Folk knowledge refers to local people`s knowledge or indigenous
knowledge (Bellon and Taylor, 1993). Folk knowledge related to soil is
important for agriculture sustainability and environmental protection,
especially in developing countries where most farmers have limited access
to soil analysis (Smalling and Braun, 1996). Farmers usually derive their
knowledge of soil from their long interaction with the environment (Altieri,
1990). It is the result of an intuitive integration of local agroecosystem
responses to environmental change, such as climate, land-use and crop
demand through time (Barrios et al., 1994). In this case, transfer
of soil knowledge from generation to generation is critical to better
understand soil which is a major part in agriculture ecosystems.
Failure to consider the local experience of farmers with soil has caused
limited adoption of new technologies in agriculture in developing countries
(Winklerprins, 1999). Increasing recognition of folk knowledge of soils
can offer many insights about managing soils in a sustainable way (Hecht,
1990). The complementary role of folk knowledge for scientific knowledge
in soil improvement has been previously acknowledged to nurture soil science
(Handayani et al., 2006; Sandor and Furbee, 1996). Handayani et
al. (2006) has provided recent information about the importance of
combining local and scientific knowledge of soil to sustain agricultural
production in the forest margins of Indonesia. In addition, there is increasing
consensus about the need for enhanced understanding of local knowledge
from farmers before planning and implementing development activities (Pawluk
et al., 1992; Mundy and Compton, 1991).
Recently, there has been limited integration of farmers` soil knowledge
into agricultural technology development and precision farming systems.
Farmer knowledge of soil fertility has been largely ignored by soil researchers.
However, the increasing interest in the participatory approach in research
and rural development, folk knowledge of soil plays an important role
in establishing programs in agriculture. This paper documents the findings
from folk knowledge of soil with regard to classification, erosion, fertility
MATERIALS AND METHODS
Study Site :The study was conducted during the year of 2000 in
three villages of Bengkulu Province, Sumatra, Indonesia. These villages
were located in the forest margins surrounding Kerinci Seblat National
Park (KSNP). The altitude ranged from 500-1000 m. The most important distinguishing
feature among the villages was the distance from protected forest in KSNP.
Tapos village is the closest distance (about 20 km), Donok and
Pal villages have distances of 50 and 80 km, respectively.
All of the villages are predominantly inhabited by people of the Rejang
ethnic groups and almost all of the households are engaged in agriculture.
All the arable land is under level terraces hill slope cultivation. Average
annual rainfall in the region is between 2800-3000 mm.
The agriculture system consists of: (a) lowland irrigated or partially
irrigated land called sawah, (b) upland rainfed sloping terraces
called kebun, (c) home gardens called pekarangan and (d)
pasture land called padang rumput. Most land is either privately
owned or rented. Some areas close to the forests are managed by the local
community. The main crops in sawah and kebun are rice and
Interviews: Information about soil knowledge from farmers was collected through
semi-structured interviews which took place in the interviewee`s house.
Thirty households were chosen at random from each village to be interviewed.
At the end of the research, focus group discussion was performed to confirm
and re-check information. Conversations, which were translated by an interpreter,
were guided towards selected topics while remaining flexible enough to
include any other topics of interest to the farmer. Topics covered included
indicator of soil fertility (i.e., plant type), soil management practices
and criteria to assess the level of soil quality and soil degradation.
Information on soil characteristics and management of the field were obtained
from discussions with farmers during interview with following questions.
Selected Questions for Interview
||What is the color of fertile soils?
||What is the color of infertile soils?
||What is/are important characteristics to detect good soils for farming?
||How do you detect if your land is not good for cropping?
||Do you utilize legumes in your farm? If yes, what kind?
||How often do you apply manures in your field?
||How do you maintain soil fertility in your land?
||Do you practice fallowing? If yes, please explain in detail.
RESULTS AND DISCUSSION
Respondent Characteristics: The main characteristics of the sample respondents, including the
gender and number of years working experience in the fields, of the interviewees
are shown in Table 1. In general, respondents
||Characteristics of the respondents
||Criteria applied by farmers to distinguish soil classification,
explanation of the criteria and the number of farmers using them
in Tapos and Pal owned more land overall (sawah
and kebun) than respondents from Donok. In Donok,
all the sawah land was irrigated, which allowed a maximum of three
crops per year and gave higher and more reliable rice yields. In all areas,
land management and the crops grown are relatively similar among fields.
