Physical Environment and Farming System in Pha Oudom District, Bokeo Province in Northern Lao PDR ― a Preliminary Survey Report ―

Bull. Inst. Trop. Agr., Kyushu Univ. 31: 39-49, 2008 39

Physical environment and farming system in Pha Oudom district, Bokeo province in northern Lao PDR ― a preliminary survey report ―

Shinji Fukuda1),*, Manythong Chanhsom2), Ulrich Schuler3), Peter Elstner3), Yoshiyuki Miyazawa4), Wolfram Spreer3), Latmany Phonesavanh2), Thongphanh Daovorn2), Shoji Shinkai5), Kuniyoshi Shimizu5) and Andreas Neef 3)

Abstract

The present study aims to report preliminary results of surveys on water and soil environments and farming systems in Pha Oudom districtof Bokeo province in northern Laos. Field surveys based on interviews and observa- tions were conducted to obtain background information for soil and farming systems. Water quality and climatological characteristics were analysed in order to evaluate the basic conditions of water environments in the area. A global climatic data set of monthly precipitation along with the mean, minimum and maximum temperatures were used for the climatological analyses. The results of the wetness index indicated a seasonal scarcity of potential water resources from October to April. The farming practices were found to depend on the seasonal availability of water resources and the soil characteristics of the area. A typical non-timber forest product (NTFP) of paper mulberry was collected during the non-harvest period, by which farmers earned additional income to their main agricultural products without increasing time between other crops. Ranking of agricultural products in terms of income and farmers’ engagement differed both within and between villages. The first priority in animal husbandry was pig, followed by poultry, goat and large animals such as cattle and buffalo. Fisheries were not common among the surveyed villages. Multiple and integrated uses of natural resources such as NTFPs could be an approach used to achieve sustainable agricultural development. Along with the transition from sifting cultivation to sedentary agriculture, an increased commercialization of cash crops and NTFPs would also need to be considered for the profit of local people. Further investigations into biophysical environments, farming systems and socioeconomic conditions are necessary to develop an analytical framework for the mechanisms of the rapidly changing landuse and livelihood in northern Laos.

Keywords: agriculture, water, soil, NTFPs, Laos

1) Institute of Tropical Agriculture, Kyushu University, Japan 2) Graduate School of Bioenvironment and Bioresource sciences, Kyushu University, Japan (present address in Laos) 3) University of Hohenheim, Uplands Program Office at Chiang Mai University, Thailand 4) JSPS research fellow, University Forest, Kyushu University, Japan 5) Faculty of Agriculture, Kyushu University, Japan *Address: 6-10-1 Hakozaki, Fukuoka 812-8581, Japan Tel: +81-92-642-3075, Fax: +81-92-642-3077 E-mail: [email protected] 40 S. Fukuda et al.

Introduction

The world population keeps on growing, which will result in considerable increase in the demand for food. Simultaneously, water resources available for agriculture are now decreasing as a result of a com- petition with non-agricultural sectors in both developing and developed countries. Under such unstable conditions with a changing world climate, it is important to aim at effective uses of water and natural resources for achieving sustainable development together with increased agricultural productivity. Towards this goal, background information on biophysical environments and agricultural systems would be essen- tial in the process of development. In northern Laos, many phenomena still remain unknown mainly due to the lack of information available for analysis. This is apparent especially in Pha Oudom district, where only a few scientific works have been conducted. For instance, Delang (2007) surveyed the availability of usable plants in fallows at different ages in one Khamu village in the uplands area of Pha Oudom district. Dannenman et al. (2007) carried out an analysis of yield and fuel property of several varieties of bamboo found in the lowlands area of Pha Oudom district. However, these works were just initial and partial studies which aimed to clarify the complex interactions between local people and the natural systems in the area. Therefore, further studies are necessary to obtain the deeper understandings and sustainable management of the natural systems at different points in time and space. To deal with the limitation of available data in northern Laos, GIS-based approaches incorporated with satellite image-derived data (Thongmanivong and Fujita, 2006) and interpolation of weather information (Inthavong et al., 2003) have been employed to evaluate the environmental conditions in the region. In northern Thailand, an integration of detailed petrographic information with local soil knowledge of farmers was successfully applied in the evaluation of soil fertility and soil suitability for cropping (Schuler et al., 2006). A global data set such as WORLDCLIM (Hijmans et al., 2005) can also be used to obtain a rough estimation of the physical environment of an unexplored area or an area with insufficient data. The accumulation of analyses based on the abovementioned data and approaches, and comparison of those results would contribute to the development of an analytical framework for sustainable resource management, not only in northern Laos, but also in other areas without sufficient information. The objective of this paper is to give a preliminary report on the water and soil environments and farming systems in Pha Oudom district of Bokeo province in northern Laos. The water environment was assessed in regard to the climatological characteristics and water quality in the area. Together with the soil distribution, ongoing farming systems were surveyed in order to better understand the relationship between the physical environment and agricultural activity in the area.

