RESEARCH REVIEW (NS) VOL. 12, NOS. 1 & 2 (1996) TRADITIONAL FARMERS' PERCEPTION OF THE SOILS IN THE NANlfMBA DISTRICT OF GHANA. Abstract T.W. Awadzi Soil classification is normally based on profile characteristics, genesis as well as chemical and physical characteristics systems. Traditional farmers all over Ghana have their own clas- sifications based on colour, texture and coarse material content of the soils. In the Nanumba District farmers have come out with four major soils based on this criteria as against seven by Soil Scientists. However, comparing the two classifications there are not many differences between them. With regard to the agronomic values of the Soils both soil scientists and tradi- tional farmers are almost in total agreement. The only differences that occur are due to the fact that the soil scientist bases agronomic values on the ranges of possibilities offered by the soils and climate while the traditional farmer, in addition, considers the culture of the area. For food production to be increased, soil scientists and extension officers must be conversant with traditional farmers' classification and perception, so as to be effective in transferring scientific knowledge to the farmers. Introduction The Nanumba district is partially in the Oti and the Daka River Basins and covens an area of about 2,000km2. It is bounded on the north and west by Eastern Gonja, on the south by the Kete Krachi district, and on the east by Eastern Dagbon and the Republic of Togo (Fig. 1). The Oti River Basin is known to be a very important food producing area. Yam is the predomi- nant crop grown followed by maize, sorghum, millet, beans and groundnuts. A soil survey of this area was conducted as part of the Oti Basin Soil Survey and information on crop production collected. Agriculture relies heavily on farmers' perception of the environ- ment and the modern scientific knowledge is yet to be transferred to them. Even if they do, it will not be easy to impart this knowledge since most of the farmers are illiterate. It may therefore be more useful to investigate and merge farmers' perception of the soils with scien- tific knowledge. The idea of making use of farmers' perception in agriculture is not new in Ghana. Benneh (1970) in his study on the attitude of the Kusasi Farmers of the Northern Region of Ghana pointed out that the Agricultural scientist, in order to improve farming techniques, cannot 25 Nakpayili V ~ ~ -* -rso — ••<— Regional boundary "" —— District boundory * District capital 'mmmmm Second etassroad ——— Third class road FIQ.1 NANUMBA DISTRICT afford to ignore the wealth of acknowledge accumulated over the years by indigenous fanners, on the physical environment. In this paper, the scientific classification of die soils of the area has been compared with the traditional fanners' classification. Suggestions have been made as to how best the traditional fanner can be helped to improve his agricultural techniques. The study was conducted in the Oti Basin lying in the Savannah Climate Zone of Ghana. Physical Background The study area experiences a single peak rainy season. The monthly totals rise slowly from March to June and then fall rapidly after September (Fig. 2). Average nmvitimm temperatures are highest hi March. The highest temperatures usually occur hi April or May just at the beginning of the nuns. The lowest average temperatures occur hi August The annual mean maximum temperature at Yendi is 33°C while the average daily mean is 27°C. The district is covered by Guinea Savannah woodland vegetation, hi its typical form, it con- sists of short-statured trees usually not forming a close canopy and very often widely spaced. The ground flora is composed of a continuous layer of grass. Many of the trees are fire resistant and have thick barks. Root suckers are also numerous and play a very important part in regen- eration. Riverine woodland vegetation is found along the major rivers and streams as the Oti and the Mo. The Guinea savannah woodland consists of Partda FUicodes, and DetariumSeneguIenses. Anogeissus schimperi Acacias are also very frequent. Riverine woodland areas have Kyaya senegaUnses as the dominant trees. However, in most places most of the trees have been cut for fuel, and only trees of commercial value such as Butyrospernum, Parkia, Acacia, AndtPtsoiua and Btiglia sapida remain. The dominant grasses are Heteropogon Cotttotttus, Imperata cylindrica and Pamisetum pofystachyion. Method The area was surveyed using the semi-detailed reconnaissance method described by Ann (1970) on the scale of 1:250,600. This involves the use of roads, paths and online traverses. The traverses were about 3 - 4km apart and were chained and pegged at 10m intervals. The soils were identified along these traverses. Five big time farmers including the chief fanner of the area were interviewed and taken to the field at different times to identify the soils according to their traditional method. The five farmers all gave the same names for the soils as well as their indicator plants. 