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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Conservation strategy for Hopea parviflora Bedd. species through storage of seeds usinhg cryopreservation techniques(Department of Silviculture and Agroforestry, College of Forestry,Vellanikkara, 2001) Ani, J R; KAU; Sudhakara, KA detailed study was conducted at College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur, Kerala during 1998-2000 to standardize the conservation strategy for Hopea parviflora Bedd. species through storage of seeds using cryopreservation. Diameter of seeds collected at seven weeks after anthesis was found to be higher than that at sixth week. Physiological maturity of the propagules is attained between five and six weeks after anthesis. The propagules were subjected to different relative humidities, vacuum and dry air for different durations as a pretreatment for cryopreservation studies. In 100 to 46.6 per cent relative humidities, the moisture content and the leachate conductivity of the propagules were found to increase with duration compared to the initial value. Equilibrium moisture content of Hopea parviflora propagules was found to lie between 75.6 to 30 per cent relative humidities. Germination parameters of seed and seed without seed coat were not decreased significantly due to desiccation by relative humidities, vacuum or dry air, but that of embryonic axes was considerably reduced as rapid drying might have been effected due to 30 and 20 per cent relative humidities and also due to vacuum and dry air with duration. High culture contamination was observed in vacuum and dry air treatments. After cryopreservation techniques, the propagules invariably failed to regenerate but could retain green colour for two to three days.ThesisItem Open Access Comparative performance of mulberry (Morus indica L.) and subabul (Leucaena leucocephala Lam.) under diverse management regimes in a coconut based fodder production system(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2016) Reshma, M Raj; KAU; Asha, K RajThe research project entitled “Comparative performance of mulberry (Morus indica L.) and subabul (Leucaena leucocephala Lam.) under diverse management regimes in a coconut based fodder production system” was carried out at Instructional Farm, College of Horticulture, Vellanikkara during 2015-2016. The main objective of the study was to assess the influence of plant density and pruning frequency on forage yield and nutritional qualities of mulberry and subabul intercropped in coconut gardens; and to explore the soil fertility changes associated with these intercropping systems. The treatments consisted of two fodder tree species; mulberry and subabul, under three levels of plant density (49,382 plants ha-1, 37,037 plants ha-1 and 27,777 plants ha-1) and three levels of pruning frequency (8, 12 and 16 weeks interval) in all possible combinations with split plot design replicated thrice. The results revealed that both subabul and mulberry produced comparable dry fodder yields under coconut plantation. However, significant variation was noted with regard to proximate composition. The CP content in fodder biomass was significantly higher and CF % lower in subabul than mulberry. However, mulberry had higher ash (6.70 %) and P content (0.58 %) than subabul. Leaf- stem ratio was found to be comparable in both the tree species. Comparing plant densities, highest density yielded more dry matter (12.48 Mg ha-1yr-1) than the lowest one (7.32 Mg ha-1yr-1), with higher leaf-stem ratio (1.34). Total N, CP and P content increased and CF % decreased at higher densities indicating closer spacing for production of tender nutritive fodder. Pruning interval had no significant influence on fresh fodder yield, whereas dry yield was higher for 12 and 16 week intervals. However, leaf -stem ratio was higher at 8 week interval, indicating more foliage production than stem fraction when harvested at shorter intervals. Pruning frequencies had profound influence on nutritive value of the forage. Harvesting at shortest interval of 8 weeks yielded fodder with maximum CP (18.51 %), and phosphorus content (1.1 %), and least CF content (41.91 %) compared to 12 and 16 weeks. Ash content (8.70 %) in fodder was significantly higher at the longest interval of 16 weeks. Comparing interaction effects, for both mulberry and subabul, planting at the highest density (49,382 