Linear Relationship of a Soil Total Water Potential Function and Relative Yield—A Technique to Control Salinity and Water Stress on Golf Courses and Other Irrigated Fields

A simple empirical approach is proposed for the determination of crop relative yield (%) through the soil total water potential (kPa). Recurring to decimal logarithms, from analytical exponential expressions, a linear simple relationship of soil total water potential Ψt (matric Ψm + potential Ψo) function and crop relative yield was studied and developed. The combination of the salinity model, the soil water retention model and the matric potential approach were used to reach this objective. The representation of turfgrass crop relative yield (%) versus a function of soil total water potential f(Ψt) values was shown through a log-normal graph (y = a + mx); the log scale axis “y” (ordinates) defines relative yield Yr, being two the origin ordinate “a” and “m” the slope; the normal decimal scale axis “x” (abscissa) is the function of soil total water potential f(Ψt). Hence, it is possible, using only two experimental points, to define a simple linear relation between a function of soil total water potential and crop relative yield, for a soil matric potential value lower than −20 kPa. This approach was first tested on golf courses (perennial turfgrass fields), but it was further decided to extend it to other annual crop fields, focused on the model generalization. The experimental plots were established, respectively, in Algarve, Alentejo and Oeiras (Portugal) and in the North Negev (Israel). Sprinkler and trickle irrigation systems, under randomized blocks and/or water and salt gradient techniques, were used for water application with a precise irrigation water and salt distribution. Results indicated that there is a high agreement between the experimental and the prediction values (R2 = 0.92). Moreover, the precision of this very simple and easy tool applied to turfgrass fields and other irrigated soils, including their crop yields, under several different sites and climatic conditions, can contribute to its generalization.

Download Full-text

Corrigenda - Measurement of the total water potential of aqueous solutions of polyethylene glycol - A comparison between osmometer, thermocouple psychrometer and equilibrated soil cores

Soil Research ◽

10.1071/sr9930001c ◽

1993 ◽

Vol 31 (1) ◽

pp. 1

Author(s):

IM Wood ◽

IK Dart ◽

HB So

Keyword(s):

Polyethylene Glycol ◽

Water Potential ◽

Close Correlation ◽

Ease Of Use ◽

Effect Of Temperature ◽

Soil Cores ◽

Total Water ◽

Matric Potential ◽

Thermocouple Psychrometer ◽

Water Potentials

This study examined two polyethylene glycol (PEG) polymers (PEG 6000 and PEG 10000) and compared measurements of water potential obtained with a thermocouple osmometer and thermocouple psychrometers at three temperatures (15, 25 and 35�C) and five osmdalities (50, 100, 200, 300 and 400 g/1000 g water). These were then compared with estimates of matric potential of three soils brought to equilibrium with PEG solutions of the same osmolalities. At the same osmolality and temperature the two PEG polymers gave essentially the same water potential. There was a significant effect of temperature on water potential which corresponded closely with changes in specific gravity of the PEG solution. There was a close correlation between the measurements of water potential of the PEG solutions obtained with the osmometer and the psychrometers (R = 0.99). However, the psychrometer gave increasingly lower values than the osmometer as water potential decreased. The differences in the measurements between the two methods are thought to be the result of design and calibration differences. The ease of use of the osmometer is such that it is recommended for routine use. The water potentials of the soil cores brought to equilibrium with the PEG 10 000 solution were linearly related to the water potentials of the PEG solutions estimated from both the osmometer and psychrometers (R2 = 0.84). However, there were clear deviations from a 1:l relationship. It was concluded that the results from the soil cores could not be used to determine which of the two instruments gave the more accurate measurement of water potential of PEG solutions.

