scholarly journals From Global Goals to Local Gains—A Framework for Crop Water Productivity

2018 ◽  
Vol 7 (11) ◽  
pp. 414 ◽  
Author(s):  
Megan Blatchford ◽  
Poolad Karimi ◽  
W.G.M. Bastiaanssen ◽  
Hamideh Nouri

Crop water productivity (CWP) has become a recognised indicator in assessing the state of Sustainable Development Goals (SDG) 6.4—to substantially increase water use efficiency. This indicator, while useful at a global scale, is not comprehensive at a local scale. To fill this gap, this research proposes a CWP framework, that takes advantage of the spatio-temporal availability of remote sensing, that identifies CWP goals and sub-indicators specific to the needs of the targeted domain. Three sub-indicators are considered; (i) a global water productivity score (GWPS), (ii) a local water productivity score (LWPS) and (iii) a land and water use productivity score (YWPS). The GWPS places local CWP in the global context and focuses on maximised CWP. The LWPS differentiates yield zones, normalising for potential product, and focuses on minimising water consumption. The YWPS focuses simultaneously on improving land and water productivity equally. The CWP framework was applied to potato in the West Bank, Palestine. Three management practices were compared under each sub-indicator. The case study showed that fields with high and low performance were different under each sub-indicator. The performance associated with different management practices was also different under each sub-indicator. For example, a winter rotation had a higher performance under the YWPS, the fall rotation had a higher performance under the LWPS and under the GWPS there was little difference. The results showed, that depending on the basin goal, not only do the sub-indicators required change, but also the management practices or approach required to reach those basin goals. This highlights the importance of providing a CWP framework with multiple sub-indicators, suitable to basin needs, to ensure that meeting the SDG 6.4 goal does not jeopardise local objectives.

2019 ◽  
Vol 11 (6) ◽  
pp. 705 ◽  
Author(s):  
Poolad Karimi ◽  
Bhembe Bongani ◽  
Megan Blatchford ◽  
Charlotte de Fraiture

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.


2019 ◽  
Vol 62 (5) ◽  
pp. 1377-1393
Author(s):  
Steven R. Evett ◽  
Gary W. Marek ◽  
Paul D. Colaizzi ◽  
David K. Brauer ◽  
Susan A. O’Shaughnessy

Abstract. Greater than 80% of the irrigated area in the Southern High Plains is served by center-pivot irrigation, but the area served by subsurface drip irrigation (SDI) is increasing due to several factors including declining well yields and improved yields and crop water productivity (CWP), particularly for cotton. Not as well established is the degree to which the reduced soil water evaporation (E) in SDI systems affects the soil water balance, water available to the crop, and overall water savings. Grain corn ( L.) and sorghum ( L. Moench) were grown on four large weighing lysimeters at Bushland, Texas, in 2013 (corn), 2014 and 2015 (sorghum), and 2016 (corn). Evapotranspiration (ET) was measured using the lysimeters and using a neutron probe in the surrounding fields. Two of the lysimeters and surrounding fields were irrigated with SDI, and the other two were irrigated with mid-elevation spray application (MESA). The lysimeter-measured evaporative losses were 149 to 151 mm greater from sprinkler-irrigated corn fields than from SDI fields. When growing sorghum, the lysimeter-measured evaporative losses were 44 to 71 mm greater from sprinkler-irrigated fields than from SDI fields. The differences were affected by plant height and became smaller when plant height reached the height of the spray nozzles, indicating that the use of LEPA or LESA nozzles could decrease the evaporative losses from sprinkler-irrigated fields in this region with its high evaporative demand. Annual weather patterns also influenced the differences in evaporative loss, with increased differences in dry years. SDI reduced overall corn water use by 13% to 15%, as determined by neutron probe, while either not significantly affecting yield (2016) or increasing yield by up to 19% (2013) and increasing CWP by 37% (2013) to 13% (2016) as compared with MESA full irrigation. However, sorghum yield decreased by 15% and CWP decreased by 14% in 2014 when using SDI compared with MESA full irrigation due to an overly wet soil profile in the SDI fields and deep percolation that likely caused nutrient losses. In 2015, there were no significant sorghum yield differences between irrigation methods. Sorghum CWP was significantly greater (by 14%) in one SDI field in 2015 compared with MESA fully irrigated sorghum. Overall, sorghum CWP increased by 8% for SDI compared with MESA full irrigation in 2015. These results indicate that SDI will be successful for corn production in the Texas High Plains, but SDI is unlikely to benefit sorghum production. Keywords: Corn, Crop water productivity, Evaporative loss, Evapotranspiration, Irrigation application method, Sorghum, Water use efficiency, Weighing lysimeter.


