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Open Access
On-farm evaluation of selected cereal fodders in prominent land use systems of Kerala
(2021) Shahina, N N; Asha K Raj
The field study entitled “On-farm evaluation of selected cereal fodders in prominent land use systems of Kerala” was carried out as two separate experiments in homegarden and coconut garden with livestock component in Madakkathara panchayath, Thrissur, Kerala during 2020-21. The study aimed to evaluate the forage yield and nutritive value of three cereal fodders viz., maize, sorghum, and bajra in major land use systems of Kerala viz., homegarden, coconut garden, and under open conditions with full sunlight. The study also assessed the relative performance of cereal fodders with hybrid napier, the popular fodder grass in Kerala. In each system, the treatments were laid out in Randomized Block Design replicated three times. The crops were cultivated during two different seasons viz., rabi and summer. In homegarden trial, all the crops established well in homegarden and contiguous open areas. In general, the growth parameters of crops were better in the open field. Among crops, maize showed better growth followed by hybrid napier, bajra, and sorghum. In open field, maize recorded significantly higher cumulative green fodder yield (93.27 Mg ha-1 in rabi and 93.32 Mg ha-1 in summer) followed by hybrid napier (70.42 Mg ha-1 in rabi and 79.20 Mg ha-1 in summer), while in homegarden, the yield of maize (57.16 Mg ha-1 and 73.50 Mg ha-1 ) and hybrid napier (60.42 Mg ha-1 in rabi and 73.51 Mg ha-1 in summer) was on par. The productivity of sorghum and bajra was poor in both land use systems. The shade tolerance of fodder grasses in homegarden is in the order; hybrid napier>maize >bajra >sorghum. Dry fodder yields also followed a similar trend. The fodder production was generally higher during the summer season than in rabi. The per day productivity was higher for bajra and maize in both land use systems. The PAR availability in homegarden as compared to open conditions during rabi and summer season was 31.72 and 49.18 percent respectively. Considering the quality aspects of fodder, the crude protein content was higher and crude fibre content was lower in homegarden than in open field, whereas xvii the dry matter and ash content showed the reverse trend. In homegarden and open field, maize had more crude protein content followed by hybrid napier, bajra, and sorghum during both seasons. The order of CF content in homegarden was in the order; maize maize > bajra > sorghum. The dry fodder yields also followed a similar trend. Per day productivity of fodder grasses was noticed more in open contiguous areas as compared to coconut garden. The maximum per day productivity was obtained by bajra and maize in both land management systems. The mean daily PAR transmittance in coconut garden during the rabi and summer season was 55.74 and 56.83 percent respectively. In the second experiment also, the crude protein content was higher and crude fibre content lower in coconut garden, whereas the dry matter and ash content observed more in open fields. In coconut garden, maize had more crude protein content followed by hybrid napier and the crude fibre content was minimum in maize. The ash content was also maximum in maize. The grasses in the coconut garden showed more N content and were recorded highest in maize. The P and K content recorded higher values in open conditions than in coconut garden. The P concentration was maximum in hybrid napier, while K content was highest in fodder bajra. In both systems, maize recorded the highest B: C ratio followed by hybrid napier. xviii Thus, the study indicates that cereal fodder, maize can be successfully and cost effectively cultivated in partially shaded tree-based systems like homegardens and coconut gardens with minimal yield loss. In comparison, yield reduction was higher under homegarden with low PAR transmission (41 percent) than that of coconut garden with higher light availability (56 percent). The study also indicated that maize outperformed hybrid napier both quantitatively and qualitatively under coconut garden with more availability of light, whereas it showed a comparable response in homegarden with intense shade indicating higher shade tolerance of hybrid napier. Bajra showed moderate performance under shady situations whereas sorghum yielded very poor results.
