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Terra PreTa Trials

Experimented by ODAM, Tiruchuli

www.odam.in

Submitted to Siemenpuu Foundation, Finland

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ODAM - Terra PreTa Trials Introduction In Tamil Nadu State, few southern districts (Ramanathapuram, Virudhunagar, Sivagangai and parts Pudukottai, Tutucorin and Tirunelveli) are highly prone to drought due to semi-arid nature of terrain and hot & humid climatic conditions and, periodic southwest monsoon is very erratic and failure of monsoon is a common occurrence in this region. As a consequence, failure in agriculture practises and loss of agriculture produce would affect both small and marginal farmers and agriculture labourers. Ultimately migration has been a continuous event from rural pockets of this region to urban and coastal regions for employment opportunity. Due to recurrent failure in agriculture, people of this region have to depend extremely on external source for cooking fuel, particularly kerosene. In early 1950s, Prosopis juliflora was introduced as an alternative to existing fuel need, which gradually started invading the cultivable fertile lands – during continuous drought – invasion was very severe and established very strongly with deep rooted; These Prosopis trees could not be removed manually, heavy machinery was required and further aggravated cost intensive. As a result, those fertile agriculture lands were degraded further intensifying due to non-occurrence of rainfall in this region. Small farmers and landless agriculture labourers were worst affected due to these above combined natural and anthropogenic activities. This severely impacted on long term livelihood activities and strategies of the people this region.

Box 1. Prosopis juliflora was introduced in India in 1877 in the district of Sind (Punjab) and later on into many parts of India such as the cities of Hageri, Bellary, Agra and Delhi. In 1913, it was introduced by the ruler of the Jodhpur State to many arid and semi-and parts of Rajasthan for stabilizing sand dunes. Later, P. juliflora has spread throughout the states of Tamil Nadu and Gujarat.

The major spread of P. juliflora was initiated in old Ramanathapuram district. In 1985, the Ramanathapuram District was trifurcated to create Virudhunagar, Ramanathapuram and Sivagangai districts (Figure 1). Later, there was a gradual shift from household consumption of Prosopis as firewood to livelihood activity of making charcoal and marketing the same. Large quantity of charcoal has been sold all over India for various large scales to small scale industries such as steel, chemical industry, metallurgy industry, etc and also consumed in hotels and tea shops of Tamil Nadu.

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Figure 1 showing the drought prone districts of Tamil Nadu

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While making and marketing charcoal, the farming community has been facing a lot of issues and problems – occupational health hazards such as respiratory problems due to inhaling of gases emitted or of having contact with the gases – causing severe ailments due to prolonged exposure to the gases. Apart from the health hazards, the community involved in charcoal making as a major livelihood activity has to fall victim of marketing forgery. Middle men and vendors are exploiting the charcoal making farmers’ unorganised system of working and there is no proper pricing of charcoal products existing. Further, middle men’s role in cash disbursement most of the time leads to dispute between the labourers and contractor or owner of the charcoal making unit. There is no direct contact between buyer and seller, which most of the time favours the middle men to exploit the farmers. Due to lack of infrastructure facility in the premises of charcoal production for storing or stacking the product would cause loss to the charcoal making farmers. Contract labouring of families (bonded labours) had led the children to forcefully undergo child labouring in the charcoal making units, becoming skilled labours causing temporary migration to different areas for charcoal making have been the root cause for many social concerns among the community. The community in this region were not aware of any further value addition beyond charcoal making also prompting the community unemployed during certain seasons particularly during Northeast monsoon. Increase in drought conditions, erratic rainfall and monsoon, agriculture failure, decrease in regular cultivation of cash crops – all are creating favourable situation to multinational & corporate companies to purchase large scale of lands for lowest price from these fragile communities causing severe land alienation. As a drought prone area with the only resource of Prosopis juliflora and associated skill of charcoal making, ODAM explored for further value addition and diversification. In 1996 with the guidance of Professor Dr. P.D. Grover (Indian Institute of Technology, Delhi), we developed the mould for making bee-hive type briquettes as alternative to fuel wood and fossil fuels to some extent in certain pockets of rural area particularly at the foot hills of western ghats and sub-urban areas surrounding the drought affected Prosopis invaded areas. As a result we developed the production of Bee-hive briquettes and demonstration was also carried out. Performance of the briquette was satisfactory but further refinement on the efficiency and ease of usage of the product could not be established due to certain factors. One of which was the subsidiary programme from the Govt. of India which made problem in marketing the briquettes and lack of financial support to continue the research and development.