plants ha-1) and pruning at shortest interval (8 weeks) yielded the maximum fodder (11.05 & 12.17 Mg ha-1yr-1 dry yields for mulberry and subabul respectively) with superior quality (T1 & T10). B:C ratio was also found to be higher in the above systems.Intercropping subabul and mulberry in coconut garden under different management practices produced significant changes in some soil parameters after the initial year of establishment. In comparison to the sole coconut plot, soil properties like OC, pH, EC, WHC and available N, P, K content significantly improved in the high yielding treatment combinations of T1 and T10. Comparing T1 and T10, all soil parameters excelled in T1 except available N content, which was higher in T10.Hence, in conclusion, forage yield and nutritive value of mulberry and subabul underneath coconut garden could be optimized at the cheapest levels by adopting a tree density of 49,382 plants ha-1 and pruning interval of 8 weeks. In comparison, subabul yielded more dry matter and CP, whereas mulberry was superior in ash and mineral content. Establishment and proper management of these tree fodders in coconut garden and feeding mixed fodders thus offers a cheap source of quality forage to Kerala farmers against the highly expensive concentrate feeds.ThesisItem Open Access Performance of calliandra (Calliandra calothyrsus meissn.) under diverse mangement regimes in a coconut based hedge row fodder production system(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Anu Sagaran, K; KAU; Asha, K RajA study entitled “Performance of calliandra (Calliandra calothyrsus Meissn.) under diverse management regimes in a coconut based hedge row fodder production system” was carried out at Instructional Farm, College of Horticulture, Vellanikkara during 2014-2015. The main objective of the study was to assess the influence of management practices like tree density, pruning height and pruning frequency on initial growth, forage yield and nutritional qualities of calliandra intercropped in coconut gardens under humid tropical conditions of Kerala. The treatments consisted of three levels of plant density (27,777; 22,222 and 17,777 plants ha-1), three levels of pruning frequency (8, 12 and 16 weeks interval) and two levels of pruning height (0.5m and 1m) in all possible combinations laid out under factorial randomized block design with three replications. The results revealed that various management practices had a profound influence on the forage yield and quality aspects of calliandra when grown as an intercrop in coconut garden. Comparing plant densities, highest density stand (27,777 plants ha-1) yielded 55 percent more forage (11.73Mg ha-1yr-1, dry basis) than the lowest density (17,777 plants ha-1), with higher foliage fraction. Quality parameters of forage like crude protein, ash, dry matter, phosphorus and potassium content increased and crude fibre content decreased at higher densities indicating closer spacing for production of tender nutritive fodder. Pruning at the prolonged interval of 16 weeks yielded more total forage, but the majority of the fodder comprised of stem fraction as indicated by the poor leaf-stem ratio. Leaf –stem ratio of fodder harvested at 8 and 12 weeks showed an increment of 125 percent over that of the 16 weeks interval, indicating more foliage production than stem fractions when harvested at shorter intervals. Pruning frequencies also had profound influence on nutritive value of the forage. Harvesting at shortest interval of 8 weeks and 12 weeks yielded fodder with maximum crude protein, phosphorus and potassium content when compared to 16 weeks. Ash and dry matter content in 99 fodder was significantly higher at the longest interval of 16 weeks. Crude fibre content of forage increased sharply from 28.33 to 49.98 percent by prolonging the harvest interval from 8 to 16 weeks thereby adversely affecting the palatability of the forage. Pruning height showed more prominent influence on forage yield of calliandra than the nutritive parameters. Dry fodder yield increased from 8.11 to 10.81 Mg ha-1yr-1 with increasing pruning height from 0.5 to 1m, with a higher leaf-stem ratio for taller stocks. Similarly there was a significant improvement in CP yield from taller stocks (1.67 Mgha-1 )when compared to shorter ones (1.23 Mgha-1) The interaction effects of plant density, pruning height and pruning frequency had no significant effect on yield