scholarly journals KARAKTERISTIK LAJU RESAPAN LUBANG BIOPORI PADA BEBERAPA JENIS SAMPAH ORGANIK

GANEC SWARA ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 1004
Author(s):  
I DEWA GEDE JAYA NEGARA ◽  
AGUSTONO SETIAWAN ◽  
HUMAIRO SAIDA ◽  
ADRI GUNAWAN
Keyword(s):  
Absorption Rate ◽  
Organic Waste ◽  
Food Source ◽  
Soil Layer ◽  
Soil Surface ◽  
Infiltration Rate ◽  
Household Waste ◽  
Residential Areas ◽  
Average Value ◽  
Test Points

      Many efforts have been made by various parties in overcoming the problem of waste and flooding, in residential areas that are starting to develop, one of which is by utilizing organic waste as a biopore filler to improve soil absorption and produce compost. The biopore infiltration hole technology can utilize organic waste to fill biopore media, which is used as a food source by biota in the soil layer. This study aims to determine the rate of biopore infiltration in the use of several types of organic waste such as (1) straw, (2) leaves and (3) household waste. Biopori is made from pipapvc 4 ”and 1 m in length with installation into the ground 80 cm and the rest above the soil surface 20 cm for testing purposes with a total of 12 test points and tested after 7 days to 21 days. For biopore holes without filler, the highest absorption rate was 85 cm / hour and the lowest was 42,167 cm / hour. The type of straw waste obtained infiltration rate of 179.34 cm / hour and the lowest infiltration rate of 86,770 cm / hour, with an average of 113.56 cm / hour. In the filler with leaf litter, the highest infiltration rate was 100,111 cm / hour and the lowest was 59,743 cm / hour, with an average value of 84.69 cm / hour. Whereas for household waste, the lowest absorption rate was 38 cm / hour and the highest was 100,111 cm / hour, and the average was 52,979 cm / hour. At the age of 7 days the waste has the highest absorption rate and after the waste is 21 days old it should be replaced with a new one.

scholarly journals Coarse Technogenic Material in Urban Surface Deposited Sediments (USDS)

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 754
Author(s):  
Andrian Seleznev ◽  
Ekaterina Ilgasheva ◽  
Ilia Yarmoshenko ◽  
Georgy Malinovsky
Keyword(s):  
Urban Landscape ◽  
Morphological Characteristics ◽  
Sem Analysis ◽  
Urban Surface ◽  
Household Waste ◽  
Residential Areas ◽  
Particle Size Fractions ◽  
Average Value ◽  
Urban Sediments ◽  
Quantitative Indicators

In the current paper, the analysis of heavy mineral concentrate (Schlich analysis) was used to study the particles of technogenic origin in the samples of urban surface-deposited sediments (USDS). The USDS samples were collected in the residential areas of 10 Russian cities located in different economic, climatic, and geological zones: Ufa, Perm, Tyumen, Chelyabinsk, Nizhny Tagil, Magnitogorsk, Nizhny Novgorod, Rostov-on-Don, Murmansk, and Ekaterinburg. The number of technogenic particles was determined in the coarse particle size fractions of 0.1–0.25 and 0.25–1 mm. The types of technogenic particle were studied by scanning electron microscopy (SEM) analysis. The amount of technogenic material differed from city to city; the fraction of technogenic particles in the samples varied in the range from 0.01 to 0.43 with an average value of 0.18. The technogenic particles in USDS samples were represented by lithoid and granulated slag, iron and silicate microspheres, fragments of brick, paint, glass, plaster, and other household waste. Various types of technogenic particle differed in morphological characteristics as well as in chemical composition. The novelty and significance of the study comprises the following: it has been shown that technogenic particles are contained in a significant part of the USDS; the quantitative indicators of the accumulation of technogenic particles in the urban landscape have been determined; the contributions of various types of particles to the total amount of technogenic material were estimated for the urban landscape; the trends in the transformation of typomorphic elemental associations in the urban sediments associated with the material of technogenic origin were demonstrated; and the alteration trends in the USDS microelemental content were revealed, taking into account the impurities in the composition of technogenic particles.

scholarly journals Coal Fly Ash and Polyacrylamide Influence Transport and Redistribution of Soil Nitrogen in a Sandy Sloping Land

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Kai Yang ◽  
Zejun Tang ◽  
Jianzhang Feng
Keyword(s):  
Fly Ash ◽  
Sandy Soil ◽  
Coal Fly Ash ◽  
Soil Layer ◽  
Nutrient Retention ◽  
Soil Surface ◽  
Rainfall Event ◽  
N Losses ◽  
N Concentration ◽  
Application Rates

