“Development of integrated rice-azolla-duck-fish farming systems with SRI methods for rice production in the Mekong River

region, Vietnam”

Nghia NguyenSoil Biology Laboratory, Department of Soil Science, College of

Agriculture & Applied Biology, Cantho University, Cantho City, Vietnam

Cornell University, 07/01/2015

This project is funded by The Toyota Foundation, Japanfrom 05/2015 to 05/2017

1. Introduction

• Allocated in Southeastern Vietnam.

• Extends 4.0 million ha, is the heart of the rice producing region of the country where water, boats, houses and markets coexist to produce a generous harvest of rice.

1. Introduction

♦ Four main farming systems in this area:

1. Rice

2. Aquaculture

3. Cash crops & fruit trees

4. Animals

♦ Rice & Aquaculture constitute a major part of diet and livelihood and for export.

1. Introduction

+ 3 crops/year (mono and intensive cultivation)

+ Continuous flooding

+ Preferably inorganic fertilizers and overdose application rate

+ Excess or improper use of agro-chemicals for plant protection

♦ Rice cultivation practices in the Mekong Delta, Vietnam:

+ Poor soil health and loss of soil biodiversity

+ Increase GHG emission

+ Severse contamination of soil, surface water and ground water with inorganic fertilizers and pesticides

1. Introduction

♦ The need for more sustainable approach:

+ Increases productivity and resilience

+ Improves soil health

+ Reduces the GHGs emission (climate change)

+ Enhances national food security and development goals

+ Saves the fresh water for other uses

+ Produces safe and organic products from agriculture for sustainable development

+ Beings friendly to environment and reduces the environmental contamination

+ Improves community health

+ Improves livelihood

A integrated Rice-Azolla-Duck-Fish farming system?

1. Introduction

2) Integrating fish and azolla into in rice-duck farming system in Asia (Cagauan et al., 2000) in Philippine

1. Introduction

1. Introduction

1. Complex agro-ecosystems for food security in a changingclimate (Uma et al., 2012) in Indonesia

♦ Affect of integrated rice-azolla-duck-fish system on soil health, soil microorganisms and green house gas emissions should be studied more and intensively.

♦ Integrated rice-azolla-duck-fish system has been established in other countries, but not yet been in the MD.

♦ Integrated rice-azolla-duck-fish system with SRI has not been yet studied in the MD of Vietnam.

Study objectives:

1. Introduction

To evaluate the potential of the integrated rice-azolla-duck-fish practice as a sustainable approach to cope with climate change.

1. Introduction

Research questions:

♦ What is performance of a integrated R-A-D-F practice production?

♦ To what extend does a integrated R-A-D-F practice contribute to soil health, soil microorganisms, green house gas emission mitigation to the climate change?

2. Methodology

1. Experiment 1: “Efficacy comparison of Azolla with and without SRI on growth, rice yield and soil chemical and biological properties under green house conditions”

♦ Study objective: To compare the effect of Azolla on rice and soil properties under 2 farming practices: with and without SRI methods. ♦ Seven treatments in total are included with 4 times of repetition in the green house; rice variety: OM5451 seed application rare: 40 kg/ha for SRI and 80 kg/ha for non SRI. Three continuous crops will be established.

T1. Control

T2: 90N-60P-30K (recommended rate for MD, inorganic fertilizer)

T3: Azolla green manure 10 tons/ha (basal application) + fresh Azolla 2 tons/ha

T4: Azolla green manure 10 tons/ha + fresh Azolla 2 tons/ha + 45N-30P-15K

T5: Cow dung manure 10 tons/ha +fresh Azolla 2 tons/ha

T6: Fresh organic mixture 10 tons/ha + fresh Azolla 2 tons/ha

T7: Fresh Azolla 2 tons/ha* Fresh organic mixture including Azolla, spent coffee ground, milled eggshells, cow dung, household charcoal waste and leather meal.

2. Methodology

♦ Water management:

1. Conventional method: 7 days after seeding application, water will be introduced continuously flooding with 20 cm above ground level thoroughly the experimental time, and draining the paddy 2-3 weeks before harvest.

2. SRI method: 7 day after seeding application, a 1-2 cm layer of water is introduced into the paddy, followed by alternate wetting and drying (during the vegetative growth period). During flowering a thin layer of water (1-2 cm) is maintained, followed by alternate wetting and drying in the grain filling period, draining the paddy 2-3 weeks before harvest.

