Living Land

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Participatory saline soil management in Thailand

Apichart Jongskul and Pranee Srihaban, Land Development Department; Worapong Waramit and Wisit Ngamsom, Focal

Point Office of Thailand to United Nations Convention to Combat Desertification and Land Development Department

The concept of participatory saline soil management

Source: LDD

he United Nations Convention to Combat

Desertification has indicated that the world popula-

tion is estimated to increase to 9.6 billion by the year

2050 and there is a need to clear 3 million hectares of new

land every year for food supply. Promotion of sustainable

land management to reclaim degraded land and turn it into

a robust foundation for food security is an urgent priority.

Participatory saline soil management in Thailand is an

approach to reclaim degraded land and enhance food security

through farmer participation. Saline soil, a prevailing problem

in agriculture land, covers 2.84 million hectares or 29 per cent

of the area of north-eastern Thailand. Soil salinity levels have

been categorized into three classes: severely saline, moder-

ately saline and slightly saline. The saline causes unfavourable

soil structures and degrades the ecosystem, particularly the

system that supports rice cultivation. Leaching of saline soils

by rainwater deteriorates natural water resources, irrigation

and underground water.

The Land Development Department (LDD) of the Ministry

of Agriculture and Cooperatives in Thailand has tried its best

to rehabilitate saline soil to return it to agricultural purpose,

particularly in severely affected sites in Tung Muang Pia in the

Ban Pai district of KhonKaen province. The project area covers

approximately 122,880 hectares where most farmers depend on

rice cultivation. Saline affects both on-site and off-site agricul-

ture areas. The former limits the area for cultivation and causes

low productive yield due to its toxicity to the root system of

rice and degradation of the soil’s physical properties. The latter

causes saline water contamination in natural streams. As a result,

it initiates the expansion of areas affected by saline soil. Paddy

rice is vulnerable to soil salinity conditions. It has been reported

that the rate of germination of paddy rice in saline soil is lower

compared to non-saline soils. Seedling and root systems will be

unhealthy and the budding rate will be low. The rice plant will

become dwarfed, with low weight and low protein in the grain.

When the paddy field becomes dry, the level of saline concentra-

tion will increase and the risk of rice plants dying will be higher.

LDD rehabilitates saline soils according to its category of

severity. In severely saline soils, it introduces both mechanical

and vegetative measures for the instant installation of drainage

systems (open drains and sub-drains) to permit rainwater to

leach the saline from soils. The salt-tolerant plant

Acasia ampli-

ceps

is grown to pioneer and generate the plant ecosystem in the

affected area. In moderately saline and slightly saline soils, LDD

constructs soil and water conservation systems for instant land

levelling and extensive water storage in paddy fields; incorpo-

rating green manure crops, growing salt-tolerant trees on the

dykes along paddy fields, and adding rice straws to paddy fields

to increase organic matter in the soil.

LDD

NSTDA

SCG

Others

TAO

Area approach

Farmers

Rice product

Income

Sustainability

Rice yield

Saline soil

rehabilitation

iving

and