Parameterising the impact of shelter on crop microclimates and evaporation fluxes

2002 ◽  
Vol 42 (6) ◽  
pp. 859 ◽  
Author(s):  
H. A. Cleugh
Keyword(s):  
Plant Growth ◽  
Evaporation Rate ◽  
Growing Season ◽  
Surface Model ◽  
Plant Canopy ◽  
Potential Evaporation ◽  
Evaporative Demand ◽  
Equilibrium Evaporation ◽  
Eastern Australia ◽  
The Impact

This paper presents the modelling framework and parameterisations adopted to enable the effects of wind shelter on crop microclimates and growth to be simulated. Two modelling components were required: the first, SCAM (Soil Canopy Atmosphere Model), is a biophysical land surface model used to simulate the effects of shelter on the plant canopy and soil energy and water exchanges. The second is the Agricultural Production Systems Simulator (APSIM) configured for crop modelling (Carberry et al. 2002). This paper describes the link between the two and the parameterisations developed to simulate the effects of shelter and provide potential evaporation estimates for input to APSIM. A series of sensitivity analyses using SCAM demonstrate, as expected, that over the course of the growing season and during meteorological conditions typical of agricultural regions in south-eastern Australia, plant evaporation is relatively insensitive to wind speed. This is consistent with theory and illustrates that reducing wind speeds will only reduce evaporation fluxes when the (unsheltered) canopy evaporation rate exceeds the equilibrium evaporation rate. In other words, reductions in water loss as a result of shelter will arise from one or a combination of the following: (i) reduced soil evaporation following rainfall; (ii) reduced evaporation of rainfall intercepted by the plant canopy; and (iii) reduced plant transpiration during wet periods and/or periods of very high demand when transpiration exceeds the equilibrium evaporation rate. Increased storage of soil moisture as a result of shelter early in the season may sustain crop transpiration later in the growing season. While this may not modify seasonal water use, increased soil water availability for the growing crop may confer an advantage in terms of final yield. The paper then describes the development and validation of a bulk scalar transfer coefficient, or resistance, based on wind tunnel experiments investigating scalar (heat and water vapour) transport in windbreak flows. This coefficient is used in SCAM to parameterise the effect of shelter on the exchanges of heat and water between the atmosphere and the soil and/or plant canopy. A simple parameterisation for this coefficient is developed and implemented. The potential effects of shelter on evaporative demand and hence plant growth are then quantified by using the predictions of plant potential evaporation, calculated from a modified version of SCAM as input to APSIM. The simulations show that events where reduced evaporative demand benefits plant growth can occur intermittently in the latter part of the growing season (i.e. post-anthesis for cereals) for some climatic regimes, as illustrated by the simulations for the Roseworthy, Esperance and Atherton sites used in the National Windbreaks Program.

Analysis of Soil Moisture Changes in Europe during a Single Growing Season in a New ECMWF Soil Moisture Assimilation System

2008 ◽  
Vol 9 (1) ◽  
pp. 116-131 ◽  
Author(s):  
Bart van den Hurk ◽  
Janneke Ettema ◽  
Pedro Viterbo
Keyword(s):  
Soil Moisture ◽  
Data Assimilation ◽  
Land Surface ◽  
Land Surface Model ◽  
Growing Season ◽  
Atmospheric Model ◽  
Surface Model ◽  
Soil Moisture Data ◽  
The Impact ◽  
Assimilation System