2007 ◽  
Vol 94 (2) ◽  
pp. 478-493 ◽  
Author(s):  
Junguo Liu ◽  
Jimmy R. Williams ◽  
Alexander J.B. Zehnder ◽  
Hong Yang

2013 ◽  
Vol 10 (3) ◽  
pp. 295-300

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.


2013 ◽  
Vol 44 ◽  
pp. 95-102
Author(s):  
Saad Ahmad Alghariani

AbstractThe looming water crisis in Libya necessitates taking immediate action to reduce the agricultural water demand that consumes more than 80% of the water supplies. The available information on water use efficiency and crop water productivity reveals that this proportion can be effectively reduced while maintaining the same, if not more, total agricultural production at the national level. Crop water productivity, which is depressingly low, can be doubled through implementing several measures including relocating all major agricultural crops among different hydroclimatic zones and growth seasons; crop selection based on comparative production advantages; realisation of the maximum genetically determined crop yields; and several other measures of demand water management. There is an urgent need to establish the necessary institutional arrangements that can effectively formulate and implement these measures as guided by agricultural research and extension services incorporating all beneficiaries and stakeholders in the process.


2007 ◽  
Vol 363 (1491) ◽  
pp. 639-658 ◽  
Author(s):  
J.I.L Morison ◽  
N.R Baker ◽  
P.M Mullineaux ◽  
W.J Davies

Globally, agriculture accounts for 80–90% of all freshwater used by humans, and most of that is in crop production. In many areas, this water use is unsustainable; water supplies are also under pressure from other users and are being affected by climate change. Much effort is being made to reduce water use by crops and produce ‘more crop per drop’. This paper examines water use by crops, taking particularly a physiological viewpoint, examining the underlying relationships between carbon uptake, growth and water loss. Key examples of recent progress in both assessing and improving crop water productivity are described. It is clear that improvements in both agronomic and physiological understanding have led to recent increases in water productivity in some crops. We believe that there is substantial potential for further improvements owing to the progress in understanding the physiological responses of plants to water supply, and there is considerable promise within the latest molecular genetic approaches, if linked to the appropriate environmental physiology. We conclude that the interactions between plant and environment require a team approach looking across the disciplines from genes to plants to crops in their particular environments to deliver improved water productivity and contribute to sustainability.


2006 ◽  
Vol 10 (3) ◽  
pp. 443-454 ◽  
Author(s):  
H. Yang ◽  
L. Wang ◽  
K. C. Abbaspour ◽  
A. J. B. Zehnder

Abstract. Amid an increasing water scarcity in many parts of the world, virtual water trade as both a policy instrument and practical means to balance the local, national and global water budget has received much attention in recent years. Building upon the knowledge of virtual water accounting in the literature, this study assesses the efficiency of water use embodied in the international food trade from the perspectives of exporting and importing countries and at the global and country levels. The investigation reveals that the virtual water flows primarily from countries of high crop water productivity to countries of low crop water productivity, generating a global saving in water use. Meanwhile, the total virtual water trade is dominated by green virtual water, which constitutes a low opportunity cost of water use as opposed to blue virtual water. A sensitivity analysis, however, suggests high uncertainties in the virtual water accounting and the estimation of the scale of water saving. The study also raises awareness of the limited effect of water scarcity on the global virtual water trade and the negative implications of the global water saving for the water use efficiency and food security in importing countries and the environment in exporting countries. The analysis shows the complexity in evaluating the efficiency gains in the international virtual water trade. The findings of the study, nevertheless, call for a greater emphasis on rainfed agriculture to improve the global food security and environmental sustainability.