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At this juncture, ODAM was aware of that Terra Preta and its application to the farming activities could be a better form of bioenergy, enhancing the fertility of nutrient poor soil and increase the yield of agriculture produce from Siemenpuu Foundation. It was felt that charcoal from the Prosopis juliflora could very well be made use of as alternative source for value addition and diversification to promote employment opportunity among affected community in this region. As a result of various natural processes and anthropogenic activities such as consumption of chemical fertilizers and introduction of Prosopis juliflora left the soil of this region less fertile, low nutrient-retention capacity, etc had led the lands unsuitable for further agriculture practices. The fertility of highly weathered soils in the tropics is low and soil organic matter plays a major role in sustaining soil productivity (Steiner et al., 2008). Due to low nutrient retention capacity and high permeability of these soils, strong tropical rainfalls (like northeast monsoon occurring in this region during October to December every year) cause rapid leaching of mobile nutrients such those applied with mineral fertilizers (Renck and Lehmann, 2004). To overcome these limitations of poor soil, low nutrient-retention capacity and accelerated SOM decay require alternative fertilisation methods (Ross, 1993; Fernandes et al., 1997). For quick release of nutrients, fallow vegetation could be applied as mulch (Sommer et al., 2004), compost, or charcoal (Lehmann et al., 2002). The existence of so-called “Terra Preta de Indio” (Indian Black earth) suggests a human-induced accumulation of SOM can be maintained over centuries (Sombroek et al., 1993). These soils are exceptionally fertile, and their productivity is most likely linked to an anthropogenic accumulation of P and Ca associated with bone apatite (Lima et al., 2002) and black C (BC) as charcoal (Glaser et al., 2001). The sustained fertility of charcoal-containing Terra Preta and the frequent use of charcoal as a soil conditioner (Steiner et al., 2004b) in Brazil provided the incentive to study the effects of charcoal application on N cycling. Charcoal acted as an adsorber which reduced N leaching in pot experiments (Lehmann et al., 2002, 2003), and charcoal additions proved to sustain fertility if an additional nutrient source is given in a field trial (Steiner et al., 2007). Charcoal plus fertilizer improved plant growth and doubled grain production in comparison to the fertilizer without charcoal (Steiner et al., 2008). These above mentioned studies, experiments and the discussions with Mr. Toni and the Siemenpuu representatives prompted ODAM to carry out the application of charcoal and role of different amendments of charcoal with various protein enriched de-oiled seed cakes (non-edible) which set objective to compare the effects of soil amendments of different de-oiled seed cakes with charcoal on the yield of vegetables in a small scale as part of the long term field trial for

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standardising suitable soil amendments to enhance the yield of agriculture produce and to acclimatise drastic climate changes being encountered by community and large agricultural lands. Materials and Methods Preparation of charcoal powder from P. juliflora Charcoal of Prosopis juliflora was purchased from the local charcoal makers for the Terra preta trials conducted by ODAM (Details of charcoal making is depicted in Box 2). The charcoal pieces were sorted into different grades as per the texture and observing carefully and ensuring that charcoal would be suitable for making char powder. More or less uniform size charcoal pieces were pounded manually by experienced women1. But it was a labourious work while making charcoal powder, women and other labours had to undergo difficult breathing process and the process is time consuming when comparing with the pulverising machines. Further spreading and flying of this charcoal made the working place into black. The powdered charcoal was kept in air tight gunny bags insulated with polythene sheets. Otherwise absorption of moisture would affect the quality of the charcoal powder.

Box 2. Charcoal making process (Kari Moottam) Charcoal making is one of the traditional practices to generate income in the rain-fed tracts of then Ramanathapuram district in off season or non-agriculture season. Kari Moottam (Plate 1) is generally prepared in non-farming periods during January – September. The burning and the process of charcoal making require 10 to 13 days (from cutting the wood logs of Prosopis juliflora, stacking, covering with mud paste, burning and packing in jute bags). A heap of pyramid like structure by keeping wood logs and roots of juliflora is prepared for making charcoal. Mostly people use fibre wastes of coconut, paddy straw or any available agriculture waste to prepare paste mixed with clay soil to cover the heap structure where inside the wood logs are stored. Finally it is covered with sand outside and water is applied over it. After burning inside over a period of 3 – 4 days, entire wood logs will be converted in to charcoal. It is transported to various districts of Tamil Nadu also certain states like Maharashtra and Gujarat for industrial purpose. The big sized charcoal produced from the roots of juliflora are graded as first quality, medium sized charcoal (tube light size) as second quality and third quality and the rest of the charcoal called as last finger size. These last finger sized charcoal is not packed for market instead of that they leave it in the ground or sell it for low price for various purposes.

