scholarly journals Evaluating Irrigation Performance and Water Productivity Using EEFlux ET and NDVI

2021 ◽  
Vol 13 (14) ◽  
pp. 7967
Author(s):  
Usha Poudel ◽  
Haroon Stephen ◽  
Sajjad Ahmad
Keyword(s):  
Water Management ◽  
Sugar Beet ◽  
Crop Yield ◽  
Water Conservation ◽  
Irrigation System ◽  
Water Productivity ◽  
Google Earth ◽  
Geographical Information ◽  
Irrigation Performance ◽  
Crop Water

Southern California’s Imperial Valley (IV) faces serious water management concerns due to its semi-arid environment, water-intensive crops and limited water supply. Accurate and reliable irrigation system performance and water productivity information is required in order to assess and improve the current water management strategies. This study evaluates the spatially distributed irrigation equity, adequacy and crop water productivity (CWP) for two water-intensive crops, alfalfa and sugar beet, using remotely sensed data and a geographical information system for the 2018/2019 crop growing season. The actual crop evapotranspiration (ETa) was mapped in Google Earth Engine Evapotranspiration Flux, using the linear interpolation method in R version 4.0.2. The approx() function in the base R was used to produce daily ETa maps, and then totaled to compute the ETa for the whole season. The equity and adequacy were determined according to the ETa’s coefficient of variation (CV) and relative evapotranspiration (RET), respectively. The crop classification was performed using a machine learning approach (a random forest algorithm). The CWP was computed as a ratio of the crop yield to the crop water use, employing yield disaggregation to map the crop yield, using county-level production statistics data and normalized difference vegetation index (NDVI) images. The relative errors (RE) of the ETa compared to the reported literature values were 7–27% for alfalfa and 0–3% for sugar beet. The average ETa variation was low; however, the spatial variation within the fields showed that 35% had a variability greater than 10%. The RET was high, indicating adequate irrigation; 31.5% of the alfalfa and 12% of the sugar beet fields clustered in the Valley’s central corner were consuming more water than their potential visibly. The CWP showed wide variation, with CVs of 32.92% for alfalfa and 25.4% for sugar beet, signifying a substantial scope for CWP enhancement. The correlation between the CWP, ETa and yield showed that reducing the ETa to approximately 1500 mm for alfalfa and 1200 mm for sugar beet would help boost the CWP without decreasing the yield, which is nearly equivalent to 44.52M cu. m (36,000 acre-ft) of water. The study’s results could help water managers to identify poorly performing fields where water conservation and management could be focused.

scholarly journals Global Satellite-Based ET Products for the Local Level Irrigation Management: An Application of Irrigation Performance Assessment in the Sugarbelt of Swaziland

2019 ◽  
Vol 11 (6) ◽  
pp. 705 ◽  
Author(s):  
Poolad Karimi ◽  
Bhembe Bongani ◽  
Megan Blatchford ◽  
Charlotte de Fraiture
Keyword(s):  
Remote Sensing ◽  
Performance Assessment ◽  
Management Practices ◽  
Local Level ◽  
Water Productivity ◽  
Irrigation Management ◽  
Irrigation Performance ◽  
Crop Water ◽  
Management Regime ◽  
Crop Water Productivity

Remote sensing techniques have been shown, in several studies, to be an extremely effective tool for assessing the performance of irrigated areas at various scales and diverse climatic regions across the world. Open access, ready-made, global ET products were utilized in this first-ever-countrywide irrigation performance assessment study. The study aimed at identifying ‘bright spots’, the highest performing sugarcane growers, and ‘hot spots’, or low performing sugarcane growers. Four remote sensing-derived irrigation performance indicators were applied to over 302 sugarcane growers; equity, adequacy, reliability and crop water productivity. The growers were segmented according to: (i) land holding size or grower scale (ii) management regime, (iii) location of the irrigation schemes and (iv) irrigation method. Five growing seasons, from June 2005 to October 2009, were investigated. The results show while the equity of water distribution is high across all management regimes and locations, adequacy and reliability of water needs improvement in several locations. Given the fact that, in general, water supply was not constrained during the study period, the observed issues with adequacy and reliability of irrigation in some of the schemes were mostly due to poor scheme and farm level water management practices. Sugarcane crop water productivity showed the highest variation among all the indicators, with Estate managed schemes having the highest CWP at 1.57 kg/m3 and the individual growers recording the lowest CWP at 1.14 kg/m3, nearly 30% less. Similarly center pivot systems showed to have the highest CWP at 1.63 kg/m3, which was 30% higher than the CWP in furrow systems. This study showcases the applicability of publicly available global remote sensing products for assessing performance of the irrigated crops at the local level in several aspects.

