scholarly journals Model parameters of four important vegetable crops for improved water use and yield estimation

Water SA ◽  
2018 ◽  
Vol 44 (4 October) ◽  
Author(s):  
JT Vahrmeijer ◽  
JG Annandale ◽  
JM Steyn ◽  
KL Bristow
Keyword(s):  
Water Use ◽  
Growth Parameters ◽  
Water Productivity ◽  
Resource Planning ◽  
Crop Growth ◽  
Climatic Conditions ◽  
Model Parameters ◽  
Vegetable Production ◽  
Vegetable Crops ◽  
Wide Range

High-value vegetable crops are typically grown under irrigation to reduce production risk. For water resource planning it is essential to be able to accurately estimate water use of irrigated crops under a wide range of climatic conditions. Crop water use models provide a means to make water use and yield estimates, but need crop- and even cultivar-specific parameters. There is generally a lack of crop-specific model parameters for some important commercially grown vegetable crops, especially parameters determined over both summer and winter seasons. The experimental site used in this study was on the Steenkoppies Aquifer, a catchment under stress and an important vegetable production area in South Africa. Crop-specific growth parameters and water use for 4 selected high-value vegetable crops (beetroot, cabbage, carrots and broccoli) were measured over multiple seasons (two summers and one winter). These were used to parameterise the Soil Water Balance (SWB) generic crop growth model for both summer and winter seasons. In seasons where the same cultivar was planted, a single set of model parameters could be used to successfully simulate crop growth and water use. Results show that the amount of irrigation water required is dependent on season and rainfall, with broccoli having the lowest (1.8–2.7 kg m−3) and beetroot the highest (12.2–23.4 kg m−3) water productivity (WPFM), defined as fresh mass of marketable product per unit water consumed. The root crops had a greater harvest index (HIDM) than cabbage and broccoli. The parameters obtained expand the current database of SWB crop growth parameters for vegetables and can be used in a wide range of mechanistic simulation models to improve water management at field and catchment levels.

scholarly journals Potential and Actual Water Savings through Improved Irrigation Scheduling in Small-Scale Vegetable Production

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 888 ◽  
Author(s):  
Christoph Studer ◽  
Simon Spoehel
Keyword(s):  
Water Use ◽  
Irrigation Water ◽  
Drip Irrigation ◽  
Water Productivity ◽  
Irrigation Scheduling ◽  
Small Scale ◽  
Vegetable Production ◽  
Usual Practice ◽  
Irrigation Water Use ◽  
Small Scale Farmers

Appropriate irrigation scheduling for efficient water use is often a challenge for small-scale farmers using drip irrigation. In a trial with 12 farmers in Sébaco, Nicaragua, two tools to facilitate irrigation scheduling were tested: the Water Chart (a table indicating required irrigation doses) and tensiometers. The study aimed at evaluating if and to what extent simple tools can reduce irrigation water use and improve water productivity in drip-irrigated vegetable (beetroot; Beta vulgaris L.) production compared with the farmers’ usual practice. Irrigation water use was substantially reduced (around 20%) when farmers irrigated according to the tools. However, farmers did not fully adhere to the tool guidance, probably because they feared that their crop would not get sufficient water. Thus they still over-irrigated their crop: between 38% and 88% more water than recommended was used during the treatment period, resulting in 91% to 139% higher water use than required over the entire growing cycle. Water productivity of beetroot production was, therefore, much lower (around 3 kg/m3) than what can be achieved under comparable conditions, although yields were decent. Differences in crop yield and water productivity among treatments were not significant. The simplified Water Chart was not sufficiently understandable to farmers (and technicians), whereas tensiometers were better perceived, although they do not provide any indication on how much water to apply. We conclude that innovations such as drip irrigation or improved irrigation scheduling have to be appropriately introduced, e.g., by taking sufficient time to co-produce a common understanding about the technologies and their possible usefulness, and by ensuring adequate follow-up support.