Methods

Study Sites The field surveys were conducted mainly at the three villages of Houay Paen, Houay Sang, and Physical environment and farming system in Pha Oudom district, northern Laos 41

Thamphakae in Pha Oudom district. The district is located about 50 km southeast from Houay Xai, the capital city of Bokeo province in northern Laos (Fig. 1, Table 1). The area can be divided into two areas of highlands at about 800 m above sea level (ASL) and lowlands at about 400 m ASL (Delang, 2007). The villages selected for the survey belong to the lowland area of the district. There were several planta- tions of teak and rubber in the area that were surveyed in this study.

Pha Oudom District

Fig. 1. Study site

Table 1. Summary of local villages selected for climatological analysis

Village Longitude Latitude Ethnic group Houay Paen 100º 48’ 30" E 20º 7’ 18" N Lameth Houay Sang 100º 47’ 5" E 20º 2’ 15" N Khamu Pha Oudom 100º 49’ 27" E 20º 5’ 14" N na Thamphakae 100º 46’ 21" E 20º 2’ 20" N Hmong

Abbreviation: na, not available 42 S. Fukuda et al.

Water Environment The water environment was assessed in regard to the climatological characteristics of the area and water quality at different sources such as rivers, canals, ponds, and so on. A series of field surveys were carried out in November of 2007. There were consecutive rainfall events during the survey. Water quality components were surveyed by using simple water quality measurements of a portable water quality sensor (MD7MS514C, Shiro. Co., Ltd., Osaka) and PACK TEST (KYORITSU CHEMICAL-CHECK Lab., Corp., Tokyo). The former was used for water temperature (TEMP), electri- cal conductivity (COND), total dissolved solids (TDS), and salinity (SALT), and the latter for ammo- nium nitrogen (NH4-N), phosphate (PO4-P), and chemical oxygen demand (COD). In the analyses, raw values were used for the former measurements whereas representative values were used for the latter because of its simplicity in the measurement process. In the climatological analyses, the wetness index proposed by Kondo (2000) was used for assessing the potential availability of water resources in the target area, which is calculated by the ratio of rainfall to evapotranspiration (Table 2). That is, (1) in which denotes the wetness index (mm mm‒1), represents the precipitation (mm) and represents the evapotranspiration (mm). The evapotranspiration levels were estimated by using the Hargreaves method for its simplicity and to meet available climatic data (Hargreaves, 1994). This method requires only the measured values of the maximum and minimum temperatures. The equation is expressed as (2) where (potential evapotranspiration) and (extraterrestrial radiation) are in the same units of equivalent water evaporation, represents the mean maximum minus mean minimum air temperatures (℃), represents the mean air temperature and is the latent heat of water volatilization (2.45) (Matsui, 2003). For the estimation, a global data set of WORLDCLIM (Hijmans et al., 2005) was used in which monthly data of precipitation and mean, minimum and maximum temperatures were available at a spatial resolution of 30 arc s (often referred to as 1-km spatial resolution). For this reason, all the analyses were done on a monthly basis. Climatic data from the four villages of Pha Oudom, Houay Sang, Thamphakae, and Houay Paen were derived in accordance with the coordinates (Table 1), of which averaged values were used in the analyses.

Table 2. Climatological classification using wetness index (Kondo, 2000)

Classification Range of WI Remarks Arid 0.0 WI 0.1 No runoff Semi-arid 0.1 WI 0.3 Runoff depends on soil Semi-humid 0.3 WI 1.0 More runoff Humid 1.0 WI Lots of runoff Physical environment and farming system in Pha Oudom district, northern Laos 43

Soil Environment The soil surveys were conducted on two transect lines from Tamphakae to Houay Sang, and in Houay Paen. A GPS was used to obtain the coordinates of the surveyed points. Physical characteristics of the soil were analyzed in accordance with the WRB system (FAO, 2006). In addition, landuse and vegetation type were recorded at each survey point to better understand the relationship between soil and farming practice.