Open Access
Growth and productivity as function of site quality and age in teak plantations of Nilambur, Kerala
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2022) Sankar Thampuran, M V; KAU; Kunhamu, T K
Teak has been one among the principal timber species widely used across the world due to its matchless combination of qualities. Kerala has around 76,710 ha of pure teak and 14,440 ha of teak with softwood plantation making up 49.08 and 9.24 per cent respectively of the total plantation area in the state. Despite having the largest share of plantations under teak, the productivity of teak plantations of Kerala are under serious decline and has been a matter of concern in the scientific parlance. Evidences suggest that even in Nilambur, the celebrated land of teak, there has been large scale decline in productivity of teak plantations. However, quantitative aspects of the productivity of teak and the drivers of changes especially in the best teak growing region in Kerala such as Nilambur, is lacking. In this backdrop, a field study entitled “Growth and productivity as function of site quality and age in teak plantations of Nilambur, Kerala” was conducted in selected plantations from Nilambur North and Nilambur South Forest Divisions. The plantations were selected based on the information available from Kerala Forest Department on their age and site quality. Four site qualities (SQ I, SQ II, SQ III and SQ IV) and five age classes (10-20, 20-30, 30-40, 40-50 and 50+) were considered for the study forming a total of 20 plantations (4 site qualities x 5 age classes = 20 plantations). Five sample plots, each of size 24m x 24m were laid out randomly in each of the selected plantations and parameters like total tree height, bole height, diameter at breast height, diameter at crown point and crown width were measured in the field. Also, soil sampling was done in four plantations of different site qualities falling in the mature age class of 40-50. For this, 1 m deep soil pits were dug, one each inside the plantation and in the respective contiguous treeless open. Sampling was done in five depth intervals (0-20, 20-40, 40-60, 60- 80 and 80-100 cm). Thus, a total of 120 samples of soil were collected for analysis. The collected soil was analysed for physical properties like bulk density and particle size distribution/ texture and chemical properties like pH, total Nitrogen, organic Carbon content, available Phosphorus and exchangeable Potassium following standard procedures. 122 The results showed that among the plantations studied in Nilambur, the SQ I plantations showed dominance in all growth parameters of teak while a predictable pattern of change was lacking across the subsequent site qualities. There was large heterogeneity among the plantations in terms of management that had a confounding effect on the potential exploitation of the site resources for optimal growth of teak. Many of the plantations had high density of invaded miscellaneous trees which have increased the effective density and seriously affected the growth of teak. The density of miscellaneous trees varied from 0 to 694 trees per hectare among the studied plantations. The competition with miscellaneous species has created large scale variability within each stand in growth attributes. Normal distribution of diameter classes was observable in the plantations studied due to high effective density. Stand density being a critical factor that decide productivity and product quality in teak plantations, the observed variability in productivity could be attributed to poor adherence to proper density regulation. Also, the productivity of the plantations has been considerably influenced by poor adherence to timely plantation management practices. The Mean Annual Increment varied from 0.56 to 8.70 m3ha-1yr-1 among all the plantations studied. On comparing with the All-India yield table for teak, the plantations showed growth and productivity estimates that were quite different from their assigned site quality. In the age class 40-50, the SQ I plantation showed a height that was corresponding to SQ III according to the yield table, while the SQ IV plantation height corresponded to the SQ II. All the observed soil parameters with in the experimental plots were well within the range required for the optimal growth of teak. However, except for SQ1, we could not observe any predictable change in soil properties across the remaining site qualities. The Bulk density of soil increased with depth, both inside and outside the plantations. The rate of increase of bulk density was higher in the treeless open areas compared to the plantations. Th soil texture remained as sandy loam or loamy sand for all the analysed soil samples. The soil pH varied from 5.17 to 5.98 between the soil samples that were analysed. The organic Carbon content in various layers of plantation soil varied from 0.58 to 2.07 %. Total Nitrogen varied from 0.077 to 123 0.223 %. Available Phosphorus varied from 2.10 to 17.33 kgha-1. Exchangeable potassium varied from 51.82 to 488.30 kgha-1. Attempts to relate the soil properties with the site productivity could not derive meaningful correlations suggesting that the productivity decline might be an effect of poor management rather than depletion of nutrient status. The study suggests that there is an urgent need to revisit and reassess the site quality of the plantations in Nilambur and to give utmost concern for adhering to scientific stand management in timebound manner for deriving optimal productivity from teak plantations of Nilambur.