Author(s):  
Pradeep Kumar Singh ◽  
R. K. Naresh ◽  
. Vivek ◽  
Yogesh Kumar ◽  
M. Sharath Chandra ◽  
...  

Decline in soil fertility is one of the major constraints to sustainable crop production and profitability. To meet the increasing demand for the growing population the issue of low soil fertility needs to be addressed moreover, excessive pumping of groundwater over the years to meet the high irrigation water requirement of rice-wheat system has resulted in over exploitation of groundwater in the Indo-Gangetic plains (IGP) of India. Replacement of traditional wheat cultivation practices under conservation agriculture (CA) based management (tillage, and crop establishment management) practices are required to promote sustainable agriculture. Furthermore, inefficient nutrient management practices are responsible for low crop yields and nutrient use efficiencies in wheat under rice-wheat cropping system (RWCS). A field experiment was conducted at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut (U.P.), India to evaluate the effects of tillage and crop establishment (TCE) methods, and nutrient management practices on crop yields, water productivity and profitability of wheat under RWCS. The main plot treatments included four combinations of TCE [Furrow irrigated raised beds (FIRB), Roto tillage (RT), Reduced tillage (RTW) and conventional tillage (CT), with six nutrient management practices [N1 Control, N2 100% Recommend Dose of Fertilizer, N3 100% RDF + NPK consortia + Bio-stimulant, N4 75% RDF + NPK consortia + Bio-stimulant, N5 100% RDF + NPK consortia + Bio-stimulant + NPK (18:18:18) spray after II irrigation, and N6 and 75% RDF + NPK consortia + Bio-stimulant + NPK (18:18:18) spray after II irrigation]. Crop water productivity and net returns under FIRB were significantly increased by 11.7% and 13.8% compared to CT respectively, during year of experimentation. Study showed that conservation agriculture based sustainable practices (FIRB) and nutrient strategies 100% RDF + NPK consortia + Bio-stimulant + NPK (18:18:18) spray after II irrigation approach provided opportunities for enhancing crop and water productivity, and profitability of wheat crop in North-West IGP of India. Treatments with N and conservation agriculture were the most profitable. A combined use of conservation agriculture and organic and chemical fertilizers is the best bet for increasing, wheat crop yield and associated return on investment.


Author(s):  
Eka Suhartanto ◽  
Lisma Safitri

The studies on the Crop Water Productivity (CWP) of cocoa to increase productivity in the midst of water scarcity and climate change are currently underdeveloped. Thus, this study aims to find out the trends in climate, productivity, crop water use and CWP of cocoa plantations. The methods included collecting climate and productivity data during 2014-2019, simulating crop water use with Cropwat 8.0 software and analysing the changing trends of CWP in cocoa plantations, DI Yogyakarta. The results indicated the changes in productivity of cocoa plantation ranged from 0,41 – 0,53 tons / ha. The Crop Water Usage (CWU)  decreased from 11.107 m3 in 2014 to 8.482 m3 in 2019 under rainfed schenario. Subsequently, the trend of CWP tended to increase from 0,037 kgm-3 in 2014 to 0,059 kgm-3 in 2019. CWP of cocoa plantation increased when CWU decreased and productivity increased. CWP value illustrated that every 1 m3 of water used have produced 0,037 – 0,059 kg of dried cocoa beans. In terms of water use efficiency, this relatively small CWP value indicates that the level of water use by cocoa plants in DI Yogyakarta is inefficient that requires improvement in the future such as increasing land productivity and precision irrigation schemes for cocoa plantations.  Keywords: Cacao (Theobroma cacao L.), crop water productivity, crop water use, D.I Yogyakarta


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