1 Hand-pounding was a similar kind activity to make rice from paddy or semi-dried rice powder for making various kinds of eatables; the hand-pounded rice would have rich in minerals and vitamins on the outer layer of the rice. The mineral and vitamins would be lost in the rice produced by modern mills

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Preparation of charcoal powder from agriculture wastes Char of Agriculture waste was prepared from the wastes of cultivated agriculture land. The dried leaves of banana tree, gram straw, outer shell of the pods of Jatropha, millet cones and dust, shells of palm fruits, sugarcane wastes, and dried sugarcane straw are collected and tightly packed in a oil drum (this is available from hardware shops) by placing a PVC tube of 6 inch diameter at the centre of the drum. At the top of the drum agriculture wastes were loaded, loose packs of the same was burnt and closed for a while to undergo pyrolysis process. During this process the drum was closed completely until the pyrolysis process come to end.

Processes involved in Producing Charcoal from Agricultural Waste (The following section about pyrolising agriculture waste in to charcoal is the work report of ODAM’s former volunteer Mr. Michael Woon) First, any material that is to be converted into charcoal must be very dry. Sun-dry waste until it is dry to the touch. For thicker material, cut or break it to check that it is fully dry inside. Charcoal is produced when organic matter such as wood or agricultural wastes is heated to a high temperature with little or no oxygen. This removes all the materials in the organic matter except for carbon which we call charcoal. When organic matter is heated to a high temperature with oxygen, the carbon burns to produce ash, therefore it is important to restrict the flow of air (oxygen). The Oil drum kiln creates an environment which agricultural waste can be heated to high temperatures without air (without burning) to convert it into charcoal. Part of the material used to produce charcoal will be burned to create heat, after which the drum will be sealed to use the heat to convert the rest into charcoal. Making an Oil Drum Kiln A complete Oil drum (with both sides intact) was obtained first then a chisel was used for the following steps:

1. Several holes (4-5cm size) were cut in one side for air to flow through the kiln (this is the bottom)

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2. A large square hole was cut in the other side to be used for filling the kiln (this is the top)

3. Another piece of metal was needed to cover the square hole. It should be a size and shape that do not allow it to fall into hole.

4. Before filling in the agriculture waste in to the kiln, oil residue in the drum was cleaned, further residue was removed by burning.

Loading the Kiln

1. The drum was filled with material to be made into charcoal, holding a big stick or pipe (8-10 cm size) at the centre of the drum.

2. Some material burnt very quickly, such as sugar cane straw, and some burns very slowly, such as millet cones.

3. Different materials had different shapes and characteristics. Dry straw was stiff and naturally had air spaces, but millet cones were soft and naturally fit very close together.

4. Different materials were placed into the drum in layers so that air could flow, and heat was distributed throughout the drum (kiln).

5. The drum was completely filled as the volume of material would decrease during burning.

6. The material was not packed too tightly as it would have poor flow of air, neither should it be packed too loosely as it would allow too much air to flow.

7. After filling in the agriculture waste, the 6 inch dia PVC tube (stick like) was carefully removed leave a hole that went up to the bottom of the drum.

Firing the Kiln

1. Before burning the waste, the drum was placed on three bricks or stones, to allow air to flow into the holes at the bottom.

2. The material at the bottom of the hole was ignited by lighting a piece of paper or cloth and pushing it to the bottom with a stick.

3. At first, the waste burnt with a thick, yellow smoke.

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4. This smoke contained gases that could be fired to make the drum burn more cleanly.

5. The kiln was allowed to burn until the fire becomes clear and produces a very thin blue smoke. At that time oil drum (kiln) was very hot.

6. The cover was placed on the kiln to slow down the flow of air into the drum. This was to reduce the oxygen so that the charcoal was not burnt. This was ensured by observing any smoke coming out of the holes.

7. If the amount of smoke increased, the cover was opened to allow the fire to burn cleanly. This also increased the heat in the drum

8. The drum was ready to be sealed when it burns well with almost no smoke and the drum was very hot.

9. The cover was placed over the hole and removed the stones from under the drum by supporting the drum with a large stick.

10. Mud was used to seal the bottom edge of the drum and any gaps at the top. It was ensured that there were no holes where smoke could be seen escaping.

11. The drum was left for cooling. The waste inside would have been carbonised after 2-4 hours. The drum should no longer be hot.

12. The sand was brushed off and the charcoal was removed. It was dry, completely black and slightly shiny.

Notes:

The drum should be sealed after about 15 minutes after the start of the burn. This time can be adjusted depending on the amount and type of waste being used.