Open Access
Evaluation of biodegradable containers for seedling production in tree nurseries
(Department of Silviculture and Agroforestry ,College of Forestry, Vellanikkara, 2020) Subhasmita, Parida; KAU; Kunhamu, T K
A nursery trial titled ‘Evaluation of biodegradable containers for seedling production in tree nurseries’ was conducted to develop alternate eco-friendly plant container as substitute for conventional polythene bag based containers at College of Forestry, Kerala Agricultural University, Thrissur. The study involved a three month long preliminary trial to explore the efficacy of various locally available materials for use as container for tree species. Based on the preliminary trial, five better performing container types were screened for detailed nursery trial to further examine their efficiency as containers for tree seedling production. Teak (Tectona grandis) being the widely produced forest planation species in Kerala, the nursery trials were performed with teak as test crop. The locally available materials used as containers for the preliminary trial included cow dung pot, sugarcane bagasse, arecanut sheath, mud pots, bamboo splits, bamboo basket, coco pot, cloth bag, nonwoven bag, bioplastic bag and treated card board. The containers were evaluated for their durability, physical stability to management practices such as irrigation and manuring, survival percent, height and collar diameter of the teak seedlings. It was observed that the bamboo splits based containers had the highest durability and can be used for two seasons while containers made from arecanut sheath, cow dung pot, sugarcane bagasee pot, bamboo basket, bioplastic bag and cloth bag totally degraded within two months suggesting their unsuitability for tree seedling production. In general, the better container types in terms of overall seedling growth performance and physical soundness were nonwoven bag, bamboo split, coco pot, treated cardboard pot and mud pot. These five container types along with coir root trainer (CRT) supplied by Kerala Forest Department were subjected to detailed nursery trial. It was observed that considerable variability existed in seedling growth characters such as height, collar diameter, number of leaves, leaf area, number of secondary and tertiary roots, lateral root length, root length: shoot length ratio, root and shoot dry and total dry weight. Among all container types studied, nonwoven bag grown seedlings showed better growth performance followed by seedlings grown in bamboo split containers while mud pot raised seedlings showed the lowest performance during all the stages of seedling growth. The overall performance of the container types followed the order: nonwoven bag > bamboo split > coco pot > treated cardboard > Coir root trainer (CRT) > mud pot. The cost of production per seedling was Rs 8.3 for non-woven bag, Rs 60.2 for coco pot, Rs 62.0 for mud pot, Rs 11.0 for bamboo split, Rs 12.8 for treated cardboard pot and Rs 25.8 for Coir root trainer (CRT). The Benefit: Cost ratio of raising 3- month old teak seedling ranged from 0.32 – 2.45. The value was highest for seedlings raised in bamboo split pot (2.45) followed by nonwoven bag (2.41) and cardboard (1.56) while it was less than one for all the remaining container types. The trial suggest that further studies are required to develop protocols for the reinforcement of biodegradable containers for increased phys ical strength and durability.
Open Access
Floristic diversity and regeneration status of moist deciduous forests in Thrissur district, Kerala :reassessment after three decades
(Department of Silviculture and Wildlife Science, College of Forestry, Vellanikkara, 2020) Abhi, Jamatia; KAU; Kunhamu, T K
Moist deciduous forests in Kerala constitute one of the most degraded forest ecosystems consequent to demographic pressure and other bio- physical factors. Field investigation was carried out to study the changes in phytosociology and vegetation dynamics of Moist Deciduous Forests in selected locations in Thrissur Forest Division, Kerala during 2018-19. The primary objective of the study was to assess the changes in floristic diversity, structure and regeneration status of moist deciduous forests compared to a similar study carried out in the same locations prior to three decades. The selected three locations were Karadippara and Kalluchal in Peechi WL sanctuary and Kuthiran in Pattikkad range. The vegetation attributes subjected to detailed assessment included species diversity, density, relative density, basal area, relative basal area, relative frequency and Importance Value Index and size class distribution of vegetation. A total of 51 species have been reported in various study locations in the Moist Deciduous Forests of Thrissur Forest Division. Kalluchal represented the highest number of woody species (48 species) followed by Karadippara (37 species) and Kuthiran recording the lowest with 26 species. Tree