scholarly journals Field Characterization of Field Capacity and Root Zone Available Water Capacity for Variable Rate Irrigation

2017 ◽  
Vol 33 (4) ◽  
pp. 559-572 ◽  
Author(s):  
Tsz Him Lo ◽  
Derek M. Heeren ◽  
Luciano Mateos ◽  
Joe D. Luck ◽  
Derrel L. Martin ◽  
...  
Keyword(s):  
Root Zone ◽  
Field Capacity ◽  
Variable Rate ◽  
Water Capacity ◽  
Spatial Characterization ◽  
Available Water ◽  
Sampling Locations ◽  
Available Water Capacity ◽  
Variable Rate Irrigation

Abstract. Accurate spatial characterization of field capacity (FC) and root zone available water capacity (R) can enhance site-specific management practices—such as variable rate irrigation—to lower input costs, reduce contaminant leaching, and/or improve crop yield. Measuring the volumetric water content after wet soils drain following substantial precipitation can provide a field estimate of FC. The average FC (FCa) for the managed root zone was determined at thirty-two locations in a topographically variable field in south central Nebraska. The difference between FC and permanent wilting point estimates—computed using a pedotransfer function—yielded values for R for the observation locations. Sampling locations were too sparse for reliable interpolation across the field. Therefore, relationships between a surrogate, or predictor, variable and soil water properties were used to provide spatial distributions of FC and R for the field. Field estimates of FCa and R were more strongly correlated to elevation (correlation coefficient, r = -0.77 and -0.76, respectively) than to deep soil apparent electrical conductivity (r = -0.46 and -0.39, respectively). Comparing maps of FCa and R from gSSURGO to maps from field characterization yielded a root mean squared difference of 0.031 m3 m-3 for FCa and 34 mm for R. Sampling seven locations across the elevation range in this field produced FCa and R prediction functions that achieved 95% and 87%, respectively, of the reduction in the standard error achievable with a larger number of sampling locations. Spatial characterization of FCa and R depends on identifying a suitable predictor variable(s) based on field knowledge and available spatial data. Well-chosen variables may allow satisfactory predictions using several sampling locations that are distributed over the entire field. Ultimately, the costs and benefits of spatial characterization should be considered when evaluating site-specific water management. Keywords: Available water capacity, Electrical conductivity, Field capacity, Permanent wilting point, Spatial variability, Variable rate irrigation.

Deep drainage and soil salt loads in the Queensland Murray - Darling Basin using soil chloride: comparison of land uses

Soil Research ◽  
2011 ◽  
Vol 49 (5) ◽  
pp. 408 ◽  
Author(s):  
P. E. Tolmie ◽  
D. M. Silburn ◽  
A. J. W. Biggs
Keyword(s):  
Root Zone ◽  
Drainage Water ◽  
Native Vegetation ◽  
Deep Drainage ◽  
Water Capacity ◽  
Available Water ◽  
Murray Darling Basin ◽  
Available Water Capacity ◽  
Secondary Salinity ◽  
Soil Chloride

Increases in deep drainage below the root-zone can lead to secondary salinity. Few data were available for drainage under dryland cropping and pastures in the Queensland Murray–Darling Basin (QMDB) before this study. Modelled estimates were available; however, without measured drainage these could not be validated. Soil chloride (Cl) mass-balance was used to provide an extensive survey of deep drainage. The method is ‘backward-looking’ and can detect low rates of drainage over longer times. Soil Cl and other soil properties were collated for a number of soils, mostly Vertosols and Sodosols, for paired native vegetation, cropped and sometimes pasture sites, from historical data and new soil sampling. Large amounts of salt and Cl had accumulated under native vegetation (Cl mean 25 t/ha, range 6–54, in 2.4 m depth), due to low rates of drainage. Steady-state Cl balances for native vegetation gave average drainage of 1.2 mm/year at wetter, eastern sites and 0.3 mm/year for Sodosols and Grey Vertosols in drier, western areas. Chloride profiles were mostly of a shape indicating matrix/piston flow. One site (Hermitage fallow trial) appeared to be affected by diffusion of Cl to a watertable. The Cl profiles from 14 longer term cropping sites (18–70 years), mainly used for winter cropping/summer fallow, indicate: (i) large losses of Cl since clearing (mean 50%, range 13-85% for 0–1.5 m soil); and (ii) drainage rates from transient Cl balance are a relatively low percentage of rainfall but are considerably higher than under native vegetation. Drainage averaged 8 mm/year and ranged from 2 to 18 mm/year. This variation is partly explained by rainfall (R2 = 0.63) (500–730 mm/year) and soil plant-available water capacity (R2 = 0.77) (80–300 mm). Deep drainage increases with increasing rainfall and with decreasing available water capacity. Drainage under pasture was less than under cropping but greater than under native vegetation. The deep drainage water (leachate) was of poor quality and will increase salinity if added to good quality groundwater. Leachate at nine sites was too saline to be used (undiluted) for irrigation (>2500 mg Cl/L) and was marginal at the remainder of sites (~800 mg Cl/L). Cropping areas in the QMDB have the precursors for secondary salinity development—high salt loads and an increase in drainage after clearing. The Vertosols and Sodosols studied occur in 90% of croplands in the QMDB. Salinisation will depend on the properties of the underlying regolith and groundwater systems.