Soil management of kebun by farmers consisted of tillage practices
or breaking up the soil, then removing the weeds and planting. Coffee
and corn were planted and sometimes intercropped with vegetables. Farmers
in Tapos and Pal have more buffalos and goats than farmers
in Donok. Most farmers applied manure from the livestock to maintain
Farmer Knowledge of Soil Classification: Farmers used certain soil properties (Table 2)
to distinguish soil productivity or soil fertility. Criteria used for
classifying soils are: soil organic matter (SOM), fallow vegetation, color,
earthworm/casting, the presence of sand and clay, structure, depth of
the roots, stickiness, subsoil, roots and acidity. Farmers mentioned a
number of processes and actions that affect soil properties, for example
soil erosion, tillage, cover crops and the use of manure. Farmers observed
the soil as a dynamic system that can be manipulated to create a better
environment for crops. More experienced, older farmers are capable of
further subdividing these nine types into sub-classes and groups by taking
into consideration parent material, weed species, consistency and water
Texture and color are predominant characteristics used by farmers to
distinguish soils. Brown-black and black soils were the most frequently
cited soil color. Red-yellow, yellowish-red or red soil was identified
by 55% of the farmers. The most recognized soil texture was clay soil,
which was mentioned by 41 farmers (45%) (Table 3). Sandy
and silty soils were identified by eight and two
||Soil classification identified by farmers
||Soil fertility classes based on soil color determined
farmers, respectively, which represented the soil classes least selected
by farmers. Similar soil classification is also found in other parts of
the world (Kerven et al., 1995; Sandor and Furbee, 1996; Talawar
and Rhoades, 1998). As expected, farmers use texture as a significant
criterion to classify soil. Soil science also regards soil texture as
a major soil characteristic influencing other properties like structure,
consistency, water retention, permeability and drainage (Talawar and Rhoades,
1998). However, most farmers only focus on properties of surface soils
and pay little attention to soil profiles. This phenomenon is similar
to Mexican farmers as described by William and Ortiz-Solorio (1981).
The farmers listed the soils in order of fertility (Table
4). Generally, the darker soils were considered to be more fertile
than yellow or red soils. This finding is similar to the results by Sandor
and Furbee (1996) who indicate that local farmers often prefer one soil
as being superior in productivity. Farmers observed that the origin of
black soil is from the high content of humus or organic matter or decomposed
plant residues. However, some farmers indicated that black soil was not
always productive because of poor drainage. The farmers generally considered
red, yellow and light gray soils to be inferior to black and brown soils.
Soils are also classified by their structure, grain-like soils with large
aggregates represent better soils and powdery or structureless soils with
no large aggregates indicate degrading soils. This is an important characteristic
used by farmers to observe the process of soil restoration during fallowing.
More large soil aggregates were found under long fallow (> 5 years)
compared to short fallow (< 3 years) (Handayani et al., 2006).
Topographic position also plays an important role in local classification.
Hill tops or puncak are identified as containing poor soils, while
the quality of hillsides or lereng depends on how steep the slope
is. The more fertile soils are concentrated in the flat areas or lembah
which have the accumulation of nutrients from hillside soils. Inherently
fertile soils or tanah lapar or hungry soils are distinguished
from tanah rusak or bad soils, which are soils degraded by inappropriate
management. Farmers mentioned that the former are likely to respond to
fertilizer applications, while the latter needs to be restored to recover
||Farmers` appraisal of factors affecting soil degradation
In Kenya, soil classification was based on soil color, texture and heaviness
of working (Mango, 2000). Indicators to assess soil fertility included
crop yields, soil color, compactness, soil odor and the composition of
vegetation. In another part of Kenya, farmers used criteria such as ease
of tillage, soil moisture retention, the presence of weeds and invertebrates
to distinguish soil productivity (Murage et al., 2000). In northern
Ethiopia, three different soil types are distinguished by farmers according
to yield, topography, soil depth, color, texture, water holding capacity
and stoniness (Corbeels et al., 2000). In southern Rwanda, soils
are classified by their agricultural potential and tillage properties
into nine major soil types based on criteria such as soil productivity,
soil depth, soil structure and soil color (Habarurema and Steiner, 1997).
Farmer Knowledge of Soil Erosion: Farmers understand that soil fertility is closely related to soil
erosion and the slope. On eroded hill tops and steep slopes, shallow and
stony soils, called tanah berbatu, dominate, while on the flat
tops of hills, concave slopes and feet of hills, deep soils with clay
soil, tanah liat, prevail. The valley bottom has dark soil and
dominates in clay texture as well. Soil erosion was mentioned by all farmers,
its main impact being on soil texture, depth and the appearance of subsoil.