density showed profound variation across sites with Kalluchal giving the highest number (691 stems ha-1) followed by Karadippara (688 stems ha-1) and lowest for Kuthiran (516 stems ha-1). Xylia xylocarpa contributed the maximum number of stems in all the three sites followed by Wrightia tinctoria and Holarrhena antidysentrica. Mean relative density was highest for upper stratum (44.62%) and 33.07% for the lower stratum and lowest for the middle stratum (22.30%). Karadippara, Kalluchal and Kuthiran sites represented 30, 45 and 20 species within frequency class I (within 1-20%) and there was conspicuous absence of species in the higher frequency class in all the three sites. All the three sites had similar total IVI around 300. The major share of the IVI was confined to the species in the upper stratum (58 to 60%) while the middle and lower stratum has a lower and similar trend in IVI distribution (20% each). Size class distribution of among various social l classes ii showed conspicuous absence of majority of tree species in the higher size class suggesting a skewed distribution pattern. Almost 85% of individuals in each species belonged to lower size classes (h50 and h100) which drastically declined with increase in size class. A comparison with the study in the same sites three decades back indicates variable results. There was overall improvement in species diversity and phyto-sociological attributes in the Kalluchal region particularly, the species density and regeneration patterns. However, the number of individuals in the present study at Karadippara and Kuthiran sites, especially in the lower size classes were far lower compared to the previous study implying that the regeneration patterns of many tree species have been seriously affected by the undesirable changes in the past three decades. Probably, apart from human influences, the impact of changing climate may also have affected the regeneration ecology and vegetation dynamics of the MDF forests in Thrissur District which necessitate further detailed investigation in this line.
Open Access
Impact of seed priming techniques on germination and seedling performance in sandal (Santalum album L.)
(Department of Silviculture and Agroforestry, College of Forestry,Vellanikkara, 2019) Chithra, P; KAU; Jijeesh, C M
Santalum album L, known as the East Indian Sandalwood is a semi-root parasitic tree native to South India and it is one of the most precious and valuable among Indian forest trees. The poor rate of germination coupled with long germination period is the major constraints in the regeneration of sandal. Present study was conducted to assess the impact of seed priming techniques on the germination and seedling growth attributes of sandal at College of Forestry, Vellanikkara, Thrissur. The effect of different duration and concentration of priming agents viz. water (Hydropriming for 3, 6, 9 and 12 days), Pseudomonas fluorescens (Biopriming at 25, 50, 75 and 100% for 2, 4, 6 and 8 days), Polyethylene Glycol 6000 (Osmopriming at 5, 10, 15 and 20% for 3, 6, 9 and 12 days) and MnSO4 (Chemical priming at 0.4, 0.6, 0.8 and 1.0 M for 3, 6, 9 and 12 days) on seed germination and subsequent seedling growth in sandal were studied. The non- primed seeds were kept as control. Primed seeds were stored for one day and one month after the completion of priming processes and the germination and seedling growth were observed. The germination was obtained only in the seeds stored for one day after priming process and the seeds stored for one month failed to germinate. Results indicated that the hydropriming of the seeds could not improve the germination of the sandal seeds compared to control. Biopriming significantly increased the seed germination and the highest germination percentage (88%) was recorded in the seeds subjected to biopriming for 8 days at 100% concentration, which was 1.9 times higher compared to control. The highest germination recorded in osmopriming was 78%. The chemical priming with MnSO4 at different concentrations for 3 days also recorded the higher germination (88%) comparable to biopriming. Electrical conductivity was the highest in the leachates of seeds hydroprimed for 12 days (1.96 dS cm-1) and was the lowest in seeds subjected to biopriming (0.03 dS cm-1). The leachate conductivity of the seeds subjected to osmopriming treatments (1.69 dS cm-1) was comparable to that of the hydropriming treatments. Although the different concentrations and duration of MnSO4 reduced the leakage of solutes from the sandal seeds, the electrical conductivity was higher than that of the biopriming treatments. Hence, biopriming treatments were the best in reducing the leakage of solutes from the cells leading to better membrane integrity and stability. Biochemical analysis of the primed and non-primed seeds indicated that the hydropriming treatments recorded significantly lower carbohydrate, protein and crude fat content compared to control.