and quality parameters of callianrda. The highest yielding combination (13.39 Mg ha-1dry basis) was found to be D1H2F2 (27,777 plants ha-1 + pruning height 1 m + pruning interval 12 weeks ) with higher foliage fraction and better nutritive parameters, compared to all other management levels, which were inferior either in forage yield or nutritive value or palatability of forage. On the whole, the study revealed that forage yield and quality of young stands of calliandra underneath coconut garden could be optimized at the cheapest level by adopting a tree density of 27,777plants ha-1, pruning height of 1m and pruning interval of 12 weeks. Moreover, based on the growth and yield performance and quality aspects, it is found that calliandra is a promising fodder tree, which can be successfully integrated with the existing coconut gardens of Kerala. Establishment and proper management of calliandra in coconut garden at appropriate management levels thus offers a cheap source of quality forage to Kerala farmers against the highly expensive concentrate feeds.ThesisItem Open Access Forage yield, soil fertility and carbon dynamics of calliandra (Calliandra calothyrsus meissn,) in coconut plantation(Departament of Silviculture and Agroforestry , College of Forestry, Vellanikkara, 2017) Jilna Joy; KAU; Asha, K RajA study entitled “Performance of calliandra (Calliandra calothyrsus Meissn.) under diverse management regimes in a coconut based hedge row fodder production system” was carried out at Instructional Farm, College of Horticulture, Vellanikkara during 2014-2015. The main objective of the study was to assess the influence of management practices like tree density, pruning height and pruning frequency on initial growth, forage yield and nutritional qualities of calliandra intercropped in coconut gardens under humid tropical conditions of Kerala. The treatments consisted of three levels of plant density (27,777; 22,222 and 17,777 plants ha-1), three levels of pruning frequency (8, 12 and 16 weeks interval) and two levels of pruning height (0.5m and 1m) in all possible combinations laid out under factorial randomized block design with three replications. The results revealed that various management practices had a profound influence on the forage yield and quality aspects of calliandra when grown as an intercrop in coconut garden. Comparing plant densities, highest density stand (27,777 plants ha-1) yielded 55 percent more forage (11.73Mg ha-1yr-1, dry basis) than the lowest density (17,777 plants ha-1), with higher foliage fraction. Quality parameters of forage like crude protein, ash, dry matter, phosphorus and potassium content increased and crude fibre content decreased at higher densities indicating closer spacing for production of tender nutritive fodder. Pruning at the prolonged interval of 16 weeks yielded more total forage, but the majority of the fodder comprised of stem fraction as indicated by the poor leaf-stem ratio. Leaf –stem ratio of fodder harvested at 8 and 12 weeks showed an increment of 125 percent over that of the 16 weeks interval, indicating more foliage production than stem fractions when harvested at shorter intervals. Pruning frequencies also had profound influence on nutritive value of the forage. Harvesting at shortest interval of 8 weeks and 12 weeks yielded fodder with maximum crude protein, phosphorus and potassium content when compared to 16 weeks. Ash and dry matter content in 99 fodder was significantly higher at the longest interval of 16 weeks. Crude fibre content of forage increased sharply from 28.33 to 49.98 percent by prolonging the harvest interval from 8 to 16 weeks thereby adversely affecting the palatability of the forage. Pruning height showed more prominent influence on forage yield of calliandra than the nutritive parameters. Dry fodder yield increased from 8.11 to 10.81 Mg ha-1yr-1 with increasing pruning height from 0.5 to 1m, with a higher leaf-stem ratio for taller stocks. Similarly there was a significant improvement in CP yield from taller stocks (1.67 Mgha-1 )when compared to shorter ones (1.23 Mgha-1) The interaction effects of plant density, pruning height and pruning frequency had no significant effect on yield and quality parameters of callianrda. The highest yielding combination (13.39 Mg ha-1dry basis) was found to be D1H2F2 (27,777 plants ha-1 + pruning height 1 m + pruning interval 12 weeks ) with higher foliage fraction