scholarly journals Influence of Spatial Resolution on Remote Sensing-Based Irrigation Performance Assessment Using WaPOR Data

2020 ◽  
Vol 12 (18) ◽  
pp. 2949
Author(s):  
Megan Blatchford ◽  
Chris M. Mannaerts ◽  
Yijian Zeng ◽  
Hamideh Nouri ◽  
Poolad Karimi
Keyword(s):  
Remote Sensing ◽  
Open Access ◽  
Performance Assessment ◽  
Spatial Resolution ◽  
Performance Indicators ◽  
Crop Production ◽  
Water Productivity ◽  
Temporal Trends ◽  
Irrigation Performance ◽  
Crop Water

This paper analyses the effect of the spatial assessment scale on irrigation performance indicators in small and medium-scale agriculture. Three performance indicators—adequacy (i.e., sufficiency of water use to meet the crop water requirement), equity (i.e., fairness of irrigation distribution), and productivity (i.e., unit of physical crop production/yield per unit water consumption)—are evaluated in five irrigation schemes for three spatial resolutions—250 m, 100 m, and 30 m. Each scheme has varying plot sizes and distributions, with average plot sizes ranging from 0.2 ha to 13 ha. The datasets are derived from the United Nations Food and Agricultural Organization (FAO) water productivity through open access of remotely sensed–derived data (the Water Productivity Open Access Portal—WaPOR) database. Irrigation indicators performed differently in different aspects; for adequacy, all three resolutions show similar spatial trends for relative evapotranspiration (ET) across levels for all years. However, the estimation of relative ET is often higher at higher resolution. In terms of equity, all resolutions show similar inter-annual trends in the coefficient of variation (CV); higher resolutions usually have a higher CV of the annual evapotranspiration and interception (ETIa) while capturing more spatial variability. For productivity, higher resolutions show lower crop water productivity (CWP) due to higher aboveground biomass productivity (AGBP) estimations in lower resolutions; they always have a higher CV of CWP. We find all resolutions of 250 m, 100 m, and 30 m suitable for inter-annual and inter-scheme assessments regardless of plot size. While each resolution shows consistent temporal trends, the magnitude of the trend in both space and time is smoothed by the 100 m and 250 m resolution datasets. This frequently results in substantial differences in the irrigation performance assessment criteria for inter-plot comparisons; therefore, 250 m and 100 m are not recommended for inter-plot comparison for all plot sizes, particularly small plots (<2 ha). Our findings highlight the importance of selecting the spatial resolution appropriate to scheme characteristics when undertaking irrigation performance assessment using remote sensing.

scholarly journals Drops for crops: modelling crop water productivity on a global scale

2013 ◽  
Vol 10 (3) ◽  
pp. 295-300
Keyword(s):  
Crop Yield ◽  
Food Policy ◽  
Water Productivity ◽  
Global Scale ◽  
Fertilizer Management ◽  
Crop Water ◽  
Crop Growth Model ◽  
Crop Water Productivity ◽  
Maize Yields ◽  
Good Agreement

There is an emerging need to support water and food policy and decision making at the global and national levels. A systematic tool that is capable of analyzing water-food relationships with high spatial resolutions would be very useful. A GEPIC model has recently been developed by integrating a crop growth model with a Geographic Information System (GIS). The GEPIC model was applied to simulate crop yield and crop water productivity (CWP) for maize at a spatial resolution of 30 arc-minutes on a global scale. A comparison between simulated yields and FAO statistical yields in 124 countries shows a good agreement. The simulated CWP values are mainly in line with the measured values reported in literature. The crop yield and CWP were simulated with the assumption of sufficient water and fertilizer supply, holding other factors unchanged. The simulation results show that many countries have the potentials in achieving high maize yields and CWP. More than 80% of African countries have the potential to double their CWP. This reflects the current poor water and fertilizer management there. The results imply that efforts have to be strengthened to improve water and fertilizer management should the malnutrition be reduced or even eliminated.

scholarly journals Thermal imaging to assess the crop water status of melon plants under tropical semi-arid climate

