scholarly journals Soil water extraction by roots and Kc for the coffee crop

2009 ◽  
Vol 13 (3) ◽  
pp. 257-261 ◽  
Author(s):  
Adriana L. da Silva ◽  
Isabeli P. Bruno ◽  
Klaus Reichardt ◽  
Osny O. S. Bacchi ◽  
Durval Dourado-Neto ◽  
...  
Keyword(s):  
Root System ◽  
Soil Water ◽  
Dry Matter ◽  
Soil Layer ◽  
Water Extraction ◽  
Area Index ◽  
Direct Measurements ◽  
Top Soil ◽  
Soil Water Extraction ◽  
Crop Coefficients

Basic information for a rational soil-water management of the coffee crop is still insufficient, particularly under irrigated conditions. Of great importance for the estimation of water requirements of coffee crops are their root distribuition and evapotranspiration crop coefficients. This study compares soil water extraction by roots of coffee plants of the variety "Catuaí Vermelho" (IAC-44), grown in Piracicaba, SP, Brazil, 3 to 5 years old, with direct measurements of root dry matter, showing a good agreement between both approaches, and confirming that most of the root system is distributed in the top soil layer (0-0.3 m) and that less than 10% of the root system reaches depths greater than 1.0 m. Calculated evapotranspiration crop coefficients are in agreement with those found in the literature, with an average of 1.1, independent of shoot dry matter, plant height and leaf area index.

Lime-slotting technique to ameliorate subsoil acidity in a clay soil II. Effects on medic root-growth, water extraction and yield

Soil Research ◽  
1995 ◽  
Vol 33 (3) ◽  
pp. 443 ◽  
Author(s):  
NS Jayawardane ◽  
HD Barrs ◽  
WA Muirhead ◽  
J Blackwell ◽  
E Murray ◽  
...  
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Surface Area ◽  
Dry Matter ◽  
Acid Soil ◽  
Water Extraction ◽  
Undisturbed Soil ◽  
Subsoil Acidity ◽  
Soil Water Extraction ◽  
Limed Soil

Subsoil acidity causes low crop production, which is often associated with shallow root development and restricted soil water extraction. In part I of this series, lime-slotting of an acid soil was shown to improve the soil physical and chemical characteristics for root growth. In a lysimeter study on an acid soil, the effects of several soil ameliorative treatments on root growth, water extraction and yields of a medic crop were evaluated. Large lysimeter cores of 0.75 m diameter and 1.35 m deep were used. The soil treatments included a non-ameliorated acid soil, lime-slotting with a 0.15 m wide and 0.8 m deep slot containing 20 t ha-1 of lime, lime-slotting combined with surface phospho-gypsum application at 10 t ha-1, and complete amelioration of the entire soil volume by mixing lime at 133 t ha-1 and repacking to a low bulk density of 1.1 t m-3. In the non-ameliorated acid soil, medic roots were confined to the surface (0.1 m) layer, resulting in limited water extraction of 32 mm during a prolonged drying cycle, and a low dry matter yield of 70 g m-2. In the lime slotted soil, roots grew within the slot to its full depth, although penetration into the undisturbed soil was restricted to the soil immediately adjacent to the slot. Consequently, the root length per unit surface area (La) at depths below 0.1 m depth was increased to 9.9 km m-2. During a drying cycle, water extraction increased to 58 mm. The increased water extraction came from both the slotted soil and the undisturbed soil between slots. This led to an increase in dry matter yields to 270 g m2. In lime-slotted soils with surface gypsum applications, the root growth and crop water extraction patterns were similar to the lime-slotted soil. Repacking limed soil resulted in similar root lengths (L(a) 10.0 km m-2) as lime-slotted soil. However, owing to more uniform distribution of roots in the repacked soil, water extraction was increased to 100 mm and yields increased to 590 g m-2. Yields of non-ameliorated soil were only 12% of the repacked, limed soil. However, lime-slotting which involves loosening only 25% of the soil surface area and addition of only one-sixth of the amount of lime required for complete soil amelioration, led to marked increases in yield (46% of the yield of repacked soil). Future field studies are required to evaluate the optimum limed-slot configurations required for different soils, crops and climatic regimes.