and better nutritive parameters, compared to all other management levels, which were inferior either in forage yield or nutritive value or palatability of forage. On the whole, the study revealed that forage yield and quality of young stands of calliandra underneath coconut garden could be optimized at the cheapest level by adopting a tree density of 27,777plants ha-1, pruning height of 1m and pruning interval of 12 weeks. Moreover, based on the growth and yield performance and quality aspects, it is found that calliandra is a promising fodder tree, which can be successfully integrated with the existing coconut gardens of Kerala. Establishment and proper management of calliandra in coconut garden at appropriate management levels thus offers a cheap source of quality forage to Kerala farmers against the highly expensive concentrate feeds.ThesisItem Open Access Autoallelopathy of selected multipurpose tree species and the effect of their leachates on Agricultural test crop(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Neenu, P; KAU; Jamaludheen, VA study carried out in the tree nursery of College of Forestry, Vellanikkara, Thrissur to assess the autoallelopathic effect of selected multipurpose trees and the effect of their leachate on agricultural test crop. The study on allelopathy is very essential in agroforestry as it effect the yield and performance of the trees and crops grown together and is essential to make judgment on the compatibility of trees and crops. The allelopathic effect of different tree part leachates such as leaf leachate, bark leachate and root leachate of selected trees viz., Acacia auriculiformis, Acacia mangium, Ailanthus. triphysa, Grevillea robusta and Swietenia macrophylla on the germination and growth of their own seedling and an agricultural test crop cowpea (Var. Anaswara) were studied. The soil for the pot culture experiment was collected from well established plantations of the MPTs and is used as potting mixture with sand in equal proportion. The pots were irrigated with leachates of different tree parts of these trees by soaking the tree part in water for 24 hours in 1:10 w/v concentration. The monthly variation in nutrient status of the soil used for pot culture experiment and the variation in the physicochemical properties of leachates at six intervals is also estimated. The effect of tree part leachates considerably varied among the germination and biomass production in both allelopathic and autoallelopathic studies. The observations on the germination per cent in allelopathic and autoallelopathic study revealed greater inhibition in the pots treated with leaf leachate in all tree species, except for S. macrophylla. With regard to biometric observations and biomass production also, S. macrophylla performed as the best compared to other selected species investigated for autoallelopathy. In case of the test crop also, it showed a better growth in pots treated with the leachates from S. macrophylla. The physicochemical analysis of the leachate of tree parts used to irrigate the pots showed increasing trend in total solid, electrical conductivity, total phenol, total carbohydrate and a decreasing trend in pH upto 36 hours. The physicochemical analysis of leachates for total phenol showed a greater concentration in the leaves than the bark and root. Results converge to the generalisation that among the five selected tree species the effect of auto allelopathy is negligible in case of S. macrophylla. The better growth performance of the test crop in S. macrophylla tree part leachates shows the compatibility of the test crop with the tree than the other selected tree species.ThesisItem Open Access Standardisation of propagation through branch cuttings in selected bamboo species of Kerala(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Sreejith, M M; KAU; Jijeesh, C MThe present study attempted root induction in the branch cuttings of three commercially important bamboo species namely; Bambusa balcooa, Dendrocalamus giganteus and Thyrsostachys oliveri. The primary branches of each species were collected during three seasons viz. October to January (Season I), February to May (Season II) and June to September (Season III). Two noded branch cuttings were prepared out of the primary branches and subjected to soaking in growth regulator solutions of IBA and NAA at different concentrations of 0 (control), 100, 250, 500 and 1000 mg l-1 