The Available-Water Capacity of Barbados Soils

1969 ◽  
Vol 5 (3) ◽  
pp. 167-182 ◽  
Author(s):  
J. C. Hudson
Keyword(s):  
Soil Water ◽  
Agricultural Soils ◽  
Field Capacity ◽  
Soil Water Deficit ◽  
Water Capacity ◽  
Available Water ◽  
Montmorillonite Clays ◽  
Available Water Capacity ◽  
Water Holding ◽  
Large Soil

SummaryLarge soil monoliths, extracted undisturbed in 44-gallon oil drums, have been used to assess the available-water capacity, and the relation between the growth of sugarcane and soil water deficit for agricultural soils in Barbados. Constancy of field capacity was studied and the effect of cultivation on the storage of available soil water. Deep montmorillonite clays and oceanic soils had storage capacities greater than 20 cm. of water in an 80 cm. profile, whereas sandy or stony montmorillonite clays and most soils developed from kaolinite clays had capacities less than 11 cm. Cultivation significantly increased the water holding capacity of soils but this was rarely as great as for fabricated composts and the water was never so freely available. The data have been used in decisions about cultivation and irrigation, and as the basis for an ecological grouping of sugar estates according to their probable water balance.

Statistical equations for estimating field capacity, wilting point and available water capacity of soils from their saturation percentage

1988 ◽  
Vol 110 (3) ◽  
pp. 515-520 ◽  
Author(s):  
I. S. Dahiya ◽  
D. J. Dahiya ◽  
M. S. Kuhad ◽  
S. P. S. Karwasra
Keyword(s):  
Soil Moisture ◽  
Estimation Error ◽  
Chemical Properties ◽  
Field Capacity ◽  
Regression Equations ◽  
Data Set ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
Wilting Point

SummaryStatistical equations were derived for estimating three soil moisture constants, i.e. field capacity (FC), wilting point (WP) and available water capacity (AWC), from soil saturation percentage (SP), which is an easily determinable parameter. The regression equations were evaluated from a data set obtained on 438 soil samples collected from different horizons of 111 profiles of the Indogangetic Plains in northern India, having a wide variation of texture and other physico-chemical properties. The three soil moisture constants were positively correlated with logarithms of SP (r = 0·985 for FC v. In SP, 0·979 for WP v. In SP, and 0·914 for AWC v. In SP). The regression equations were thetested on an independent set of experimental data on 57 samples collected from 14 representative soil profiles of the study area. Values of the three moisture constants of this data set, predicted from the regression equations, were in exceptionally good agreement with the observed values. The mean estimation error (the error of the estimated value relative to the measured value) was only 0·55% for FC, 0·12% for WP and 0·67% for AWC.

scholarly journals ATRIBUTOS FÍSICO-HÍDRICOS DO SOLO VIA FUNÇÕES DE PEDOTRANSFERÊNCIA EM SOLOS DOS TABULEIROS COSTEIROS DE PERNAMBUCO

Irriga ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 69-86
Author(s):  
Fernanda Helena Nascimento Andrade ◽  
Ceres Duarte Guedes Cabral de Almeida ◽  
Brivaldo Gomes de Almeida ◽  
João Audifax Cézar Albuquerque Filho ◽  
Bruno Campos Mantovanelli ◽  
...  
Keyword(s):  
Irrigation Management ◽  
Field Capacity ◽  
Linear Regression Method ◽  
Coastal Plains ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
Permanent Wilting Point ◽  
Santa Maria ◽  
Wilting Point