Crop Yield and Water Productivity Responses in Management Zones for Variable-Rate Irrigation Based on Available Soil Water Holding Capacity

2017 ◽  
Vol 60 (5) ◽  
pp. 1659-1667 ◽  
Author(s):  
Weixia Zhao ◽  
Jiusheng Li ◽  
Rumiao Yang ◽  
Yanfeng Li
Keyword(s):  
Winter Wheat ◽  
Growth Parameters ◽  
Water Productivity ◽  
Crop Growth ◽  
Variable Rate ◽  
Summer Maize ◽  
Area Index ◽  
Management Zones ◽  
Water Holding ◽  
Variable Rate Irrigation

Abstract. Effective management of variable-rate irrigation (VRI) is a critical factor for maximizing the benefit of a VRI system. In this study, the influences of soil properties on winter wheat and summer maize were studied to verify whether differences in soil available water holding capacity (AWC) had an influence on crop growth parameters, yield, and water productivity (WP). A center-pivot VRI system was employed to deliver irrigation water across the field in an alluvial flood plain in China, and AWC was used to delineate VRI management zones. Three management zones with substantial differences in AWC were created, with AWC varying from 152 to 161 mm, from 161 to 171 mm, and from 171 to 185 mm for zones 1, 2, and 3, respectively. All zones were managed using the same allowed depletion. In the two-year study, the seasonal irrigation amount was basically equivalent among management zones for both winter wheat and summer maize. Differences in crop growth parameters were detected in plant height and leaf area index for winter wheat. The maximum plant height and leaf area index observed in zone 2 were 5 cm and 2.1 greater, respectively, than in the other zones. For both winter wheat and summer maize, the highest yield and WP were observed in zone 2, except for summer maize WP in the 2014 season. Compared with the average value for this field, the yields in zone 2 were 27% and 23% greater for winter wheat and 4% and 11% greater for summer maize in the 2014 and 2015 seasons, respectively. We demonstrate that AWC is an effective parameter for zone identification in VRI management, and differences in AWC and the layered-textural soils in a field may influence the crop growth parameters, yield, and WP of winter wheat and summer maize. Keywords: Center-pivot irrigation, Critical soil moisture deficit, Management zone, Summer maize, Variable-rate irrigation, Winter wheat.

scholarly journals Vegetable growing of the Republic of Kazakhstan in terms of pandemic

2021 ◽  
pp. 101-107
Author(s):  
Y. E. Gridneva ◽  
◽  
G. Sh. Kaliakparova ◽  
◽  
◽  
...  
Keyword(s):  
High Performance ◽  
Agricultural Sector ◽  
Raw Materials ◽  
Public Support ◽  
Global Changes ◽  
Vegetable Production ◽  
Industrial Complex ◽  
Vegetable Crops ◽  
Wide Range ◽  
The Republic

With the spread of the COVID-19 pandemic in most countries, after the adoption of emergency measures to prevent the spread of coronavirus infection, various economic measures have been implemented to support the population and stabilize the economy. Global changes are taking place in the world, which is associated with issues of cooperation, management activities using a wide range of methods, transformations in agro-industrial complex. To ensure food security of the country, the role of agricultural sector of the republic is increasing. The authors explored main directions of the effective development of vegetable growing in the southern region of the country. The issues of vegetable-growing subcomplex of agri-industrial complex have been identified. Based on the analysis, their assessment, as well as the potential of the industry's innovative activity are presented. There are great prospects for vegetable market, as the consumption of these products, which are rich in vitamins, minerals necessary for the organism, as well as a balanced diet, is increasing. The solution to the problems is in the transition to industrial technologies, the widespread dissemination of business ideas. The measures necessary to expand the scope of introduction of high-performance technologies in the vegetable sector are considered. The importance of public support for the growth of vegetable production is shown. The destabilizing factors of competitiveness of vegetable growing in Kazakhstan have been identified, proposals on improvement of the efficiency of this industry have been developed which are based on innovation. The authors state the need for innovative restructuring in breeding and seed production of vegetable crops, public variety testing, and control over the use of pesticides. The level of provision of the population with vegetable products, and processing industry with raw materials are determined by the development and location of vegetable growing in the republic, as well as labor provision and transport accessibility of sales markets.

scholarly journals Inoculant, nitrogen and phosphorus improves photosynthesis and water-use efficiency in soybean production

2021 ◽  
pp. 1-14
Author(s):  
C. E. N. Savala ◽  
A. N. Wiredu ◽  
J. O. Okoth ◽  
S. Kyei-Boahen
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Management Practices ◽  
Climatic Conditions ◽  
Growth Stages ◽  
Nitrogen And Phosphorus ◽  
Area Index ◽  
Physiological Processes ◽  
Wide Range ◽  
Use Efficiency