for 24 hours and planted horizontally in two media viz. sand alone and mixture of sand, soil and cow dung (1:1:1) filled in plastic trays. Results indicated that sprouting attributes of bamboo species varied among different treatments. In B. balcooa, sprouting percentage varied from 1.67 (branch cuttings of season I treated with IBA 250 mg l-1 kept in second medium) to 48.33% (branch cuttings of season II treated with NAA 250 mg l-1 kept in the sand). In D. giganteus, sprouting in the branch cuttings ranged from 5.00 to 43.3%. The highest sprouting was observed during season II in cuttings treated with NAA 500 mg l-1 kept in the second media and the least was in control of NAA kept in sand in the same season. Meanwhile, in T. oliveri, maximum sprouting was observed in cuttings treated with IBA 100 mg l-1 (41.67%) in third season kept in sand, while sprouting was absent in some treatment combinations along with the control. However, sprouted cuttings failed to initiate rooting in any of treatment combinations in three bamboo species. Further trials were conducted with higher concentrations (0, 1000, 2000 and 3000 mg l- 1 ) of growth regulators in sand medium. Maximum sprouting in B. balcooa, was observed in cuttings treated with IBA 1000 mg l-1 (36.66%) while, the least was in those treated with NAA 1000 mg l-1 (10.00%). Branch cuttings treated with IBA 1000 mg l-1 recorded the highest sprouting (26.66%) and those treated with IBA 3000 mg l-1 recorded the lowest value (10.00%) in T. oliveri. Here also, the expected rooting of cuttings was not observed. Hence, another trial with the application of NAA and IBA by quick dip method at concentrations 0(control), 1000, 1500 and 2500 mg l-1 was carried out. In B. balcooa, the highest sprouting was in the cuttings treated with NAA 1000 mg l-1 (30%) and the lowest was in those treated with IBA 2500 mg l- (6.00%). Whereas, in T. oliveri highest sprouting was observed in cuttings treated with IBA 1000 mg l-1 (33.33%) followed by IBA 1500 mg l-1 (23.33%). The least sprouting was observed in cuttings treated with NAA 2500 mg l-1 (13.33 %) followed by control (15%). Here also, the rooting was absent in different treatments. In the last experiment, B. balcooa branch cutting were treated with IBA and NAA solutions 0, 500, 1000, 1500 and 2000 mg l-1 concentration and planted in standard nursery beds. The lowest sprouting percentage was observed in cuttings treated with NAA 2000 mg l-1 (20.00 %) and the highest sprouting was in cuttings treated with IBA 500 and 1000 mg l-1 (40 %) but the sprouted cuttings did not produce any root. As the present study did not give the expected results, further trials are needed for the standardization of propagation through branch cuttings in the selected bamboo species.ThesisItem Open Access Biomass production and root distribution pattern of selected acacias(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2014) Mereena, M J; KAU; JamaludheenA field study was conducted with acacia species on an 18-year-old stand with 3m×3m spacing at the arboretum of College of Forestry, Thrissur, Kerala to evaluate the growth, biomass production, carbon sequestration and nutrient accumulation in four acacia species viz. Acacia auriculiformis, Acacia mangium, Acacia crassicarpa and Acacia aulacocarpa. The objective of the study included quantifying the biomass production potential, harvest related nutrient export from the site, characterising the root distribution pattern of these trees and to develop allometric equations for aboveground biomass, aboveground C sequestration, volume and bole volume. The above ground biomass was estimated from 20 destructively sampled trees from each species and the belowground biomass was estimated following root excavation of average sized trees of each species. Significant differences were observed for the tree growth parameters except DBH. Acacia aulacocarpa recorded the highest growth rates in terms of height closely followed by Acacia auriculiformis. Among the species, Acacia auriculiformis recorded the highest stand total biomass (432.08 Mg ha-1) and the lowest by Acacia mangium (367.76 Mg ha-1). The most important component of total biomass undoubtedly, was the bole while foliage contributed least to biomass yield. Maximum aboveground and belowground biomass was recorded for Acacia auriculiformis (336.29 Mg ha-1and 95.79 Mg ha- 1respectively). Carbon sequestration potential was