Dynamics of Soil Surface Bulk Density: Role of Water Table Elevation and Rainfall Duration

2008 ◽  
Vol 72 (2) ◽  
pp. 412-423 ◽  
Author(s):  
B. Augeard ◽  
L. M. Bresson ◽  
S. Assouline ◽  
C. Kao ◽  
M. Vauclin
Soil Research ◽  
1976 ◽  
Vol 14 (3) ◽  
pp. 337 ◽  
Author(s):  
T Talsma ◽  
AVD Lelij

Infiltration, swelling, and water movement were studied during ponding on a swelling clay soil. The soil was uniform in texture and clay mineralogy to 2 m depth. Most structural heterogeneity, caused by gilgai and shrinkage cracks, had been removed by grading, cultivation, and pre-ponding irrigations. Measurements were made of infiltration, moisture content, soil water potential, hydraulic conductivity, bulk density, vertical soil swelling, and the effect of overburden on tensiometer readings. Infiltration was rapid and water penetrated deeply during the first ponding day. Thereafter, qualitative agreement was found between measured infiltration and that expected from theory from 1 to 45 days after ponding. From 45 to 120 days after ponding, the development of a time-variable flow restriction near the soil surface prevented the attainment of a final, steady infiltration rate. During ponding a transient water table developed, moisture profiles were distinctly hydric, and seepage to a deep water table or aquifer was not negligible. Core sample values of hydraulic conductivity agreed with those obtained from mean flux and potential gradients, although conductivity and infiltration rate varied greatly from place to place. Measured swelling compared favourably with that calculated from bulk density changes. The maximum measured soil swelling, in the rather narrow range of moisture contents involved, was 25 mm. This is consistent with reported data on similar soils. Mean values of � = �/P near saturation at 0.2 and 0.4 m depth were between 0.20 and 0.25, indicating that the effect of overburden potential on flow was not large.


2006 ◽  
Vol 41 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Nicolas Stämpfli ◽  
Chandra A. Madramootoo

Abstract Recent studies have shown subirrigation (SI) to be effective in reducing nitrate losses from agricultural tile drainage systems. A field study was conducted from 2001 to 2002 in southwestern Québec to evaluate the effect of SI on total dissolved phosphorus (TDP) losses in tile drainage. In an agricultural field with drains installed at a 1-m depth, a SI system with a design water table depth (WTD) of 0.6 m below the soil surface was compared with conventional free drainage (FD). Subirrigation increased drainage outflow volumes in the autumn, when drains were opened and water table control was interrupted for the winter in the SI plots. Outflows were otherwise similar for both treatments. Throughout the study, the TDP concentrations in tile drainage were significantly higher with SI than with FD for seven out of 17 of the sampling dates for which data could be analyzed statistically, and they were never found to be lower for plots under SI than for plots under FD. Of the seven dates for which the increase was significant, six fell in the period during which water table control was not implemented (27 September 2001 to 24 June 2002). Hence, it appears that SI tended to increase TDP concentrations compared with FD, and that it also had a residual effect between growing seasons. Almost one-third of all samples from the plots under SI exceeded Québec's surface water quality standard (0.03 mg TDP L-1), whereas concentrations in plots under FD were all below the standard. Possible causes of the increase in TDP concentrations in tile drainage with SI are high TDP concentrations found in the well water used for SI and a higher P solubility caused by the shallow water table.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 961
Author(s):  
Meryem Touzani ◽  
Ismail Mohsine ◽  
Jamila Ouardi ◽  
Ilias Kacimi ◽  
Moad Morarech ◽  
...  

The main landfill in the city of Rabat (Morocco) is based on sandy material containing the shallow Mio-Pliocene aquifer. The presence of a pollution plume is likely, but its extent is not known. Measurements of spontaneous potential (SP) from the soil surface were cross-referenced with direct measurements of the water table and leachates (pH, redox potential, electrical conductivity) according to the available accesses, as well as with an analysis of the landscape and the water table flows. With a few precautions during data acquisition on this resistive terrain, the results made it possible to separate the electrokinetic (~30%) and electrochemical (~70%) components responsible for the range of potentials observed (70 mV). The plume is detected in the hydrogeological downstream of the discharge, but is captured by the natural drainage network and does not extend further under the hills.


2010 ◽  
Vol 40 (8) ◽  
pp. 1485-1496 ◽  
Author(s):  
Sakari Sarkkola ◽  
Hannu Hökkä ◽  
Harri Koivusalo ◽  
Mika Nieminen ◽  
Erkki Ahti ◽  
...  

