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.

Crop production and water-use. III. The development and validation of a water-use model for potatoes

1994 ◽  
Vol 123 (3) ◽  
pp. 299-311 ◽  
Author(s):  
P. J. C. Hamer ◽  
M. K. V. Carr ◽  
E. Wright
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Crop Production ◽  
Limited Data ◽  
Two Phase ◽  
Data Set ◽  
Canopy Development ◽  
Different Depths ◽  
Soil Water Extraction ◽  
Development And Validation

SUMMARYAs a prerequisite for developing crop-yield/water-use functions for potatoes 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), and its application to the sugarbeet crop by Hamer et al. (1994). In this paper the development and validation of the model for potatoes is described.The canopy was modelled in terms of intercepted incoming solar radiation using functions based on thermal time and time. Four phases of growth were identified: emergence, expansion, plateau and senescence. An empirical drought factor was included to allow for the effects of water stress on canopy development during the expansion phase. Root development was described using a two-phase model: linear and maximum depth (both time dependent).Independent data from various sources 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 potatoes.

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.

Cropping frequency, wheat classes and flexible rotations: Effects on production, nitrogen economy, and water use in a Brown Chernozem

2003 ◽  
Vol 83 (4) ◽  
pp. 667-680 ◽  
Author(s):  
R. P. Zentner ◽  
C. A. Campbell ◽  
F. Selles ◽  
B. G. McConkey ◽  
P. G. Jefferson ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Harvest Index ◽  
Crop Production ◽  
Water Control ◽  
Mineral N ◽  
Nitrogen Yield ◽  
Cropping Frequency ◽  
N Yield ◽  
N Concentration

Producers in the semiarid Canadian prairies rely on frequent summerfallowing (F) to conserve water, control weed infestations, and maximize soil mineral N reserves, but this practice often results in soil degradation. A crop rotation experiment was initiated in 1987 on a medium-textured, Orthic Brown Chernozem at Swift Current, Saskatchewan, to determine the most ideal cropping frequency for wheat in this region and whether a fixed rotation such as fallow-wheat (Triticum aestivum L.) - wheat (F-W-W) or F-W-W-W would be more effective than flexible rotations in which fallowing is decided each spring based on criteria such as available soil water (if water), or the need to control perennial weed infestations (if weeds). The study also compared the production of traditional Canada Western Red Spring (CWRS) wheat class with the newer higher-yielding (Hy), Canada Prairie Spring (CPS) wheat class. We analyzed results of six rotations over the first 12 yr of the study. The rotations included F-W-W, F-W-W-W, F-Hy-Hy, Continuous wheat (Cont W), Cont W (if weeds), and Cont W (if water). Reduced tillage management was used and stubble was cut tall to enhance snowtrap. Fertilizer N was applied based on soil tests and fertilizer P was applied based on the general recommendations for the region. Over the 1988–1999 period, weather conditions were generally favourable and yields were above average for this region. Canada Prairie Spring wheat outyielded CWRS by 32% when grown on fallow and by 17% when grown on stubble; however, straw yields of the two wheat classes were similar on fallow and CPS was 11% less than CWRS on stubble. Harvest index (HI) averaged 44% for CPS and 37% for CWRS wheat. Water use efficiency for CWRS wheat grown on fallow averaged 7.2 kg ha-1 mm-1 and for CPS 9.4; when grown on stubble the respective values were 6.3 and 7.5 kg ha-1 mm-1. Grain N concentration for CWRS was slightly higher for wheat grown on fallow (25.7 g kg-1) than on stubble (24.5 g kg-1), but was similar for CPS wheat on grown on fallow and stubble (21.9 g kg-1). Straw N concentration averaged 3.8 g kg-1 for CWRS and 4.4 g kg-1 for CPS. Nitrogen yield for grain from CPS was 9% greater than from CWRS when grown on fallow, but there was no effect of wheat class when grown on stubble. Nitrogen yield of CPS straw was 15% greater than for CWRS when grown on fallow, but on stubble N yield was generally not affected by wheat class. Nitrogen harvest index (NHI) averaged about 80% for both wheat classes, whether grown on fallow or stubble. On a rotation basis, grain produced with F-W-W was 1502 kg ha-1 yr-1. The F-W-W-W and Cont W (if weeds) rotations produced 9% more grain than F-W-W, while Cont W (if water) produced 24% more, F-Hy-Hy produced 26% more, and Cont W produced 30% more than F-W-W. Nitrogen production in the grain, straw and aboveground plant material was lowest in F-W-W, highest in Cont W, and intermediate for other rotations. Although the economic and soil quality assessments have yet to be completed, a preliminary conclusion based on crop production characteristics alone suggests that a flexible cropping system in which available soil water in spring is used as the determining criterion is superior to a fixed F-W-W or F-W-W-W rotation. Key words: Yield, N concentration, N yield, water deficit, wheat classes, regressions

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.