26 KETE KRACH1 YENOI 800 _ C50 * COO _l < ISO z Se too 50 0 - - "i-T - eo - to 2 5 S 3OO 250 100 50 J F M A M J J A S O ND J F M A M J J A S O ND Fig. 2 MEAN MONTHLY/ANN UAL RAINFALL AND TEMPERATURE FOR KETE KRACHI AND YENDI Seuroc: Ohana M*f««re w Results The soils found in the district are developed on Voltaian sandstones, mudstones and shales. However, the most extensive soils found in the area are those over Voltaian sandstones. Scien- tifically, these soils have been classified as the Ejura-Amantin-Denteso soil Association (Smith, 1962). On the summit and upper dopes occur Wenchi, Kintampo, Techuaan and Ejura series. On the middle to lower slopes occur Antantm series followed oa the lower to bottom slopes by Dentenso series. The valley bottom soil, Sene series, is however not very common apparently because part of the areas covered had been taken up by the VoltaLake. Detailed description of the soils has been given below. Weachi Series - the series occurs as small isolated patches on summit and upper slope sites in the district It is a very shallow soil consisting of frequent to abundant ironstone concretions and pieces of iron pan in brown to reddish brown fine matrix. This layer is underlain by massive ironstone at less than 30cm from the surface. Elsewhere hi the area erosion has caused the exposure of the ironpan at the surface. . Kintampo Series (Lhhk Ustorthent, USDA): This soil also occurs in small patches on sum- mits and upper slopes. Occasionally it may also be found along stream banks where there is a break of slope. It is a very shallow soil consisting of very frequent to abundant pieces of sandstone hi a brown to reddish brown loamy sand matrix. This layer overlies massive sand- stone rock at less than 30cm from the surface. Techiman Series (Rhodk Pakustaif, USDA): The soil occurs on summit and upper slope sites where gradients rarely exceed 2- per cent Normally the profile consists of 1 - L.5 meters of frequent to abundant iron concretion and ferrngmized sandstone brash in a fine sandy loam to clay matrix. The dominant colour is reddish brown to yellowish red but the top 20 - 30cm is usually stained dark greyish brown to d ak brown by organic matter: The concretionary layer grades below into decomposing yel- lowish or reddish feldspathic sandstone; In some localised areas the concretionary layers of the Techiman soils overlie ironpan usually at the depth of more than 40cm. The ironstone is often con^jaetbutfriaMeandgeaeiaflyconsi^offenugu^^ downwards into weathered sandstone. . , Ejora Series (Typic PaktutaH* USDA): These soils occur on the upper summits of the slop- ing topography. They consist of deep, well drained yellowish red sandy loams free of gravel. The typkal Ejwra''series am chaaeterisod try5 - 8cm ofdarkyellowi^ brown sandy toam top soil which is generally dry and leached tf¥i with a towto moderate organic matter content The topsoil ovwiksa^eUowish redsaagy ctay loam subsoil followed at about 2 meters by a motttedlayer Iwriafeooveriafyiag weathefingsfuidsto^e OAiroi^Mtn which commonly develops Apart from the typical Ejura soils a shallow phase of it occurs in irregular patches within the main body of the deeper Ejura soils. This soil is free of concretions and stones for up to about a meter. It has a slightly lower clay content so that die soil is somewhat droughty. Aauutin Series (Typfc Pakutaif, USDA): These are deep, imperfectly drained, hillwash soils occurring on middle to lower slopes of gently sloping topography. They sometimes occur at deprtssional sites of the upper and middle slopes. The normal profile consists of 0 - 30cm of dark brown loamy fine sands over a horizon (30 - 120cm) which consists of strong brown fine sandy to loam material. This overlies a strong brown, mottled reddish brown, fine sandy clay loam horizon. Deatnuo Series (ArenkPaleustmlf, USDA): Denteam aeries is the valley bottom soil of the association. It is poorly drained and derived mainly as wash from Amantin and Ejura series. The normal profile consists of 0.30cm of pinkish grey, loamy fine sand, over a meter of pink- ish grey mottled brown fine sand with frequent tiny pan boulders and sandstone gravel which overlie ironpan. Traditional Farmers Perception of the soils The soils described above were based on soil series which is the basic unit of soil classification consisting of soils that are essentially alike in all major profile characteristics except the tex- ture of the A-horizon. However, traditional farmers identify and classify their soils not according to profile charac- teristics but on colour, texture and coarse material content In addition, indicator plants are used for their identification. Below is a Namunba classification of the soils in the district Tasdaoze soils are red and are found on summits and upper slope and are normally associated with/Mfefom, Ariaddm Kmtutga as major indicator plants. Bihigu soil - This occurs in the middle stapes. It is dark brown sandy loam or fine loamy sands. This soil is not as perfectly drained as Taadaaze soils. The soil is associated wim Diacore* tp and Prima as the major indicator plants. This soil is the Ejura series in the scientific classification. Batapeni wH is the lower valley bottom soil and is characteristically loamy sands. B is poorly drained and farmers associate it also v/i6i pg g soils are found in the valley bottoms. They ace normally waterlogged in the rainy season and crack during ^ ^ ^ ^^ jug j, ^ s ,^ ^g m kt described in die scientific classification. They are however not very common in