Towards the consideration of soil-root resistances in root water uptake models with macroscopic representations of hydraulic root architecture

2021 ◽  
Author(s):  
Jan Vanderborght ◽  
Valentin Couvreur ◽  
Felicien Meunier ◽  
Andrea Schnepf ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Root System ◽  
Soil Water ◽  
Water Uptake ◽  
Root Distribution ◽  
Root Architecture ◽  
Soil Layer ◽  
Root Water Uptake ◽  
Hydraulic Architecture ◽  
Root Segments ◽  
Soil Volume

<p>Plant water uptake from soil is an important component of terrestrial water cycle with strong links to the carbon cycle and the land surface energy budget. To simulate the relation between soil water content, root distribution, and root water uptake, models should represent the hydraulics of the soil-root system and describe the flow from the soil towards root segments and within the 3D root system architecture according to hydraulic principles. We have recently demonstrated how macroscopic relations that describe the lumped water uptake by all root segments in a certain soil volume, e.g. in a thin horizontal soil layer in which soil water potentials are uniform, can be derived from the hydraulic properties of the 3D root architecture. The flow equations within the root system can be scaled up exactly and the total root water uptake from a soil volume depends on only two macroscopic characteristics of the root system: the root system conductance, K<sub>rs</sub>, and the uptake distribution from the soil when soil water potentials in the soil are uniform, <strong>SUF</strong>. When a simple root hydraulic architecture was assumed, these two characteristics were sufficient to describe root water uptake from profiles with a non-uniform water distribution. This simplification gave accurate results when root characteristics were calculated directly from the root hydraulic architecture. In a next step, we investigate how the resistance to flow in the soil surrounding the root can be considered in a macroscopic root water uptake model. We specifically investigate whether the macroscopic representation of the flow in the root architecture, which predicts an effective xylem water potential at a certain soil depth, can be coupled with a model that describes the transfer from the soil to the root using a simplified representation of the root distribution in a certain soil layer, i.e. assuming a uniform root distribution.</p>

Temporal and spatial patterns of soil water extraction and drought resistance among genotypes of a perennial C4 grass

2013 ◽  
Vol 40 (4) ◽  
pp. 379 ◽  
Author(s):  
Yi Zhou ◽  
Christopher J. Lambrides ◽  
Matthew B. Roche ◽  
Alan Duff ◽  
Shu Fukai
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Drought Resistance ◽  
Field Experiments ◽  
Root Length Density ◽  
Water Extraction ◽  
Root Characteristics ◽  
Green Cover ◽  
C4 Grass ◽  
Soil Water Extraction

The objective of this study was to investigate patterns of soil water extraction and drought resistance among genotypes of bermudagrass (Cynodon spp.) a perennial C4 grass. Four wild Australian ecotypes (1–1, 25a1, 40–1, and 81–1) and four cultivars (CT2, Grand Prix, Legend, and Wintergreen) were examined in field experiments with rainfall excluded to monitor soil water extraction at 30–190 cm depths. In the study we defined drought resistance as the ability to maintain green canopy cover under drought. The most drought resistant genotypes (40–1 and 25a1) maintained more green cover (55–85% vs 5–10%) during water deficit and extracted more soil water (120–160 mm vs 77–107 mm) than drought sensitive genotypes, especially at depths from 50 to 110 cm, though all genotypes extracted water to 190 cm. The maintenance of green cover and higher soil water extraction were associated with higher stomatal conductance, photosynthetic rate and relative water content. For all genotypes, the pattern of water use as a percentage of total water use was similar across depth and time We propose the observed genetic variation was related to different root characteristics (root length density, hydraulic conductivity, root activity) although shoot sensitivity to drying soil cannot be ruled out.