Sandy soils are prone to nutrient losses, and consequently do not have as much as agricultural productivity as other soils. In this study, coal fly ash (CFA) and anionic polyacrylamide (PAM) granules were used as a sandy soil amendment. The two additives were incorporated to the sandy soil layer (depth of 0.2 m, slope gradient of 10°) at three CFA dosages and two PAM dosages. Urea was applied uniformly onto the low-nitrogen (N) soil surface prior to the simulated rainfall experiment (rainfall intensity of 1.5 mm/min). The results showed that compared with no addition of CFA and PAM, the addition of CFA and/or PAM caused some increases in the cumulative NO3−-N and NH4+-N losses with surface runoff; when the rainfall event ended, 15% CFA alone treatment and 0.01–0.02% PAM alone treatment resulted in small but significant increases in the cumulative runoff-associated NO3−-N concentration (p < 0.05), meanwhile 10% CFA + 0.01% PAM treatment and 15% CFA alone treatment resulted in nonsignificant small increases in the cumulative runoff-associated NH4+-N concentration (p > 0.05). After the rainfall event, both CFA and PAM alone treatments increased the concentrations of NO3−-N and NH4+-N retained in the sandy soil layer compared with the unamended soil. As the CFA and PAM co-application rates increased, the additive effect of CFA and PAM on improving the nutrient retention of sandy soil increased.

Application of the vertical model of the seasonally thawed layer for the Tulik Lake area (Alaska)

2021 ◽  
pp. 4-15
Author(s):  
Виктор Михайлович Белолипецкий ◽  
Светлана Николаевна Генова
Keyword(s):  
Air Temperature ◽  
Stefan Problem ◽  
Soil Layer ◽  
Vertical Direction ◽  
Soil Surface ◽  
Dirichlet Condition ◽  
Transfer Model ◽  
Problem Solution ◽  
Computational Domain ◽  
Lake Area

Практический интерес в районах вечной мерзлоты представляет глубина сезонного оттаивания. Построена одномерная (в вертикальном направлении) упрощенная полуэмпирическая модель динамики вечной мерзлоты в “приближении медленных движений границ фазового перехода”, основанная на задаче Стефана и эмпирических соотношениях. Калибровочные параметры модели выбираются для исследуемого района с использованием натурных измерений глубины оттаивания и температуры воздуха. Проверка работоспособности численной модели проведена для района оз. Тулик (Аляска). Получено согласие рассчитанных значений глубины талого слоя и температуры поверхности почвы с результатами измерений Due to the change in global air temperature, the assessment of permafrost reactions to climate change is of interest. As the climate warms, both the thickness of the thawed soil layer and the period for existence of the talik are increased. The present paper proposes a small-size numerical model of vertical temperature distributions in the thawed and frozen layers when a frozen layer on the soil surface is absent. In the vertical direction, thawed and frozen soils are separated. The theoretical description of the temperature field in soils when they freeze or melt is carried out using the solution of the Stefan problem. The mathematical model is based on thermal conductivity equations for the frozen and melted zones. At the interfacial boundary, the Dirichlet condition for temperature and the Stefan condition are set. The numerical methods for solving of Stefan problems are divided into two classes, namely, methods with explicit division of fronts and methods of end-to-end counting. In the present work, the method with the selection of fronts is implemented. In the one-dimensional Stefan problem, when transformed to new variables, the computational domain in the spatial variable is mapped onto the interval [0 , 1]. In the presented equations, the convective terms characterize the rate of temperature transfer (model 1). A simplified version of the Stefan problem solution is considered without taking into account this rate (“approximation of slow movements of the boundaries of the phase transition”, model 2). The model is tuned to a specific object of research. Model parameter values can vary significantly in different geographic regions. This paper simulates the dynamics of permafrost in the area of Lake Tulik (Alaska) in summer. Test calculations based on the proposed simplified model show its adequacy and consistency with field measurements. The developed model can be used for qualitative studies of the long-term dynamics of permafrost using data of the air temperature, relative air humidity and precipitation

scholarly journals MODIFIKASI BARU ALGORITMA KOLONI LEBAH BUATAN UNTUK MASALAH OPTIMASI GLOBAL