Farming System Based on a uniform questionnaire format, farming systems in the three villages were surveyed by in- terviewing 10 farmers in Houay Paen, and 20 farmers each in Houay Sang and Thamphakae. The seasonal calendar of cropping, farming practice, and ranking of crops and some non-timber forest products (NTFPs) in terms of income and farmers’ engagement were the main focus in this study. All of the results were analysed at village level and used for the comparison.

Results & Discussions

Water environment Water quality in Pha Oudom district during the survey period was found to be suitable for both irrigation and drinking (Tables3&4;AyersandWestcot, 1985; World Health Organization, 2006).That is, the water quality parameters of COND, TDS, NH4-N, and PO4-P were found to be in the ranges of 0-3 dS m‒1 (equivalent to 0-3000 µS cm‒1),0-2000mgl‒1 (equivalent to ppm), 0-5 mg l‒1, 0-2 mg l‒1, respec- tively (Ayers and Westcot, 1985). This could be partly because of the consecutive rainfall events during the survey period in November of 2007. There were no clear trends between the water quality parameters and sources of water in the area. Only TDS was slightly higher than the others in the water from ponds and gravity water, which might be ascribed to the geological setting (e.g., bed material) of the area. Further studies which monitor the seasonal dynamics of water quality would be necessary since water can be stagnant and scarce, especially in the dry season. Intensive agriculture and rapidly changing lifestyles may induce water quality degradation in the following years. Despite the simple analysis applied in this study, the present result reflected the climatological condition in the target area. The wetness index ranged from 0.09 to 2.59 and resulted in 0.89 in annual basis. This indicates both annual and seasonal scarcity of potential water resource (Fig. 2). Although it starts raining from April, the area remained dry condition due to the higher evapotranspiration than rainfall (i.e., low availability of potential water resource). As it is described later, the seasonal dynamics of potential water availability agreed quite well with agricultural activities in the area.

Soil environment The soil property of survey points are summarized in Table 5. From the elevation along the transect lines, Houay Paen and Houay Sang were found to lie around a sloping area, but Thamphakae was around 44 S. Fukuda et al.

Table 3. Water quality at each sampling point in Pha Oudom district in November 2007, in which titles of column are the same as in the text.

Sampling TEMP COND TDS SALT NH4-N PO4-P COD Source of Point (℃) (µS cm‒1) (ppm) (ppm) (ppm) (ppm) (ppm) water

HP1 23.3 337 223 161 0.5 0.2-0.5 20 River HP2 22.8 530 352 253 0-0.5 0.2 20 Pond HP3 23.5 518 341 246 0.4 0.2 13 Pond HP4 22.5 533 354 254 0.4 0.5 20 Gravity water HP5 22.3 365 241 172 0.5 0.2 5 Canal NH1 21.1 311 207 148 1 0.5 50 Canal NH2 22.3 394 257 188 0-0.5 0.5 50 River NH3 22.9 358 241 174 0-0.5 0.2 20 Canal NH4 22.9 332 222 158 0-0.5 0.1 5-10 Paddy field NH5 22.6 417 277 199 0.5 0.2 20 Canal NH6 24.7 546 363 262 0.5 0.5 20 Pond NH7 24.2 320 213 154 0-0.5 0.2 20 River TPK1 22.6 171 115 84 0.5 0.0 20 Paddy field TPK2 22.6 619 414 199 0 0.1 10 Gravity water KK1 22.2 265 176 128 0.5 0.2 13 Gravity water KK2 21.2 196 131 95 0.5 0.2 10 Canal KK3 23.8 245 159 114 0.5 0.1 50 Fish pond KK4 22.1 262 172 123 0.5 0.2 10 Dam KK5 22.8 246 163 118 0 0.2 20 Gravity water PO1 23.3 254 169 121 0 0.2 10 Canal PO2 23.6 189 127 91 0.5 0.2 20 Pond NK1 22.9 280 187 135 0 0.2 10 Canal NK2 27.7 268 177 128 0 0.2 10 River PL1 26.0 256 172 124 0.5 0.1 13 River PL2 25.9 237 158 115 0 0.1 5 Canal

Abbreviations: HP, Houay Paen; NH, Na Hom; TPK, Thanphakae; KK, Kaenkham; PO, Pha Oudom; NK, Namkha; PL, Pounglath

Table 4. Water quality averaged at different water sources in Pha Oudom district in November 2007, in which the unit of the water quality parameters are the same as in Table 3

River Pond Canal Paddy field Gravity water Dam TEMP 24.7 23.7 22.8 22.8 22.5 22.1 COND 315 406 302 252 416 262 TDS 208 268 201 169 277 172 SALT 151 193 145 121 175 123