Abstract Soybean yield within the Southern Africa falls below its potential despite similar climatic conditions across some agroecologies, replicable agronomic management practices and introduced improved varieties. Understanding physiological processes and water-use efficiency (WUE) of soybean offer information on bridging this yield gap. A field study was conducted in 2017 and 2018 seasons in two agroecologies (Angonia and Ruace) in Mozambique to evaluate the effects of Bradyrhizobium diazoefficiens strain USDA110 formerly known as Bradyrhizobium japonicum inoculant, nitrogen and phosphorus on nodulation, physiology and yield of non-promiscuous (Safari) and promiscuous (TGx 1740-2F) soybean varieties. Data on transpiration, photosynthesis, leaf area index, radiation interception and WUE from the beginning of flowering to maturity were collected. Transpiration rate varied considerably with interaction between locations, growth stages, varieties and treatments. At podding, phosphorus-treated soybean at Angonia transpired less (6.3 mmol/m2/s) than check plants (6.6 mmol/m2/s). Photosynthesis rate and WUE were distinct with variety, growth stages and inputs within agroecologies. For instance, in Angonia 2018 season, phosphorus fertilized TGx 1740-2F photosynthesized more at flowering (25.3 μmol/m2/s) while the lowest was phosphorus-treated Safari at podding with 17.2 μmol/m2/s. At the same site in 2017, inoculated soybean photosynthesized more at 22.8 μmol/m2/s leading to better WUE of 3.6 that corresponded to 2894 kg/ha yield. Overall, soybean WUE was higher when inoculated than N-treated, while P application yielded better. Results from this study will complement breeders’ effort in developing phosphorus efficient varieties suited for a wide range of changing climatical conditions.

Combination of indicators for increasing irrigation sustainability. Definition of a Hydrosustainable Index.

2021 ◽  
Author(s):  
Alejandro Galindo ◽  
Mireia Corell ◽  
María Jose Martín-Palomo ◽  
Teresa Carrillo ◽  
Ignacio Girón ◽  
...  
Keyword(s):  
Water Use ◽  
Water Footprint ◽  
Irrigation System ◽  
Irrigation Management ◽  
Irrigation Scheduling ◽  
Climatic Conditions ◽  
Wide Range ◽  
Definition Of ◽  
Water Scarce ◽  
Different Levels

<p>The scarcity of natural resources around the world has obligated to consider the concept of sustainability in all human activities. Agriculture is not an exception, it is the activity where sustainability is more important, mainly in irrigated orchards. Sustainable water uses are commonly associated with a low water footprint. Water footprint works conclude that the main differences are in the water management at the orchard level. The olive orchard is located at an arid, water scarce location where irrigation water needs are very high and therefore the water footprint. However, an efficient, sustainable water use could be performed in these situations. The aim of this work is the design of an index (Hydrosustainable index, HydroSOS) to estimate the olive grower’s effort at orchard level for improving the sustainability of irrigated olive groves. HydroSOS marks a wide range of field activities link to irrigation management. All these are grouped into hydraulic and agronomic components. Each component has different levels and marks according to its relation to the increase in water sustainability. Irrigation scheduling components are the most valued in the index, though others such as water use efficiency, irrigation system, or soil management are also included.  Four different levels are considered in relation to the final mark. HydroSOS is designed as a dynamic index to improve the objectivity in the evaluation of grower’s effort in irrigation optimization. Two cases of study are presented in two superhigh density olive orchards. Although both orchards are very similar in applied water and climatic conditions, HydroSOS index separated in two very different classifications.</p>

scholarly journals Water-Yield Relations of Drip Irrigated Watermelon in Temperate Climatic Conditions

2016 ◽  
Vol 65 (1-2) ◽  
pp. 53-59
Author(s):  
Borivoj Pejić ◽  
Ksenija Mačkić ◽  
Srdjan Pavković ◽  
Branka Ljevnaić-Mašić ◽  
Miroljub Aksić ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Irrigation Water ◽  
Water Productivity ◽  
Relative Yield ◽  
Climatic Conditions ◽  
Yield Response ◽  
Water Yield ◽  
Irrigation Water Use ◽  
Use Efficiency

