Ökologischer Landbau in Sri Lanka - unter besonderer Berücksichtigung von Tee-Anbausystemen (Camellia sinensis (L.) O. Kuntze)

In Sri Lanka the agricultural structure of smallholder production has changed with population growth and land reforms. In former days a farm family could life from the production of their home garden through subsistence farming and barter economy. Additional income was achieved by selling surplus products like spices on the local markets. Today living standards and life style have changed and monetary needs for housing, schooling, electricity, telephone, household goods and transport facilities are much higher. Many smallholders are involved in single cash crop cultivation and outside employment for income generation. Lack of available arable land and infrastructure are main reasons for the limited economical success of many smallholders in Sri Lanka. This study investigated whether the formation of farmer groups under patronage of an organisation and private company next to adoption of organic agriculture practices can be recommended as an economical viable and ecological sound alternative. Hence a survey was conducted in Kandy District of Sri Lanka, as well as field and laboratory experiments carried out in co-operation with the Tea Research Institute, Talawakele and the Post Graduate Institute of Agriculture, University of Peradeniya. Data from 529 organic tea smallholders (TSHs) were collected between 1997 and 1999. From the findings the study describes the present situation of organic TSHs production systems in Kandy District, Sri Lanka organised under Bio Foods Ltd. Organic Tea and Spices and Gami Seva Sevana (GSS) a Non Governmental Organisation (NGO). Methods applied include taking of farm inventory, questionnaires and semi-structured interviews with farmers and key respondents, drawing of land sketches, evaluation of data records from respective organisations and engagement in post harvest processes (extension, processing, packing, export, inspection). Results showed that 92 % of the organic tea smallholders cultivated plots on former tea plantation land with an average size of 0.4 ha and a given agricultural structure. Mainly seedling tea was grown on steep slopes and 70 % of the farmers cultivated less than 1000 bushes. In depth studies at 23 TSH sites revealed 77 plant species of economical value. For about 35 % of the organic holdings animal production served as an additional source of income (milk, meat, drought power). Out of the whole calculated farm income 42 % was generated from tea, 24 % from fruit and spices and 16 % from treacle, nuts, coffee and cacao. If dairy cows are present 18 % of the farm income is generated from milk sales. Through contract farming with experienced organisations, as well as professional processing and marketing of tea as an exclusive organic product, the farmers obtained premium green leaf prices and a stable income. The stable income served as an incentive to improve the performance of agricultural standards. Here the support of a dedicated extension service brings beneficial inputs. Tea production of the investigated organic TSHs rose by 16 % from 1998 until 2000. Including the marketing of organic fruit and spices there is a high potential for resource poor organic tea smallholders to overcome ecological and economical limitations. Next to the evaluation of the production system, maintaining and improving soil fertility is a major issue for the level of production. Organic manuring is often restricted due to the unavailability of recommended organic materials in adequate quantities. Preparation of compost is time consuming and work intensive and without animal faeces less effective and accepted. The dissemination of biogas plants in the project area gave the incentive to carry out investigations regarding the use of bioslurry for organic tea cultivation. Hence field experiments were conducted to evaluate the effect of organic amendments, namely bioslurry, goat compost and bokashi, on the establishment, growth and yield of tea (Camellia sinensis). Goat compost was made out of goat manure and the remaining materials from the roughage feed given to the goats. Bokashi is a special fermented fertilizer made according to a Japanese recipe (Ahmed, 1995) using soil (50 %), chicken manure (30 %), pressed rape seed oil cake (15 %), rice bran (2-3 %), charcoal (1 %) and boiled livestock bone (about 1 %). Cow and pig excreta passing through a biogas plant, undergoing an anaerobe digestion process for about 70 days are referred to as bioslurry. These three organic amendments at a rate of 3/48/63 t ha-1 year-1 DM were chosen for planting a new tea field. Growth assessments indicated higher plant growth rates of the bioslurry plots when compared with compost treatments. Nutrient balance of a mature tea field partly manured with bioslurry at a rate of 10 l plant-1 year-1 and 12 kg compost respectively showed that bioslurry in combination with mana grass mulch has the potential to add sufficient amounts of nutrients to the soil in order to replace nutrient loss through harvest material. However considering nutrient uptake for plant growth and volatile losses, especially of ammonia, bioslurry application has to be increased and a combination with compost application is recommended. Since organic agriculture plays a key role in maintaining soil fertility and biodiversity, protecting the environment and keeping social standards a model farm with organic tea cultivation as a cash crop was designed. Research findings and personal experiences were taken as a basis for a location specific model of plant production including fodder cultivation, SALT (Sloping Agriculture Land Techniques) hedges, animal husbandry and operation of a 4m3 biogas plant. As main cash crops about 3,000 tea plants are cultivated in a mixed cropping system with 50 pepper vines (Piper nigrum), 56 betel nut palms (Areca catechu) and 100 gliricidia trees (Gliricidia sepium). Remaining 148 plants are grown around the tea field, along the border and surrounding the house. From an average plant species richness of 41 per 0.47 ha with a total of 3,354 plants a monetary value of about 78,000 SL Rs (1998: 1,054 €) per year from plant production was calculated. The total monetary value of cow and goat milk yield added up to approximately 20,000 SL Rs (1998: 270 €) per year. Generated income from farming covers the costs of production. Initial investments for animals, stables and set up of a biogas plant have to be covered by savings and loans. Systematic conversion of smallholder lands with livestock integration becomes financially viable after three years. Specialisation next to diversification ensures income generation and biodiversity as well as an improved nutritional diet for the farm family. Integration of SALT hedges for erosion control also serves as fodder and mulch material. Cultivation of fodder grass assures continuous fodder supply and cuts down walking hours for carrying fodder material from further distances. Proper use of the biogas plant reduces the need for firewood, increases soil fertility through the distribution of bioslurry and improves the sanitary situation. In spite of favourable climatic and soil conditions, Sri Lanka is not self sufficient in its food crop production. Population growth, land fragmentation, ownership patterns, lack of infrastructure and erosion are main factors for low productivity causing land migration because of high rural poverty rates. Alternatives and different objectives of production are required for the survival of the existing population, to solve shortages of food and feed biomass and threats to sustainability. Organic practices use cheap and locally available resources. The productivity of agricultural systems can be improved in the absence of factors like mineral fertilizer, synthetic pesticides, improved seeds and access to credits over which farmers have little control. Organic agriculture techniques replace external inputs by ecological services and farmer’s management skills. This study investigated the status quo of an organic farming system. The interpretation of the survey results led to the design of a location specific model farm, where production goals were matched as close as possible to the resource base.