Abstract This study aims at stimulating the development of soil moisture data assimilation systems in a direction where they can provide both the necessary control of slow drift in operational NWP applications and support the physical insight in the performance of the land surface component. It addresses four topics concerning the systematic nature of soil moisture data assimilation experiments over Europe during the growing season of 2000 involving the European Centre for Medium-Range Weather Forecasts (ECMWF) model infrastructure. In the first topic the effect of the (spinup related) bias in 40-yr ECMWF Re-Analysis (ERA-40) precipitation on the data assimilation is analyzed. From results averaged over 36 European locations, it appears that about half of the soil moisture increments in the 2000 growing season are attributable to the precipitation bias. A second topic considers a new soil moisture data assimilation system, demonstrated in a coupled single-column model (SCM) setup, where precipitation and radiation are derived from observations instead of from atmospheric model fields. For many of the considered locations in this new system, the accumulated soil moisture increments still exceed the interannual variability estimated from a multiyear offline land surface model run. A third topic examines the soil water budget in response to these systematic increments. For a number of Mediterranean locations the increments successfully increase the surface evaporation, as is expected from the fact that atmospheric moisture deficit information is the key driver of soil moisture adjustment. In many other locations, however, evaporation is constrained by the experimental SCM setup and is hardly affected by the data assimilation. Instead, a major portion of the increments eventually leave the soil as runoff. In the fourth topic observed evaporation is used to evaluate the impact of the data assimilation on the forecast quality. In most cases, the difference between the control and data assimilation runs is considerably smaller than the (positive) difference between any of the simulations and the observations.

New Ornamental Garden

2011 ◽  
Author(s):  
Simon Rickard
Keyword(s):  
Drought Tolerance ◽  
Plant Growth ◽  
Water Availability ◽  
Evaporation Rate ◽  
Cold Water ◽  
Growing Season ◽  
Exotic Plants ◽  
Root Competition ◽  
Temperate Climate ◽  
Rainfall Patterns

This book takes a fresh look at garden-worthy plants for Australian conditions. It will help gardeners to reappraise their climate, select appropriate plants and modify gardening practices to create beautiful gardens featuring native and exotic plants with proven drought tolerance, reliability and minimal weed potential. The New Ornamental Garden shows how heat, cold, water availability, rainfall patterns, length of growing season, evaporation rate and humidity influence plant growth in Australia, from the wet sub-tropics to the temperate climate of southern Australia. It also discusses the influence of microclimates within a garden: dry sun, dry shade, moist sun, moist shade, seaside conditions, exposed sites, urban situations and root competition from eucalyptus and allelopaths. The main focus of the book is the plant index, which contains notes on hundreds of plant varieties and how they function in the garden. All gardeners will benefit from reading this book!

scholarly journals Evaluation of Individual Plant Growth Estimation in an Intercropping Field with UAV Imagery

Agriculture ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 102
Author(s):  
Norazlida Jamil ◽  
Gert Kootstra ◽  
Lammert Kooistra
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Digital Terrain Model ◽  
Ground Truth ◽  
Growing Season ◽  
Field Investigation ◽  
Surface Model ◽  
Individual Plant ◽  
Automatic Assessment ◽  
The Individual

Agriculture practices in monocropping need to become more sustainable and one of the ways to achieve this is to reintroduce intercropping. However, quantitative data to evaluate plant growth in intercropping systems are still lacking. Unmanned aerial vehicles (UAV) have the potential to become a state-of-the-art technique for the automatic estimation of plant growth. Individual plant height is an important trait attribute for field investigation as it can be used to derive information on crop growth throughout the growing season. This study aimed to investigate the applicability of UAV-based RGB imagery combined with the structure from motion (SfM) method for estimating the individual plants height of cabbage, pumpkin, barley, and wheat in an intercropping field during a complete growing season under varying conditions. Additionally, the effect of different percentiles and buffer sizes on the relationship between UAV-estimated plant height and ground truth plant height was examined. A crop height model (CHM) was calculated as the difference between the digital surface model (DSM) and the digital terrain model (DTM). The results showed that the overall correlation coefficient (R2) values of UAV-estimated and ground truth individual plant heights for cabbage, pumpkin, barley, and wheat were 0.86, 0.94, 0.36, and 0.49, respectively, with overall root mean square error (RMSE) values of 6.75 cm, 6.99 cm, 14.16 cm, and 22.04 cm, respectively. More detailed analysis was performed up to the individual plant level. This study suggests that UAV imagery can provide a reliable and automatic assessment of individual plant heights for cabbage and pumpkin plants in intercropping but cannot be considered yet as an alternative approach for barley and wheat.