estimated for both aboveground and belowground biomass. Maximum mean tree C sequestration was recorded for Acacia auriculiformis (176.38 kg C tree-1) followed by Acacia aulacocarpa (165.54 kg C tree-1). The bole portion sequester major portion of C (63.61% to 71.28%) followed by root portion (19.1% to 23.78%). MAI in total stand C sequestration was maximum for Acacia auriculiformis (10.89 Mg C ha-1yr-1) closely followed by Acacia aulacocarpa (10.22 Mg C ha-1yr-1). Stand level biomass C sequestration in the leaf and twig portion varied significantly among the acacias. Soil C sequestration under each species was estimated upto one meter depth. Maximum soil organic carbon (SOC) was accumulated in the surface soil (0-20 cm) for all the species. Acacia auriculiformis (77.96 Mg C ha-1) recorded the highest total SOC followed by Acacia mangium (74.75 Mg C ha-1). The treeless plots consistently recorded the lowest value of SOC in all the depth zones. Nutrient concentrations (N, P and K) in the biomass components were recorded highest for the leaf portion and the highest stand nutrient accumulation was recorded for the bole portion. The order of nutrients in the plant were N> K> P. The nutrient accumulation in the stand level was also recorded highest for Acacia auriculiformis. The order of nutrient accumulation in the soil was N> P> K. No significant variation was observed in root distribution pattern of different acacia species. However, the maximum root spread was recorded for Acacia mangium (5.23 m) and root length for Acacia crassicarpa (1.49 mThesisItem Open Access Performance of selected medicinal herbs under rubber and cashew plantations(Department of silviculture and agroforestry, College of forestry, Vellanikkara, 2015) Mir, Faizan Anwar; KAU; Jamaludheen, VA field experiment was conducted at Vellanikkara, Thrissur, Kerala to assess the understorey productivity of three herbaceous medicinal crops viz. Zingiber officinale (ginger), Curcuma longa L. (turmeric) and Kaempferia galanga L. (Lesser galangal) under mature rubber (Hevea brasiliensis Muell. Arg,) and cashew (Anacardium occidentale L.) plantations. The biophysical attributes influencing the productivity of the land management systems and the biochemical changes in the products of understorey crops were studied. Additionally, soil carbon sequestration in both the given land use systems and the treeless open plot was estimated. Mean mid day (12–1p.m) understorey photosynthetic photon flux density (PPFD) levels were more in cashew (1275 μ moles m-2sec-1) than rubber (1072.5 moles μ m-2sec-1) with respective understorey PAR transmittance of 56.62percent and 44.1percent of full sunlight. The stand leaf area index (LAI) values in rubber and cashew were 1.98 and 1.43 respectively. Growth parameters of understorey crops varied noticeably among land use systems. Plant height and pseudostem length of ginger were greater in rubber and that of turmeric was in cashew. Leaf spread of galangal was higher in rubber. Root length of all crops was maximum in treeless open plot followed by cashew and rubber plantations. Ginger and turmeric exhibited highest tiller and leaf production in treeless open plot followed by cashew and rubber. However, higher tiller and leaf production in galangal were in rubber. Rhizome yield varied appreciably among the land use systems over the growth period. Rhizome yield at final harvest for ginger and galangal was maximum in treeless open (3.46 and 3.06 Mg ha-1 respectively) while that of turmeric was in the cashew plot (7.63 Mg ha-1) explicating the influence of PAR on understorey productivity. Regression equation relating PAR rhizome yields showed statistical reliability with high coefficient of determination (R2) values. Total chlorophyll content of understorey crops was highest in rubber followed by cashew and open. Oleoresin also showed such a trend with highest 148 percent of 10.68, 4.49 and 2.60 for turmeric, ginger and galangal respectively under rubber. However, nutrient accumulation in the above and below ground parts of all the crops was higher in cashew compared to rubber. With respect to carbon sequestration, soil organic carbon stocks in the upper most layer (0-20 cm) were higher in rubber (18.38 Mg ha-1) followed by cashew (18.28 Mg ha-1) and treeless open plot (15.07 Mg ha-1) validating the influence of trees in improving the soil through addition of organic matter. This zone being important