How does plastic film mulching affect crop water productivity in an arid river basin?

2021 ◽  
Vol 258 ◽  
pp. 107218
Author(s):  
Wang Zhang ◽  
Yong Tian ◽  
Zan Sun ◽  
Chunmiao Zheng
Keyword(s):  
River Basin ◽  
Water Productivity ◽  
Plastic Film ◽  
Crop Water ◽  
Plastic Film Mulching ◽  
Crop Water Productivity ◽  
Film Mulching

scholarly journals Water availability, water demand, and reliability of in situ water harvesting in smallholder rain-fed agriculture in the Thukela River Basin, South Africa

2009 ◽  
Vol 6 (4) ◽  
pp. 4919-4959 ◽  
Author(s):  
J. C. M. Andersson ◽  
A. J. B. Zehnder ◽  
G. P. W. Jewitt ◽  
H. Yang
Keyword(s):  
South Africa ◽  
River Basin ◽  
Water Availability ◽  
Assessment Tool ◽  
Water Productivity ◽  
Water Harvesting ◽  
Crop Water ◽  
Water Demands ◽  
Crop Water Productivity

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.

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

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.

scholarly journals Water availability, demand and reliability of in situ water harvesting in smallholder rain-fed agriculture in the Thukela River Basin, South Africa

2009 ◽  
Vol 13 (12) ◽  
pp. 2329-2347 ◽  
Author(s):  
J. C. M. Andersson ◽  
A. J. B. Zehnder ◽  
G. P. W. Jewitt ◽  
H. Yang
Keyword(s):  
River Basin ◽  
Water Availability ◽  
Water Productivity ◽  
Maize Yield ◽  
Coefficient Of Determination ◽  
Water Harvesting ◽  
Crop Water ◽  
Crop Water Productivity ◽  
Uncertainty Band

Abstract. Water productivity in smallholder rain-fed agriculture is of key interest for improved 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 potential in situ WH, and supplemental water demand (SWD) in smallholder agriculture in South Africa's Thukela River Basin (29 000 km2, mean annual precipitation 550–2000 mm yr−1). The study includes process dynamics governing runoff generation and crop water demands, quantification of prediction uncertainty, and an analysis of the reliability of in situ WH. The agro-hydrological model SWAT (Soil and Water Assessment Tool) was calibrated and evaluated with the Sequential Uncertainty Fitting algorithm against observed discharge (at ten stations) and maize yield (the dominant crop type) for the period 1997–2006. 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 water availability ≥SWD. This reflects the risks of failure induced by the temporal variability in the water availability and the SWD. The calibration reduced the predictive uncertainty and resulted in a satisfactory model performance. For smallholder maize yield, the Root Mean Squared Error was 0.02 t ha−1 during both the calibration and the evaluation periods. The width of the uncertainty band was reduced by 23% due to the calibration. For discharge during the calibration (evaluation) period, the ten-station range in the weighted coefficient of determination (Φ) was 0.16–0.85 (0.18–0.73), and in the coefficient of determination (R2) 0.42–0.83 (0.28–0.72). The calibration reduced the width of the uncertainty band by 25% on average. The results show that the smallholder crop water productivity is currently 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.

Crop water productivity of an irrigated maize crop in Mkoji sub-catchment of the Great Ruaha River Basin, Tanzania

2006 ◽  
Vol 85 (1-2) ◽  
pp. 141-150 ◽  
Author(s):  
Henry E. Igbadun ◽  
Henry F. Mahoo ◽  
Andrew K.P.R. Tarimo ◽  
Baanda A. Salim
Keyword(s):  
River Basin ◽  
Water Productivity ◽  
Crop Water ◽  
Maize Crop ◽  
Crop Water Productivity
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