There should be a very small amount of ash in the charcoal

If the charcoal material is not completely carbonised, allow the fire to burn longer before covering

Preparation of the mixture of manure of de-oiled seed cake with charcoal powder Different kinds of non-edible tree-borne oil seed cakes were subjected to prepare different combination of char (terra preta) trials. Combinations of de-oiled seed cake and charcoal powder were prepared broadly in to different categories. One was individual de-oiled seed cakes were mixed with charcoal powder and

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directly applied to the pits dug for vegetable cultivation and another category was after mixing Jatropha de-oiled seed cake with powdered charcoal subjected to water saturation. This saturation process was periodically carried out at regular interval of 3 to 4 days for first month and later once in a week in the next month and kept in a closed condition for facilitating to undergo fermentation. The following were the two different categories of soil amendments of char to the vegetables:

Table: 1. Different categories of soil amendment with charcoal powder in the first row.

Biomass and Charcoal powder combinations Application type

Category I (Unsaturated with P. Juliflora charcoal powder)

Neem de-oiled seed cake + Dry Charcoal Powder Single

Silk cotton de-oiled seed cake + Dry Charcoal Powder Single

Pinnai de-oiled seed cake + Dry Charcoal Powder Single

Pongamia de-oiled seed cake + Dry Charcoal powder Single

Silk cotton + Neem + Jatropha + Pongamia de-oiled seed cake + Dry Charcoal Powder

Single

Category II (Saturated with P. Juliflora charcoal powder )

Jatropha de-oiled seed cake + Charcoal powder (P. Juliflora) - saturated with water (Both oil cake and Charcoal powder mixed together first and then saturated with water for 60 days)

Triplicate

Apart from the above two broad categories, de-oiled seed cakes were tried with single and in combination with one or three 3 de-oiled seed cakes. Then powdered charcoal was also tried as such and with partial saturation. The following are other type categories with or without charcoal powder:

Table: 2. Different categories of biomass application of soil amendments and charcoal powder only in the first row:

Biomass only Application type

Indian Beech (Pongamia) de-oiled seed cake Single pit Jatropha de-oiled seed cake Single Neem de-oiled seed cake Single Silk cotton de-oiled seed cake Single Jatropha + Neem de-oiled seed cake Single Jatropha + Pongamia de-oiled seed cake Single Jatropha + Silk cotton de-oiled seed cake Single Jatropha + Pinnai de-oiled seed cake Single Neem + Pongamia de-oiled seed cake Single

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Neem + Silk cotton de-oiled seed cake Single Neem + Pinnai de-oiled seed cake Single Silk cotton + Pongamia de-oiled seed cake Single Silk cotton + Pinnai (Calophyllum ionophyllum) de-oiled seed cake Single Silk cotton + Neem + Jatropha + Pongamia de-oiled seed cake Single

Charcoal only Charcoal (not pulverised) of big pieces Single Dry Charcoal granules (After powdering the charcoal, fine powder will be sieved and remaining unfiltered charcoal granules)

Single

Charcoal powder (P. Juliflora) – Dry Powder Duplicate Charcoal powder (P. Juliflora) – Saturated with water Single Control Without any manure only seeds and seedling planted Triplicate

Twenty different soil amendments in 30 pits of first row were experimented including a control with three replicates (see above table).

Table: 3. Different categories of soil amendments in the second row No. Description Application

type 1. Saturated Charcoal powder of Prosopis juliflora Four 2. Charcoal powder of agriculture waste Duplicate 3. Charcoal powder of Prosopis juliflora Sixteen 4. De-oiled seed cake of Silk cotton Single 5. De-oiled seed cake of Pongamia Single 6. De-oiled seed cake of Jatropha Single 7. De-oiled seed cake of Neem Single 8. De-oiled seed cakes of Silk cotton + Pongamia + Jatropha +

Neem Single

9. Control Triplicate

In the second row, totally 9 soil amendments were experimented in 30 pits including a control with three replicates (see above Table). Traditionally, in Tamil Nadu farmers used to apply certain de-oiled seed cakes for land preparation to enhance the fertility level of the land and eradicate the pests before the onset of southwest or northeast monsoon or sowing seeds. Among the de-oiled seed cakes, groundnut seed cake is being used for enhancing fertility of the land. Other de-oiled cakes of non-edible oil seeds such as neem, pongamia, maghuva and calophyllum are being utilised for eradicating pests, pupa of insects and other soil-borne diseases. Usually, in rural Tamil Nadu, households farming community used to dig the pit at their backyard of kitchen on or before ‘Aadi 18’ (usually it falls on August 3rd) and it is called as Plant Pit (in Tamil it is called as Payir Kuzhi). Exactly on 18th Aadi month of Tamil, vegetable seeds or seedlings will be sown or planted. It was considered as auspicious day for sowing the seeds in the rain-fed areas and transplantation in the wetland cultivation. In the present Terra Preta (char) trials, similar kind of ‘plant pits’ were dug in the land opposite to bio-diesel unit (in three rows; each row consisting of 30 pits) to effectively utilise the biomass manure and char powder of P. juliflora and agriculture waste.