This finding is different compared to the results of Steiner (1998), who
reported that farmers in Rwanda did not mention erosion as the major cause
for soil degradation. In this study, farmers believed that soil erosion
depends on the steepness of slope.
Farmers are aware of inappropriate soil management increasing soil degradation.
They observe tillage practices (frequency and inappropriate tillage),
soil erosion, lack of fallow and limited manure application as the major
causes for declining soil fertility (Table 5). Limited
fallow is due to land shortage which consequently reduces the areas of
fertile soils and increases soil erosion. During cultivation, hoeing causes
soil disturbance and increases decomposition of soil organic matter, thus
creating more soil erosion. Frequent tillage removes topsoil and accumulates
it on the lower part of the field, causing the upper parts of the fields
to become unproductive. Although farmers realize the negative effects
of frequent tillage, they see no alternative, as hoeing downslope is the
only practical way of tilling steep slopes.
Farmers realize that soil types influence the way soil should be managed,
for example, sandy soils need to be treated differently from clay soils.
The primary indicator of the best soil is organic matter content because
it is a major source of plant nutrients. Manure is regarded as the principal
soil amendment to improve soil productivity.
When farmers were asked to describe the process of soil erosion, about
80% of farmers were aware of the negative impacts of run off. This result
is compatible with reports of farmer perceptions of soil erosion in Africa
(Reij et al., 1996; Steiner, 1998). Seventy percent of the farmers
attributed knowledge of soil erosion to extension agents, representatives
of government-sponsored project and soil scientists at local universities
that promoted soil conservation. The other 30% of the farmers learned
about soil erosion from their parents or from personal observation. Most
farmers (85%) have little interest in soil conservation and only about
15% of farmers have adopted soil conservation practices using vegetative
methods. This is due to limited funds.
Farmer Knowledge of Soil Fertility: The majority of the farmers (90%) reported declining soil fertility
and crop yields on sandy soils, red soils and red-yellow soils. They noticed
a lighter color and coarser texture of soils near the village, indicating
a decrease in soil organic matter. Farmers attributed these changes to
the increase in the area of permanent cultivation or long-term continuous
cropping, the decrease of fallow fields, the limited inputs of manure
from livestock and soil erosion. Only 8% of the farmers felt that there
had been a decline in fertility in sawah and 95% of them believed
that kebun soils had lost fertility (these soils gain low input
fertilizers). In addition, the Javanese ethnic group reported no declines
in soil fertility on their fields, which was attributed to constantly
high inputs. Farmers described the process of declining soil fertility
level after opening the new land or forest with the lowest soil fertility
after 5 years of cultivation and often characterized by the spread of
Imperata cylindrica or cogon grassland. After cropping for 5 years,
farmers observed that some of the field will need to be rested as fallow
(lahan tidur) until shrubs such as Chromolaena odorata or
Lantana camara dominate. Farmers also noticed the development of
darker soil under Chromolaena odorata. Both vegetations are considered
the best indicators that the soils are ready to cultivate again after
fallowing. Previous findings from De Foresta and Schwartz (1991) showed
Chromolaena odorata is an important component of natural fallow
systems in Africa. It contributes to the maintenance of soil organic matter,
weed suppression, soil fertility and soil erosion control. Sharma et
al. (2005) observed that Lantana has become the dominant species
and contributes to soil organic matter maintenance in deforested areas.
Many researchers have also noted the use of weed growth and weed species
as indicators of soil fertility. For example, weeds are used to identify
areas of good agricultural potential (Barrios et al., 1994), environmental
conditions (Handayani et al., 2006) and to detect the process of
soil restoration following intensive cultivation (Corbeels et al.,
2000; Handayani et al., 2006; Mango, 2000).
Farmer Knowledge of Soil Management: Farmers had complex ecological knowledge particularly about soil,
but there is variation among farmers on the depth of knowledge. The individual
preferences depend on the farmer`s capacity to enact successful agricultural
performances and to exploit an evolving range of opportunities. These
are based on the use of their local knowledge, as well as on their communication
and creative capacities. Table 6 shows different soil
management practices that are commonly applied by farmers on their kebun.
In general farmers were aware of important factors enhancing soil fertility
such as fallowing the land (87%), the use of soil amendments (90%), the
use of legume and compost (100%). On an individual basis, knowledge is
obtained from personal experiences and overlapping communication pathways,
both of which are influenced by social factors, including age, gender
and family ties. Uncertainties arise when the knowledge is incomplete
and incapable of dealing with risks outside of community partial perspective,
which creates a plurality of perspectives (Kerven et al., 1995).