the study area. Fwmenanociate 28 Mferft&M as tiKmqjor indicator plant. Taeriasja soils ace fallow summit and upper slope soils with ironstone concretion and ironpan at a depth of less than 30cm. AgreaoMkValne Weacki series (Tmerimga) is non-agricultuial being too shallow, too concrctiooaiy aad too droughty to be cultivated. Techfanaa series (TwuUmzc) is permeable throughout Run-off is moderate and internal drainage is somewhat excessive so that they dry out speedily in the dry season. The shattowness of the top soil together with the doughtiness restrict the agricultural value of these soils. The soils are near neutral to slightly acid hi the top soils but throughout the concretionary subsoil, acidity increases very slightly with depth. Maize, sorghum, millet and groundnuts can be cultivated with success on the soils. They require careful tillage and management as top soil erosion often leads to the exposure of the concretionary subsoil. The sous are therefore marginal for mechanized cultivation and deep ploughing must be avoided. Ejura Series: {Bttugu) is well drained for the first one meter of the profile. Thereafter, drain- age is somewhat imperfect The topsoil tends to be droughty but subsoil moisture is retained longer in the dry season than in the case of the Tecbiman series. Because of its depth, non- concretionary nature and the absence of stones it can be tilled easily both by hand and with machines. Topsoil reaction is neutral but subsoil horizons, are generally slightly acid with values which lie around pH6.2. Ejura soils are ideal for the cultivation of maize but yams, sorghum, tobacco, kenaf, cotton, soya beans, nullet and a variety of crops may be profitably grown on the series. It is suscep- tible to erosion and therefore contour ploughing and mulching need to be maintained in order to check soil losses (Awadzi, 1975). Aatantia Series: (Batampetti) is deep imperfectly drained, porous and medium textured. It is moderately well supplied with organic matter although ft has fairly low plant nutrient reserves. Owing to its sandy texture the soil is susceptible to drought On the other hand, in years of exceptionally high rainfall it may be partially saturated with water. However, as the soil Is deep, free of concretions and gravel and can be easily cultivated, it may be readily used for maize and other crops listed under Ejura Series although yields can be expected to be low. The low natural fertility requires that the soil be manurcdperiomcaUy. As ft is susceptible to severe erosion the soil requires more protection from this hazard than Ejam Series. D e i t ew Scries (fl«r—yrwp is poorly drained aad sabjectto seasonal watcrtogging or flood- ing for varying periods but generally becomes droughty during the dry season. Becmse of the 29 very low clay content, very low crop yields may be expected from this soil. By establishing interceptor drains, maintenance of organic matter and the use of adequate fertilizers, rice, tobacco and vegetables may successfully be grown on Pcnlc—o Series. Farmers' Appraisal of Agronomic Value of the Major Soils Fanners appraisal of the agronomic values of the soils is greatly influenced by the major staple food of the people as well as th« major cash crop that fe produced in the area. In the Nanumba area, miBet asd sorghum a*S the most important staples. However, because of the emerging cash crop economy in fibs" area every piece of land is valued first, on thebasisof its suitability for yam cultivation. The farmers identify the agronomic values of the soils by using colour and indicator plants. The Nanumba fanners rank Tmtdmne soils as suitable for the cultivation of yams. However, they contend that hi times of exceptionally heavy rains^ the soils are washed away from the mounds because of its high content of coarse gravels. Where land is available for yams, they recommend that these soils be cultivated to sorghum, millet and vegetables to reduce soil erosion. Farmers identify mis soil by Aristida Ker&tinga as the major indicator plant and also by its high loose concretions. The farmers identify Batampem by its 'grey' colour. Farmers contend that, though soil-mois- ture relationship is poor, they gfre ttgh yieWs m the first year after which fertility declines rapidly. Batampeni Soils arenot suMtfe-foryam cultivation but vegetables are recommended especially at the end of the rains. Bihigu soils are the most preferred soils for the cultivation of rice add many other crops. These soils are identified by the existence of prima grass and by its colour. Bayftgri (Seme series) soils which are valley bottom soils, clayey and liable to waterlogging in the rainy season are not very common in the area. These Soils are not tanked as an important soil hi terms of yam cultivatioa Farmers use it for rice and vegetables. " Taering* Soils (WencM Series) are not used by fanners for ihe coWvatioa of wry crop: They Dfectusion Farmers in the Nanumba area were completely unaware of fite Kiestiflc ciassirlcatioa «ff fee soils of the area, and being iffitaratelt istKBkdy flat Hie* will *?er be able to understood let alone use the scientific te»n$ of the soil sciatffefc However, comparing the ctesJficatioHof Ac wit sdesflsts « t t « t « T lK tnrittiojal & r nw to the MBBoort« district it is clear ftat-* g » c «l bo