Your search found 3 records
1 Xiang, Z.; Bailey, R. T.; Nozari, S.; Husain, Z.; Kisekka, I.; Sharda, V.; Gowda, P.. 2020. DSSAT-MODFLOW: a new modeling framework for exploring groundwater conservation strategies in irrigated areas. Agricultural Water Management, 232:106033. (Online first) [doi: https://doi.org/10.1016/j.agwat.2020.106033]
Groundwater table ; Water conservation ; Models ; Strategies ; Decision support systems ; Water depletion ; Irrigated land ; Crop yield ; Pumping ; Wells ; Aquifers / USA / Kansas / Ogallala Aquifer
(Location: IWMI HQ Call no: e-copy only Record No: H049527)
(15.40 MB)
Groundwater models are often used to assess the impact of climate or management strategies on groundwater resources in arid and semiarid regions of the world. However, these models do not account for crop growth and crop yield, and thus cannot be used for evaluating long-term impacts of climate and management strategies on water use efficiency and farm profitability of agricultural systems while managing the aquifers sustainably. This study presented a linkage between DSSAT, an agronomic model, and MODFLOW, a groundwater flow model. The linkage between these two models occurred on an annual basis, with rates of irrigation and deep percolation from an ensemble of field-scale DSSAT simulations converted to pumping rates and recharge rates for the MODFLOW simulation. MODFLOW simulated groundwater head, which can be used to update saturated thickness and thereby well capacities for each pumping well in the model domain. Simulated well capacities were then used to constrain irrigation applications in the DSSAT simulations during the following growing season. Python scripts were used to convert output from one model to input files for the other model. The DSSAT-MODFLOW modeling system was applied to the Ogallala aquifer underlying Finney County, Kansas, a region experiencing significant groundwater depletion due to irrigation practices, and was tested against observed water table elevation and crop yield. Over a decadal period, well capacity decreased by > 50 % for many pumping wells in the county. A no-irrigation scenario for this same time period resulted in average water table elevation increasing by 2 m, but also a 70 % decline in crop yield. Additional work is needed to balance groundwater conservation with crop yield. The DSSAT-MODFLOW modeling system can be used in regions worldwide to assess changes in irrigation technologies, crop selection, and climate change adaptation strategies.
2 Montanaro, G.; Nangia, V.; Gowda, P.; Mukhamedjanov, S.; Mukhamedjanov, A.; Haddad, M.; Yuldashev, Tulkun; Wu, W. 2021. Heat units-based potential yield assessment for cotton production in Uzbekistan. International Journal of Agricultural and Biological Engineering, 14(6):137-144. [doi: https://doi.org/10.25165/j.ijabe.20211406.4803]
Cotton ; Crop production ; Crop yield ; Yield gap ; Yield potential ; Assessment ; Heat units ; Climate variability ; Agriculture / Uzbekistan
(Location: IWMI HQ Call no: e-copy only Record No: H050907)
https://ijabe.org/index.php/ijabe/article/download/4803/pdf
https://vlibrary.iwmi.org/pdf/H050907.pdf
https://vlibrary.iwmi.org/pdf/H050907.pdf
(0.77 MB) (792 KB)
Cotton yields in Uzbekistan are significantly lower than those in similar agro-climatic regions, requiring the estimation of crop potential and baseline yield to track progress of production enhancement efforts. The current study estimated potential cotton development and baseline yield (maximum given no production constraints) using total heat units (THU) and potential cotton yield (PCY), respectively. Calculations were based on heat units (HU) for a 30-year (1984-2013) period. Long-term average THU and PCY, as well as PCY at three different exceedance probabilities (p=0.99, p=0.80, and p=0.75), were calculated for 21 selected weather stations across cotton-growing areas of Uzbekistan. After confirmation that the current planting date (April 15) is optimal, a comparison of THU with the accepted cotton production cutoff threshold (1444°C) suggested that areas with lower elevations and latitudes are more appropriate for cotton production. Yield gap analysis (relative difference between long-term average PCY and actual yields) confirmed that Uzbekistan cotton production is below potential, while the spatial distribution of yield gaps outlined where efforts should be targeted. Areas near the stations of Nukus, Kungrad, Chimbay, and Syrdarya should be further investigated as benefit/cost ratio is highest in these areas. A comparison between state-set yield targets and PCY values, taking into account climatic variability, suggested that all areas except Jaslyk, Nurata, and Samarkand have safe, appropriate targets. These results present a starting-point to aid in strategic actions for Uzbekistan cotton production improvement.
3 Singh, J.; Angadi, S.; Begna, S.; VanLeeuwen, D.; Idowu, O. J.; Singh, P.; Trostle, C.; Gowda, P.; Brewer, C. 2024. Deficit irrigation strategy to sustain available water resources using guar. Industrial Crops and Products, 211:118272. (Online first) [doi: https://doi.org/10.1016/j.indcrop.2024.118272]
Water resources ; Water availability ; Irrigation water ; Rainfall ; Drought stress ; Irrigation management ; Biomass production ; Crop yield ; Aquifers ; Soil profiles
(Location: IWMI HQ Call no: e-copy only Record No: H052630)
(4.30 MB)
The gradual depletion of irrigation water is a major threat to the agricultural economy in the arid and semi-arid regions of the world. Drought–tolerant crops and improved irrigation management practices may help the sustainability of agriculture in the region. A three–year field experiment (2018–2020) was conducted to assess the effects of pre–and in–season irrigations on the physiology, biomass production, yield, and yield components of two diverse guar (Cyamopsis tetragonoloba) cultivars. A split-split plot design was used, where the main plot was pre–irrigation, subplots consisted of in–season irrigation treatments, and sub-sub plots were cultivars. Each treatment was replicated four times each year. Pre–irrigation improved the averaged final seed yield by 32% compared to plots with no pre–irrigation. Seed yield was significantly affected by in–season growth stage based irrigation treatments. Averaged over the years, full irrigation achieved the highest seed yield, although not significantly different from no irrigation during the vegetative growth stage in any study year. Cultivar Kinman performed better than Monument in biomass production and seed yield. Overall, pre–irrigation improves guar growth and development, leading to greater seed yield and biomass production. The most sustainable strategy to utilize the available water resources will be to grow guar with restricted irrigation during the vegetative growth stage, save 22% of water, and maintain a similar seed yield to plots that received irrigation throughout the crop season.
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