2021 ◽  
Author(s):  
Márcio Facundo Aragão ◽  
Luis Gonzaga Pinheiro Neto ◽  
Thales Vinícius de Araújo Viana ◽  
Juan Manzano-Juarez ◽  
Claudivan Feitosa Lacerda ◽  
...  
Keyword(s):  
Crop Yield ◽  
Soil Cover ◽  
Water Status ◽  
Water Productivity ◽  
Irrigation Scheduling ◽  
Leaf Water ◽  
Crop Water ◽  
Thermal Images ◽  
Irrigation Regimes ◽  
Semi Arid

Abstract Deficit irrigation (DI) strategies and soil cover are highly effective to improve the the water productivity in semi-arid regions. However, the effective monitoring of plant water status under DI strategies becomes crucial. The main objective of this study was to evaluate the use of thermal images to estimate the water status of melon plants cultivated in soil with and without mulching under different irrigation regimes. The experience was carried out from October to December 2018. The study was carried out in a randomized block design, in a split plot arrangement. Plots were composed by soil cover (with and without mulching with plant material), and subplots by 5 irrigation regimes (120, 100, 80, 60 and 40% of crop evapotranspiration-ETc), with five replicates. The following variables were evaluated: canopy temperature (Tcanopy), leaf water potential (Ψleaf), air temperature (Tair), soil moisture, crop yield and the thermal index (ΔT), this being defined as the difference between Tcanopy and Tair. ΔT showed high correlations with crop yield and crop water consumption, evidencing that thermography is an efficient tool to identify the water status of melon plants and could be employed for a proper irrigation scheduling under the tropical semi-arid scenarios. Moreover, the use of thermal images also allowed the identification of beneficial effects of soil cover on leaf water status and crop yield, mainly under moderate DI. The obtained results also demonstrate that mulching is essential to increase melon yield and water productivity in tropical regions.

scholarly journals Effect of Deficit Irrigation under Different Crop on Crop Productivity and Water Use Efficiency- A Review

2020 ◽  
pp. 30-37
Author(s):  
Dessie Gieta Amare ◽  
Zigijit Kassa Abebe
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Water Conservation ◽  
Deficit Irrigation ◽  
Irrigation System ◽  
Water Productivity ◽  
Crop Productivity ◽  
Promising Alternative ◽  
Irrigation Level ◽  
Use Efficiency

Deficit irrigation is a strategy which could be applied to utilize water efficiently. The goal of the article was to review and examine different irrigation deficit to compare its crop morphological characters, yield, water productivity and water use efficiency under different crop type. The overall idea and results are very actual and useful over the world in the semi-arid and arid area interms of water managment and better economic return per applied water.The maximum production in dryland, tomato should be irrigated using drip irrigation system with 100%ETc watering amount [17]. On the other hand 85%, 75% and 30% are also effective in terms of water saving and yield. 85%ETc irrigation level water applied system appears to be a promising alternative for water conservation and labor saving with negligible trade-off in yield of maize [15]. The application of deficit irrigation (75%ETc) could be adopted in lettuce production [16]. Form the review I have seen that The WP increased as the irrigation level reduced.

Climate change impacts on crop water productivity in Africa using a multi-model inter-comparison

2020 ◽  
Author(s):  
Imeshi Weerasinghe ◽  
Celray James Chawanda ◽  
Ann van Griensven
Keyword(s):  
Climate Change ◽  
Crop Yield ◽  
Crop Yields ◽  
Water Productivity ◽  
Baseline Scenario ◽  
Crop Water ◽  
Yield Data ◽  
Water Vapour Flux ◽  
Crop Models ◽  
Crop Water Productivity

&lt;p&gt;Evapotranspiration (ET) or the water vapour flux is an important component in the water cycle and is widely studied due to its implications in disciplines ranging from hydrology to agricultural and climate sciences. In the recent past, growing attention has been given to estimating ET fluxes at regional and global scales. However, estimation of ET at large scales has been a difficult task due to direct measurement of ET being possible only at point locations, for example using flux towers. For the African continent, only a limited number of flux tower data are openly available for use, which makes verification of regional and global ET products very difficult. Recent advances in satellite based products provide promising data to fill these observational gaps.&lt;/p&gt;&lt;p&gt;In this study we propose to investigate the Climate Change (CC) impact on crop water productivity across Africa using ET and crop yield predictions of different crop models for future climate scenarios. Different model outputs are evaluated including models from both the ISI-MIP 2a and 2b protocols. Considering the problem of direct observations of ET being difficult to obtain, especially over Africa, we use ET estimates from several remotely sensed derived products as a references to evaluate the crop models (maize) in terms of magnitude, spatial patterns and variations between models. The crop model results for crop yield are compared to FAO reported crop yields at country scale. The results show a very strong disagreement between the different crop models of the baseline scenario and when compared with ET and crop yield data.&amp;#160; Also, a very large uncertainty is obtained for the climate change predictions. It is hence recommended to improve the crop models for application in Africa.&lt;/p&gt;

scholarly journals Accessing future crop yield and crop water productivity over the Heihe River basin in northwest China under a changing climate