2018 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Nursyiva Irsalinda ◽  
Sugiyarto Surono
Keyword(s):  
Food Source ◽  
Artificial Bee Colony ◽  
Selection Process ◽  
Optimization Technique ◽  
Food Sources ◽  
Abc Algorithm ◽  
Average Value ◽  
Bee Colony ◽  
Objective Function Values ◽  
Better Than

Artificial Bee Colony (ABC) algorithm is one of metaheuristic optimization technique based on population. This algorithm mimicking honey bee swarm to find the best food source. ABC algorithm consist of four phases: initialization phase, employed bee phase, onlooker bee phase and scout bee phase. This study modify the onlooker bee phase in selection process to find the neighborhood food source. Not all food sources obtained are randomly sought the neighborhood as in ABC algorithm. Food sources are selected by comparing their objective function values. The food sources that have value lower than average value in that iteration will be chosen by onlooker bee to get the better food source. In this study the modification of this algorithm is called New Modification of Artificial Bee Colony Algorithm (MB-ABC). MB-ABC was applied to 4 Benchmark functions. The results show that MB-ABC algorithm better than ABC algorithm

scholarly journals Salinity Status of Lajas Valley Soils

1969 ◽  
Vol 41 (1) ◽  
pp. 25-34
Author(s):  
Juan A. Bonnet ◽  
Eduardo J. Brenes
Keyword(s):  
Electrical Conductivity ◽  
Hydraulic Conductivity ◽  
Soil Layer ◽  
Soil Surface ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Surface Layers ◽  
Alkali Soils ◽  
The World ◽  
Sodium Percentage

1. The area of soils surveyed in Lajas Valley was 24,656 acres. 2. The soils were classified into normal, saline, saline-alkali, and non- saline-alkali at depths of 0 to 8, 8 to 24, 24 to 48, and 48 to 72 inches, respectively. 3. A large percentage of normal soils was found in the upper soil layer and of saline-alkali soils in the lower layers. 4. Normal soils occupied about 86 percent of the surface area to a depth of 8 inches and about 63 percent at a depth of 8 to 24 inches. 5. Soils with a salinity problem increased from 9 percent at a depth of 8 inches to 28.3, 58.8 and 68.5 percent, respectively, at depths of 8 to 24, 24 to 48, and 48 to 72 inches. 6. The soils with a salinity problem were largely of the saline-alkali class. 7. In four soil-profile samples taken from Lajas Valley, the saturation percentage varied from 58 to 191, the electrical conductivity from 0.8 to 28.4 millimhos per centimeter, the exchangeable-sodium percentage from 2.2 to 46.0, the soil pH from 8.1 to 8.9, the content of gypsum from 0 to 21.9 tons per acre-foot, the gypsum requirement from 0 to 23.8 tons per acre-foot, and the hydraulic conductivity from less than 0.005 to 6.24 inches of water per hour. Higher gypsum contents were found in the deep subsoil layers of two soils (profiles 1 and 4). Amounts of gypsum varying from 9.9 to 20.3 tons per acre-foot of depth, are required for the reclamation of the surface layers of these two profiles. In general, the hydraulic- conductivity values show that the soil-surface layers are more permeable than the subsoil layers. 8. The procedure and methods used in this paper were found to be accurate, simple, rapid, and practical. They are recommended for the coordination of data related to the classification and reclamation of soils affected by salinity problems in the different countries of the world.

scholarly journals Dynamics simulation of ammonia nitrogen absorption in a rural–urban canal on the Northeast China Plain

2018 ◽  
Vol 78 (3) ◽  
pp. 622-633 ◽  
Author(s):  
Yujia Song ◽  
Xiaodong Wang ◽  
Haiying Zhang
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Absorption Rate ◽  
Ammonia Nitrogen ◽  
Dynamics Simulation ◽  
Background Concentration ◽  
Absorption Length ◽  
Average Value ◽  
Variation Range

Abstract To study dynamic laws of ammonia nitrogen retention in a typical rural–urban fringe canal, NaBr was selected as a conservative tracer agent, and NH4Cl as an additive nutritive salt to conduct an instantaneously added tracer experiment outdoors. On this basis, tracer additions for spiralling curve characterisation (TASCC) method and nutritive spiral indexes were used for the quantitative depiction of retention dynamics of NH4+-N. The Michaelis–Menten (M-M) model was used to simulate absorption dynamic characteristics of NH4+-N. Results showed that the variation range of absorption length of NH4+-N under background concentration was 93.94–295.54 m with an average value of 177.41 m, the variation range of mass transfer coefficient was 0.16–0.38 mm/s with an average value of 0.26 mm/s, and the variation range of absorption rate was 0.16–0.38 mg/(m2⋅s) with an average value of 0.26 mg/(m2⋅s). The maximum absorption rate of NH4+-N obtained via M-M equation simulation was 0.59–1.38 mg/(m2⋅s), and the subsaturation constant was 1.10–5.03 mg/L. The variability of the dynamic absorption length, overall dynamic absorption rate, and overall dynamic mass transfer coefficient shown by NH4+-N within the range from background concentration to saturation concentration certified that TASCC could analyse the dynamic process of NH4+-N retention and absorption by the canal.