scholarly journals Tracking of Zinc Ferrite Nanoparticle Effects on Pea (Pisum sativum L.) Plant Growth, Pigments, Mineral Content and Arbuscular Mycorrhizal Colonization

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 583
Author(s):  
Reda E. Abdelhameed ◽  
Nagwa I. Abu-Elsaad ◽  
Arafat Abdel Hamed Abdel Latef ◽  
Rabab A. Metwally
Keyword(s):  
Pisum Sativum ◽  
Plant Growth ◽  
Zinc Ferrite ◽  
Crop Improvement ◽  
Nanocrystalline Structure ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Transmission Electron ◽  
Agricultural Applications ◽  
The Impact

Important gaps in knowledge remain regarding the potential of nanoparticles (NPs) for plants, particularly the existence of helpful microorganisms, for instance, arbuscular mycorrhizal (AM) fungi present in the soil. Hence, more profound studies are required to distinguish the impact of NPs on plant growth inoculated with AM fungi and their role in NP uptake to develop smart nanotechnology implementations in crop improvement. Zinc ferrite (ZnFe2O4) NPs are prepared via the citrate technique and defined by X-ray diffraction (XRD) as well as transmission electron microscopy for several physical properties. The analysis of the XRD pattern confirmed the creation of a nanocrystalline structure with a crystallite size equal to 25.4 nm. The effects of ZnFe2O4 NP on AM fungi, growth and pigment content as well as nutrient uptake of pea (Pisum sativum) plants were assessed. ZnFe2O4 NP application caused a slight decrease in root colonization. However, its application showed an augmentation of 74.36% and 91.89% in AM pea plant shoots and roots’ fresh weights, respectively, compared to the control. Moreover, the synthesized ZnFe2O4 NP uptake by plant roots and their contents were enhanced by AM fungi. These findings suggest the safe use of ZnFe2O4 NPs in nano-agricultural applications for plant development with AM fungi.

scholarly journals Exogenous application of growth stimulators improves the condition of maize exposed to soil drought

2021 ◽  
Vol 43 (4) ◽  
Author(s):  
Agnieszka Ostrowska ◽  
Maciej T. Grzesiak ◽  
Tomasz Hura
Keyword(s):  
Plant Growth ◽  
Developmental Stages ◽  
Aminolevulinic Acid ◽  
Stem Elongation ◽  
Development Stage ◽  
Photochemical Activity ◽  
Soil Drought ◽  
Beneficial Effects ◽  
Induced Changes ◽  
The Impact

AbstractSoil drought is a major problem in plant cultivation. This is particularly true for thermophilic plants, such as maize, which grow in areas often affected by precipitation shortage. The problem may be alleviated using plant growth and development stimulators. Therefore, the aim of the study was to analyze the effects of 5-aminolevulinic acid (5-ALA), zearalenone (ZEN), triacontanol (TRIA) and silicon (Si) on water management and photosynthetic activity of maize under soil drought. The experiments covered three developmental stages: three leaves, stem elongation and heading. The impact of these substances applied during drought stress depended on the plant development stage. 5-ALA affected chlorophyll levels, gas exchange and photochemical activity of PSII. Similar effects were observed for ZEN, which additionally induced stem elongation and limited dehydration. Beneficial effects of TRIA were visible at the stage of three leaves and involved leaf hydration and plant growth. A silicon preparation applied at the same developmental stage triggered similar effects and additionally induced changes in chlorophyll levels. All the stimulators significantly affected transpiration intensity at the heading stage.

scholarly journals The impact of multifactorial stress combination on plant growth and survival

2021 ◽  
Author(s):  
Sara I. Zandalinas ◽  
Soham Sengupta ◽  
Felix B. Fritschi ◽  
Rajeev K. Azad ◽  
Rachel Nechushtai ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth And Survival ◽  
The Impact

scholarly journals The Impact of Salt Stress on Plant Growth, Mineral Composition, and Antioxidant Activity in Tetragonia decumbens Mill.: An Underutilized Edible Halophyte in South Africa