Ditch networks in drained peatland forests are maintained regularly to prevent water table rise and subsequent decrease in tree growth. The growing tree stand itself affects the level of water table through evapotranspiration, the magnitude of which is closely related to the living stand volume. In this study, regression analysis was applied to quantify the relationship between the late summer water table depth (DWT) and tree stand volume, mean monthly summertime precipitation (Ps), drainage network condition, and latitude. The analysis was based on several large data sets from southern to northern Finland, including concurrent measurements of stand volume and summer water table depth. The identified model demonstrated a nonlinear effect of stand volume on DWT, a linear effect of Ps on DWT, and an interactive effect of both stand volume and Ps. Latitude and ditch depth showed only marginal influence on DWT. A separate analysis indicated that an increase of 10 m3·ha–1 in stand volume corresponded with a drop of 1 cm in water table level during the growing season. In a subsample of the data, high bulk density peat showed deeper DWT than peat with low bulk density at the same stand volume.


Geomorphology ◽  
2014 ◽  
Vol 204 ◽  
pp. 683-691 ◽  
Author(s):  
Franci Gabrovšek ◽  
Philipp Häuselmann ◽  
Philippe Audra
Keyword(s):  

1981 ◽  
Vol 97 (3) ◽  
pp. 557-568 ◽  
Author(s):  
R. K. Belford

SUMMARYThe response of winter wheat cv. Maris Huntsman to waterlogging was studied in two experiments in soil columns outdoors. Winter waterlogging treatments increased nodal root production and the proportion of aerenchyma within roots, but caused chlorosis and premature senescence of leaves, and decreased tillering. For all treatments, grain losses were much less than expected from the extent of tiller loss in winter; losses after single waterlogging events ranged from 2% (after 47 days with the water-table at 5 cm) to 16% (after 80 days with the water-table at the soil surface). Yield losses after three waterloggings at the seedling, tillering and stem elongation stages of growth were additive, and totalled 19%. In many treatments, grain loss was associated with lighter individual grain weights, suggesting that the size of the root system or efficiency of water and nutrient uptake by roots at the later stages of growth may have been less after earlier waterlogging. The importance of nitrogen fertilizer in maintaining a satisfactory plant nitrogen status was shown when nitrogen was with held before a 3-week waterlogging treatment during stem elongation; tiller and floret survival was subsequently greatly restricted and grain yields decreased 22% below those of plants waterlogged at the same stage of growth but supplied with nitrogen.


Irriga ◽  
2003 ◽  
Vol 8 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Amauri Nelson Beutler ◽  
José Frederico Centurion ◽  
Cassiano Garcia Roque ◽  
Zigomar Menezes de Souza

INFLUÊNCIA DA COMPACTAÇÃO E DO CULTIVO DE SOJA NOS ATRIBUTOS FÍSICOS E NA CONDUTIVIDADE HIDRÁULICA EM LATOSSOLO VERMELHO   Amauri Nelson BeutlerJosé Frederico CenturionCassiano Garcia RoqueZigomar Menezes de SouzaDepartamento de Solos e Adubos, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP. CEP 14870-000. E-mail: [email protected], [email protected]  1 RESUMO              Este estudo teve como objetivo determinar a influência da compactação e do cultivo de soja nos atributos físicos e na condutividade hidráulica de um Latossolo Vermelho de textura média. O experimento foi conduzido na Universidade Estadual Paulista – Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal (SP). Os tratamentos foram: 0, 1, 2, 4 e 6 passadas de um trator, uma ao lado da outra perfazendo toda a superfície do solo, com quatro repetições. O delineamento experimental foi inteiramente casualizado para a condutividade hidráulica e, em esquema fatorial 5 x 2 para os atributos físicos. Foram coletadas amostras de solo nas faixas de profundidades de 0,02-0,05; 0,07-0,10 e 0,15-0,18 m, por ocasião da semeadura e após a colheita para determinação da densidade do solo, porosidade total, macro e microporosidade do solo. A condutividade hidráulica do solo foi determinada após a colheita. O tempo entre a semeadura e a colheita de soja foi suficiente para aumentar a compactação do solo apenas na condição de solo solto. A compactação do solo reduziu a condutividade hidráulica em relação a condição natural (mata) e a condição de solo solto, sendo que esta não foi reduzida, após a primeira passagem, com o aumento no número de passagens.  UNITERMOS: Densidade do solo, porosidade do solo, infiltração de água, soja.  BEUTLER, A. N.; CENTURION, J. F.; ROQUE, C. G.; SOUZA, Z. M. COMPACTION AND SOYBEAN GROW INFLUENCE ON PHYSICAL ATTRIBUTES AND  HYDRAULIC CONDUCTIVITY IN RED LATOSSOL SOIL   2 ABSTRACT  The purpose of this study was to determine the influence of compaction and soybean grow on physical attributes and hydraulic conductivity of a Red Latossol, medium texture soil. The experiment was carried out in the experimental farm at the Paulista State University  – Agricultural Science College, Jaboticabal – São Paulo state. The treatments were 0, 1, 2, 4 and 6 side-by-side tractor strides on the soil surface with four replications. The experimental design was completely randomized for hydraulic conductivity and a 5 x 2 factorial design for soil physical attributes. Soil samples have been collected at 0.02-0.05, 0.07-0.10 and 0.15-0.18 m depth at sowing season and after harvest in order to determine soil bulk density, total porosity, macro and micro porosity. Soil hydraulic conductivity was determined after harvest. The time period between the soybean sowing and harvesting was enough to increase soil compaction only in loose soil condition. Soil compaction reduced hydraulic conductivity compared to the natural (forest) and loose soil condition  KEYWORDS: Bulk density, soil porosity, water infiltration, soybean.