Use of water extraction variability to screen for sunflower genotypes well adapted to soil water limitation

2012 ◽  
Vol 39 (12) ◽  
pp. 999
Author(s):  
Ando M. Radanielson ◽  
Jeremie Lecoeur ◽  
Angelique Christophe ◽  
Lydie Guilioni
Keyword(s):  
Soil Water ◽  
Phenotypic Variability ◽  
Water Extraction ◽  
Breeding Programs ◽  
Mean Values ◽  
Relative Value ◽  
Water Uptake Capacity ◽  
Extraction Properties ◽  
Soil Water Extraction ◽  
The Mean

In conditions of water deficit, plant yield depends mostly on the ability of the plant to explore soil profile and its water uptake capacity per unit volume of soil. In this study, the value of soil water extraction properties for use in sunflower breeding was evaluated. Five experiments were carried out in pots, in greenhouses, from 2005 to 2009, in Montpellier, France. Elite sunflower cultivars and experimental hybrids obtained from a factorial cross between five female and five male inbred lines were grown. The soil water extraction performance of the plants was characterised by the soil water content at minimal stomatal conductance (SWCgs = 0) and the index of water extraction (IEgen), which was calculated as the relative value of SWCgs = 0 to the performance of the cultivar NKMelody. Heritability (H2) was estimated for the experimental hybrids. Phenotypic variability of the SWCgs = 0 was observed with a significant effect of the environment and the genotype. The latest released cultivars were observed as the best performing one in water extraction with an IEgen under 0.85. This trait was found to be suitable for use in comparisons of the soil water extraction performances of different genotypes. The high H2 value for SWCgs = 0 (0.77 and 0.81) and the significant correlation (r2 = 0.70, P < 0.001) between the values obtained for the experimental hybrids and the mean values of the general combining ability (GCA) for the parental lines showed that this trait is heritable and could be used in plant breeding programs. Phenotyping methods and the usefulness of this trait in crop modelling are discussed.

Preliminary investigation of clay soils' behaviour under furrow irrigated cotton

Soil Research ◽  
1984 ◽  
Vol 22 (1) ◽  
pp. 99 ◽  
Author(s):  
D Mcgarry ◽  
KY Chan
Keyword(s):  
Soil Water ◽  
Management Practice ◽  
Preliminary Investigation ◽  
Air Permeability ◽  
Water Extraction ◽  
Growth And Yield ◽  
First Year ◽  
Physical Status ◽  
Soil Water Extraction ◽  
Wheel Track

Six experimental sites were selected, in the Namoi Valley, N.S.W., all on self-mulching cracking clay soil, to provide a variety of both management practice and length of time under cotton. Within each of the sites randomly located plots were positioned to cover both wheel-track and non-wheel-track areas. The design allowed assessment of both during-season effects caused by tractor wheels and between-site effects. Neither soil physical status (as measured by soil water extraction, air permeability and recovery of air-filled pores) nor yield was influenced by during-season tractor passes. However, non-wheel areas had significantly taller plants and more green cotton bolls per plant than wheel-influenced areas. Pronounced differences between sites in both soil physical status and cotton growth and yield were measured. For those sites in their first year of cotton there was greater soil water extraction, greater air permeability and more rapid recovery of air-filled porosity. They also produced up to 30% more yield in comparison with sites growing cotton for 8-17 years. At no site did any evidence arise to show 'ploughpan' or 'hardpan' formation.

Crop production and water-use. II. The development and validation of a water-use model for sugarbeet

1994 ◽  
Vol 123 (1) ◽  
pp. 15-24 ◽  
Author(s):  
P. J. C. Hamer ◽  
M. K. V. Carr ◽  
E. Wright
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Crop Production ◽  
Data Set ◽  
Area Index ◽  
Canopy Development ◽  
Three Phase ◽  
Different Depths ◽  
Soil Water Extraction ◽  
Development And Validation

SummaryAs a prerequisite for developing crop-yield/water-use functions for sugarbeet using the results of historical irrigation experiments, it was necessary to develop a water-use model which could operate with a limited data set. The general form of this model has been reported by Wright et al. (1994). In this paper the development and validation of the model for the sugarbeet crop is described.The canopy was modelled in terms of the leaf area index and the relative interception of incoming solar radiation using functions based on thermal time and time. Four phases of growth were identified: emergence, slow-growth, fast-growth and full-canopy. An empirical drought factor was included to allow for the effects of water stress on canopy development during the slow- and fastgrowth expansion phases. Root development was described using a three phase model: initial (temperature dependent), linear and maximum depth (both time dependent).Independent data previously reported from Broom's Barn Experimental Station were then used to validate the model in terms of its capacity to predict crop canopy development, with and without drought stress, soil water extraction at different depths and soil water deficits during the season. The study confirmed the validity of the model for predicting the water-use of sugarbeet.

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