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Study area and experimental set up The experiment was conducted with a field trial established 8 km northeast of Tiruchuli near the Biodiesel demonstration unit established by ODAM. The area is classified as semi-arid with a mean annual rainfall ranging between 500 and 600 mm having its seasonal maximum between mid-October and mid-December. The soil might be classified as a weathered oxisol red soil, coarse or medium textured with sandy.

Land preparation for Terra preta trial Pit digging Terra preta trial plots were carried out opposite to the Bio diesel extraction unit nearby Tiruchuli. The selected land portion for demonstrating the trial plots was ploughed very before the onset of monsoon. Thirty pits were dug at an interval of one meter. Likewise 90 pits were dug in three rows. The distance between two rows was 2 meter. The following schematic diagram shows the pits in the trial plot.

1 2 3 4 27 28 29 30

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Preparation of biomass manure and terra preta combinations

1. De-oiled seed cakes of Pongamia, Jatropha, Neem, Silk cotton were made into small pieces and applied to the pits after applying top soil at the bottom of the pit. Again after applying the de-oiled seed cake into the pits top soil was filled up in the pit.

2. Mixtures of two de-oiled cakes were made in 8 combinations in the ratio of 1:1. E.g. One portion of Jatropha de-oiled seed cake + one portion of Neem de-oiled seed cake. The cakes were made into small pieces and mixed well together. The application process was like that of previous one. In this type of mixture, additionally one more species, Calophyllum inophyllum was added.

3. Mixture of four de-oiled cake was made in one combination. All the seeds used in the single combination were used for this amendment.

4. Charcoal of Prosopis juliflora of big pieces was also applied as such in one of the pits in the first row.

5. Charcoal granules (small pieces size ranging from 0.5 cm to one cm) collected after sieving the charcoal powder was also applied in one of the pits in the first row.

6. Dry charcoal powder was applied in two pits of the first row

7. Charcoal saturated with water kept for 15 days before application into the pit

8. De-oiled seed cakes of neem, silk cotton, Clophyllum and Pongamia were mixed altogether with charcoal powder in the ratio of 1:1:1:1.

9. Jatropha de-oiled seed cake was mixed with 1:2 ratios with charcoal powder and saturated with water. This saturation process was periodically carried out at regular interval of 3 to 4 days for first month and later once in a week in the next month and kept in a closed condition for facilitating to undergo fermentation.

10. Charcoal powder from agriculture wastes such as dried banana leaves, seeni avarai, outer shells of Jatropha pods, dust and cones of minor millet, dried palm fruit shells, dried sugarcane straw and sugarcane waste (after extracting the juice) were subjected to make char using a tar drum by pyrolysis method (details given in the section preparation of charcoal powder of methodology).

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The pits were dug for 2 x 2 x 1.5 (breadth x width x depth) feet dimension. After digging the pits, top soil was filled in for the half of the deep, and then manure as described in the previous section was filled in for 2 to 3 inch of the pit. Again top soil was filled for two inches above the manure and manure treated with terra preta soil.

Following Table shows common and botanical names of the vegetables experimented and non-edible tree-borne seeds, etc.

S. No. Popular name Botanical Name

Trial vegetable plants 1. Lady’s finger Hibiscus (Abelmoschus) esculenta 2. Tomato Lycopersicon esculentum 3. Brinjal Solanum melongena Biomass amendments

1. Silk cotton Bombax ceiba

2. Neem Azadirachta indica

3. Jatropha Jatropha curcas

4. Indian beech (Pongamia) Pongamia pinnata 5. Ballnut (Pinnai) Calophyllum inophyllum Charcoal powder Seemai karuvel, Prosopis Prosopis juliflora Agriculture waste

Dried banana leaves, seeni avarai, outer shells of Jatropha pods, dust and cones of minor millet, dried palm fruit shells, dried sugarcane straw and sugarcane waste

Seed sowing and Plantation Seeds of Bhindi (Lady’s finger), Tomato and Brinjal were sown in the pits. Four seeds of each species were sown in each pit on 6.12.2008, in the middle of northeast monsoon. During the subsequent rainy days, seeds of tomato and brinjal were washed off from the pit area. The seeds of Bhindi germinated and survived. Later, tomato and brinjal seedlings were borrowed from the neighbouring vegetable farmer who is residing at Puliankulam 2 km north of the Biodiesel unit. The seedlings were transplanted on 23.12.2008 in the same pits used for sowing the seeds initially. After transplantation, each pit contained 12 plants altogether (4 each of vegetable species). Watering, weeding out and gap filling Watering was done at frequent and appropriate interval manually using hose pipe connected with borewell tank. Growth of the plants was also observed closely, but no records on height and other parameters like leaf count were maintained. Gap filling was carried out during the early stages of mortality of seedlings in the pits.