PCV tube for water management in the SRI method

2. Methodology

♦ Collected parameters: 1. Agronomic parameter for rice: Weekly measurements of plant height of rice, number and diameter of tillers, and number of leaves. Other agronomic parameters determined include, the grain yield, grain size, leaf length and width, panicle length, flowering and maturity days.

2. Weed: Recording weed constituents in each treatment, fresh and dry weed weight/m2

and consuming time for manually weed control//m2/each time.

3. Soil chemical parameters: pH, EC, OM, C/N ratio, N-Total , P-Total, K- Total, CaO, MgO, Fe, Cu, Zn, Si at T-0 and T-End.

4. Soil and leave microbiological parameters: Total bacteria/fungi cells, number of free nitrogen fixing bacteria, phosphate solubilizing bacteria and the number of endophyte bacteria in rice roots and leaves at day 0, 10, 20, 30, 50, 70 and 90 will be determined. While soil microbial diversity (DGGE), methane oxidizing gene (pmoA) and methane producing gene (mcrA) will be detected at T-0 and T-End.

2. Methodology

2. Experiment 2: “Efficacy comparison of Rice-Azolla-Duck-Fish system with and without SRI on growth, rice yield and soil chemical and biological properties under field conditions”

♦ Study objective: To compare the effect of Rice-Azolla-Duck-Fish system on rice and soil properties under 2 farming practices: with and without SRI methods.

♦ Three treatments in total are included with 3 times of repetition in the field; rice variety: OM5451. Experimental site: Allocated at My Loc Village, Tam Binh District, Vinh Long Province. Three continuous crops will be established.

T1. Conventional method

T2: Conventional method with Rice-Azolla-Duck-Fish system

T3: SRI method with Rice-Azolla-Duck-Fish system

♦ Seed application rate: 40 kg/ha for SRI and 80 kg/ha for conventional method.

♦ Fertilizer application rate: 90N-60P-30K, inorganic fertilizer for conventional method and organic fertilizer which would show the best performance of rice’s yield from the green house experiment will be used as organic fertilizer for the SRI method.

♦ Water management:

1. Conventional method: 7 days after seedling application, water will be kept continuously flooding with 20 cm above ground level thoroughly the experimental time, and draining the paddy 2-3 weeks before harvest.

2. SRI method: after 7 day after seedling application, a 1-2 cm layer of water is introduced into the paddy, followed by alternate wetting and drying (during the vegetative growth period). During flowering a thin layer of water (1-2 cm) is maintained, followed by alternate wetting and drying in the grain filling period, draining the paddy 2-3 weeks before harvest.

2. Methodology

2. Methodology

PCV tube for water management in the SRI method

♦ Collected parameters: 1. Agronomic parameter for rice: Weekly measurements of plant height of rice, number and diameter of tillers of tillers and number of leaves. Other agronomic parameters determined include, the grain yield, grain size, leaf length and width, panicle length, flowering and maturity days.

2. Weed: Recording weed constituents in each treatment, fresh and dry weed weight/m2 and consuming time for manually weed control//m2/each time. 3. Soil physical properties: Soil bulk density, soil porosity and soil aggregates.

4. Soil chemical parameters: pH, EC, OM, C/N ratio, N-Total , P-Total, K- Total, CaO, MgO, Fe, Cu, Zn, Si at T-0 and T-End.

5. Soil and leave microbiological parameters: Total bacteria/fungi cells, number of free nitrogen fixing bacteria, phosphate solubilizing bacteria and the number of endophyte bacteria in rice roots and leaves at day 0, 10, 20, 30, 50, 70 and 90 will be determined. While soil microbial diversity (DGGE), methane oxidizing gene (pmoA) and methane producing gene (mcrA) will be detected at T-0 and T-End.

2. Methodology

6. Green house gas emission: CH4, CO2, N2O will be collected at each growth period of rice (2 times in vegetative growth period; 1 time at flowering period, 1 time at grain filling period and 1 time at maturating period).

2. Methodology

3. Expected results and future perspectives

1. In both green house and field experiments the SRI method will give a better results than the conventional method in improvement of plant growth and yield and as well as soil physical, chemical and microbiological properties.

2. There will be more methane oxidizing bacteria and less green house gases emit from soil in the SRI method than these in the conventional method.

Any Question? Suggestion? Comments?

Acknowledgement

Prof. Uphoff Norman and others from Cornell University

Thanks you very much!