Central Island Agriculture Research Institute
Important Announcements:

Natural Resource Management


  • Silpaulin and geo-membrane are found as suitable lining materials for effectively controlling the seepage losses from the farm pond. However, lining material should be covered with suitable material for protection from higher daily insolation in A&N islands located close to equator for increased life. A new technique for lining of the tank with plastic film and reinforced plaster (1:6) on sides and 15 cm thick soil layer at bottom for higher life period has been evolved.

  • Water balance analysis in terms of water resource potential, realizable potential water requirement and water resource development was estimated for Kaju Nallah watershed. Based on monthly well recuperation test, it is recommended that the recharge structure cum-well system should be developed in valley areas, where longitudinal slope of nallah is less, to get significantly enhanced and consistent well yield during the dry season.

  • On the basis of pH, EC, cation exchange capacity, exchangeable bases, soil acidity, base saturation percent, available nutrient contents and fertility constraints for crop production, fertility capability classification were made for rice growing areas of South Andaman. Poor drainage during monsoon and Aluminum toxicity are the major constrain for crop production. Soil fertility map for North, Middle and South Andaman Islands have been developed for further soil resource planning.

  • Assessment of tsunami affected soils and water in the post tsunami period (2005-2009) revealed that the temporal and spatial variability in soil pH, electrical conductivity and microbial loads are approaching towards normal pre tsunami condition due to the leaching of excess soluble salts by monsoon rainfall.

  • Application of different organic amendments increased the soil pH relative to control. The relative liming efficiency was highest for poultry manure and least for coconut husk used alone. The RLE was found to be highest between 120 to 150 days of application.

  • The net productivity and return analysis of application of different manures and fertilizer levels on Okra yield indicated that at moderate input supply inorganic + vermicompost @ 75 % recommended dose gave higher return. Similarly, under only organic input supply vermicompost + poultry manure @ 75% recommended dose was found to be best combination.

  • Integrated farming systems tested for different micro-farming situations revealed better socio-economic prospect in terms of high net returns and employment generation. In case of integration of fish-cum-poultry-cum-duckery in the farming system, pond water should not be used for house hold purposes as microbial load increases substantially during summer season. No mortality was observed when introduced gradually to saline water of different concentrations up to 15 ppt. On an average, net return of Rs 25600 can be obtained from fresh water based farming system in which animal and crop component contributed 92% and 6%, respectively under on-farm condition. Similarly, in brackish water based system, animal component contributed 97% towards the net returns.

  • Adoption of Broad Bed and Furrow (BBF) system provides opportunity for crop diversification in low lying paddy lands. Higher net return can be realized by growing radish-chillies on the beds and rice-ratoon (azolla + fish: singhi + magur)-groundnut in the furrows. Cropping intensity of rice areas can be increased from 100 % to 300-500 % on the beds and up to 300 % on the furrows through BBF system.

  • SRI method led to significantly higher yield (2613 kg ha-1) than conventional method (2400 kg ha-1) apart from saving of seed and planting time. SRI method of planting was found to be economical in terms of energy compared to line and mechanical transplanting as energy ratio was more (3.9).

  • Bold seeded groundnut varieties (SG 99, ICGS 76, TG 37A and GPBD 4) can be grown as profitable crop in rice fallow areas. Sowing of SG 99 or ICGS 76 of varieties of table purpose groundnut is recommended by manual line sowing during last week of December to first week of January. Net return of Rs. 56000/ha can be obtained in rice fallow lands having sandy or sandy loam soils. Further, two irrigations at life and pegging with paddy straw mulch on 45 DAS can be advocated for realizing higher pod yield, net returns, B:C ratio and water productivity. More than two irrigations leads to reduced pod yield.

  • Seed production of table purpose groundnut can be taken up profitably in coconut plantation during wet season. Application of 10 t ha-1 of FYM with ICGS76 or TG37A variety is found suitable for higher kernel seed yield. Around 62% higher kernel seed yield can be obtained in younger plantations than old plantations (>10 years).

  • Supplemental irrigation at knee high, tassel initiation and grain filling stages of maize, flowering, pod setting stages of green gram, 4-5 leaf stage, flowering, pod setting stages of sesamum, early vegetative, flowering, fruit formation stages of ladies finger and chilli were identified to achieve higher yield and profitability during post-monsoon season.

  • Kalmegh should be grown during summer season under irrigated condition with 45 x 30 cm spacing along with basal application of FYM @12.5 t ha-1 to achieve higher biomass yield and net returns under Island conditions.

  • A modified greenhouse was developed with 60% reduced cost towards two-exhaust fans, shading nets, cooling system and humidity control system that maintained inside temperature (1oC higher) and relative humidity (23% lower) than existing greenhouse resulting in saving of energy and water.

  • The capacity of CIARI pedal operated, KAU hand operated coconut dehuskers and local tool sabbal was 119, 68 and 170 nuts/hr, respectively. Even farm women found CIARI pedal operated dehusker comfortable and safe in operation.

  • Solar dryer made using local materials saved 33% time in comparison to open sun drying of coconut, black pepper, mushroom, green chillies, jack fruit pulp and fish.  It also improved the quality of dried products as there were no attack of maggot and insect pest.

  • Ventilation area of more than 12% of polyhouse area is to be kept for maintaining the temperature inside the poly house. Spacing of 60 X 60 cm can be recommended for capsicum under polyhouse conditions in bay islands to realize higher yield. High value crops such as cauliflower, capsicum and lettuce can be recommended for higher yield and returns from the investment made for polyhouse.

  • Water balance approach was used to design the optimal size of lined tank fed from impermeable rooftop or plastic mulched vegetable area. In case of 50 m2 rooftop area to harvest rainwater in lined tank, 361 cu m and 322 cu m capacity tank can provide supplemental irrigation at IW/CPE ratio 0.5 to 18 coconut plants or 160 arecanut plants in 1000 m2 in 8 out of 10 years during the dry period. In case of plastic mulched area of 1000 m2 to harvest rainwater, 290 cu m capacity tank can provide supplemental irrigation at IW/CPE ratio 0.5 in the same area with 2778 capsicum plants.

  • Out of 60 plant samples tested 23.0 % of the samples were detected with pesticide residues. Among the OC compounds, α endosulfan, β endosulfan and endosulfan sulphate were detected in 7 % of samples which were found in cabbage, bhendi and French bean samples. The residues of SP compounds such as α-cypermethrin and λ-cyhalothrin were detected in 12% of samples tested. The residues of OP compounds such as profenophos, chlorpyriphos, monocrotophos and triazophos were found in 12% samples which were found in brinjal, cauliflower, bhendi, green chilli and French bean samples. Off the positive samples detected 14 % of the samples were found to contain residues exceeding the prescribed MRL. The highest concentrations of pesticide residues were found in soils under vegetable cultivation (up to 54.190 µg kg-1 soil) followed by fallow lands which were earlier under rice or vegetable cultivation (up to 13.38 µg kg-1 soil).

  • Verification of forecasted and observed values of rainfall under Agromet weekly advisories for A&N Islands revealed that on an average forecasted and observed values of rainfall are matching to the tune of 53.7 % during post monsoon period while it is only 23.4 % for monsoon period.



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