Open Access
Productivity of tree fodder banks in selected homegardens of central Kerala
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2019) Anush Patric; KAU; Asha, K Raj
The field study entitled “Productivity of tree fodder banks in selected homegardens of Central Kerala” was carried out as three separate experiments in selected small, medium, and large scale homegarden with livestock component in Arimboor panchayath, Thrissur, Kerala during 2018-2019. The study aimed to assess the forage yield and nutritive value of five fodder tree species viz. Mulberry (Morus indica), Agathi (Sesbania grandiflora), Moringa (Moringa oleifera), Gliricidia (Gliricidia sepium) and Calliandra (Calliandra calothyrsus) under hedgerow planting (45 x 45 cm spacing) in homegardens; and to explore the short term changes in soil nutrient status of homegardens with tree fodder integration. The treatments were laid out in randomized block design replicated four times. The trees were harvested at 1m height and at the interval of two months during rainy season and three months during summer season The result revealed that all the tree species established well in the homegardens after planting. Initial growth of Agathi and Calliandra was faster in terms of plant height, whereas Gliricidia showed excellence in lateral branching. In general, coppice parameters were better for Gliricidia followed by Agathi and Calliandra. The annual green and dry forage yields were higher for Gliricidia (24.27 & 4.39 Mg ha-1) and Calliandra (16.38 & 4.60 Mg ha-1) respectively followed by Agathi and Mulberry. The yield from Moringa was comparatively poor. Seasonal fodder yields were higher for rainy period than summer. Forage quality also differed among tree species. Calliandra (22.57 %) and Gliricidia (19.99 %) fodder had more crude protein content and yield followed by Mulberry (16.74 %). Crude fibre content was lower in Gliricidia, Calliandra and Mulberry than other species. Mulberry (7.93 %), Moringa (7.61 %) and Agathi (7.12 %) had higher ash content, whereas Moringa and Mulberry had higher P and K content. Dry matter content was significantly higher for Calliandra (30.40 %) and Mulberry (28.73 %). Higher leaf-stem ratio was observed in Mulberry (2.09) and Gliricidia (2.05), followed by Calliandra (1.67). In general, Gliricidia and Calliandra had higher forage yields and protein content, followed by Agathi. Mulberry showed intermediate performance with respect to yield and quality. Moringa was inferior in forage yields but rich in quality attributes like ash, minerals and P content. Comparing homegardens, yield performance of fodder banks was higher in medium homegarden (MHG) followed by large (LHG) and small homegarden (SHG). Whereas reverse trend was observed in quality attributes of fodder. Survival count of the trees after one year of planting was significantly higher in Mulberry (80.06 %) and Calliandra (71.13 %), followed by Gliricidia (44.35 %), whereas survival was drastically lower for Agathi (31.55 %) and Moringa (31.55 %). Inspite of poor yields of Mulberry in the initial year, higher persistence of Mulberry indicates its better performance in the subsequent years. Comparing different homegardens, survival percentage was higher for SHG (59.47 %) and MHG (54.46 %) followed by LHG (41.07 %). Low survival in LHG was due to waterlogging during rainy season. In general, the soil organic carbon, N and P content improved with fodder tree integration in SHG and MHG. There was no visible changes in K content. Soil N and P levels also improved in LHG whereas SOC showed a declining trend. Comparing tree species, Agathi plots showed more soil improvement with higher SOC and NPK levels whereas soil depletion was more evident in Moringa with respect to carbon, P and K, and in Calliandra in terms of carbon and nitrogen. PAR transmittance ranged from 50.10 % in SHG to 52.75 % in MHG and LHG which were on par. PAR transmittance levels in various tree plots ranged from 45.50 – 58.57 % with no statistical significance. A marginal reduction in transmittance was observed in Mulberry (45.50 %) when compared to other species. The economics of fodder bank cultivation in homegardens varied significantly with respect to tree species. Gliricidia fodder banks generated higher returns and B: C ratio (1.28) whereas all other species showed B: C ratio of less than one. The initial cost for raising fodder banks in homesteads is high whereas the forage yield in the initial year of planting is comparatively less as trees are under the establishment phase. Hence, in conclusion, fodder trees like Gliricidia, Calliandra, and Mulberry with good yield/persistence are found to be ideal for hedgerow planting in the understorey of homesteads. Agathi is not amenable to heavy pruning, hence frequent replanting is a management option due to its faster growth. Cultivation of Moringa should be confined to light intensive as well as dry areas of homesteads. Moreover, pruning of overhead trees in homesteads to enhance understorey light regimes can further elevate the yield levels of fodder banks. Scientific cultivation and management of multispecies tree fodder banks and feeding mixed forages will provide quality and balanced nutrition to enhance livestock production at minimal cost in homegardens.
