῏
J. Jpn. Soc. Soil Phys.
ῐ῎῍ῑῒ῏
No. +*/, p. 13ῌ2, ῍,**1῎Soil Doctor System of Land Development Departmentin Thailand as one of participatory methods
Kunnika HOMYAMYEN*, Somsak SUKCHAN* and Hiromasa HAMADA*** Land Development Department, ,**-/0+ Phaholyothin Rd., Chattuchak, Bangkok, +*3**, Thailand** Japan International Research Center for Agricultural Sciences,+ῌ+, Ohwashi, Tsukuba, Ibaraki, -*/ῌ2020, Japan+.

Introduction

Thailand covers a land area of /+-,++/ km, andextends about +,0,* km from north to south and1/* km at its widest point from east to west.
The population of Thailand is 0.,10/,***. The
climate of Thailand is sub-tropical with longhours of sunshine and high humidity. There
are three seasons, summer (February-May), rainyseason (June-October) and winter (NovemberFebruary) (http : //www.thaistudents.com/project/geography.html). Mean minimum temperature of a day is ,-ῌ and maximum is --ῌ.
The geographic and climatic conditions makethe country suitable for the cultivation of awide range of tropical and semi-tropical agricultural crops. Land use for agriculture inThailand is approximately ,-/,+0+ km, (.0ῌ ofthe total area) (http : //www.ldd.go.th).
Main agricultural products are rice, cassava,sugarcane, para rubber, corn, oil palm, soybean,durian, longan, lichee, mangosteen and pineapple. However, improper land utilization has
resulted in soil degradation and poor living
conditions of farmers (their income is lower
than /** U$/year). Soil erosion, the most severe
soil problem, of which restoration is urgentlyneeded, is found in ,+.,.** km, (.+ῌ of the totalarea), including forest, agriculture and pastureareas. Soil with low organic matter content
covers +/0,2** km, (-*ῌ of the total area).
Other problems about soil conditions such as
saline soil, acid soil, peat soil, shallow soil andsandy soil are found in +-1,//, km, (,1ῌ of thetotal area) (http : //www.rakbankerd.com).
To solve these problems, the sta# of Land
Development Department (LDD) is searchingfor and implementing suitable soil management solutions.
,.

Land Development Department (LDD)

LDD is the core organization to conserve andimprove soil resources for agricultural productivity, food security, and sustainable land use.
LDD was established on ,- May +30- under theMinistry of National Development, which waslater abolished. After several years, the government agencies were restructured on ,3 September +31,. Then, LDD was transferred to the
Ministry of Agriculture and Cooperatives. LDD
has about ,,*** sta# and consists of ,2 major
divisions (Fig. +).
The main strategy of LDD is to improve thequality of soil and water resources for agriculture and to make their services accessible toThai people. For example, LDD supplies YaPhaeg (vetiver grass) to farmers for soil andwater conservation. It is a simple method toconserve soil and water that farmers can implement (Photo +).
The activities of LDD can be estimated byvarious indicators such as the area of suitableland use zoning for agricultural productivity,
the number of rehabilitated areas, the beneﬁt
to households, the number of irrigation ponds
in rainfed agricultural areas and the percentage of satisﬁed people after receiving services
from LDD. However, ,,*** sta# is not enoughῐΐῐ῎῔῕ῑ ῒ +*/ ῏ ῌ,**1῍

80Fig. +

Land Development Department Organization Chart.
* Land development regional o$ce has +, divisions.

to carry out their missions in the whole ofThailand. LDD is encouraging farmers andlocal people to participate in their activities.
-.

Soil doctor system

For the improvement of soil and water resources, LDD has launched some projects suchas the training of agriculturalist, information
technology services to small districts, theincrease of agricultural productivity and thedevelopment of water sources in rural areas.

Participation from farmers and local peopleis required in such projects especially on thepart of spreading the recommendations of LDD
and information survey of household/person.
“Soil doctors” have been established since +33/
in order to increase the e$ciency of the activities of LDD. The soil doctors are in chargeof coordinating of land development among
farmers in the village, transferring new technology to their neighbors and participating insome activities of LDD. Vetiver propagation isῌ῍ : Soil Doctor System of Land Development Department in Thailand as one of participatory methods

Photo +81

Ya-Phaeg (vetiver grass).
Long roots and grasses prevent soil erosion and the leaves are used for improving soil properties.

Fig. ,Relationship between LDD and soil doctors

one example of transferring new technologies(Photo +).
Fig. , shows the relationship between LDD
and soil doctors. First, LDD has a meeting withvillagers about soil management and land use.
After the meeting, villagers who are interested

in soil management inform LDD that theywant to be soil doctors. LDD trains them tomaster soil test kits for the measurement of N,P, K and pH and to understand land development techniques such as how to use organic
fertilizers for improving soil properties. TheyB K  +*/  !,**1"82

are representatives of LDD in their villages
who give farmers a better understanding ofsoil management and follow up land development practices. They also are trained how to
use soil maps (+ : /*,***) by LDD and show
farmers the soil distribution suitable for various crops using soil map and some posters.
With the soil NPK test kit, they are able toexamine soils on farms around their villages,
and give local farmers basic recommendations
about fertilizer management
They are the messengers in distributing theinformation about land development from LDD
to the villagers, and sometimes transferring
messages regarding land use problems fromthe farmers to LDD. According to farmer’s
requests, LDD constructed demonstration plots
to solve problems of saline soil and acid soil,gave information on methods about a betteruse of organic fertilizer and provided some

seeds for soil conservation.
All soil doctors are volunteers. They receive
no salary, but LDD o#ers to construct a small
pond on their farms as an incentive. Now
Thailand has 03,+03 soil doctors (July, ,**0).
Before the soil doctor system was established,
it took one year to spread the recommendations of LDD to the whole of Thailand. Now ittakes only two or three months.
..

FutureIn the future, LDD has a plan to establish acenter for soil doctors and to increase thenumber of soil doctors in order to improve thee$ciency of the soil doctor network.
References
http : //www.ldd.go.th
http : //www.rakbankerd.com
http : //www.thaistudents.com/project/geography.
html soil doctor Kunnika HOMYAMYEN* Somsak SUKCHAN* ***  ,**-/0+ Phaholyothin Rd., Chattuchak, Bangkok, +*3**, Thailand**  +ῌ+

!LDD" #$ %&'() *+,-./01234567 89:;5<=>?4@ 2A BCDE FG'HI-JKLM7=34NO PQ7RS0TUV
U4@ W X;Y Z[0\]347# LDD^_`ab>#cd>-U@ eX>f7ghijklm no0p64 Soil doctor qr0s85@ Soil doctor # ft LDD 7uvwx0yb4ab>-; LDD tz{34HI-BῌDEJKLM PQ

fWY LDD m |}0~4_i 0 @ Soil doctor qr s87V LDDz{34LMt> 7PQ34 7-5@ :    BJK noMy : ,**0  3  +3 yK : ,**0  +*  -* 