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Yield and harvesting Total yield of three different vegetables planted in the first and second rows with various soil amendments is depicted in the Table 3 & 4. Ripe vegetables were harvested at periodic intervals. In Lady’s finger plants, first harvest was done on 27.01.2008 whereas in Tomato and brinjal first harvest was done on 04.03.2009. Total number of harvests was carried out for all the three vegetable are given in the following Table. The results of pits of rows 1 and 2 were taken into consideration for the discussion. The results of pits of row 3 were all of controls. These results were more or less similar to the results of the pits selected for control application in the rows one and two.

No. Vegetable Name Total no. of harvest

Start End

1. Lady’s Finger 20 27.01.2009 21.04.2009 2. Tomato 13 04.03.2009 21.04.2009 3. Brinjal 13 04.03.2009 21.04.2009

Results and discussion Row One: While the yields of Lady’s finger and Tomato were significantly (quantitatively but not statistically) higher for certain soil amendments like the saturated charcoal powder with de-oiled seek cake of Jatropha, the yield of Brinjal was observed at low level. Different soil amendments prepared for the present trials were not uniform both sample size and replicates of amendments. However, among the three vegetables Tomato showed higher yields than Lady’s finger and Brinjal. The following are the minimum and maximum values observed among the yield of three vegetables. No. Vegetable species Mini

(gms) Description Maxi

(gms) Description

1. Lady’s finger 10 De-oiled seed cakes of neem and silk cotton

1731* De-oiled seed cake of Jatropha + Charcoal powder saturated water

2. Tomato 0 In 5 soil amendments# 2871* De-oiled seed cake of Jatropha + Charcoal powder saturated water

3. Brinjal 0 In 5 soil amendments 1147 De-oiled seed cake of Jatropha * - Average total of three replicates

# - Data and amendments given in Table 4.

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The total yield for Lady’s finger was achieved in 20 times of harvest period from 27.01.2009 to 21.04.2009 (about 3 months) but the total yield for tomato and brinjal2 was completed in less than two months (04.03.2009 to 21.04.2009). The maximum yield i.e. peak of the harvest (about 4.70 kg) for tomato and (1.44 kg) was observed towards end of the harvest with gradual decrease in yield. Lady’s finger showed maximum yield in the second harvest from then onwards yield was gradually decreasing towards the end. Among the non-charcoal soil amendments the mixture of de-oiled seed cakes of Jatropha and neem yielded maximum harvest of 1.32 kg and 2.5 kg for lady’s finger and tomato respectively. De-oiled seed cake of Jatropha amendment itself yielded maximum quantity of brinjal about 1.15 kg. The average yield of controls of Lady’s finger, Tomato and Brinjal recorded were 338, 100 and 55 gms respectively (Table 4 and Figures).

Table: 4. Total yield and average total yield of vegetables for single, and replicate trials with and without soil amendments

S. No. Amendments of Biomass & Charcoal mixture

Ladies Finger (in grams)

Tomato (in grams)

Brinjal (in grams)

1. Silk cotton 131 625 336

2. Neem 706 1564 0

3. Jatropha 930 1258 1147

4. Indian beech (Pongamia) 1248 0 0

5. Jatropha + Neem 1325 2535 158

6. Pongamia + Jatropha 1032 15 81

7. Pongamia + Neem 337 25 0

8. Silk cotton + Jatropha 441 0 0

9. Neem + Silk cotton 10 478 14

10. Silk cotton + Pongamia 62 0 414

11. Silk cotton + Calophyllum 817 462 994

12. Calophyllum + Jatropha 837 1221 306

13. Calophyllum + Neem 739 0 544

14. S. Cotn. + Neem + Jatr. + Pong. 381 643 651

15. Charcoal without grinding 249 844 0

16. Charcoal granules 428 100 160

17. Dry Charcoal powder (2) 169 1466 98

2 It was studied that the life span for brinjal was nine months; the yield of brinjal would continue after a short break with shedding leaves; after 60th day of transplantation, brinjal will start yielding; after having completed the first harvest, there will be again two yields for 6 months, in between, three times leaves will be shed at regular intervals. In the present experiment, harvest was stopped due to lack of man power and financial support.

