Objective of organic tea cultivation is to have an ecologically sustainable plantation, aimed at the conservation of ecology and natural habit without polluting soil, air and water and yet maintaining sustainable tea production. Tea is produced in the absence of synthesized chemicals like pesticides, fungicides, herbicides, growth regulators and concentrated fertilizers. Naturally occurring, mined products and bulky and concentrated organic manures are used for resistant cultivars, regulation of micro-climate or by the introduction of biological control agents/the use of biological products, naturally extracted without the use of inorganic solvents.
Selection of Site:
The area needs to be sufficiently isolated to ensure that there is no possibility of any pollutants or contaminants flowing or drifting into it from any known or unknown sources. There should be a buffer zone on sufficient width on all sides of the plot depending on the topography of the area, to ensure the above safety. The minimum width of buffer zone should be 100 metres. The minimum depth of soil profile should be 1.5 to 2.0 metres and organic matter status should be medium to high level depending on the elevation and rainfall of the area. A perennial source of water free from pollutants is required in the estate for large scale compost preparation, which is essential for organic tea cultivation. A detailed history of a period of about ten years, fully documented to give details of external inputs during preconversion period, should be maintained to facilitate inspection of organic tea cultivation.
The minimum conversion period should be three years from the last usage of synthetic agrochemicals. One can start marketing the tea as “in conversion organic tea” only after the lapse of one year from the start of conversion. Tea can be marketed as “organic tea” only after the completion of conversion of three years.
Livestock is an integral feature of organic farming for cowdung, sheep, goat, poultry and pig manure.
Additional workers are required for organic tea cultivation in comparison to conventional tea cultivation and they are required for trenching, compost preparation, weed control, application of bulky and concentrated organic manures and shade regulation.
Soil Water Conservation Measures:
Adoption of proper soil and water conservation measures is essential for organic tea cultivation. Trenching and mulching conserve rain water and make the moisture available to the plants on a sustained basis. Tea pruning, leaf litter and compost should be buried in trenches. Mulching can be done with Guatemala grass (Tripsacum laxum), weeping love grass (Eragrostis curvula), bracken fern, shade tree loppings and other plant materials. Guatemala grass can be planted in large vacant patches with the twin objectives of rehabilitating the soil raising mulch material.
Soil pH should be maintained at about 5.0 by application of agricultural lime or dolomite lime once in a pruning cycle and the quantity of liming material should be determined on the basis of soil pH, rainfall and crop yield.
Manuring ensures the availability of essential nutrients that deficient in the soil at optimum quantities and to return the nutrients removed by using the manures of organic origin demanded by the tea bushes for a sustainable productivity. Compost, oil cakes and rock phosphate are the main inputs to substitute the removal on nutrients. Nitrogen is also supplied by regular lopping of low and medium shade trees and leguminous trees (Gliricidia sepium, Gliricidia maculate) which can be grown along roadsides and other vacant patches. Bone meal, fish meal and other manures of organic origin can also be used in available from unpolluted environment; wood ash can also be applied. The recommendations on manuring of organic tea are as given in Tables 1 and 2.
Standards for Organic Manure:
Fertilizer Advisory Development and Information Network for Asia and Pacific (FADINAP), Bangkok has formulated the following standards for organic manure.
pH (1%): 6.5-7.5 more or less neutral; organic matter should not be less than 20.0%; Carbon:Nitrogen ratio (C:N ratio), 10:1 to 15:1; moisture content should not exceed 25.0% and free from pathogens (pathogens and heavy metals originate mainly from sewage sludge and urban garbage). The above specification are also applicable for organic manures suitable for tea plantations. In addition, electrical conductivity (EC) is also considered to judge their suitability for use in tea fields. EC (1%) up to 0.50 dSm-1recommended for young tea EC (1%) up to 1.5 dSm-1 recommended for mature tea only Minimum rate of organic manures suggested for application in tea fields is 5 t/ha and the maximum rate is 20 to 25 t/ha to be applied in two equal splits.
Adequate attention to the maintenance of optimum stand of shade should be given in organic tea cultivation and should be regulated properly by annual lopping.
Weeds should be controlled manually by hand pulling during dry period and slashing during monsoon; uprooted and slashed weeds may be retained in the field.
Pest and disease management:
Pest and disease control in organic tea cultivation is primarily preventive rather than curative. If insects and diseases occur, non-toxic biological methods are applied. Within a balanced ecological system, the pests and diseases are controlled by the use of resistant clones, balanced nutrient supply, parasites and predators, pheromones, herbal sprays and by appropriate cultural operations. Certain caterpillars like flushworm, leaf rollers and tea tortrix can be controlled to a certain extent by manually removing the infested shoots during plucking. Blister blight disease can be controlled by the use of resistant clones and by modifying the micro-climate by the thinning of shade trees.
Post-harvest and Manufacturing Practices:
Manufacturing practices: For manufacturing, only mechanical and physical process are allowed with natural fermentation. It can be manufactured as orthodox, CTC, oolong or green tea.
Isolation of manufacturing facility: Manufacturing of organic tea should be carried out in a separate factory to eliminate all changes and possibilities of coming into contact with the conventional tea. The manufacture of “organic tea in conversion” and “organic tea” should be done on separate days; care should be taken for proper cleaning and washing the factory with water under pressure before the manufacture of “organic tea” and after manufacture of “organic tea in conversion”.
Storage and packing: There should be separate store for organic tea where no fumigation, insecticides or fungicides are used. Vacuum, steam or high pressure water cleaning is permitted. Organic tea should be packed in plywood chests or biodegradable packing materials on the same day of production and the organic quality grade should be clearly indicated on each chest or container along with the invoice number of dispatch.
Transportation and shipment: The chests of organic tea should be transported separately and there should not be any chance of it coming into contact with the conventional tea. Before shipment to destination, it should be stored in an isolated place, away from the conventional tea.
Inspection and Certification
Soil analysis: Soil analyses of zero to 30 cm depth should be necessarily done each year, regularly, for macro and micronutrients and heavy metal status. This will reveal fertilizer usage and contamination from sources other than intentional application such as wind drift from neighboring plantations or water migrating from plantations above.
Leaf analysis: Issue analysis of mother leaf should also be carried out, annually, for pesticide and fungicide residues and for the levels of macro and micronutrients and heavy metals. This will reveal mineral nutrient status and pesticide and fungicide usage, if any.
Marketable tea analysis: The marketable organic tea should be analysed twice in a year, pre- and post- monsoon, for pesticide resides, flavour and quality.
Book-keeping: Book keeping should be properly maintained to make an audit trial of inputs and marketable tea supplied to consumer. The invoice number should be mentioned on tea chests, in the factory book and in the documents. With the invoice number, the origin of the tea can be traced back to when it was manufactured, the quantity manufactured and the site and quantity of leaves plucked in the field with the factory diary and field book.
Inspection by independent agency: Inspection by the representatives of an independent agency unannounced at least once in a year is required by field visits to check the organic growing techniques, taking samples of leaf and marketable tea at random and also to check the maintenance of book-keeping system.