Rice water use productivity in CambodiaACIAR project
Rice water use productivity in Cambodia ACIAR project LWR2009/46Dr Evan Christen (CSIRO) & Dr Seng Vang (CARDI)in collaboration with:HE Pich Veasna & Mr Prum Kanthel (TSC MOWRAM)Mdme Men Nareth & Dr Oeurng Chantha (ITC)Dr Philip Charlesworth (IDE)
Improved irrigation water management to increase rice productivity in CambodiaBackground• Rice is staple food and yields are low (2.4t/ha), much poverty that could be alleviated by increased agricultural output• Rice irrigation water management has been identified as a key constraint to increasing farmer incomes and Cambodian production of rice for consumption and export• Compared to neighbouring countries rice yields in Cambodia are low.Problems• flooding in rainy season, limited/variable water supply in dry season, poor irrigation, infrastructure, small plots, low inputsObjectives• Develop an improved understanding of farm-level water management constraints and opportunities;• Research and develop adapted water management and agronomic interventions at a farm and district level to increase productivity;• Support CAVAC extension efforts by providing timely, practical on-farm water management information especially in the areas of canal rehabilitation by CAVAC in Takeo and Kampot.
The projectPartners:• Cambodian Agricultural Research and Development Institute (CARDI)• Ministry of Water Resources& Meteorology (MoWRM) – Technical Services Centre (TSC)• Institute of Technology Cambodia (ITC)• International Development Enterprises (IDE)The Project:• 4 years, start 2011 – still in first year• ACIAR funding $1.06M, total funding $1.7M• Work with CAVAC in providing readily adoptable interventions• Target lowland rice where some control over irrigation & drainage• Target rice crops with supplemental or full irrigation
Methods• Surveys of communes (Takeo province)1. Socio-economic of communes - to understand irrigation and agronomic practices and constraints.2. Infrastructure and topographical survey of same communes Link the two above to identify links between irrigation/drainage infrastructure and rice productivity Identification of improved water management approaches - participatory process, identification of “case studies of success”, which will then be tested in field trials.
Methods• Laser levelling tested/demonstrated with farmers (CARDI) and when irrigation areas are redeveloped (MoWRAM).• Field studies to measure rice water and fertiliser use under the current management practices identified in the initial surveys and under the options for improved water and fertiliser management.• Analysis of groundwater quality and suitability for irrigation• Weather data for agricultural management 1. Compiling of historical weather data 2. Installation of Automatic Weather Stations• Bring together the field studies and data gathering for water balance and crop growth modelling - leading to the development of improved agronomic practices for increased productivity.
Results – farming system analysis• Rice farming systems, Takeo (analysis of CAVAC data 2009) • Rice yields show a lot of variation – reasons? • Best wet season yields are higher than worst dry season and early wet season – much work to be done increasing yields of all seasons.
Results – farming system analysis• Rice farming systems, Takeo (analysis of CAVAC data 2009) • Wet season and early wet season - area per farmer < 2 ha • Dry season half farmers < 2 ha, but some quite large areas grown
Results – farming system analysis• Rice farming systems, Takeo (analysis of CAVAC data 2009) • Total area of dry season rice nearly twice wet season rice – economic importance?