scholarly journals The Soil Moisture during Dry Spells Model and Its Verification

Resources ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 85
Author(s):  
Małgorzata Biniak-Pieróg ◽  
Mieczysław Chalfen ◽  
Andrzej Żyromski ◽  
Andrzej Doroszewski ◽  
Tomasz Jóźwicki
Keyword(s):  
Soil Moisture ◽  
Least Squares Method ◽  
Soil Depth ◽  
Soil Layer ◽  
Atmospheric Precipitation ◽  
Soil Surface ◽  
Model Verification ◽  
Individual Measurement ◽  
Dry Spells ◽  
Dry Spell

The objective of this study was the development and verification of a model of soil moisture decrease during dry spells—SMDS. The analyses were based on diurnal information of the occurrence of atmospheric precipitation and diurnal values of soil moisture under a bare soil surface, covering the period of 2003–2019, from May until October. A decreasing exponential trend was used for the description of the rate of moisture decrease in six layers of the soil profile during dry spells. The least squares method was used to determine, for each dry spell and soil depth, the value of exponent α , which described the rate of soil moisture decrease. Data from the years 2003–2015 were used for the identification of parameter α of the model for each of the layers separately, while data from 2016–2019 were used for model verification. The mean relative error between moisture values measured in 2016–2019 and the calculated values was 3.8%, and accepted as sufficiently accurate. It was found that the error of model fitting decreased with soil layer depth, from 8.1% for the surface layer to 1.0% for the deepest layer, while increasing with the duration of the dry spell at the rate of 0.5%/day. The universality of the model was also confirmed by verification made with the use of the results of soil moisture measurements conducted in the years 2009–2019 at two other independent locations. However, it should be emphasized that in the case of the surface horizon of soil, for which the process of soil drying is a function of factors occurring in the atmosphere, the developed model may have limited application and the obtained results may be affected by greater errors. The adoption of calculated values of coefficient α as characteristic for the individual measurement depths allowed calculation of the predicted values of moisture as a function of the duration of a dry spell, relative to the initial moisture level adopted as 100%. The exponential form of the trend of soil moisture changes in time adopted for the analysis also allowed calculation of the duration of a hypothetical dry spell t, after which soil moisture at a given depth drops from the known initial moisture θ0 to the predicted moisture θ. This is an important finding from the perspective of land use.

scholarly journals EXPERIMENTAL INVESTIGATION OF BIOGAS PRODUCTION USING FATTY WASTE/BIODUJŲ GAMYBOS EKSPERIMENTINIAI TYRIMAI PANAUDOJANT RIEBALINES ATLIEKAS/ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ ПРОИЗВОДСТВА БИОГАЗА C ИСПОЛЬЗОВАНИЕМ ЖИРОВЫХ ОТХОДОВ

2008 ◽  
Vol 16 (4) ◽  
pp. 178-187 ◽  
Author(s):  
Pranas Baltrėnas ◽  
Mindaugas Kvasauskas
Keyword(s):  
Experimental Investigation ◽  
Sewage Sludge ◽  
Organic Waste ◽  
Biogas Production ◽  
Ph Indicator ◽  
Ph Change ◽  
Average Value ◽  
Temperature Mode ◽  
Biogas Output ◽  
Sulphuretted Hydrogen

