Water use by a groundwater dependent maize in a semi-arid region of Inner Mongolia: Evapotranspiration partitioning and capillary rise

Spatiotemporal rainfall variability and low soil fertility are the primary crop production challenges facing poor farmers in semi-arid environments. However, there are few solutions for addressing these challenges. The literature provides several crop upgrading strategies (UPS) for improving crop yields, and biophysical models are used to simulate these strategies. However, the suitability of UPS is limited by systemization of their areas of application and the need to cope with the challenges faced by poor farmers. In this study, we reviewed 187 papers from peer-reviewed journals, conferences and reports that discuss UPS suitable for cereals and biophysical models used to assist in the selection of UPS in semi-arid areas. We found that four UPS were the most suitable, namely tied ridges, microdose fertilization, varying sowing dates, and field scattering. The DSSAT, APSIM and AquaCrop models adequately simulate these UPS. This work provides a systemization of crop UPS and models in semi-arid areas that can be applied by scientists and planners.

Section: Use Of Groundwatermentioning

confidence: 99%

Crop Upgrading Strategies and Modelling for Rainfed Cereals in a Semi-Arid Climate—A Review

Silungwe

Graef

Bellingrath-Kimura

et al. 2018

“…Calibration focuses on the crop parameters K cb and p, the soil evaporation parameters Z e , TEW and REW, and the RO and DP parameters. Otherwise, default parameters can be used because errors are small when using well selected default parameters [45,50]; thus, the parameters obtained for the calibration at Paysandú should be further used as default in other locations of western Uruguay.…”

Section: Modelingmentioning

confidence: 99%

Predicting Maize Transpiration, Water Use and Productivity for Developing Improved Supplemental Irrigation Schedules in Western Uruguay to Cope with Climate Variability

Giménez

Petillo

Paredes

et al. 2016

Self Cite

Abstract:Various maize irrigation treatments including full and deficit irrigation were used to calibrate and validate the soil water balance and irrigation scheduling model SIMDualKc at Paysandú, western Uruguay. The model adopts the dual crop coefficient approach to partition actual evapotranspiration (ET c act ) into actual transpiration (T c act ) and soil evaporation (E s ). Low errors of estimation were obtained for simulating soil water content (Root mean square errors (RMSE) ď 0.014 cm 3¨c m´3 with calibrated parameters, and RMSE ď 0.023 cm 3¨c m´3 with default parameters). The ratio E s /T c act ranged from 26% to 33% and E s /ET c act varied from 20% to 25%, with higher values when the crop was stressed offering less soil coverage. Due to rainfall regime, runoff and deep percolation were quite large. The Stewarts phasic model was tested and used to predict maize yield from T c act with acceptable errors, in the range of those reported in literature. Water productivity values were high, ranging 1.39 to 2.17 kg¨m´3 and 1.75 to 2.55 kg¨m´3 when considering total water use and crop ET, respectively. Using a 22-year climatic data series, rainfed maize was assessed with poor results for nearly 40% of the years. Differently, alternative supplemental irrigation schedules assessed for the dry and very dry years have shown good results, particularly for mild deficit irrigation. Overall, results show appropriateness for using SIMDualKc to support the irrigation practice.

“…Ma et al [35] analyzed the relationship between vegetation ecotypes and groundwater depth in the HSL, and showed that the ranges of water table depth for hygrophyte, mesophyte, mesoxerophyte and xerophyte varied from 0.45 m to 1.66 m, 0.95 m to 2.20 m, 2.20 m to 4.59 m, and 3.45 m to 7.45 m, respectively. Wu [36] found that groundwater was key to vegetation growth in the HSL, and accounted for 36% of the total evapotranspiration (i.e., 162 mm) on average. Such a percentage could be increased to 60% (i.e., 270 mm) in a dry year such as in 2009.…”

Section: Introductionmentioning

confidence: 99%

Spatio-Temporal Patterns of Water Table and Vegetation Status of a Deserted Area

Duan

Liu

Wang

et al. 2015

Self Cite

Understanding groundwater-vegetation interactions is crucial for sustaining fragile environments of desert areas such as the Horqin Sandy Land (HSL) in northern China. This study examined spatio-temporal variations in the water table and the associated vegetation status of a 9.71 km 2 area that contains meadowland, sandy dunes, and intermediate transitional zones. The depth of the water table and hydrometeorologic parameters were monitored and Landsat Thematic Mapper (TM) and Moderate Resolution Imaging Spectroradiometer (MODIS) data were utilized to assess the vegetation cover. Spatio-temporal variations over the six-year study period were examined and descriptive groundwater-vegetation associations developed by overlaying a water table depth map onto a vegetation index map derived from MODIS. The results indicate that the water table depends on the local topography, localized geological settings, and human activities such as reclamation, with fluctuations occurring at annual and monthly scales as a function of precipitation and potential evapotranspiration. Locations where the water table is closer to the surface tend to have more dense and productive vegetation. The water table depth is more closely associated with vegetative density in meadowlands than in transitional zones, and only poorly associated with vegetation in sandy dunes.