric CO 2 by the weathering of silicate and carbonate rocks on the continents, and the deposition of carbonate minerals and organic matter in oceanic sediments; and (2) the release of CO 2 to the atmosphere via the weathering of kerogen in sedimentary rocks and degassing resulting from the volcanic–metamorphic–diagenetic breakdown of carbonates and organic matter at depth. Sensitivity analysis indicates that an important factor affecting CO 2 was the rise of vascular plants in the Palaeozoic. A large Devonian drop in CO 2 was brought about primarily by the acceleration of weathering of silicate rock by the development of deeply rooted plants in well–drained upland soils. The quantitative effect of this accelerated weathering has been crudely estimated by present–day field studies where all factors affecting weathering, other than the presence or absence of vascular plants, have been held relatively constant. An important additional factor, bringing about a further CO 2 drop into the Carboniferous and Permian, was enhanced burial of organic matter in sediments, due probably to the production of microbially resistant plant remains (e.g. lignin). Phanerozoic palaeolevels of atmospheric CO 2 calculated from the GEOCARB model generally agree with independent estimates based on measurements of the carbon isotopic composition of palaeosols and the stomatal index for fossil plants. Correlation of CO 2 levels with estimates of palaeoclimate suggests that the atmospheric greenhouse effect has been a major factor in controlling global climate over the past 600 million years.

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CO2 fluxes and carbon balance of an agricultural grassland in southern Finland

10.5194/egusphere-egu2020-6618 ◽

2020 ◽

Author(s):

Laura Heimsch ◽

Annalea Lohila ◽

Liisa Kulmala ◽

Juha-Pekka Tuovinen ◽

Mika Korkiakoski ◽

...

Keyword(s):

Climate Change ◽

Organic Matter ◽

Soil Organic Matter ◽

Carbon Balance ◽

Management Practices ◽

Agricultural Soils ◽

Weather Conditions ◽

Factors Affecting ◽

Management Procedures ◽

Mitigate Climate Change

Agriculture is globally a significant source of carbon emissions to the atmosphere. Main causes for these high emissions are conventional intensive management practices which include such as frequent ploughing, monocropping and high use of agrochemicals. These practices contribute to the loss of biodiversity and soil organic matter, as well as to the CO2 emissions from land use. Recently, it has been recognised that agriculture functioning on the basis of regenerative practices is one of the most potential tools to mitigate climate change.It is well known that topsoil layer and especially humus-rich soils can store more carbon than atmosphere and vegetation together. Therefore, increasing the amount of soil organic matter in the agroecosystems, by applying enhanced management practices such as reduced tillage, high biodiversity and cover cropping, agricultural soils would not only help to mitigate climate change but also to restore soil quality and fertility. To understand the carbon dynamics on different agricultural sites, factors affecting and comprising the carbon balance, and to verify soil carbon and ecosystem models, continuous long-term monitoring of the GHG fluxes is essential at such managed ecosystems. Here we present results from a new eddy covariance (EC) flux study site located in southern Finland.Continuous CO2 flux measurements using the EC method have been conducted at Qvidja farm on mineral (clay) soil forage grassland in Parainen, southern Finland (60.29550&#176;N, 22.39281&#176;E) since the spring 2018. Based on the flux and biomass data, the annual carbon balance was estimated to be negative, i.e. the site acted as an overall sink of carbon even in the dry and hot year 2018. However, the seasonal CO2 fluxes were greatly dependent on weather conditions and management procedures. Results from 2019 show that the growing season accompanied with more mature and dense grass, a bit higher precipitation and lower temperatures, as well as higher cutting height was more favorable for carbon uptake in Qvidja as compared to year 2018.

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