Download Full-text

Evaporation from porous media as influenced by osmotic potential

10.5194/egusphere-egu2020-9693 ◽

2020 ◽

Author(s):

Adil Salman ◽

Deep Joshi ◽

Mahyar Naseri ◽

Wolfgang Durner

Keyword(s):

Porous Media ◽

Water Potential ◽

Osmotic Potential ◽

Soil Surface ◽

Natural Soil ◽

Total Water ◽

Matric Potential ◽

Model Calculations ◽

Two Stages ◽

Saline Solutions

<p>The measurement of the water potential is important to characterize solute transport in soil and water uptake by plants. Many researchers have characterized the matric potential and its impact on evaporation from porous media. However, only few studies have been carried out to characterize the effect of the osmotic potential. In this study, we investigated the simultaneous influences of the osmotic and matric potentials on the evaporation from soil. Our hypothesis was that both potential components affect the two stages of evaporation and that the osmotic potential in direct vicinity of the soil surface is a controlling variable. To meet our objective, we performed evaporation experiments on columns filled with pure quartz sand and natural soil materials with different textures, under climate-controlled laboratory conditions. The soils were initially saturated with different concentrations of saline solutions and evaporation from each column was measured daily. Our results show that the osmotic potential reduced the amount of evaporated water from the investigated porous media. The amount of reduction due to the osmotic potential is compared with model calculations that consider the total water potential at the soil surface.</p>

Download Full-text

Measurement of the total water potential of aqueous solutions of polyethylene glycol - A comparison between osmometer, thermocouple psychrometer and equilibrated soil cores

Soil Research ◽

10.1071/sr9930001 ◽

1993 ◽

Vol 31 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

IM Wood ◽

IK Dart ◽

HB So

Keyword(s):

Polyethylene Glycol ◽

Water Potential ◽

Close Correlation ◽

Ease Of Use ◽

Effect Of Temperature ◽

Soil Cores ◽

Total Water ◽

Matric Potential ◽

Thermocouple Psychrometer ◽

Water Potentials

Download Full-text

The importance of liquid-seed contact during the germination of Medicago tribuloides Desr.

Australian Journal of Agricultural Research ◽

10.1071/ar9630646 ◽

1963 ◽

Vol 14 (5) ◽

pp. 646 ◽

Cited By ~ 19

Author(s):

RH Sedgley

Keyword(s):

Seed Germination ◽

Water Potential ◽

Liquid Water ◽

Total Water ◽

Matric Potential ◽

Small Pressure ◽

Plate Apparatus

At a given matric potential, rates of uptake of water and rates of seed germination on a suction plate apparatus were increased by improving the degree of contact between liquid water and seed. The conclusion of Collis-George and Sands (1962) that small matric potentials, as such, influence the rate of seed germination is critically reviewed in the light of the present investigation. The rate of germination of seeds was not influenced by small pressure potentials, which like matric potentials are a non-osmotic component of the total water potential.

Download Full-text

Yield response of bananas to trickle irrigation

Australian Journal of Experimental Agriculture ◽

10.1071/ea9810448 ◽

1981 ◽

Vol 21 (111) ◽

pp. 448 ◽

Cited By ~ 4

Author(s):

T Trochoulias ◽

RD Murison

Keyword(s):

Water Potential ◽

Root System ◽

Yield Response ◽

Pan Evaporation ◽

Total Water ◽

Trickle Irrigation ◽

Class A ◽

Distribution Studies ◽

Gravimetric Sampling ◽

Class A Pan

Supplementary trickle irrigation applied twice a week by single microtube at replacement rates of 0 (control), 20, 40, 60, 80, 100 and 120% of Class A pan evaporation (El from 1970 to 1976 increased bunch weight significantly (P= 0.02) above 40% E. Treatment 60% E gave a bunch weight of 27.6 kg compared with 25.7 for the control. The control, 20 and 40% treatments did not affect hand number from 1970 to 1976 while all other treatments increased hand number by 0.3 hands each year. Means of treatments over all years for fingers showed an annual increase of 4.6,4.0,5.8 and 5.0 fingers for 60,80,100 and 12O0Io treatments, respectively. Gravimetric sampling in 1974 showed the control plot had a lower water potential than other plots. There was little change in water potential in any of the other treatments. There was a significant linear decrease in water potential with increase in radius from the emitter. Root distribution studies showed that about 70% of the root systems in all treatments were concentrated in the upper 40 cm of soil. Forty per cent of the total root system was confined to a square, 60 x 60 cm, close to the base of the plant. Thus trickle irrigation with an emitter positioned near the base of the plant and a slow flow rate (3 litres/h) would reach most of the root system. Four out of the six years of the experiment were very wet (greater than 1700 mm rainfall). Only 29% of the total water over the 6 years in the 60% E treatment was provided by trickle irrigation. This experiment showed that 60% of Class A pan evaporation can be used as a reliable guide for the trickle irrigation of bananas on the East coast of Australia with free draining soils.