The traditional belief system and its associated practices are not equally
spread and appear to be eroding in importance in many locations, especially
among the younger generations who chose different professions besides
farming and in semi-urban areas that have limited agricultural fields.
Farmers recognized several constraints in land productivity. Table
6 shows that only 5% of the farmers used mineral fertilizers and 20%
of them applied vegetative conservation methods. In other circumstances,
farmers relied on their local knowledge of soil characteristics and plant
indicators to focus efforts in their planting strategies on addition of
nutrients with the goal of maximizing nutrient
||Soil management practices for kebun
cycling. For example, farmers value fertile niches around earthworm holes,
earthworm casts, Pterydophyta and Chromolaena odorata. The importance
of these practices has been widely qualified in numerous scientific studies
(Esse et al., 2001; Fujisaka et al., 2000; Hiernaux et
al., 1999; Wezel et al., 2000).
A similar dynamic nature of soil fertility is viewed by farmers in northern
Ethiopia who see their land moving between reguid (fertile soils),
mehakelay (moderately fertile soils) and rekik (poor soils)
types depending on how it is managed (Corbeels et al., 2000) and
weeds (Handayani et al., 2006; Sharma et al., 2005). In
addition, Schmidt et al. (1993) reported that land management is
the key to increasing the soil fertility beyond its inherent levels. This
fits with the view expressed by some researchers that soil fertility is
a human-made technical attribute rather than inherent soil property (William
and Ortiz-Solorio, 1981; Karlen et al., 2003). In the interview,
we found that farmers would describe long-term soil management strategies
for each of their individual fields and then show fields that had been
infertile 5 years ago but through careful management had been made fertile.
This study shows that farmers in Bengkulu, Indonesia have a well-defined
and comprehensive set of knowledge of soil classification, soil erosion,
soil fertility and soil management. Generally, farmers observed soil characteristics
by seeing, feeling or smelling their soils based on their own experiences
during cultivation in the fields. Farmers recognized the importance of
texture, color, fallow vegetation and soil organic matter to classify
the soil, but only texture and color were most used. Soil classes are
divided into nine categories, namely tanah hitam (black soil),
tanah coklat (brown soil), tanah merah (red soil), tanah
merah-kekuningan (red yellow soil), tanah abu-abu (gray soil),
tanah liat (clay soil), tanah berpasir (sandy soil), tanah
berbatu (stony soil) and tanah berdebu (silty soil). One interesting
finding from this study was the importance of environmental factors mentioned
as indicators by farmers. These included factors such as flooding and
landslides during the rainy season (November to February), frequent earthquakes
and crop destruction by wild pigs, all of which would affect soil productivity
and make farmers think of alternative ways to better manage the soils.
Farmers observe soil fertility as a dynamic process integrating the soil
properties, its agricultural requirements (i.e., crops) and environmental
factors (i.e., soil erosion, soil management). They see themselves as
active participants who can change soil fertility. Farmers claimed that
soil can be restored eventually, but only the topsoil. They indicated
that fertile soils are black, brown and mixed brown-black. They were also
aware of the effects of inappropriate tillage practices, erosion, limited
fallow and limited manure applications on soil. Farmers (> 90%) utilized
compost, manure and crop residues as soil amendments and legumes during
crop rotations. Short fallow (2 years) is a common practice to restore
the soil fertility after five years continuous crop production.
This study provides additional insights into qualitative soil knowledge.
Distinctions among soils were made primarily on the basis of readily observable
classes of soils. Therefore, local soil terminologies often do not provide
sufficient information for technology development. However, folk knowledge
of soils would facilitate the exchange of empirical farmer knowledge and
scientific knowledge to enhance participative rural development projects.
In summary, the combination of local, scientific and technical knowledge
of soil will help extension workers and scientists work more closely with
The work discussed in this paper would not have been possible without
the support and collaboration of the farmers in Bengkulu, Indonesia. Special
thanks are given to the farm communities in Tapos, Talang Donok and Pal
Villages for sharing their knowledge about soils and their management.
The assistance of local government and non-government organizations (Lembaga
Swadaya Masyarakat) is gratefully acknowledged. Financial support for
this study was provided by the Biodiversity Foundation of Indonesia (Yayasan
Kehati). We thank to anonymous reviewers for comments that significantly
improved the quality of this manuscript.