from intercropping point of view, relevance of wooded land use systems for understorey productivity is emphasised. The total carbon stocks in 1m soil depth, were highest in cashew (68.70 Mg ha-1) followed by rubber (64.74 Mg ha-1) and open (52.04 Mg ha-1). It may be thus deduced from the present study that in terms of yield attributes, ginger, turmeric and galangal have better prospects in wooded land use system in general and the specific advantage of cashew over rubber was also obvious. This may be attributed to relatively better PAR transmission, higher nutrient accumulation and lesser root competition in cashew. Further, the better quality of rhizomes under comparably higher shade levels suggests their suitability in tree-based land use systemsThesisItem Open Access Biomass production, carbon sequestration and nutrient flux in Ailanthus triphysa (DENNST.) Alston(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2014) Sukanya, S; KAU; Kunhamu, T KA field study was carried out to evaluate the biomass production, carbon sequestration and nutrient dynamics in a 22-year-old Ailanthus triphysa stand managed at variable densities viz., 2360 trees ha-1, 1560 trees ha-1, 900 trees ha-1 and 560 trees ha-1. Total number of 80 trees (20 from each density regime) was destructively sampled for the biomass and carbon stock assessment. Also nutrient stocks (N, P and K) in various tissue types were assessed following standard procedures. The soil carbon and nutrient contents were assessed for one meter soil depth at regular depth intervals. The average stand height and bole height were 12.84 m and 8.19 m respectively which varied significantly with stand density with maximum value recorded for 1560 trees ha-1. The average dbh, mean tree volume and bole volume put in by the 22- yearold A. triphysa stand was 18.78 cm, 0.15 m3 and 0.16 m3 respectively which however could not yield a predictable trend with stand density. Despite this, the stand volume exhibited a proportional increase with stand density. The mean tree biomass production by the stand was 129.81 kg tree-1 that varied with stand density. Biomass production at stand level showed a consistent increase with increasing stand density with highest produced corresponding to 2360 trees ha-1 stand (384.67 Mg ha-1) and lowest for 560 trees ha-1 stand (93.86 Mg ha-1). Component wise biomass allocation was highest for stemwood (63 %) followed by roots (20 %) for all the density regimes while twig portion registered the least (0.97 %). The mean tree C stocks and corresponding MAI for A. triphysa at 22 years of stand age were 74.54 kg tree-1 and 3.38 kg tree-1 yr-1 respectively which was comparable with many fast growing MPT’s similar growth habit in humid tropics. Elemental carbon storage at stand level showed proportionate increase with density (177.00 Mg ha-1, 2360 tree ha-1; 140.47 Mg ha-1, 1560 tree ha-1; 49.06 Mg ha-1, 900 trees ha-1 and 43.33 Mg ha-1, 560 trees ha-1). Allometric models were developed for total aboveground biomass, bole biomass, aboveground carbon sequestration, total volume and bole volume using dbh and height as predictor variables. Among various models tried single variable (dbh) quadratic equations were best fitting with high R2 value. The nutrient concentration varied substantially among various biomass components with foliage registering highest N, P and K concentration (%). Tissue nutrient concentration followed the general order: leaves> twig> branch> root> stemwood. Biomass nutrient stocks at stand level varied considerably with stand density which was closely following biomass production trends. Nutrient storage followed the order N > P > K with highest stocks corresponding to stemwood followed by roots, branchwood, leaves and twigs. High nutrient accumulation in the stemwood suggests possible higher levels of nutrient export from the site through harvest. Transfer of nutrient rich leaf biomass into the soil at harvest would be a viable strategy in this context that replenish the nutrient loss through harvest. Carbon and nutrient contents in the soil were substantially higher in all sampled depths implying the dominant role of trees in improving the soil productivity in wooded systems. Study converges to the generalization that A. triphysa trees have a good potential for volume and biomass production under proper silvicultural management regimes.
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