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18. Charcoal saturated with water 127 686 30

19. Neem + Charcoal powder 804 351 282

20. Silk cotton + Charcoal 389 0 40

21. Calophyllum + Charcoal 349 901 139

22. Pongamia + Charcoal 735 382 713

23. S.Cotn+Neem+Jatr.+Pong + Char 646 163 1069

24. Jatropha + Char. Powder (Saturated with water) (3) 1732 2871 133

25. Control (3) 338 100 55

Row Two:

In the case of yield of vegetables in the second row with different soil amendments the range between minimum and maximum values recorded were narrower than the results exhibited by first row. The average total values recorded for different soil amendment replicates are depicted in the following Table 5 and Figure 5.

The minimum and maximum values recorded for Lady’s finger were 26 gm in the pit applied with charcoal powder made from agriculture waste and 280 gm in neem pit. In the case of tomato yield, the range varied between 124 g and 671 in the pit silk cotton and charcoal powder of agriculture waste. The yield of Brinjal was 20gm as minimum in the Saturated Charcoal powder of Prosopis juliflora and 700 gm as maximum in mixed amendments of Silk cotton, Pongamia, Jatropha and Neem. The average total values for controls were of 129 gm, 166 gm and 215 gm for Lady’s finger, Tomato and Brinjal respectively.

Table showing the average total values of vegetables harvested in the second row.

No. Treatment Description Lady’s Finger ( in grams)

Tomato ( in grams)

Brinjal ( in grams)

1. Saturated Charcoal powder of Prosopis juliflora (4)

39.3 378.5 20.00

2. Charcoal powder of Agri waste (2) 26.0 671.0 45.5 3. Charcoal Powder (P. j) (16) 43.0 530.0 50.6 4. Silk cotton (1) 68 124 82 5. Pongamia (1) 226 327 178 6. Jatropha (1) 252 586 227 7. Neem (1) 280 254 456 8. S + P + J + N (1) 215 628 700 9. Control (3) 129 166 215

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As was expected many of the soil amendments with charcoal powder yielded more vegetables when compared with controls. Particularly, de-oiled seed cake of Jatropha and charcoal powder saturated with water and kept fermentation and saturated again with water at regular intervals. This could be attributed to the large surface area available for the storage of nutrients and increased water retention capacity of the soil amendment prepared with charcoal powder. Folke Gunther (2007) explained that when the inner area of the charcoal is full of nutrients and soil micro-organisms, it will work as a sponge for nutrients, readily available to interact with the plant roots, keeping the nutrients away from leakage. Therefore, the inner surface of the charcoal should be saturated with nutrients before or during its addition to the soil. He further added that this could be done by mixing the charcoal, manure, urine or nitrogen fixed by Leguminous plants before or during the addition to the soil (Incidentally, without referring to any manual or published research articles, we attempted the process of saturating the charcoal with de-oiled seed cake of Jatropha using water as medium which exhibited better result than any other soil amendments). In contrast, mixture of de-oiled cake with charcoal powder without undergoing for any saturation processes yielded moderate output. But certain amendments like de-oiled seed cake with charcoal showed poor yield or no yield particularly for tomato and brinjal. This could be due to their accumulation of toxic characters or availability of such de-oiled seed cakes in overdoses. This needs further investigation on certain species.

Future investigations

Repetition of the reporting trials with more scientific inputs

o Analysing soil samples before and after the trials – NPK and SOM

o Length / weight relationship of plants under different soil

amendments

o Comparison of biomass of both treated and control – on wet weight

and dry weight basis

o Trials will be conducted as per the guidelines provided by

International Biochar Initiative

o Separate trial plots with equal number of soil amendment

19

o Adaptive mechanisms will be tested for certain vegetables during

non-seasons (continuous plantation throughout the year) or during

different seasons of plantations

Soil amendments to be finalised after interacting with local progressive

farmers

o Saturating charcoal powder with Farm Yard Manure (FYM) at

different levels and ratios for standardising maximum yield

o Locally available resources or local people’s choice will be given

preference to select the biomass manure to be mixed and saturated

with charcoal powder.

Blending with organic farming techniques and inputs will be incorporated

Saturating charcoal with fresh manures like green leaves or compost green

manure

Saturating charcoal amendments for wetland crops like rice, banana,

cardamom etc.