NH4-N 0.3 0.4 0.3 0.4 0.2 0.5

PO4-P 0.3 0.2 0.2 0.1 0.3 0.2 COD 22.6 24.6 16.3 13.8 15.8 10.0 Physical environment and farming system in Pha Oudom district, northern Laos 45

a flat area. In the following, soil environment will Evapotranspiration be discussed based on the transect line from Rainfall Wetness Index Thamphakae to Houay Sang. Minimum temperature Maximum temperature Most soils were classified as Acrisols (Fig. 3), 3 which were characterized by a translocation of clay 2 from the topsoil to the subsoil. Their cation ex- 1 change capacity and base saturation was rather low. 0

35 Wetness index As most nutrients occur in the topsoil, preservation 30 of the surface soil with its all-important organic 500 25 matter and preventing erosion are preconditions for 400 farming in an area with Acrisols soil. Adapted 20 300 cropping systems with complete fertilization and 15 200 careful management are required if sedentary farm- 10 ing is to be practiced on Acrisols soil. Slash and 100

Temperature (degrees Celsius) 5 burn is sustainable if occupation periods are short Rainfall, Evapotranspiration (mm/month) 0 0 and followed by a sufficiently long generation pe- 123456789101112 Month of the year riod. Agroforestry is recommended as a soil- protecting alternative to shifting cultivation to Fig. 2. Climatological characteristics of Pha Oudom achieve higher yields without requiring expensive district

Table 5. Soil property and vegetation type at each survey point

Village Rock WRB Vegetation Elevation Houay Sang claystone, siltstone Anthrosol paddy rice 437 Houay Sang claystone Acrisol sesame, maize 446 Houay Sang limestone Acrisol paper mulberry 489 Houay Sang limestone Luvisol shrub at 3 yrs fallow 517 Houay Sang claystone Acrisol upland rice 575 Thanphakae claystone Acrisol Maize 436 Thanphakae claystone Anthrosol paddy rice 428 Thanphakae limestone Cambisol Forest 430 Thanphakae claystone, limestone Anthrosol Maize 435 Thanphakae claystone Anthrosol paddy rice, peanut 417 Thanphakae claystone Acrisol Sesame 415 Thanphakae claystone Acrisol rubber tree 451 Thanphakae claystone Anthrosol paddy rice 407 Houay Paen sandstone Acrisol shrub at 3 yrs fallow 454 Houay Paen claystone Acrisol Bamboo 484 Houay Paen claystone Acrisol rice (last year) 504 Houay Paen limestone Acrisol evergreen trees 446 Houay Paen alluvial deposite Fluvisol Pasture 403 Houay Paen limestone Acrisol paper mulberry 454 Houay Paen limestone Acrisol paper mulberry 554 Houay Paen claystone Acrisol maize (last year) 382 Houay Paen claystone Anthrosol grass, paddy rice 454 46 S. Fukuda et al.

Fig. 3. Transect line of soil and landuse from Tamphakae to Houay Sang inputs. Along the streams and in the plains with possibility for irrigation, Anthrosols were found. These soils are best suited for paddy rice cultivation. On steep slopes, Cambisols were detected and best kept under forest. On limestone, Luvisols were also found, which are similar to Acrisols but more fertile and therefore suitable for a wide range of agricultural uses (FAO, 2006). Finally, land evaluations for paddy rice, maize and rubber were carried out. For the plains and valleys with water supplies, paddy rice is recommended. If the water supply is not sufficient, maize could be cultivated instead of paddy rice. Rubber could be cultivated on the gentle sloping land. Steep sloping land should be kept under forest or agroforestry systems in order to prevent soil erosion and secure the drinking water quality.

Farming system The farming systems were different among the villages of Thamphakae, Houay Sang, and Houay Paen in Pha Oudom district (Fig. 4). This could be ascribed to different landscapes which may appear in the difference in rice cultivation: paddy rice in flat areas (Thamphakae) and upland rice in sloping areas (Houay Sang and Houay Paen). The same trend as in the case of upland rice were found concerning buffalo as no farmers raise buffalo in Thamphakae. On the contrary, famers in Thamphakae raise more cattle than the famers in Houay Sang and Houay Paen. In terms of animal husbandry, the top priority might be given to pig and followed by poultry, goat, and large animals such as cattle and buffalo. Fisheries did not seem to be common in the area. Since many international organizations have been promoting animal production, the farming structure found from the present survey may change together with the improvement of access to the market and shift to the intensive cash crop production. Physical environment and farming system in Pha Oudom district, northern Laos 47