Download Full-text

Irrigation of Geraniums with an Automatic Controlled Water Table System

HortScience ◽

10.21273/hortsci.33.3.522d ◽

1998 ◽

Vol 33 (3) ◽

pp. 522d-522 ◽

Cited By ~ 1

Author(s):

J.W. Buxton ◽

D.L. Ingram ◽

Wenwei Jia

Keyword(s):

Water Potential ◽

Leaf Area ◽

Water Table ◽

Nutrient Solution ◽

Irrigation System ◽

Central Area ◽

Dry Weight ◽

Trickle Irrigation ◽

Run Off ◽

Optimum Water

Geraniums in 15-cm pots were irrigated automatically for 8 weeks with a Controlled Water Table (CWT) irrigation system. Plants were irrigated with a nutrient solution supplied by a capillary mat with one end of the mat suspended in a trough below the bottom of the pot. The nutrient solution remained at a constant level in the trough. Nutrient solution removed from the trough was immediately replaced from a larger reservoir. The vertical distance from the surface of the nutrient solution and the bottom of the pot determined the water/air ratio and water potential in the growing media. Treatments consisted of placing pots at 0, 2, 4, and 6 cm above the nutrient solution. Control plants were irrigated as needed with a trickle irrigation system. Geraniums grown at 0,2 and 4 CWT were ≈25% larger than the control plants and those grown at 6 CWT as measured by dry weight and leaf area. Roots of plants grown at 0 CWT were concentrated in the central area of the root ball; whereas roots of plants in other treatments were located more near the bottom of the pot. Advantages of the CWT system include: Plant controlled automatic irrigation; no run off; optimum water/air ratio.

Download Full-text

High probability of yield gain through conservation agriculture in dry regions for major staple crops

Scientific Reports ◽

10.1038/s41598-021-82375-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yang Su ◽

Benoit Gabrielle ◽

Damien Beillouin ◽

David Makowski

Keyword(s):

Management Practices ◽

Crop Yields ◽

Positive Impact ◽

Relative Yield ◽

Conservation Agriculture ◽

Conventional Tillage ◽

Machine Learning Algorithms ◽

Agricultural Practice ◽

Crop Species ◽

Yield Gain

AbstractConservation agriculture (CA) has been promoted to mitigate climate change, reduce soil erosion, and provide a variety of ecosystem services. Yet, its impacts on crop yields remains controversial. To gain further insight, we mapped the probability of yield gain when switching from conventional tillage systems (CT) to CA worldwide. Relative yield changes were estimated with machine learning algorithms trained by 4403 paired yield observations on 8 crop species extracted from 413 publications. CA has better productive performance than no-till system (NT), and it stands a more than 50% chance to outperform CT in dryer regions of the world, especially with proper agricultural management practices. Residue retention has the largest positive impact on CA productivity comparing to other management practices. The variations in the productivity of CA and NT across geographical and climatical regions were illustrated on global maps. CA appears as a sustainable agricultural practice if targeted at specific climatic regions and crop species.