Open Access
Selection and evaluation of superior planting materials of Ailanthus triphysa (Dennst.) in Thrissur
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2018) Abijith, R; Jamaludheen, V
A nursery and field experiment was conducted to evaluate the superior performance of selected candidate plus trees of Ailanthus triphysafrom the Thrissur District, Kerala. The demand of this timber was very much increased because of its fast growing nature and diversity of utilizations. Hence, the tree improvement of this species is the need of the hour that might result increased quality and reduced rotation time. The possible gain expected through the phenotypic selection can also be directly utilised by the tree growers. The candidate plus trees were identified and selected by adopting the comparison tree method. The seeds collected were used to study the germination parameters at tree nursery of College of Forestry, Kerala Agricultural University. The initial growth performances of the progenies of the selected CPTs were evaluated at nursery in a completely randomised design and also at the field in a randomised block design and the data were statistically analysed using Analysis of Variance technique. The progenies of the selected CPTs showed significant variation in their initial growth parameters. The highest germination per cent of 83.50 was exhibited by CPT-11 and the lowest of 67 per cent by CPT-1. After the six months of observation in the nursery, CPT-11 attained the maximum height of 88.67cm and lowest height by CPT-5 (76.33cm). The maximum plant height (99 cm) and girth (21.04 cm)in the field was also exhibited by CPT-11. The CPT-11, CPT-10 and CPT-9 were the top performers compared to other selections. The CPT-1 was the inferior in the nursery and also in the field. The CPTs that exhibited superiority in germination percentage, germination value and mean daily germination also exhibited distinctively superior growth in the nursery and in the field. In fact, the identification and selection of superior quality planting materials of Ailanthus triphysahas a greater role in the tree improvement. The single tree selection is the best method for the production of superior progenies and this can be useful for the future afforestation and seedling production for getting high quality timber with short rotation period. From this study we recommend CPT-11, CPT-10 and CPT-9 for achieving these objectives.
Open Access
Productivity, carbon and nutrient stocks in mulberry (Morus indica L.) and subabul (Leucaena leucocephala Lam.) based high density fodder production system in coconut
(Department of Silviculture and Agroforestry College of Forestry, Vellanikkara, 2018) Acsah Rose, John; KAU; Asha K Raj
The research programme entitled “Productivity, carbon and nutrient stocks in mulberry (Morus indica L.) and subabul (Leucaena leucocephala Lam.) based high density fodder production system in coconut”, was conducted at Instructional farm, College of Horticulture, Vellanikkara during 2017-18, to evaluate the influence of tree density and harvest interval on forage yield, carbon and nutrient stocks of three- years- old mulberry and subabul fodder banks in coconut garden. The study also examined the variation in coconut productivity and soil fertility changes associated with fodder bank integration in coconut plantations. The treatments included intercropping of fodder tree species like mulberry and subabul-1 at three levels of tree densities (49,382; 37,037 and 27, 777 plants ha-1 ) and three levels of harvest intervals (8, 12 and 16 weeks) in all possible combinations with randomized block design replicated thrice. The study indicated that annual fresh fodder yield from fodder tree banks per hectare of coconut garden in the third year of intercropping was significantly higher in mulberry (33.93 Mg ha-1 yr ) than that of subabul (20.14 Mg ha-1 yr ). Forage yields of tree banks increased from 18.97 to 35.04 Mg ha yr from lower to higher density classes, and were also found to be higher (33.98 Mg ha-1 yr ) for medium harvest interval of 12 weeks than longer or shorter intervals. Comparing the cumulative effects of stand management practices, forage yields of mulberry and subabul stands showed drastic variation which ranged from 16.40 to 63.38 and 