Existing trees planted can be checked (like coconut, mango, teak etc)

Coastal, Terikadu (Red Soil region in some pockets of southern districts like Tirunelveli,

Thoothukudi)

20

Ladies Finger

0 500 1000 1500 2000

Silk cotton 1.

Neem 2.

Jatropha 3.

Pongamia 4.

Jatropha + Neem 5.

Pongamia + Jatropha 6.

Pongamia + Neem 7.

Silk cotton + Jatropha 8.

Neem + Silk cotton 9.

Silk cotton + Pongamia 10.

Slk cotn + Calophyllum 11.

Calophyllum + Jatropha 12.

Calophyllum + Neem 13.

S. Ctn. + Nm + Jtr. + Png. 14.

Charcoal without grnd 15.

Charcoal granules 16.

Dry Charcoal powder 17.

Charcoal S. with water 18.

Neem + Charcoal powder 19.

Silk cotton + Charcoal 20.

Calophyllum + Charcoal 21.

Pongamia + Charcoal 22.

S.Ctn+Nm+Jtr.+Png + Char 23.

Jatropha + Char. Pow. (SW) 24.

Control 25.

Bio

mas

s C

ombi

natio

ns

Weigt in grams

Figure 2 Showing variations in harvested quantities of Lady’s finger in the pits row one

21

Tomato

0 500 1000 1500 2000 2500 3000 3500

Silk cotton 1.

Neem 2.

Jatropha 3.

Pongamia 4.

Jatropha + Neem 5.

Pongamia + Jatropha 6.

Pongamia + Neem 7.

Silk cotton + Jatropha 8.

Neem + Silk cotton 9.

Silk cotton + Pongamia 10.

Slk cotn + Calophyllum 11.

Calophyllum + Jatropha 12.

Calophyllum + Neem 13.

S. Ctn. + Nm + Jtr. + Png. 14.

Charcoal without grnd 15.

Charcoal granules 16.

Dry Charcoal powder 17.

Charcoal S. with water 18.

Neem + Charcoal powder 19.

Silk cotton + Charcoal 20.

Calophyllum + Charcoal 21.

Pongamia + Charcoal 22.

S.Ctn+Nm+Jtr.+Png + Char 23.

Jatropha + Char. Pow. (SW) 24.

Control 25.

Bio

mas

s co

mbi

natio

n

Weight in grams

Figure 3 Showing variations in harvested quantities of Tomato in the pits row one

22

Brinjal

0 200 400 600 800 1000 1200 1400

Silk cotton 1.

Neem 2.

Jatropha 3.

Pongamia 4.

Jatropha + Neem 5.

Pongamia + Jatropha 6.

Pongamia + Neem 7.

Silk cotton + Jatropha 8.

Neem + Silk cotton 9.

Silk cotton + Pongamia 10.

Slk cotn + Calophyllum 11.

Calophyllum + Jatropha 12.

Calophyllum + Neem 13.

S. Ctn. + Nm + Jtr. + Png. 14.

Charcoal without grnd 15.

Charcoal granules 16.

Dry Charcoal powder 17.

Charcoal S. with water 18.

Neem + Charcoal powder 19.

Silk cotton + Charcoal 20.

Calophyllum + Charcoal 21.

Pongamia + Charcoal 22.

S.Ctn+Nm+Jtr.+Png + Char 23.

Jatropha + Char. Pow. (SW) 24.

Control 25.

Bio

mas

s co

mbi

natio

ns

Weight in grams

Figure 4 Showing variations in harvested quantities of Brinjal in the pits row one

23

Yield of vegetables in Row Two

0

200

400

600

800

Sam

ple

(4)

Cha

r of A

gri w

aste

(2)

Cha

rcoa

l Pow

der (

P. j

) (16

)

Silk

cot

ton

(1)

Pon

gam

ia (1

)

Jatro

pha

(1)

Nee

m (1

)

S +

P +

J +

N (1

)

Con

trol (

3)

Treatment

Wei

ght i

n gr

ams

Lady’s FingerTomatoBrinjal

Figure 5 showing yield of Lady’s finger, tomato and brinjal in the pits of row two

24

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Organic Matter in Archaeological Soils (Terra Preta) of the Brazilian Amazon Region, in Rees, R. M., Ball, B. C., Campbell, C. D., Watson, C. A.: Sustainable management of soil organic matter. CABI Publishing, Wallingford, pp. 190–194.

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Nehls, T., Steiner, C., Glaser, B. (2002): Slash and char – a feasible alternative for soil fertility management in the central Amazon? 17th World Congress of Soil Science, Bangkok, Thailand, The International Union of Soil Sciences, pp. 1–12

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