Zero-tillage influence on canola, field pea and wheat in a dry subhumid region: Agronomic and physiological responses

1994 ◽  
Vol 74 (3) ◽  
pp. 411-420 ◽  
Author(s):  
Sylvia Borstlap ◽  
Martin H. Entz
Keyword(s):  
Grain Yield ◽  
Soil Water ◽  
Water Use ◽  
Field Pea ◽  
Water Extraction ◽  
Water Evaporation ◽  
Zero Tillage ◽  
Crop Species ◽  
Tillage System ◽  
Soil Water Extraction

Field trials were conducted over 4 site-years in southern Manitoba to compare the response of Katepwa wheat, Westar canola and Victoria field pea to zero tillage (ZT). The experimental design was a split plot with tillage system as the mainplot (ZT vs. conventional tillage (CT)) and crop species as the subplot. All crops received protection from insect, weed and disease pests. Tillage system had only a limited impact on crop dry matter accumulation or grain quality. Where differences were observed, crop performance was enhanced under ZT. Seasonal evapotranspiration (ET) was either reduced or unaffected by ZT, while ET efficiency (ETE: kg ha−1 mm−1 ET) was either increased or unchanged by the shift from CT to ZT. Higher ETE under ZT was attributed to less soil water evaporation. Significant tillage system × crop species (T × S) interactions for growth parameters, ET and ETE indicated that field pea often benefitted more than wheat or canola from ZT. A significant T × S interaction at one of the four sites indicated that water extraction between 30 and 90 cm was higher for pea and canola in the ZT compared with CT treatment, while soil water extraction by wheat was reduced under ZT. At a second site, lower ET for all three crops under ZT was attributed to reduced water use between 90 and 130 cm. Despite some effects of ZT on crop growth and water use, no significant tillage, T × S, or site × tillage interactions were observed for grain yield. It was concluded that under the conditions of this study (i.e. precipitation and temperature conditions close to the long-term average), Westar canola, Victoria field pea and Katepwa wheat were, for the most part, equally suited to ZT production. Key words: Soil water extraction, evapotranspiration efficiency, crop quality, grain yield, canopy development

scholarly journals Efeito da Irrigação Suplementar na Produtividade e Eficiência no Uso de Água da Palma Forrageira

2020 ◽  
Vol 13 (6) ◽  
pp. 2744
Author(s):  
Elaine Cristina Batista da Silva ◽  
José Romualdo De Sousa Lima ◽  
Antônio Celso Dantas Antonino ◽  
Airon Aparecido Silva de Melo ◽  
Eduardo Soares de Souza ◽  
...  
Keyword(s):  
Water Balance ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Crop Yields ◽  
Promising Technique ◽  
Cactus Pear ◽  
Area Index ◽  
Supplementary Irrigation ◽  
Use Efficiency

A irrigação suplementar pode ser uma técnica promissora para o aumento da produção da palma forrageira, contudo, depende da evapotranspiração (ET). A irrigação e a ET estão estritamente relacionados com a produtividade das culturas (P), de modo que a relação entre P e ET resulta na eficiência no uso de água (EUA). Assim, objetivou-se avaliar P, ET e EUA em palma, sob irrigação suplementar. O experimento foi conduzido em campo, com palma submetida a irrigação por gotejamento com intervalos de reposição de água no solo de 7 (T7), 14 (T14) e 21 (T21) dias, mais o tratamento de sequeiro (T0), em blocos ao acaso, com 4 repetições. O crescimento da palma foi monitorado por meio da medição da largura (LC), do comprimento (CC), da área (AC), do índice de área (IAC) e da espessura dos cladódios (EC). Ao longo do ciclo da cultura também foram monitoradas as condições meteorológicas. A ET foi obtida como termo residual da equação do balanço hídrico. Os tratamentos não tiveram efeitos significativos nas variáveis biométricas e na produtividade da palma forrageira. A menor ET foi obtida no T0 (406,1 mm total e 1,7 mm d‑1), sendo que o T7 apresentou a maior ET (664,4 mm total e 2,8 mm d-1). A maior EUA (392,8 kg MF ha-1 mm-1) foi obtida no tratamento sob sequeiro (T0). Com base na produtividade e na EUA da palma forrageira, recomenda-se, para as condições do município de Garanhuns, que o cultivo da mesma seja realizado sob condições de sequeiro.Effect of the Supplemental Irrigation on Yield and Water Use Efficiency of Cactus Pear A B S T R A C TThe supplementary irrigation may be a promising technique to increase forage cactus yield, however, it depends of evapotranspiration (ET). Irrigation and ET are closely related to crop yields (P), so the relationships between P and ET result in water use efficiency (WUE). Thus, the objective was to evaluate P, ET and WUE in cactus pear, under supplementary irrigation. The experiment was conducted under field conditions with cactus pear submitted to drip irrigation with soil water replacement intervals of 7 (T7), 14 (T14) and 21 (T21) days, plus the rainfed treatment (T0), in blocks with 4 replicates. Cactus pear growth, by the measurements of width (WC), length (LC), area (CA), area index (CAI) and thickness of cladodes (CD), was monitored. Meteorological conditions along the cactus pear cycle were monitored. The ET was quantified by the soil water balance method. The treatments had no effects on the biometric variables and yield of cactus pear. ET was lower in T0 (406.1 mm total and 1.7 mm day-1), with T7 showing the highest values of ET (664.4 mm total and 2.8 mm day-1). It was observed that the largest WUE (392.8 kg MF ha-1 mm-1) was in the rainfed treatment (T0). On the basis of the yield and WUE of the cactus pear, it is recommended, for the conditions of the municipality of Garanhuns that the cultivation of the same be carried out under conditions of rainfed.Key words: Soil moisture; evapotranspiration; water balance.

