1st Edition

Water Productivity of Sunflower under Different Irrigation Regimes at Gezira Clay Soil, Sudan

By Eman Rahamtalla Ahmed Elsheikh Copyright 2016
    166 Pages
    by CRC Press

    166 Pages
    by CRC Press

    The Gezira Scheme is Sudan's oldest and largest gravity irrigation system. The scheme has played an important role in the economic development of the country, and is a major source of foreign exchange. The farming system of the Gezira Scheme is dominated by crop production. The main crops grown are sorghum, wheat, groundnut and the oilseed crop sesame. Sunflower (Helianthus annuus L.) is an important oil crop in the world and a new edible oil crop in Sudan. Knowledge of the effects of irrigation scheduling on sunflower production and water productivity under water stress conditions is becoming increasingly important. Irrigation scheduling is particularly important since many field crops are more sensitive to water deficit at specific phonological stages. Sunflower has several growth stages: emergence, vegetative, reproductive, flowering, seed formation and maturity. Water stress in each stage results in reduction in seed yield and oil content. The treatments in the test plots, which were conducted to study the effect of water stress at different growth stages, showed that sunflower was significantly affected by water stress that occurred in the sensitive flowering and seed formation stages. Highest seed yield was obtained when water stress was avoided during these stages. The AquaCrop model was used to simulate the seed yield and water productivity. The model was able to precisely simulate seed yield, but overestimated water productivity under different irrigation treatments.

    1 Introduction
    1.1 Structure of the thesis

    2 Background and objectives
    2.1 Country characteristics
    2.2 Water resources in Sudan
    2.3 Crop production in Sudan
    2.4 Increase in total crop production
    2.5 Land use and land cover
    2.6 Problem description
    2.7 Hypothesis
    2.8 Research questions
    2.9 Research objectives

    3 Agriculture in Sudan
    3.1 Agricultural practices
    3.1.1 Rainfed agriculture
    3.1.2 Irrigated agriculture
    3.1.3 Flood/spate irrigation agriculture
    3.2 Water management for agriculture
    3.3 Agricultural policies and strategies
    3.4 Sunflower (Helianthus annuus L) description
    3.5 Sunflower growth stages
    3.6 Sunflower seed production

    4 Irrigation schemes in Sudan
    4.1 Introduction
    4.2 Surface irrigation
    4.2.1 Supplemental irrigation (SI)
    4.3 Irrigation scheduling
    4.4 Water balance
    4.5 Furrow irrigation
    4.6 Main irrigation scheme
    4.6.1 New Halfa Scheme
    4.6.2 Rahad Scheme
    4.7 Gezira Irrigation Scheme
    4.7.1 Description of the scheme area
    4.7.2 General climatic conditions
    4.7.3 Design of Gezira Scheme
    4.7.4 Gezira clay soil
    4.7.5 Water application management in the field
    4.7.6 Water users associations in Gezira Scheme

    5 Crop coefficient (Kc) for irrigated Winter Sunflower (Helianthus annuus L)
    5.1 Introduction
    5.2 Study area
    5.3 Calculation method
    5.4 Reference evapotranspiration (ETo)
    5.5 Evapotranspiration (ETc)
    5.5.1 Soil moisture measurements
    5.6 Estimation of the Winter Sunflower crop coefficient (Kc)
    5.7 Concluding remarks

    6 Deficit irrigation effect on Sunflower production under different environmental conditions
    6.1 Concept of deficit irrigation
    6.2 Deficit irrigation and Sunflower yield

    7 Field experiments and study area
    7.1 Description of the study area
    7.2 Climate of Gezira area
    7.3 Experiment One (winter season 2011, 2012 and 2013)
    7.3.1 Experiment description and lay out
    7.3.2 Irrigation water measurement
    7.4 Experiment Two (summer season 2012 and 2013)
    7.5 Experiment Three (winter season 2012/2013 and 2013/2014)
    7.6 Crop parameters measurement

    8 Results and discussion of the field experiments
    8.1 Different irrigation intervals (experiment One)
    8.1.1 Seed yield (kg/ha)
    8.1.2 Oil content (%)
    8.1.3 Application of irrigation water
    8.2 Concluding remarks on experiment One
    8.3 Experiment Two (summer seasons 2012 and 2013)
    8.4 Experiment Three (winter seasons 2012/2013 and 2013/2014)
    8.4.1 Seed yield (kg/ha)
    8.4.2 Number of seeds per head
    8.4.3 Oil and protein content (%)
    8.4.4 Total applied water (TAW)
    8.5 Comparison between summer and winter seasons
    8.6 Concluding remarks

    9 Water productivity (WP) for Sunflower
    9.1 Introduction
    9.2 The concept of water productivity
    9.2.1 The term water productivity (WP)
    9.2.2 Study area and experiment lay out
    9.3 Economic water productivity (EWP) US$/m3
    9.3.1 Economic water productivity (EWP) for experiment One
    9.4 Concluding remarks on experiment One
    9.4.1 Water productivity (WP) for experiment Two (summer season)
    9.4.2 Water and economic water productivity for experiment Three (winter season)
    9.4.3 Economic water productivity (EWP) for experiment Two
    9.4.4 Economic evaluation under different irrigation regimes
    9.5 Concluding remarks

    10 Modelling of Sunflower water productivity under different irrigation intervals by using AquaCrop
    10.1 AquaCrop model description
    10.2 AquaCrop model input data
    10.2.1 Climatic data
    10.2.2 Crop phenological data
    10.2.3 Soil information
    10.3 Calibration of the AquaCrop model
    10.3.1 Reference evapotranspiration data
    10.3.2 Evapotranspiration data for model calibration
    10.3.3 Irrigation management data for model calibration
    10.4 Validation of the AquaCrop model
    10.5 Simulation with the AquaCrop model
    10.6 Application of AquaCrop model under different treatments
    10.6.1 Model Calibration for the winter season 2011
    10.6.2 Validation of the AquaCrop model
    10.6.3 Canopy cover development (%)
    10.6.4 Model calibration and validation for the summer seasons 2012 and 2013
    10.6.5 Results and discussion for the summer seasons 2012 and 2013
    10.6.6 Model calibration and validation for the winter seasons 2012 and 2013
    10.7 Concluding remarks

    11 Evaluation and recommendations
    11.1 Assessment of the existing irrigation system
    11.2 Assessment of AquaCrop model in simulating yield under Gezira conditions
    11.3 Recommendations for improvement

    12 References

    Annexes

    Biography

    Eman R.A. Elsheikh graduated from Gezira University, Faculty of Agricultural Sciences in 2000. She works in the Agricultural Research Corporation, Land and water Research Centre, WadMedani since 2003. She started her master programme in 2005 in the Water Management and Irrigation Institute, University of Gezira, and completed her master study in 2007.She participated in the international short course on Integrated Watershed Management, Bangkok, Thailand in 2008. In January 2010 she worked at the Forestry Research Centre in Khartoum. In 2009 she attended the Watershed and River Basin Management short course at UNESCO-IHE Institute for Water Education. During this course she met Professor Bart Schultz for her PhD proposal, and got a full scholarship in January 2011 from the Netherlands Fellowship Programme (NFP) for her PhD study at UNESCO-IHE, Department of Water Science and Engineering. Her PhD research is on Water Productivity for Sunflower (Helianthus annuus L) under Gezira clay conditions, Sudan. In 2014 she gained another grant for research from the International Foundation for Sciences (IFS). She attended two annual PhD seminars during her PhD study.