Results – surveys of communes (CARDI)Objectives•Understand the irrigation practices for rice production, and differencesbetween districts.•Assess groundwater use and any problems with water qualities reported byfarmers•Identify key farmers to work with demonstration on land leveling, water andfertilizer management.Location•Takeo province: Angkor Borei, Koh Andeth, and Kirivong districts.•Villages selected to include partially irrigated rice, fully irrigated rice andsurface and groundwater used for irrigation
Results – surveys of communes (CARDI), continuedMethods• Farmer workshops, farmer individual interviews, and key informantsinterviews such as local authority leaders, service providers, and farmer wateruser community (FWUC) leader.• 7-10 farmers in each workshop with a total of 85 farmers in 9 villages.• 80 households in-depth interviews.• GPS point coordinates were recorded - mapping of farmer field and irrigationinfrastructure survey (by MoWRAM TSC team)Linking socio-economics with the paddy field condition and irrigationinfrastructure, survey by TSC of:• Paddy field size• Paddy field levelness• Irrigation infrastructure condition• Water availability
Results – Laser levelling demonstration • Laser levelling demonstration - Kandal Stung Model site (3/4/12) and Kpok Trabek (Upper Slaku) on 4/4/12 , Angkor Borei (19/3/12)1. SURVEY 2. PLOUGH Explaining laser levelling to the farmers 3. LEVELLING 4. CHECK LEVEL Conducted as a collaboration between CARDI and TSC
Results – rice water use monitoring at research stationLysimeters used for measuring water balance components Energy balance instrumentation used for directly measuring rice crop evapotranspiration Total water applied to rice paddy Conducted as a collaboration between CARDI, ITC and TSC
Results – Rice evapotranspiration by Bowen Ratio equipmentBowen ratio data Full season crop factor = 1.07, ETcrop 535 mm (99 days)This does not include percolation losses, these were 250- 500mm (not finalised)
Results – Groundwater samplingPreliminary sampling of groundwater undertaken in Angkor Borei – to testmethods – sampling methods, Temp, salinity, pH and field kits (alkalinity, Fe)
Results – Groundwater samplingSome salinities quite high and one elevated Iron (Fe) level Date Location Village T (oC) EC pH Alkalinity Fe (dS m-1) (mg L-1 (mg L-1) CaCO3) 18/3/20 11‟02‟11 44”N, Toul Sangkor 30 0.935 6.52 230 nd 12 104‟57‟07‟95E 11‟02‟06 32”N, Toul Sangkhor 31.1 0.959 6.75 240 nd 104‟56‟55‟72”E **11‟01‟35 Toul Sangkhor** 31.2 0.488 6.6 250 0.11 76”N, 104‟56‟55‟72”E 11‟01‟31. 41”N, Toul Sangkhor 30.6 0.777 6.75 268 0.01 104‟57‟26.58”E 19/3/20 11‟02‟34. 00”N, Ta Ei 31.1 1.31 6.7 157 0.0 12 104‟58‟17.53”E 11‟02‟26. 56”N, Ta Ei 31.4 1.36 6.71 162 0.01 104‟58‟16.98”E 11‟02‟29. 53”N, Ta Ei 31.2 1.31 6.7 161 0.0 104‟58‟23.39”E 11‟02‟52. 67”N, Ta Ei 30.7 1.09 6.72 238 0.0 104‟56‟36.19”E ** Domestic well used for washing and drinking not irrigation. NB elevated iron.
Results – Groundwater analysisLaboratory capability and methods used at CARDI need to be improved:-Water supply, use of filters and reagents- lab protocols for Na, K, Ca and Mg and nutrients in agricultural watersamples are required Dr Wendy Quayle (CSIRO) with Mrs Saosrey Touch (CARDI laboratory technician) in the CARDI laboratory
Results – Cambodian weather data • Established 3 automatic weather stations – Takeo, Kampot, Kampong Thom (new station of CARDI) • Developed web based data storage and access • Collated all historic weather data Website for the weather data from the automatic weather stationsPDWRAM staff Mr. Yuk Narin atAutomatic weather station in Takeo http://weather.irrigateway.net/cambodia/
Results – „Case studies of success‟An Example is farmer Chhim Son who presented a poster at the Angkor Borei laser levelling demonstration explaining that he wanted to use laser levelling on his farm to increase yields and so be able to send his children to a better school Website for the weather data from the automatic weather stations
Conclusions• The project is just gaining momentum, 1st year• Much room for improvement in rice yields across all seasons• Wide distribution of rice yields, 2 fold in wet season and 4 fold in dry season – learn from the best farmers• Laser land levelling is ready for adoption in Cambodia – filling the gaps in business models required (CAVAC collaboration)• Getting MOWRAM engaged in on-farm results is critical to improving returns from government investment in irrigation infrastructure• Rice water requirement for evapotranspiration (dry season) is about 5mm/day, percolation, lateral leakage and any draining of paddies will increase this.• Need to understand „leakiness‟ of soils better to understand total water requirements for rice in any particular region• Linking irrigation infrastructure and paddy field condition with socio-economics is unique exercise and should be very informative