The paper presents the findings of experimental investigation of biogas production using hen manure and sewage sludge with fatty waste (from margarine production). The following mixtures were made using this organic waste: hen manure and sewage sludge were mixed with fatty waste at 75% : 25%, 50% : 50% and 25% : 75% in volume. The paper analyses quantitative and qualitative composition of biogas: gas emission content, the concentrations of methane, sulphuretted hydrogen and oxygen in it as well as temperature and pH change during the experiment. Mixing hen manure with fatty waste at 75% : 25% and maintaining psychrophilic temperature mode, the highest biogas output (0.09 m3) from 0.2 m3 substrate in 32 days was recorded. When using the mixture of sewage sludge and fatty waste at 75% : 25% and maintaining psychrophilic temperature mode, the highest biogas output (0.10 m) from 0.2 m substrate in 32 days was recorded. When using these mixtures, the concentration of methane was also the highest, and the average values reached 58.5% (with hen manure) and 61.7% (with sewage sludge). The evaluation of gas emissions and methane concentration in gas shows that the most efficient use of biogas could be obtained using biogas emitted from the mixture of hen manure and sewage sludge with fatty waste mixed at 75% : 25%. The concentration of sulphuretted hydrogen in biogas did not exceed 3%, the concentration of oxygen decreased from 4.9 % to 1.8%. pH indicator was decreasing when more fatty waste was added to the mixture. When using hen manure, the average value of pH changed from 6.4 to 6.3, when using sewage sludge ‐ from 6.6 to 6.3. Santrauka Pateikiami eksperimentinių biodujų gamybos tyrimų, naudojant vištų mėšlą ir nuotekų valymo dumblą su riebalinėmis (margarino gamybos) atliekomis, rezultatai. Iš šių organinių atliekų buvo paruošti mišiniai: vištų mėšlas bei nuotekų valymo dumblas buvo maišomas su riebalinėmis atliekomis 75 % : 25 %, 50 % : 50 % ir 25 % : 75 %. Darbe nagrinėjama biodujų kiekybinė ir kokybinė sudėtis: išsiskyrusių dujų kiekis, metano, sieros vandenilio ir deguonies koncentracija jose, temperatūros bei pH pokytis eksperimento metu. Eksperimentų metu bioreaktoriuose buvo palaikomas psichrofilinis temperatūrinis režimas. Nustatyta, kad didžiausias biodujų kiekis (0,09 m3 ) išsiskiria vištų mėšlą maišant su riebalinėmis atliekomis santykiu 75 % : 25 %. Naudojant nuotekų valymo dumblo ir riebalinių atliekų mišinį (75 % : 25 %), taip pat gauta didžiausia biodujų išeiga per visą eksperimento laikotarpį – 0,10 m3 . Metano koncentracija naudojant šiuos mišinius taip pat buvo didžiausia. Vidutinė reikšmė siekė 58,5 % (su vištų mėšlu) bei 61,7 % (su nuotekų dumblu). Įvertinus išsiskyrusių dujų kiekį ir metano koncentraciją jose, nustatyta, kad efektyviausiai būtų galima naudoti biodujas, išsiskyrusias iš vištų mėšlo ir nuotekų valymo dumblo su riebalinėmis atliekomis, kurių santykis 75 % : 25 %. Sieros vandenilio koncentracija biodujose neviršijo 3 %, deguonies koncentracija mažėjo nuo 4,9 % iki 1,8 %. pH rodiklis mažėjo į biomasės mišinį įdedant daugiau riebalinių atliekų. Naudojant vištų mėšlą vidutinė pH reikšmė kito nuo 6,4 iki 6,3, naudojant nuotekų valymo dumblą – nuo 6,6 iki 6,3. Резюме Представлены результаты экспериментальных исследований по производству биогаза с использованием куриного помета и ила сточных вод с жировыми отходами (от производства маргарина). Были исследованы следующие смеси из органических отходов: куриный помет и ил сточных вод были смешаны с жировыми отходами в объеме 75% : 25%, 50% : 50% и 25% : 75%. Проанализирован количественный и качественный состав биогаза: газовое содержание эмиссии, концентрации метана, сероводорода и кислорода, а также изменение температуры и фактора pH в течение эксперимента. Во время эксперимента в биореакторе поддерживался психрофильный температурный режим. Было установлено, что при смешивании куриного помета с жировыми отходами в соотношении 75% : 25% и поддерживании психрофильного температурного режима наибольший выпуск биогаза (от 0,09 м3 до 0,2 м3 субстрата) обнаружен спустя 32 дня. При использовании смеси из ила сточных вод и жировых отходов в соотношении 75% : 25% и поддерживании психрофильного температурного режима был установлен наибольший выпуск биогаза (от 0,10 м3 до 0,2 м3 субстрата) спустя 32 дня. При использовании этих смесей концентрация метана также была самая большая, ее средние значения составляли 58,5% (с куриным пометом) и 61,7% (с илом сточных вод). В результате оценки газовой эмиссии и концентрации метана в эмиссии установлено, что наиболее эффективным будет использование биогаза, получаемого от смеси куриного помета и ила сточных вод с жировыми отходами в соотношении 75% : 25%. Концентрация сероводорода в биогазе не превышала 3%, концентрация кислорода уменьшилась от 4,9% до 1,8%. Индикатор фактора pH уменьшался, когда к смеси добавлялось больше жировых отходов. При использовании только куриного помета среднее значение фактора pH менялось от 6,4 до 6,3, при использовании ила сточных вод – от 6,6 до 6,3.