The farming practices seem to depend on the seasonal availability of potential water resources in the region (Figs. 2 & 5). The seasonal calendar shows that all of the crops were basically grown under the slash-and-burn farming in which farmers work on slashing and burning of the forest towards the end of the dry season, farm the land for crops, and then harvesting around the end of the rainy season (Fig. 5).In contrast, a typical non-timber forest product (NTFP) of paper mulberry was collected during non-harvest season in the area, by which farmers could earn additional income to the main agricultural products such as maize or rice without an increase in the time between other crops. Table 6 also shows the significance of paper mulberry. Even though the income from paper mulberry was ranked at lower grade, many farmers engaged in paper mulberry and other NTFPs such as broom grass and muak bark. The importance of NTFPs in northern Laos has also been recognised by the previous studies (Dannenmann et al., 2007; Delang, 2007; NAFRI, NUoL & SNV, 2007).

100% Houay Paen 90% Thamphakae 80% Houay Sang 70% 60% 50% 40% 30% 20% 10% 0% Paddy Upland Buffalo Cattle Pig Goat Poultry rice rice

Fig. 4. Farming practice in three villages of Pha Oudom district

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec.

Upland Burning & Slashing Planting Weeding (three times) Harvesting rice Clearing

Maize Slashing Burning Planting Weeding (twice) Harvesting

Burning & Chili Slashing Planting Weeding Harvesting Clearing

Burning & Slashing Planting Harvesting Sesame Clearing

PM Harvesting Selling Propagation Planting Weeding

Fig. 5. Seasonal calendar of cropping systems in Pha Oudom district, in which PM stands for paper mulberry 48 S. Fukuda et al.

Table 6. Ranking of agricultural and forest products regarding to income and farmers’ engagement (quoted from Ogata et al., 2008)

Ranking (income) Village 1 2345 Houay Sang sesame ground nut PM muak bark － Houay Paen maize sesame sugar palm BG PM Thamphakae maize sesame ground nut rice PM Ranking (engagement) Village 1 2345 Houay Sang PM sesame muak bark ground nut － Houay Paen maize/PM muak bark sugar palm BG sesame Thamphakae sesame PM maize muak bark rice

abbreviation: PM, paper mulberry; BG, broom grass

Future perspectives The present paper showed a brief overview of the current situation in Pha Oudom district, focusing on the physical environment and farming systems, in which seasonality and site specificity was found in both environment and agriculture. It is necessary to deal with the rapidly changing landuse and farming systems in the area. Multiple and integrated uses of natural resources such as NTFPs (paper mulberry, bamboo, etc.) could be an important approach towards sustainable agricultural development in terms of food security and income generation. Along with the transition from sifting cultivation to sedentary agriculture, an increased commercialization of cash crops and NTFPs would also need to be considered for the profit of local people. Finding food functionality of the NTFPs may raise profitability and foster commercialization of the products. From the beginning of this study, there was a limitation of available data for the detailed analyses, both in temporal and spatial scales. To cope with this problem, the use of satellite data and GIS technique together with local governmental data could be more frequently applied to a large-scale analysis as used by Thongmanivong and Fujita (2006). Integration of detailed information with local knowledge could also be an approach for upscaling the locally achieved information to large scale analyses (for instance, soil information in northern Thailand; Schuler et al., 2006). It is also necessary to monitor and clarify the effect of the government policy along with its imple- mentation as shown in the report by Daovorn (2007), which demonstrated an approach to evaluate the ef- fects of land and forest allocation policy on the livelihood of people in Pha Oudom district. Together with the government, international organizations including NGOs could play an important role in rural development. With consideration of the different points in time and space, further studies on biophysical environment, farming systems and socioeconomic conditions are necessary to develop an analytical framework for the mechanisms of rapidly changing landuse and livelihood in northern Laos. Physical environment and farming system in Pha Oudom district, northern Laos 49

Acknowledgement

The authors wish their thanks to B. Mohns at Lao-German Program Rural Development in Mountainous Areas of Northern Lao PDR and his staff members for their support in the field works. The authors would like to express our gratitude to the local staff members of Pha Oudom district and all villag- ers in the area. The invaluable help of Wirachinee Tajeena in the field survey is also gratefully acknowl- edged. The authors thank Prof. Dr. K. Ogata at the Institute of Tropical Agriculture, Kyushu University for his kind support in all phases of this study. This study was partly supported by Kyushu University Interdisciplinary Programs in Education and Projects in Research Development (P&P), Japan.

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