scholarly journals A GROUND-BASED LIDAR AND IMAGING SPECTROMETER SYNCHRONOUS EXPERIMENT ON VEGETATION

2017 ◽  
Vol IV-2/W4 ◽  
pp. 219-225
Author(s):  
T. Hong ◽  
X. Luo ◽  
H. Chen ◽  
J. Hui
Keyword(s):  
Canopy Structure ◽  
Structure Parameters ◽  
Vegetation Canopy ◽  
Data Set ◽  
Imaging Spectrometer ◽  
Area Index ◽  
Practical Applications ◽  
Passive Data ◽  
Ground Based Lidar ◽  
Development And Validation

Extraction of vegetation canopy structure parameters is of great significance for researching global ecosystem and environment. Focused on the effective synergy between active and passive sensors, we carried out some ground-based observations about different vegetation on different terrains. In different experimental sites, a light detection and ranging (LiDAR) data and an imaging spectrum data of typical vegetation were collected from different directions and angles. Meanwhile, a variety of canopy structure parameters, including plant height, crown breadth, leaf area index, etc, were measured. The whole observed results form a comprehensive ground synchronous data set corresponding to flight data and provide data support for development and validation of synergic retrieval methods of vegetation canopy structure parameters. Our specific experimental objectives and design are introduced, including the selection of sampling plots, arrangement of observation stations, acquisition of active and passive data, and measurement of auxiliary data. The processing and practical applications of those obtained synchronous data are also discussed. Finally, our experimental experience is summarized and it is a valuable reference for remote sensing researchers.

Responses of grain sorghum to varying irrigation frequency in the Ord irrigation area. II. Evapotranspiration, water use efficiency and root distribution of different cultivars

1984 ◽  
Vol 35 (1) ◽  
pp. 31 ◽  
Author(s):  
RJK Myers ◽  
MA Foale ◽  
AA Done
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Root Distribution ◽  
Soil Depth ◽  
Unit Length ◽  
Grain Sorghum ◽  
Root Penetration ◽  
Area Index ◽  
Irrigation Area ◽  
Irrigation Interval

Four grain sorghum cultivars (Quicksilver, Texas 610SR, E57 and Q7844), representing early-to-late maturity types, were grown under different irrigation frequencies (7-day, 14-day, 28-day or 42-day intervals or once-only-at-sowing) in the dry season in the Ord Irrigation Area. Soil water distribution, root distribution and evapotranspiration were determined periodically. Frequent irrigation resulted in shallow root development and most water use was from the surface 40 cm of soil. Depth of water extraction increased with plant age and with less frequent irrigation. The depth of root penetration determined by direct measurement was similar to that inferred from soil water profiles. Water uptake per unit length of root was related to soil water content only in the 0-40 cm soil layers. Ea/Ep (actual evapotranspiration/pan evaporation) was classified into three stages according to the degree of soil drying after irrigation. During the first stage, immediately after irrigation, Ea/Ep was generally close to 0.75 irrespective of cultivar, leaf area index (LAI) or irrigation interval. During the second stage, linear functions adequately described Ea/Ep as a function of LA1 for LA1 less than 5. During the third stage, which commenced when total soil water to 1.8 m declined to 545 mm, poor relationships between Ea/Ep. Following an analysis of the soil water use data, it is believed that maximum yields of sorghum may be attainable with irrigation at sowing followed by three carefully timed irrigations.

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