scholarly journals Assessing Crop Water Productivity under Different Irrigation Scenarios in the Mid–Atlantic Region

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1826
Author(s):  
Manashi Paul ◽  
Masoud Negahban-Azar ◽  
Adel Shirmohammadi

The continuous growth of irrigated agricultural has resulted in decline of groundwater levels in many regions of Maryland and the Mid–Atlantic. The main objective of this study was to use crop water productivity as an index to evaluate different irrigation strategies including rainfed, groundwater, and recycled water use. The Soil and Water Assessment Tool (SWAT) was used to simulate the watershed hydrology and crop yield. It was used to estimate corn and soybean water productivity using different irrigation sources, including treated wastewater from adjacent wastewater treatment plants (WWTPs). The SWAT model was able to estimate crop water productivity at both subbasin and hydrologic response unit (HRU) levels. Results suggest that using treated wastewater as supplemental irrigation can provide opportunities for improving water productivity and save fresh groundwater sources. The total water productivity (irrigation and rainfall) values for corn and soybean were found to be 0.617 kg/m3 and 0.173 kg/m3, respectively, while the water productivity values for rainfall plus treated wastewater use were found to be 0.713 kg/m3 and 0.37 kg/m3 for corn and soybean, respectively. The outcomes of this study provide information regarding enhancing water management in similar physiographic regions, especially in areas where crop productivity is low due to limited freshwater availability.

2009 ◽  
Vol 6 (4) ◽  
pp. 4919-4959 ◽  
Author(s):  
J. C. M. Andersson ◽  
A. J. B. Zehnder ◽  
G. P. W. Jewitt ◽  
H. Yang

Abstract. Water productivity in smallholder rain-fed agriculture is of key interest for food and livelihood security. A frequently advocated approach to enhance water productivity is to adopt water harvesting and conservation technologies (WH). This study estimates water availability for in situ WH and supplemental water demands (SWD) in smallholder agriculture in the Thukela River Basin, South Africa. It incorporates process dynamics governing runoff generation and crop water demands, an explicit account of the reliability of in situ WH, and uncertainty considerations. The agro-hydrological model SWAT (Soil and Water Assessment Tool) was calibrated and evaluated with the SUFI-2 algorithm against observed crop yield and discharge in the basin. The water availability was based on the generated surface runoff in smallholder areas. The SWD was derived from a scenario where crop water deficits were met from an unlimited external water source. The reliability was calculated as the percentage of years in which the water availability ≥ the SWD. It reflects the risks of failure induced by the temporal variability in these factors. The results show that the smallholder crop water productivity is low in the basin (spatiotemporal median: 0.08–0.22 kg m−3, 95% prediction uncertainty band (95PPU). Water is available for in situ WH (spatiotemporal median: 0–17 mm year−1, 95PPU) which may aid in enhancing the crop water productivity by meeting some of the SWD (spatiotemporal median: 0–113 mm year−1, 95PPU). However, the reliability of in situ WH is highly location specific and overall rather low. Of the 1850 km2 of smallholder lands, 20–28% display a reliability ≥25%, 13–16% a reliability ≥50%, and 4–5% a reliability ≥75% (95PPU). This suggests that the risk of failure of in situ WH is relatively high in many areas of the basin.


Author(s):  
Meseret Dawit ◽  
Megersa Olumana Dinka ◽  
Olkeba Tolessa Leta

Integration of advanced irrigation systems and technology is essential to improve crop water productivity and yields, especially in developing countries. This study aims at investigating the effects of adopting a drip irrigation system combined with hand-dug wells on crop water productivity and yields of household farmers and their perception on the proposed scheme over two cropping seasons in the Haramaya District, Ethiopia. We chose three locally called “Kebeles” within the District, and selected a certain number of household farmers that had similar characteristics within each Kebele. The selected farmers had practiced both the proposed drip irrigation with private hand-dug wells water supply (intervention pilots) and traditionally-used surface irrigation with communal water supply (non-intervention pilots) schemes. We also conducted interviews with the selected household farmers, personal observations, and measurements on crop water productivity and yields for both intervention and non-intervention pilots. We found that the proposed drip irrigation system significantly improved the crop productivity and yields of the farmers. More importantly, findings indicated that the use of drip irrigation system combined with hand-dug well water supplies reduced the over-exploitation of water (water savings) and labor-intensive manual-irrigation. The latter particularly helped women to work less on their farm works and thus provided them a flexible system to expand their plot sizes and grow a variety of crops. Overall, the drip irrigation system with water supply from hand-dug wells is highly recommended as it allows a flexible system for household farmers and provides an opportunity to expand their plot sizes with a variety of crops, which is also expected to mitigate the negative implications of climate change on freshwater water resources and crop productivity. However, the farmers of the Haramaya District expressed their need on capacity building, financial and technical supports from local to regional governments and other agencies to ensure an efficient and cost-effective drip irrigation system and to further improve their crop water productivity and yield, food self-sufficieny, and livelihoods. It is also important to consider market-based farming approaches, while promoting efficient irrigation systems and self-supply to ensure quick investment returns. This study recommends to adopt and expand the proposed drip irrigation system at household levels in Sub-Saharan and other similar regions.