ATRIBUTOS FÍSICO-HÍDRICOS DO SOLO VIA FUNÇÕES DE PEDOTRANSFERÊNCIA EM SOLOS DOS TABULEIROS COSTEIROS DE PERNAMBUCO   FERNANDA HELENA NASCIMENTO DE ANDRADE1; CERES DUARTE GUEDES CABRAL DE ALMEIDA2; BRIVALDO GOMES DE ALMEIDA3; JOSÉ AUDIFAX CÉZAR DE ALBUQUERQUE FILHO1; BRUNO CAMPOS MANTOVANELLI4 E JOSÉ COELHO DE ARAÚJO FILHO5   1 Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola da Universidade Federal Rural de Pernambuco - UFRPE, Rua Dom Manuel de Medeiros, S/N, Dois Irmãos, CEP: 52171-900, Recife, PE, Brasil, [email protected], [email protected] 2 Colégio Agrícola Dom Agostinho Ikas, Programa de Pós-Graduação em Engenharia Agrícola da Universidade Federal Rural de Pernambuco - UFRPE, Rua Dom Manuel de Medeiros, S/N, Dois Irmãos, CEP: 52171-900, Recife, PE, Brasil, [email protected]. 3 Departamento de Agronomia, Programa de Pós-Graduação em Ciência do Solo da Universidade Federal Rural de Pernambuco - UFRPE, Rua Dom Manuel de Medeiros, S/N, Dois Irmãos, CEP: 52171-900, Recife, PE, Brasil, [email protected]. 4 Departamento de Ciências Rurais, Programa de Pós-Graduação em Ciência do Solo da Universidade Federal de Santa Maria - UFSM, Avenida Roraima, n° 1000, Camobi, CEP: 97105-900, Santa Maria, RS, Brasil, [email protected]. 5 Empresa Brasileira de Pesquisa Agropecuária, EMBRAPA Solos - UEP Recife, Rua Antônio Falcão, n° 402, Boa Viagem, CEP: 51020-240, Recife, PE, Brasil, [email protected].     1 RESUMO   Objetivou-se gerar funções de pedotransferência (FPT) com base em dados das frações granulométricas, distribuição do tamanho de poros, densidade do solo e de partículas para estimar a umidade do solo equivalente à capacidade de campo (CC), ponto de murcha permanente (PMP) e a capacidade de armazenamento de água disponível (CAD) em Argissolos Amarelos representativos dos tabuleiros costeiros na zona da mata norte de Pernambuco. Para isso, foram coletadas amostras deformadas e indeformadas na camada 0,00 - 0,20 m de profundidade. As FPTs foram geradas a partir do método de regressão linear múltipla aplicando a técnica de stepwise backward. Este método eliminou alguns atributos físico-hídricos do solo baseado nos valores de R2 e no Teste t. Os coeficientes de regressão do modelo proposto para predição de CAD, CC e o PMP apresentaram significância de 1% de probabilidade para as variáveis independentes selecionadas para cada modelo, indicando que esses parâmetros podem ser preditos, com ótima precisão, a partir do conteúdo de areia, argila, mesoporosidade, microporosidade e densidade do solo, as quais são fáceis de serem determinadas e obtidas, pré-requisito básico para construção das FPTs.   Palavras-chave: manejo de irrigação, stepwise backward, índices estatísticos.     ANDRADE, F. H. N.; ALMEIDA, C. D. G. C.; ALMEIDA, B. G.; ALBUQUERQUE FILHO, J. A. C.; MANTOVANELLI, B. C.; ARAÚJO FILHO, J. C. SOIL PHYSICAL-HYDRIC PROPERTIES BY PEDOTRANSFER FUNCTION IN SOILS OF COASTAL PLAINS OF PERNAMBUCO   2 ABSTRACT   Aimed to generate pedotransfer functions (PTF) based on particle size, pore size distribution, soil and particle density to estimate the field capacity (CC), permanent wilting point (PMP) and available water capacity (CAD) in Ultisol Typic Fragiaquults in coastal plains of Pernambuco. Thus, deformed and undeformed samples were collected at 0.00 - 0.20m depth. PTFs were generated from multiple linear regression method by stepwise backward technique. This method eliminated some hydro-physical soil attributes, based on the values of R2 and t test. CAD, CC and PMP estimated values showed a significant correlation of 1% probability for independent variables selected for each model. Thus, available water capacity, field capacity and permanent wilting point can be predicted with great precision by sand, clay content, mesoporosity, microporosity and soil density, which are easy to determine and obtain, basic prerequisite for construction of PTFs.   Keywords: irrigation management, stepwise backward, statistical indexes.

scholarly journals Available water capacity of the surface layer of various soils from the arid and semiarid region of Puerto Rico

1969 ◽  
Vol 36 (2) ◽  
pp. 134-140
Author(s):  
M. A. Lugo López
Keyword(s):  
Surface Layer ◽  
Puerto Rico ◽  
Sandy Loam ◽  
Field Capacity ◽  
Semiarid Region ◽  
Water Capacity ◽  
Semiarid Regions ◽  
Available Water ◽  
Available Water Capacity ◽  
Arid And Semiarid

The available water of soils is considered to be in the moisture range from field capacity to permanent wilting percentage. The customary procedures for determining these two soil constants are quite inconvenient. Although data are presented that show good agreement between moisture equivalents and field-capacity values in selected soils, it was not possible to obtain a reliable regression with soils from the arid and semiarid regions of Puerto Rico. The regression of permanent wilting percentages by the plant method to 15-atmosphere percentages is expressed by the equation, Y = 2.37 + 0.76 X, in which Y is the permanent wilting percentage and X is the 15- atmosphere percentage. Data on the available water capacity of the surface layer of sons from the arid and semiarid regions of Puerto Rico are presented. The range of available water is adequate in most soils, fluctuating from about 18 to 25, except in sands where it is lower. It is about the same in heavy soils such as clays and clay loams as in lighter ones such as sandy loam and sandy clay loams.

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