Horticulturae ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 140
Author(s):  
Avela Sogoni ◽  
Muhali Jimoh ◽  
Learnmore Kambizi ◽  
Charles Laubscher
Keyword(s):  
Antioxidant Activity ◽  
Plant Growth ◽  
Mineral Composition ◽  
Nutrient Solution ◽  
Crop Production ◽  
Saline Water ◽  
Total Yield ◽  
Control Treatment ◽  
Antioxidant Power ◽  
The Impact

Climate change, expanding soil salinization, and the developing shortages of freshwater have negatively affected crop production around the world. Seawater and salinized lands represent potentially cultivable areas for edible salt-tolerant plants. In the present study, the effect of salinity stress on plant growth, mineral composition (macro-and micro-nutrients), and antioxidant activity in dune spinach (Tetragonia decumbens) were evaluated. The treatments consisted of three salt concentrations, 50, 100, and 200 mM, produced by adding NaCl to the nutrient solution. The control treatment had no NaCl but was sustained and irrigated by the nutrient solution. Results revealed a significant increase in total yield, branch production, and ferric reducing antioxidant power in plants irrigated with nutrient solution incorporated with 50 mM NaCl. Conversely, an increased level of salinity (200 mM) caused a decrease in chlorophyll content (SPAD), while the phenolic content, as well as nitrogen, phosphorus, and sodium, increased. The results of this study indicate that there is potential for brackish water cultivation of dune spinach for consumption, especially in provinces experiencing the adverse effect of drought and salinity, where seawater or underground saline water could be diluted and used as irrigation water in the production of this vegetable.

scholarly journals The Impact of Climate Change on the Sugar Content of Grapes and the Sustainability of their Production in the Czech Republic

2020 ◽  
Vol 13 (1) ◽  
pp. 222
Author(s):  
Miroslava Navrátilová ◽  
Markéta Beranová ◽  
Lucie Severová ◽  
Karel Šrédl ◽  
Roman Svoboda ◽  
...  
Keyword(s):  
Climate Change ◽  
Czech Republic ◽  
Sugar Content ◽  
Growing Season ◽  
Vegetation Period ◽  
The Czech Republic ◽  
Impact Of Climate Change ◽  
Secondary Sources ◽  
The Impact ◽  
Growing Region

The aim of the presented article is to evaluate the impact of climate change on the sugar content of grapes in the Czech Republic during the period 2000–2019 through selected indicators on the basis of available secondary sources. Attention is focused on the developments in both the main wine-growing regions of Moravia and Bohemia. In the field of viticulture and wine-growing, the sugar content of grapes, as a basic parameter for the classification of wines, plays an important role. In the Czech Republic, the average sugar content of grapes has had a constantly growing trend. This trend is evident both in the wine-growing region of Bohemia and in the wine-growing region of Moravia. The impact of climate change, especially the gradual increase of average temperatures in the growing season, cannot be overlooked. It greatly affects, among other things, the sugar content of grapes. Calculations according to the Huglin Index and the Winkler Index were used to determine the relationship between climate and sugar content. These indexes summarize the course of temperatures during the entire vegetation period into a single numerical value. The results show that both indexes describe the effect of air temperature on sugar content in both wine regions of the Czech Republic in a statistically significant way. The Huglin Index shows a higher correlation rate. The Winkler Index proved to be less suitable for both areas. Alternatively, the Winkler Index calculated for a shorter growing season was tested, which showed a higher degree of correlation with sugar content, approaching the significance of the Huglin Index.

scholarly journals Application of Plant Extracts in Micropropagation and Cryopreservation of Bleeding Heart: An Ornamental-Medicinal Plant Species

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 542
Author(s):  
Dariusz Kulus ◽  
Natalia Miler
Keyword(s):  
Tissue Culture ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Plant Extracts ◽  
The Other ◽  
White Gold ◽  
Natural Extracts ◽  
Other Hand ◽  
The Impact

