Stockholm university

Research project Recognizing Wetland Ecosystem Services for Sustainable Rice Farming in the Mekong Delta, Vietnam

The overall aim of this project is to analyse if less intensive rice farming strategies, such as rice-fish farming could provide sustainable alternatives to more intensive rice monocropping in the Mekong Delta.

Rice farrming

The aims are to compare the 1) ecological 2) economic and 3) social impact of integrated rice farming with intensive rice monocropping systems, and 4)provide guidance for more sustainable rice farming and safer use of pesticides.

The purpose with the project is to show, based on field surveys with farmers, that less intensive rice production systems can help to sustain or even enhance ecosystem services (ESS) from the Mekong Delta. This in turn, help to improve the farmers’ income, health and diversify his/her livelihoods. Altogether, a transformative change towards a less intensive and more diversified food production can lead to an increased food security and means to adapt to climate change in the Mekong Delta.

Project description

The Mekong Delta is one of the largest and most densely populated wetlands in the world and it plays a vital role in the lives of local people and the socio-economic development of the region (Berg, 2012). The Mekong Delta covers only 12% of Vietnams area but supplies more than 50% of the country’s rice production and is the most important region for rice production in Vietnam (Berg et al. 2019). Increased rice yields over the years have been achieved through more intensive farming methods, and increased use of pesticides and fertilizers (Berg et al. 2012).  Construction of high dikes with compartments for rice cultivation, have also helped to increase the rice yields (Dung et al. 2018).

This quick expansion has provided means for increased income and food security but has also been followed by negative environmental impacts, such as pollution and biodiversity change. Tam et al. (2015) reported that farmers spraying organophosphates on rice fields resulted in both reduced growth and survival rates of fish, and Dasgupta et al. (2007) found that over 35% of 190 rice farmers in the Mekong Delta, experienced acute pesticide poisoning.

Increased dikes have decreased the aquatic connectivity within the delta, followed by a decreased inflow of nutrient rich water and sediments to agriculture areas. The natural high productivity in the delta derives from aquatic connectivity that facilitates the natural flow of water, sediment, nutrients, and organism, enabling a unique mosaic of diverse habitats across the landscape (Schiemer, 2014). The connectivity determines the interaction between an organism and the environment and is fundamental for the deltas ecological functions and provision of ecosystem services (Baran et al., 2015; Schofield et al., 2018).

Thus, intensified agriculture method with more dikes and increased use of pesticides has potentially decreased the natural productivity of rice and other aquatic organism, such as fish through a decreased input on nutrient rich water and sediments and though the negative impact of pesticides on aquatic organisms and natural enemies to pests. Increased reliance of agrochemicals and reduced exchange of water has also reduced the water quality in large part of the delta.

In addition to these local environmental pressures the delta is heavily impacted by climate change and upstreams dams. Several new dam constructions have changed the flow of water and sediments with dwindling sediment loads that can counterbalance ongoing sea-level rise and river water that can flush salt water during the wet season (Smajgl et al 2015; Minderhoud et. al 2019). Increasing salinity levels in the Mekong Delta have substantially reduced agricultural productivity, in particular for crops and varieties with a low tolerance to salt (Smajgl et al 2015). Substantial economic losses are estimated to occur for farmers because of 20-65% reduced inputs of nutrient rich sediment, which must be balanced with substantial investments in fertilizer inputs to maintain present production levels (Smajgl et al. 2015). To adapt to these increasingly unpredictable conditions, following from climate change and upstream dams, there is a need for altered cropping systems that are more resilient to future changes (Smajgl et al. 2019).

Project members

Project managers

Håkan Berg

Universitetslektor, docent

Department of Physical Geography
Håkan Berg

Members

Håkan Berg

Universitetslektor, docent

Department of Physical Geography
Håkan Berg

Nguyen Thanh Tam

PhD

Dept. of Aquaculture Faculty of Fisheries, Nong Lam University ,Vietnam

Chau Thi Da

PhD

Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam.

Thai Huynh Phuong Lan

PhD

Faculty of Agriculture and Natural Resources, An Giang University, Vietnam