2020 ◽  
Author(s):  
Chen Sun ◽  
Xu Xu

<p>Haihe plain is an important food production area in China, facing an increasing water shortage. The water used for agriculture accounts for about 70% of total water resources. Thus, it is critical to optimize the irrigation scheduling for saving water and increasing crop water productivity (CWP). This study firstly simulated crop yield and CWP for winter wheat in historical scenario during 1961-2005 for Haihe plain using previously well-established SWAT model. Then scenarios under historical irrigation (scenario 1) and sufficient irrigation (scenario 2) were respectively simulated both with sufficient fertilizer. The crop yield in scenario 2 was considered as the potential crop yield. The optimal irrigation scheduling with sufficient fertilizer (scenario 3) was explored by iteratively adjusting irrigation scheduling based on the scenario 1 and previous studies related to water stress on crop growth. Results showed that net irrigation amount was reduced 23.1% in scenario 3 for winter wheat when compared with scenario 1. The CWP was 12.1% higher with very slight change of crop yield. Using optimal irrigation scheduling could save 8.8×10<sup>8</sup> m<sup>3</sup> irrigation water and reduce about 16.3% groundwater over-exploitation in winter wheat growth period. The corresponding yield was 18.5% less than potential yield for winter wheat but using less irrigation water. Therefore, it could be considered that the optimal irrigation was reasonable, which provided beneficial suggestions for increasing efficiency of agricultural water use with sustainable crop yield in Haihe plain.</p>


2021 ◽  
Vol 6 (1) ◽  
pp. 37-43
Author(s):  
Gary W. Marek ◽  
Thomas H. Marek ◽  
Steven R. Evett ◽  
Yong Chen ◽  
Kevin R. Heflin ◽  
...  

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 756
Author(s):  
AbdAllah M. El-Sanatawy ◽  
Ahmed S. M. El-Kholy ◽  
Mohamed M. A. Ali ◽  
Mohamed F. Awad ◽  
Elsayed Mansour

Water shortage is a major environmental stress that destructively impacts maize production, particularly in arid regions. Therefore, improving irrigation management and increasing productivity per unit of water applied are needed, especially under the rising temperature and precipitation fluctuations induced by climate change. Laboratory and field trials were carried out in the present study, which were aimed at assessing the possibility of promoting maize germination, growth, grain yield and crop water productivity (CWP) using seed priming under different irrigation regimes. Two seed priming treatments, i.e., hydro-priming and hardening versus unprimed seeds, were applied under four irrigation regimes, i.e., 120, 100, 80 and 60% of estimated crop evapotranspiration (ETc). The obtained results indicated that increasing irrigation water from 100% up to 120% ETc did not significantly increase grain yield or contributing traits, while it decreased CWP. Deficit irrigation of 80 and 60% ETc gradually decreased grain yield and all attributed traits. Seed priming significantly ameliorated seedlings’ vigor as indicated by earlier germination, higher germination percentage, longer roots and shoots, and heavier fresh and dry weight than unprimed seeds with the superiority of hardening treatment. Additionally, under field conditions, seed priming significantly increased grain yield, yield contributing traits and CWP compared with unprimed treatment. Interestingly, the results reflect the role of seed priming, particularly hardening, in mitigating negative impacts of drought stress and enhancing maize growth, grain yield and attributed traits as well as CWP under deficit irrigation conditions. This was demonstrated by a significant increase in grain yield and CWP under moderate drought and severe drought conditions compared with unprimed treatment. These results highlight that efficient irrigation management and seed priming can increase maize yield and water productivity in arid environments.


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.


2015 ◽  
Vol 62 (1) ◽  
pp. 53-68 ◽  
Author(s):  
Wolde Mekuria ◽  
Andrew Noble ◽  
Matthew McCartney ◽  
Chu Thai Hoanh ◽  
Somphasith Douangsavanh ◽  
...  

2015 ◽  
Vol 522 ◽  
pp. 428-438 ◽  
Author(s):  
Xiaolin Yang ◽  
Yuanquan Chen ◽  
Steven Pacenka ◽  
Wangsheng Gao ◽  
Li Ma ◽  
...  

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