Lamprocapnos spectabilis (L.) Fukuhara (bleeding heart) is valued both in the horticultural and pharmaceutical markets. Despite its great popularity, information on the in vitro tissue culture technology in this species is limited. There is also little knowledge on the application of plant extracts in the tissue culture systems of plants other than orchids. The aim of this study is to compare the utility of traditional plant growth regulators (PGRs) and natural extracts—obtained from the coconut shreds, as well as oat, rice, and sesame seeds—in the micropropagation and cryopreservation of L. spectabilis ‘Gold Heart’ and ‘White Gold’. The biochemical analysis of extracts composition is also included. In the first experiment related to micropropagation via axillary buds activation, the single-node explants were cultured for a 10-week-long propagation cycle in the modified Murashige and Skoog medium fortified either with 1.11 µM benzyladenine (BA) and 1.23 µM indole-3-butritic acid (IBA) or with 10% (v/v) plant extracts. A PGRs- and extract-free control was also considered. In the cryopreservation experiment, the same 10% (v/v) extracts were added into the medium during a seven-day preculture in the encapsulation-vitrification cryopreservation protocol. It was found that the impact of natural additives was cultivar- and trait-specific. In the first experiment, the addition of coconut extract favoured the proliferation of shoots and propagation ratio in bleeding heart ‘Gold Heart’. Rice extract, on the other hand, promoted callus formation in ‘White Gold’ cultivar and was more effective in increasing the propagation ratio in this cultivar than the conventional plant growth regulators (4.1 and 2.6, respectively). Sesame extract suppressed the development of the explants in both cultivars analysed, probably due to the high content of polyphenols. As for the second experiment, the addition of plant extracts into the preculture medium did not increase the survival level of the cryopreserved shoot tips (sesame and oat extracts even decreased this parameter). On the other hand, coconut extract, abundant in simple sugars and endogenous cytokinins, stimulated a more intensive proliferation and growth of shoots after rewarming of samples. Analysing the synergistic effect of conventional plant growth regulators and natural extracts should be considered in future studies related to L. spectabilis.

Can repeated soil amendment with biogas digestates increase soil suppressiveness toward non-specific soil-borne pathogens in agricultural lands?

2020 ◽  
pp. 1-12
Author(s):  
L. M. Manici ◽  
F. Caputo ◽  
G. A. Cappelli ◽  
E. Ceotto
Keyword(s):  
Plant Growth ◽  
Biomass Production ◽  
Soil Amendment ◽  
Plant Biomass ◽  
Amended Soils ◽  
Soil Suppressiveness ◽  
Soil Microbial ◽  
Soil Borne Pathogens ◽  
The Impact ◽  
Plant Biomass Production

Abstract Soil suppressiveness which is the natural ability of soil to support optimal plant growth and health is the resultant of multiple soil microbial components; which implies many difficulties when estimating this soil condition. Microbial benefits for plant health from repeated digestate applications were assessed in three experimental sites surrounding anaerobic biogas plants in an intensively cultivated area of northern Italy. A 2-yr trial was performed in 2017 and 2018 by performing an in-pot plant growth assay, using soil samples taken from two fields for each experimental site, of which one had been repeatedly amended with anaerobic biogas digestate and the other had not. These fields were similar in management and crop sequences (maize was the recurrent crop) for the last 10 yr. Plant growth response in the bioassay was expressed as plant biomass production, root colonization frequency by soil-borne fungi were estimated to evaluate the impact of soil-borne pathogens on plant growth, abundance of Pseudomonas and actinomycetes populations in rhizosphere were estimated as beneficial soil microbial indicators. Repeated soil amendment with digestate increased significantly soil capacity to support plant biomass production as compared to unamended control in both the years. Findings supported evidence that this increase was principally attributable to a higher natural ability of digestate-amended soils to reduce root infection by saprophytic soil-borne pathogens whose inoculum was increased by the recurrent maize cultivation. Pseudomonas and actinomycetes were always more abundant in digestate-amended soils suggesting that both these large bacterial groups were involved in the increase of their natural capacity to control soil-borne pathogens (soil suppressiveness).

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