scholarly journals Determinants of Household Solid Waste Generation and Composition in Homs City, Syria

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Mohamad Noufal ◽  
Liu Yuanyuan ◽  
Zena Maalla ◽  
Sylvia Adipah
Keyword(s):  
Waste Management ◽  
Solid Waste ◽  
Organic Waste ◽  
Solid Waste Management ◽  
Household Head ◽  
Household Waste ◽  
Waste Generation ◽  
Entire Study ◽  
Household Solid Waste ◽  
Starting Point

The absence of accurate information on the state of waste is a challenge to the solid waste management system in Syria. The local authorities commonly estimate the quantity of waste produced and its characterisation, which is the starting point for solid waste management planning. So, this paper aims to evaluate the generation and composition of household solid waste in Homs city, Syria. Also, the study presents factors influencing the waste generation rate and the waste composition. The study was carried out in 300 families from four zones in Homs city, and three sampling stages were conducted during the study duration, which started in July 2017 and ended in February 2019. The outcomes show that an average of 0.68 kg/per/day solid waste generated was calculated for the entire study area in Homs city. Also, the data analysis presents that organic waste constitutes the largest component in the waste mixture (69.1%) followed by plastic (10.6%), inert materials (8.7%), paper (4.6%), textile (2.5%), metal (1.2%), glass (1.1%), wood (0.6%), and hazardous materials (1.6%). The multiple linear regression results showed that the adjusted R2 value was found to be 0.557, 0.839, and 0.709 for the waste generation per capita, the daily household organic waste generation, and the daily household packaging waste generation, respectively. Also, according to Pearson’s coefficient values, a positive correlation was found between household waste generation and monthly income (r = 0.626), household size (r = 0.37), and age of the household head (r = 0.517), whereas a negative correlation was found between household waste generation and the education level of the household head (r = −0.649).

scholarly journals Characteristics of Soil Moisture and Evaporation under the Activities of Earthworms in Typical Anthrosols in China

2020 ◽  
Vol 12 (16) ◽  
pp. 6603
Author(s):  
Li Ma ◽  
Ming’an Shao ◽  
Tongchuan Li
Keyword(s):  
Soil Temperature ◽  
Soil Water ◽  
Agricultural Development ◽  
Soil Layer ◽  
Soil Surface ◽  
Soil Evaporation ◽  
Water Evaporation ◽  
Soil Columns ◽  
Soil Surface Temperature ◽  
Water Holding

Earthworms have an important influence on the terrestrial ecological environment. This study assesses the effect of different earthworm densities on soil water content (SWC) and evaporation in a laboratory experiment. Four earthworm densities (0 no-earthworm, control [C]; 207 earthworms m−2, low density [LDE]; 345 earthworms m−2, medium density [MDE]; and 690 earthworms m−2, high density [HDE]) are tested in soil columns. Results show that cumulative evaporation occurs in the decreasing order of densities: C (98.6 mm) > LDE (115.8 mm) > MDE (118.4 mm) > HDE (124.6 mm). Compared with the control, earthworm activity decreases cumulative soil evaporation by 5.0–20.9%, increases soil temperature to 0.46 °C–0.63 °C at 8:00, and decreases soil temperature to 0.21 °C–0.52 °C at 14:00 on the soil surface. Temperature fluctuations reduce with increasing earthworm densities. A negative correlation is found between cumulative soil evaporation and earthworm density (R2 = 0.969, p < 0.001). Earthworms significantly (p < 0.05) decrease the surface SWC loss (0–20 cm) soil layer but increase the subsoil SWC loss (60–100 cm) by adjusting the soil temperature and reducing soil water evaporation. Earthworm activities (burrows, casts…) improve the soil water holding ability by adjusting soil temperature and reducing soil water evaporation. Thus, the population quantity of earthworms may provide valuable ecosystem services in soil water and heat cycles to save water resources and realize sustainable agricultural development.

Sign in / Sign up

Export Citation Format

Share Document