Download Full-text

Carbon balance in relation to drying in four epiphytic mosses growing in different vertical ranges

Canadian Journal of Botany ◽

10.1139/b79-249 ◽

1979 ◽

Vol 57 (19) ◽

pp. 1994-1998 ◽

Cited By ~ 17

Author(s):

Peter L. Tobiessen ◽

Nancy G. Slack ◽

Keith A. Mott

Keyword(s):

Water Potential ◽

Water Content ◽

Carbon Balance ◽

The Other ◽

Moss Species ◽

Relationship Of ◽

The Relationship ◽

Neckera Pennata ◽

Lower Water Content ◽

Photosynthesis And Respiration

The response of photosynthesis and respiration to drying was measured in four species of epiphytic mosses, Ulota crispa (Hedw.) Brid., Neckera pennata Hedw., Anomodon rugellii (C. Mull.) Keissl., and Plagiomnium cuspidatum (Hedw.) T. Kop., from habitats along a desiccation gradient. There was little difference among the mosses in these responses. The relationship of water content to water potential did differ among the mosses, with Plagiomnium, the facultative epiphyte, showing a typical response of more mesic species and the other three showing a more xeric response, i.e., water potential does not begin to fall steeply until a lower water content is reached in Ulota, Neckera, and Anomodon. Both photosynthesis and respiration in all four moss species were quite sensitive to moderate water stress.

Download Full-text

The Decay of Disease Association with Declining Linkage Disequilibrium: A Fine Mapping Theorem

10.1101/052381 ◽

2016 ◽

Cited By ~ 1

Author(s):

Mehdi Maadooliat ◽

Naveen K. Bansal ◽

Jiblal Upadhya ◽

Manzur R. Farazi ◽

Zhan Ye ◽

...

Keyword(s):

Monte Carlo ◽

Linkage Disequilibrium ◽

Fine Mapping ◽

Disease Model ◽

Disease Association ◽

Simple Relationship ◽

Locus System ◽

Using Data ◽

Relationship Of ◽

The Relationship

AbstractSeveral important and fundamental aspects of disease genetics models have yet to be described. One such property is the relationship of disease association statistics at a marker site closely linked to a disease causing site. A complete description of this two-locus system is of particular importance to experimental efforts to fine map association signals for complex diseases. Here, we present a simple relationship between disease association statistics and the decline of linkage disequilibrium from a causal site. A complete derivation of this relationship from a general disease model is shown for very large sample sizes. Quite interestingly, this relationship holds across all modes of inheritance. Extensive Monte Carlo simulations using a disease genetics model applied to chromosomes subjected to a standard model of recombination are employed to better understand the variation around this fine mapping theorem due to sampling effects. We also use this relationship to provide a framework for estimating properties of a non-interrogated causal site using data at closely linked markers. We anticipate that understanding the patterns of disease association decay with declining linkage disequilibrium from a causal site will enable more powerful fine mapping methods.

Download Full-text

DINÂMICA DA ÁGUA NO SISTEMA SOLO-PLANTA NO CULTIVO DA PIMENTA TABASCO SOB DÉFICIT HÍDRICO1

Irriga ◽

10.15809/irriga.2016v1n01p246-261 ◽

2018 ◽

Vol 1 (01) ◽

pp. 246

Author(s):

Lígia Borges Marinho ◽

José Antonio Frizzone ◽

João Batista Tolentino Júnior ◽

Janaina Paulino ◽

Danilton Luiz Flumigan ◽

...

Keyword(s):