Author(s):  
Reem Ismail ◽  
Saeid Shafieiyoun ◽  
Riyadh Al Raoush ◽  
Fereidoun Rezanezhad

Most of the prediction theories regarding dissolution of organic contaminants in the subsurface systems have been proposed based on the static water conditions; and the influence of water fluctuations on mass removal requires further investigations. In this study, it was intended to investigate the effects of water table fluctuations on biogeochemical properties of the contaminated soil at the smear zone between the vadose zone and the groundwater table. An automated 60 cm soil column system was developed and connected to a hydrostatic equilibrium reservoir to impose the water regime by using a multi-channel pump. Four homogenized hydrocarbon contaminated soil columns were constructed and two of them were fully saturated and remained under static water conditions while another two columns were operated under water table fluctuations between the soil surface and 40 cm below it. The experiments were run for 150 days and relevant geochemical indicators as well as dissolved phase concentrations were analyzed at 30 and 50 cm below the soil surface in all columns. The results indicated significant difference in terms of biodegradation effectiveness between the smear zones exposed to static and water table fluctuation conditions. This presentation will provide an overview of the experimental approach, mass removal efficiency, and key findings.


Irriga ◽  
2001 ◽  
Vol 6 (2) ◽  
pp. 62-68
Author(s):  
Marcos Henrique Sias Silveira ◽  
Antonio Evaldo Klar

PRODUÇÃO DE MATÉRIA SECA E EVAPOTRANSPIRAÇÃO REAL DA AVEIA PRETA (Avena strigosa S.) EM SEIS NÍVEIS FREÁTICOS  Marcos Henrique Dias SilveiraAntonio Evaldo KlarDepartamento de Engenharia Rural –  Faculdade de Ciências Agronômicas – UnespBotucatu – SP  Cep: 18603-970Fone: (0xx14) 6802-7165 – [email protected]  1  RESUMO Para avaliar os efeitos de seis diferentes níveis freáticos na produção de matéria seca e na evapotranspiração real ou de cultura da aveia preta (Avena strigosa S.) foi conduzido um experimento em casa de vegetação, no Departamento de Engenharia Rural da FCA - Campus de Botucatu - UNESP.  Foram semeadas 21 sementes de aveia por vaso, construído de anéis de PVC, com diâmetro nominal de 0,15m x 0,07m de comprimento e alturas totais variando entre 0,21m e 0,91m, de modo a simular os efeitos de níveis freáticos de 0,17m, 0,31m, 0,45m, 0,59m, 0,73m e 0,87m de profundidade.  Após a emergência das plântulas procedeu-se ao desbaste,  deixando-se 8 plantas por vaso, com 06 repetições (seis vasos) para cada nível freático, totalizando 36 vasos em delineamento inteiramente casualizado.  Dados de evapotranspiração real foram coletados diariamente e computados semanalmente.  As plantas foram cortadas rente ao solo ao final da 12.ª semana após a semeadura.  Foram avaliadas as produções de matéria seca da parte aérea e do sistema radicular em cada nível freático.  Os resultados mostraram maior produção de matéria seca para o nível freático mais superficial (0,17m), com queda gradativa à medida que o nível freático se aprofundava. A evapotranspiração da cultura  mostrou a mesma tendência, variando entre 591,6 mm  no tratamento com nível freático a 0,17m de profundidade e 215,4 mm para o de 0,87m de profundidade. UNITERMOS: evapotranspiração, níveis freáticos, aveia preta.  SILVEIRA, M. H. D., KLAR, A. E.  DRY MATTER PRODUCTION AND EVAPOTRANSPIRATION OF OAT         ( Avena strigosa S.) UNDER  SEVERAL TABLE LEVELS.  2  ABSTRACT The aim of this study was to evaluate the influence of six different water table levels on yield and evapotranspiration of oat (Avena strigosa S.) .  21 seeds were sowed  per  pot, which was built with PVC rings (0.15m nominal diameter x 0.07m lenght).  6 water table levels were used: 0.17; 0.31; 0.45; 0.59; 0.73; and 0.87 m measured from the soil surface replicated  6  times.  The completely randomised design was used.  After seedling emergency, 8 plants were maintained  per  pot.  The evapotranspiration were daily measured from reservoirs connected to the pots.  The plants were cut at the soil surface level after 12 weeks from the sowing.The results showed greater dry matter production at the most superficial water table level with progressive decrease with water level distance from the soil surface.  The  evapotranspiration  showed  the  same tendency: the higher values occurred on the 0.17m water table (591.6 mm) until 0.87m water table (215.4 mm). KEYWORDS:  water table, evapotranspiration, Avena strigosa S.


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