Summary The objective of the study, conducted in Vojvodina a northern part of the Serbia Republic, was to analyse the effect of drip irrigation on yield, evapotranspiration and water productivity of watermelon (Cirullus lanatus Thunb.) grown with plasticulture. Irrigation was scheduled on the basis of water balance method. Daily evapotranspiration was computed using the reference evapotranspiration and crop coefficient. The yield of watermelon in irrigation conditions (37,28 t/ha) was significantly higher compared to non irrigated (9,98 t/ha). Water used on evapotranspiration in irrigation conditions was 398 mm and 117 mm on non irrigated variant. The crop yield response factor of 1,04 for the whole growing season reveals that relative yield decrease was nearly equal to the rate of evapotranspiration deficit. The values of irrigation water use efficiency and evapotranspiration water use efficiency were 9,93 kg/m3 and 10,29 kg/m3 respectively. The determined results could be used as a good platform for watermelon growers in the region, in terms of improvement of the optimum utilization of irrigation water.

scholarly journals Sensitivity of Direct Runoff to Curve Number Using the SCS-CN Method

2019 ◽  
Vol 5 (12) ◽  
pp. 2738-2746
Author(s):  
Abdul Ghani Soomro ◽  
Muhammad Munir Babar ◽  
Anila Hameem Memon ◽  
Arjumand Zehra Zaidi ◽  
Arshad Ashraf ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Water Availability ◽  
Curve Number ◽  
Resource Planning ◽  
Model Parameters ◽  
Rainfall Runoff ◽  
Direct Runoff ◽  
Wide Range ◽  
The Impact ◽  
Scs Cn

This study explores the impact of runoff curve number (CN) on the hydrological model outputs for the Morai watershed, Sindh-Pakistan, using the Soil Conservation Service Curve Number (SCS-CN) method. The SCS-CN method is an empirical technique used to estimate rainfall-runoff volume from precipitation in small watersheds, and CN is an empirically derived parameter used to calculate direct runoff from a rainfall event. CN depends on soil type, its condition, and the land use and land cover (LULC) of an area. Precise knowledge of these factors was not available for the study area, and therefore, a range of values was selected to analyze the sensitivity of the model to the changing CN values. Sensitivity analysis involves a methodological manipulation of model parameters to understand their impacts on model outputs. A range of CN values from 40-90 was selected to determine their effects on model results at the sub-catchment level during the historic flood year of 2010. The model simulated 362 cumecs of peak discharge for CN=90; however, for CN=40, the discharge reduced substantially to 78 cumecs (a 78.46% reduction). Event-based comparison of water volumes for different groups of CN values—90-75, 80-75, 75-70, and 90-40 —showed reductions in water availability of 8.88%, 3.39%, 3.82%, and 41.81%, respectively. Although it is known that the higher the CN, the greater the discharge from direct runoff and the less initial losses, the sensitivity analysis quantifies that impact and determines the amount of associated discharges with changing CN values. The results of the case study suggest that CN is one of the most influential parameters in the simulation of direct runoff. Knowledge of accurate runoff is important in both wet (flood management) and dry periods (water availability). A wide range in the resulting water discharges highlights the importance of precise CN selection. Sensitivity analysis is an essential facet of establishing hydrological models in limited data watersheds. The range of CNs demonstrates an enormous quantitative consequence on direct runoff, the exactness of which is necessary for effective water resource planning and management. The method itself is not novel, but the way it is proposed here can justify investments in determining the accurate CN before initiating mega projects involving rainfall-runoff simulations. Even a small error in CN value may lead to serious consequences. In the current study, the sensitivity analysis challenges the strength of the results of a model in the presence of ambiguity regarding CN value.

Changing Dynamics of Cropping Pattern and Constraints Perceived by the Vegetable Growers in Himachal Pradesh

2021 ◽  
Keyword(s):  
Sampling Method ◽  
Insect Pests ◽  
Climatic Conditions ◽  
Himachal Pradesh ◽  
Institutional Constraints ◽  
Cropping Pattern ◽  
Vegetable Crops ◽  
Production Constraints ◽  
The Past ◽  
Wide Range

Himachal Pradesh has various agro-climatic conditions suitable for producing a wide range of vegetable crops around the year. Sixty vegetable growers were selected from the Hamirpur district of Himachal Pradesh using a three-stage random sampling method. In the past 30 years, there was a massive reduction in cereals, pulses and oilseeds; it would be due to the introduction of vegetable crops. On average, the total area put under vegetable crops was 0.2974 and 0.3158 hectares during the summer and winter seasons, respectively, on the overall farm situation. The incidence of insect pests & diseases was the significant constraint related to production. Getting a loan from the bank was time-consuming, and lack of extension facilities were the most critical financial and institutional constraints, respectively. Training should be provided to the farmers to be aware of the latest technologies of KVKs and SAUs to overcome production constraints. For financial and institutional constraints, training camps should be held to provide knowledge about new schemes of state and centre government.

