Climate change impacts on crop yield, crop water productivity and food security – A review

<p>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.</p><p>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.&#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.</p>

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

Geoscience Letters ◽

10.1186/s40562-020-00172-6 ◽

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.

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

Global NEST Journal ◽

10.30955/gnj.000486 ◽

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.

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Food Security Via Improving Crop Water Productivity in Some Arab Countries

World Journal of Agriculture and Soil Science ◽

10.33552/wjass.2019.02.000532 ◽

2019 ◽

Vol 2 (2) ◽

Author(s):

Nassar Atef

Keyword(s):

Food Security ◽

Water Productivity ◽

Arab Countries ◽

Crop Water ◽

Crop Water Productivity

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Improvements in crop water productivity increase water sustainability and food security—a global analysis

Environmental Research Letters ◽

10.1088/1748-9326/8/2/024030 ◽

2013 ◽

Vol 8 (2) ◽

pp. 024030 ◽

Cited By ~ 110

Author(s):

Kate A Brauman ◽

Stefan Siebert ◽

Jonathan A Foley

Keyword(s):

Food Security ◽

Global Analysis ◽

Water Productivity ◽

Crop Water ◽

Water Sustainability ◽

Crop Water Productivity ◽

Productivity Increase

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Assessing crop yield and crop water productivity and optimizing irrigation scheduling of winter wheat and summer maize in the Haihe plain using SWAT model

Hydrological Processes ◽

10.1002/hyp.9759 ◽

2013 ◽

Vol 28 (4) ◽

pp. 2478-2498 ◽

Cited By ~ 27

Author(s):

Chen Sun ◽

Li Ren

Keyword(s):

Winter Wheat ◽

Crop Yield ◽

Water Productivity ◽

Swat Model ◽

Irrigation Scheduling ◽

Crop Water ◽

Summer Maize ◽

Crop Water Productivity

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Validation of Aquacrop for Different Irrigation Regimes of Onion (Allium Cepa) in Bontanga Irrigation Scheme

International Journal of Irrigation and Agricultural Development (IJIRAD) ◽

10.47762/2017.964x.19 ◽

2018 ◽

Vol 1 (1) ◽

pp. 1-12

Author(s):

Y. K. Agbemabiese ◽

A-G Shaibu ◽

V. D. Gbedzi

Keyword(s):

Allium Cepa ◽

Crop Yield ◽

Water Productivity ◽

Leaf Biomass ◽

Crop Water ◽

Irrigation Scheme ◽

Crop Water Productivity ◽

Irrigation Regimes ◽

Aquacrop Model ◽

Mean Square Errors

Crop water productivity models are important tools in evaluating the effect of different irrigation regime on crop yield. AquaCrop model is a crop water productivity model adopted by the Land and Water Division of FAO in the year 2009. It simulates yield response to water for herbaceous crops, and it is particularly suitable in addressing conditions where water is a key limiting factor in crop production such as in northern Ghana. The objective of this study was to calibrate the AquaCrop model for different irrigation regimes for onion (Allium cepa), to determine its effect on crop growth and yield parameters of the crop at the Bontanga irrigation scheme. To achieve these, the Randomised Complete Block Design (RCBD) was used on Red Creole onion variety. RCBD was made up of four irrigation treatment regimes, 117%, 100%, 80% and 60% crop water requirements (CWR) of onion, with five replicates. Results indicated that there was no significant variation in yield, dry bulb biomass and total biomass, but there was difference for dry leaf biomass of onion at 0.05 significance level. The AquaCrop model simulated satisfactorily the crop yield, biomass and evapotranspiration water productivity of onion. There was a strong correlation and a significant linear relation between the simulated and measured crop yield, biomass and evapotranspiration water productivity. Validation of AquaCrop model using Nash-Sutcliffe efficiency (E), Root mean square errors (RMSE) and index of agreement (d) showed that, AquaCrop model can be used to simulate CWR of bulb crops, such as onion.

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Evolution of Crop Water Productivity in the Nile Delta over Three Decades (1985–2015)

Water ◽

10.3390/w10091168 ◽

2018 ◽

Vol 10 (9) ◽

pp. 1168 ◽

Cited By ~ 7

Author(s):

Samia M. El-Marsafawy ◽

Atef Swelam ◽

Ashraf Ghanem

Keyword(s):

Crop Yield ◽

Water Consumption ◽

Nile Delta ◽

Water Productivity ◽

Climatic Conditions ◽

Weather Data ◽

Crop Water ◽

Field Crops ◽

Crop Water Productivity ◽

Winter Vegetables

Estimating crop water productivity (CWP) for spatially variable climatic conditions in Egypt is important for the redistribution of crop planting to optimize production per unit of water consumed. The current paper aims to estimate maximum CWP trends under conditions of the Northern Nile Delta over three decades to choose crops that exhibit a higher productivity per unit of water and positive trends in the CWP. The Kafr El Sheikh Governorate was selected to represent the Northern Nile Delta Region, and mean monthly weather data for the period of 1985 to 2015 were collected to calculate standardized reference evapotranspiration and crop water use for a wide array of crops grown in the region using the CROPWAT8.0 model. The CWP was then calculated by dividing crop yield by seasonal water consumption. The CWP data range from 0.69 to 13.79 kg·m−3 for winter field crops, 3.40 to 10.69 kg·m−3 for winter vegetables, 0.29 to 6.04 kg·m−3 for summer field crops, 2.38 to 7.65 kg·m−3 for summer vegetables, 1.00 to 5.38 kg·m−3 for nili season crops (short-season post summer), and 0.66 to 3.35 kg·m−3 for orchards. The crops with the highest CWP values (kg·m−3) over three decades in descending order are: sugar beet (13.79), potato (w2) (10.69), tomato (w) (10.58), eggplant (w) (10.05), potato (w1) (9.98), cucumber (w) (9.81), and cabbage (w) (9.59). There was an increase in CWP of 41% from the first to the second and 22% from the second to the third decade. The CWP increase is attributed to a small decrease in water consumption and to a considerable increase in crop yield. The yield increases are attributed mainly to the planting of higher yielding varieties and/or the application of better agronomic practices.

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