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Qi Liu ◽  
Jun Niu ◽  
Bellie Sivakumar ◽  
Risheng Ding ◽  
Sien Li
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Crop Yield ◽  
Water Productivity ◽  
Heihe River Basin ◽  
Future Climate Change ◽  
Heihe River ◽  
Crop Water ◽  
Crop Water Productivity ◽  
The Heihe River Basin

AbstractQuantitative evaluation of the response of crop yield and crop water productivity (CWP) to future climate change is important to prevent or mitigate the adverse effects of climate change. This study made such an evaluation for the agricultural land over the Heihe River basin in northwest China. The ability of 31 climate models for simulating the precipitation, maximum temperature, and minimum temperature was evaluated for the studied area, and a multi-model ensemble was employed. Using the previously well-established Soil and Water Assessment Tool (SWAT), crop yield and crop water productivity of four major crops (corn, wheat, barley, and spring canola-Polish) in the Heihe River basin were simulated for three future time periods (2025–2049, 2050–2074, and 2075–2099) under two Representative Concentration Pathways (RCP4.5 and RCP8.5). The results revealed that the impacts of future climate change on crop yield and CWP of wheat, barley, and canola would all be negative, whereas the impact on corn in the eastern part of the middle reaches of the Heihe River basin would be positive. On the whole, climate change under RCP8.5 scenario would be more harmful to crops, while the corn crops in the Minle and Shandan counties have better ability to cope with climate change.

scholarly journals Effect of decision variables on yield and water productivity of onion under conventional furrow irrigation system in bako woreda, Ethiopia

2021 ◽  
Vol 11 (1) ◽  
pp. 92-100
Author(s):  
G Genemo ◽  
T Seyoum
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Flow Rate ◽  
Irrigation System ◽  
Water Productivity ◽  
Furrow Irrigation ◽  
Crop Water ◽  
Crop Water Use ◽  
Decision Variables ◽  
Use Efficiency

Flow rate and furrow length are the main irrigation decision variables currently affecting yield and water productivity at farm level. Improper selection of these variables produces an over use of water and loss in crop production. The general objective was to investigate the effect of decision variables on yield and water productivity of onion under conventional furrow irrigation system, with specific objective to analyze the effect of flow rate, furrow length and their interaction on yield and water productivity of onion. The field experiment was laid out in randomized complete block design with factorial arrangement of three levels of flow rate (0.7, 0.98 and 1.3 L/S) and three levels of furrow length (25, 35 and 50 m) with three replications. Inflow out flow method was used to determine the infiltration characteristics of the soil and Irrigation depth was controlled by using 3-inch Parshall flume. The maximum non-erosive flow rate to the experimental site was fixed through design equation considering soil textural class and furrow bed slope. Effect of furrow length and flow rate on yield and water productivity of the onion were used for evaluation. Their analyses indicated that effect of furrow length and their interaction with flow rate on yield were not significant (p<0.05). However, the flow rate showed highly significant (p<0.01) effect on yield of onion. The ranges of mean yield gained from furrow length and flow rate were F1 (14.75 ton ha-1) to F3 (15.96 ton ha-1) and Q1 (13.59 ton ha-1) to Q3 (19.69 ton ha-1), respectively. The effect of furrow length on crop water use efficiency and field water use efficiency was not significant (p<0.05). However, the flow rate has showed highly significant (p<0.01) effect on crop water use efficiency and field water use efficiency. The range of mean crop water use efficiency and field water use efficiency from furrow length and flow rate were F1 (33.65 kg/ha/mm) to F3 (36.41 kg/ha/mm) and Q1 (30.99 kg/ha/mm) to Q3 (38.65kg/ha/mm) and F1 (2.06 kg/m3) to F3 (2.23 kg/m3) and Q1 (1.89 kg/m3) to Q3 (2.36 kg/m3), respectively. Therefore, it can be concluded that a furrow length of 50 m is suitable to use 1.3 L/S of flow rate for better onion yield and water productivity under similar soil type of study area. Int. J. Agril. Res. Innov. Tech. 11(1): 92-100, June 2021

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