scholarly journals Assessment of water footprint of vegetable crops

2021 ◽  
pp. 57-64
Author(s):  
A. Y. Fedosov ◽  
A. M. Menshikh ◽  
M. I. Ivanova
Keyword(s):  
Water Use ◽  
Water Footprint ◽  
Economic Benefits ◽  
Vegetable Production ◽  
Vegetable Crops ◽  
Search Terms ◽  
Online Databases ◽  
Food Needs ◽  
Urban Consumption ◽  
Future Population

Relevance. Agricultural production is the main consumer of water. Globally, about 70% of fresh water is annually used for agricultural (food and non-food) production. Nearly 40% of the world's food supply comes from irrigation. Globally, the scarcity of irrigation water due to competition between industry and urban consumption threatens food security. Future population growth, income growth and changes in nutrition are expected to increase demand for water. The rate of warming in Russia since the mid-1970s about 2.5 times the global average. The highest rate of temperature increase occurs at high latitudes. The entire territory of Russia is subject to warming, both as a whole for the year and in all seasons. Water Footprint Accounting (WF), proposed by the Water Footprint Network (WFN), has the potential to provide important information for water management, especially in water-stressed regions that rely on irrigation to meet food needs.Methodology. The purpose of this systematic review was to collate and synthesize available data on global water use in vegetable production. Searched online databases covering the areas of environment, social sciences, public health, nutrition and agriculture: Web of Science Core Collection, Scopus, OvidSP MEDLINE, EconLit, OvidSP AGRIS, EBSCO GreenFILE, and OvidSP CAB Abstracts. The search was conducted using predefined search terms that included the concepts of "vegetable crops" and "water footprint".Results. This article provides a brief overview of the vegetable growing water footprint and the sustainability of the blue water footprint. In general, a high green or overall (green + blue) WF may indicate that the vegetable crops are having low yields or inefficient water use. Low green and high blue WF indicate inefficient use of rainwater, which can lead to overexploitation of surface and groundwater. The water footprint can be considered a good economic ergometer, showing the level of water consumption required to obtain a certain vegetable product, whether it brings economic benefits or not, beneficial to society or not.

scholarly journals Modelling transpiration of soilless greenhouse cucumber and its relationship with leaf temperature in a Mediterranean climate

2018 ◽  
pp. 911 ◽  
Author(s):  
Georgios Nikolaou ◽  
Damianos Neocleous ◽  
Nikolaos Katsoulas, Constantinos Kittas
Keyword(s):  
Water Resource Management ◽  
Correlation Coefficients ◽  
Prediction Equation ◽  
Climatic Conditions ◽  
Leaf Temperature ◽  
Model Parameters ◽  
Area Index ◽  
Wide Range ◽  
Winter Crop ◽  
Greenhouse Cucumber

Three experiments (spring and autumn-winter seasons) with soilless cucumber crop (cv. Phenomeno) were conducted in order: (i) to calibrate the simplified Penman -Monteith model equation as affected by greenhouse microclimate (ii) to validate the prediction efficiency of the model at different climatic conditions and (iii) to establish a relationship between transpiration and leaf temperature. To determine Penman-Monteith model parameter variables related to the plants such as transpiration and leaf area index (LAI), so as environmental variables (i.e., radiation, temperature, humidity) were recorded. The results revealed that the determined model parameters were suitable for the whole cucumber cultivation cycle and a wide range of climatic conditions. However, parameterization of the model using autumn-winter crop data revealed superiority compared to spring data, as indicated by the correlation coefficients. Model validation showed a good fit between simulates and measures allowing implementation in commercial soilless practices. With respect to greenhouse microclimate, cooling affected daily mean air temperature and vapor pressure deficit, so as model coefficients. Leaf temperature indicated a good correlation with transpiration and the prediction equation was validated under different greenhouse climatic conditions. These results may be of value in Mediterranean greenhouses, enabling a more efficient water resource management without significant losses in agricultural productivity.   

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