Water Potential ◽

Soil Water ◽

Water Deficit ◽

Water Extraction ◽

Soil Matric Potential ◽

Water Restriction ◽

Matric Potential ◽

Mato Grosso ◽

Vegetative Phase ◽

E Mail

DINÂMICA DA ÁGUA NO SISTEMA SOLO-PLANTA NO CULTIVO DA PIMENTA TABASCO SOB DÉFICIT HÍDRICO1 LÍGIA BORGES MARINHO2; JOSÉ ANTONIO FRIZZONE3; JOÃO BATISTA TOLENTINO JÚNIOR4; JANAÍNA PAULINO5; DANILTON LUIZ FLUMIGNAN6 E DIEGO BORTOLOTI GÓES3 (1) Artigo extraído da tese do primeiro autor (2) Departamento Tecnologia e Ciências Sociais, Universidade do Estado da Bahia, av. Edgard Chastinet, São Geraldo, CEP 48905-680, Juazeiro, BA. Fone (74) 3611-7363. E-mail: [email protected](3) Departamento de Engenharia de Biossistemas/Escola Superior de Agricultura “Luiz de Queiroz” USP, Av. Pádua Dias, 11, CEP 13.418-900, Piracicaba/SP, E-mail(s): [email protected], [email protected]; (4) Campus Curitibanos, Universidade Federal de Santa Catarina, Curitibanos, SC. [email protected] (5) Universidade Federal de Mato Grosso UFMT, campus Sinop, Avenida Alexandre Ferronato Nº 1.200. Bairro: Setor Industrial. CEP: 78.550-000, Sinop-MT, Email: [email protected] (6) Empresa Brasileira de Pesquisa Agropecuária, Agropecuária Oeste. Rodovia BR 163, km 253, Zona Rural, 79804970 - Dourados, MS, Email: [email protected] 1 RESUMO O objetivo da pesquisa foi acompanhar a variação da condição hídrica do solo e da planta de pimenta ‘Tabasco’ em função dos manejos de déficits hídricos impostos e determinar seu coeficiente de estresse hídrico. O experimento foi conduzido em ambiente protegido, no Departamento de Engenharia de Biossistemas da ESALQ - USP, Piracicaba-SP, de setembro de 2009 a julho de 2010. O delineamento experimental foi blocos casualizados, com quatro repetições, utilizando-se lâminas de irrigação a 100, 80, 60 e 40% da evapotranspiração da cultura diferenciadas a partir da fase vegetativa e da fase reprodutiva. O potencial da água na folha e no solo foi aferido com a câmara de pressão e tensiômetros, respectivamente. Houve variação do potencial mátrico, da extração de água no solo e do potencial de água na folha em função das lâminas e das épocas de diferenciação. Menores potenciais mátricos foram verificados quando o déficit de irrigação foi inicializado na fase vegetativa da pimenta. Os valores de coeficiente de estresse hídrico e o potencial de água na folha, ao alvorecer, indicaram que as pimenteiras estavam sob estresse moderado e severo, sendo a época reprodutiva da pimenta Tabasco a mais sensível à restrição hídrica.Palavras-chave: Capsicum frutencens L, tensiômetro, potencial da água no solo. MARINHO, L. B.; FRIZZONE, J. A.; TOLENTINO JÚNIOR, J. B.; PAULINO, J.; FLUMIGNAN, D. L.; GÓES, D. B.WATER DYNAMICS IN SOIL-PLANT SYSTEM IN THE CULTIVATION OF PEPPER TABASCO UNDER WATER DEFICIT 2 ABSTRACT The objective of the research was to determine the change in soil water condition and in Tabasco pepper plant according to the managements of water deficits. The experiment was conducted in a greenhouse at the Department of Biosystems Engineering of ESALQ - USP, Piracicaba-SP, from September 2009 to July 2010. The experimental design was randomized blocks with four replications, using irrigation depths to 100, 80, 60 and 40% of crop evapotranspiration in the vegetative phase and reproductive phase. The soil matric potential was measured by tensiometers installed at 0-20 and 20-40 cm depth. The most negative values of matric potential occurred in treatments submitted to the greater water deficit treatments that had higher water restriction imposed by the vegetative phase. For these, greater increase in water extraction in the deepest layer (40 cm) were also found.There were differences in matric potential of the soil, in ground water extraction and in leaf water potential in relation to the water depths and differentiation phases. The deficit irrigation that started in the vegetative phase led to greater reduction in soil matric potential due to the accumulated water deficit. The pepper plants have moderate to severe sensitivity to water deficit in the soil, with a higher sensitivity of the plants when water restriction is imposed during reproductive stages than when it is imposed during growing stages. Keywords : Capsicum frutencens, tensiometer; soil water potential

Download Full-text