Charles Sturt University
Graham Centre for Agricultural Innovation

Conservation Cropping

Project NameImproving water and nutrient management to enable double cropping in the rice growing lowlands of Lao PDR and Cambodia 
Project LeaderAssociate Professor Phil Eberbach
PersonnelDr Camilla Vote (Research Fellow), Agronomist, Charles Sturt University
OrganisationCharles Sturt University
Funding SourceAustralian Centre for International Agricultural Research (ACIAR)
Duration1/12/14 - 30/11/18
Location of ResearchLao and Cambodia


Goals and objectives

The aim of this project is to improve the profitability of lowland farming systems by increasing dry season crop production through the improved management and use of water, improved crop nutrition and the alleviation of key soil constraints.


The specific objectives are:

Objective 1: Identify water and soil chemical constraints to the adoption of non-rice dry season crops in Lao and Cambodia.

Objective 2: Develop technologies and practices for improving water and nutrient management and mitigating soil limitations across the lowlands.

Objective 3: Produce and communicate appropriately packaged technical and financial information, to support the adoption of dry-season cropping.


The World Food Program has identified Cambodia and Lao PDR as two of the most impoverished nations in South East Asia with high rates of poverty, food insecurity and poor nutrition particularly amongst small landholders. The prevailing climate of the region exhibits distinct annual wet and dry cycles and during the wet-season, rainfall may exceed 2000 mm. Rainfed lowlands occupy ~80% of all rice growing areas in each country (Fukai and Ouk 2012), with crops primarily grown in the wet season. Conversely, during the dry season, the lack of water limits options for agricultural production throughout the region except where irrigation infrastructure exists.

Soils of the region are relatively infertile being acidic in aerobic conditions, structurally unstable and with hard pans (Wade 1999; Seng et al. 2001b; Seng et al. 2008). However, there is potential to increase farm productivity by better exploitation of the dry-season. It may be possible to increase farm incomes significantly by growing high value short-duration grain and forage crops in the dry season through improving water and nutrient management where irrigation exists, and better use of residual soil water remaining after the wet season. Previous work in this region (reviewed in Appendix 8.1) provides preliminary evidence that better management of dry season water resources, increased understanding of soil constraints and nutrient supply, can enable dry season cropping with high value crops such as mungbean, soybean, peanut (Kukal and Aggarwal 2003; Haefele et al. 2006; Bunna et al. 2011; Vial et al. 2013) to significantly increase farmer incomes.

This project will address several research questions:

  • What is the temporal and spatial availability of water, the nature of water resources, soils and topographic suitability for dry season cropping?
  • What are the key constraints limiting crop productivity during periods of high, medium and low water availability?
  • What are the water requirements of dry season crops? How can residual moisture after wet season rice be utilised for non-rice dry season crops, both with and without irrigation and what constraints exist which may limit adoption?
  • What soil constraints need to be overcome to enable successful dry-season and multiple cropping activities?
  • What is the role of organic/inorganic fertiliser and amendments to enhance soil fertility and crop nutrition in improved crop rotations?

The opportunity

In areas where irrigation infrastructure exists, there is potential for high value dry season crops such as grains, legumes and vegetables to be grown during the dry season as an alternative to rice. In these areas, production is limited by farmer knowledge and soil / nutrition limitations rather than water. In areas without irrigation water supply, the primary limitation for dry season cropping is water. Previous work (Wade 2009) has shown that residual soil moisture often remains after the rice harvest and may offer opportunities for dry season cropping. In other areas, with access to supplementary irrigation (groundwater, ponds) both soil physical and nutrient constraints and a lack of farmer knowledge and cash flow limit their ability to utilise these available dry season water reserves. Previous ACIAR funded projects (Fukai 2006a, 2006b; Wade 2009) have indicated that in Cambodia and Lao, the environment is suitable for the production of various non-rice, dry-season crops such as mungbean, soybean, maize and peanut. These projects highlight that important issues exist which include sowing time, requirement of bed and furrow planting, control of insects, sufficient amount of water to maintain crop growth, disruption of soil hard pans and nutrient limitations. Some of these issues are related to labour costs, field maintenance, poor market access and ineffective value chains. Nevertheless, the region has the potential to intensify and diversify the production systems. Increased production will be driven by new technologies, increased knowledge of soils, knowledge transfer across regions / countries and regionally specific agronomy demonstrations and education for landholders.

The present project will build on previous project outcomes to identify economically viable intensification and diversification options for high value, dry-season, grain, forage and other crops in lowland farming systems across the Lao-Cambodia region. 


Research activities will be undertaken through a partnership between Australian scientists (CSU and DEAKIN) and with Lao PDR (NAFRI, Champassak University) and Cambodian (CARDI, ITC) agricultural research and teaching organisations. In-country partners in this project form a critical link between water supply/management, on-farm management and teaching and learning institutions which will be needed to achieve maximum on ground impact around improved water and nutrient management. In addition, the project will have a strong capacity building focus through key links with NGO organisations, SNV (Cambodia and Lao) and IDE (Cambodia). Both these organisations are heavily involved in the IFAD PADEE programme as capacity development organisations (SNV leads the knowledge brokering and capacity development activities in 'PADEE'). SNV will assist to integrate, up skill and equip researchers and extension providers and will develop strong partnerships with other relevant NGO's which can be used as a conduit for developing impact pathways and ultimate dissemination of tools and techniques developed in the project. The non-research agencies involved in this project will include the Cambodian Ministry of Water Resource and Management (MOWRAM-TSC).