9.33 to 30.96 Mg ha-1 yr-1respectively under various management levels, there by indicating the critical role of proper management for productivity enhancement from tree fodder banks. Maximum yield was obtained from the highest density stand (49,382 plants ha-1 ) and at medium harvest interval of 12 weeks in both the tree species. In general, fodder tree intercropping and various management regimes showed no significant influence on coconut productivity. However, a slight decrease in nut yield was observed under very high fodder tree density (49,382 plants ha-1 ), especially with that of mulberry, there by pointing out the need for crop specificnutrient and moisture supplementation to prevent competition and yield loss in coconut under high density intercropping. Intercropping of fodder trees and various management practices resulted in significant enhancement in total biomass production and carbon storage potential of coconut plantations (82.70-108.48 Mg ha-1 ) than that of coconut monoculture system (75.35 Mg ha-1 ). The intercropped fodder trees have fixed additional carbon to a maximum of 33 Mg ha-1 in the plant biomass and in soil up to 40 cm depth, thereby making considerable contribution for reducing atmospheric carbon dioxide levels. Significant difference was observed in nutrient uptake by the two fodder tree species, tree density and harvest schedule. N, P and K uptake was found to be significantly higher for mulberry (70.77, 4.80 and 38.22 kg ha-1 ) than that of subabul (51.62, 2.97 and 24.45 kg ha-1 ). N, P and K uptake enhanced by 81, 113 and 96 per cent from lower to higher densities. The nutrient uptake was higher in the medium interval of 12 weeks when compared to shorter or longer intervals. In general, intercropping practices in coconut have overall improved the fertility status of soil compared to coconut monoculture. However, proper nutrient supplementation should be ensured while adopting very high tree densities to avoid any possible competition with coconut palms. Fodder tree species and tree density had significant effect on soil properties like pH and water holding capacity (WHC) in mulberry and subabul plots intercropped in coconut plantation. Soil pH was observed higher in subabul (4.84) than mulberry (4.58). Water holding capacity (WHC) was observed higher in mulberry plots (53.96 %) than that of subabul (50.84%). Comparing the economics of tree fodder integration in coconut garden, significantly higher B: C ratio was obtained from mulberry (2.94) than subabul (2.54). B: C ratio showed an increasing trend (2.26 to 3.05) from lower to higher density classes. The highest B: C ratio (3.07) was obtained from 12 weeks harvest interval.Hence, the present field study clearly demonstrates the possibility of integrating mulberry and subabul fodder banks in coconut gardens of Kerala to enhance quality forage production, so as to minimize farmer’s expenses on feed cost. Adoption of ideal stand management practices viz., tree density of 49,382 plants ha-1 and 12 weeks harvest interval, can generate higher forage yields from limited land area. Moreover, the intercropped fodder trees have fixed additional carbon to a maximum of 33 Mg ha-1 , thereby making considerable contribution for reducing atmospheric CO2 levels to minimize global warming. Thus, establishment and proper management of mulberry and subabul fodder banks in coconut garden is a low cost technology to enhance quality forage production in humid tropics, and a promising strategy for climate change mitigation via carbon sequestration.
Open Access
Understorey productivity of selected fodder grasses in mature coconut and rubber plantations
(Department of Silviculture and Agroforestry, Vellanikkara, 2018) Rose Mary Jose; KAU; Jamaludheen, V
A field experiment was conducted at Vellanikkara, Thrissur, Kerala from May 2017 to February 2018 to assess the understorey productivity of four fodder grasses viz congosignal (Brachiaria ruziziensis), guinea (Panicum maximum) and two hybrid napier cultivars CO-3 and CO-5 when grown under mature coconut (Cocos nucifera L.) and rubber (Heavea barsiliensis Muell. Arg,) plantations, which are the two prominent land use systems in Kerala. The biophysical attributes influencing the productivity of these land use systems and the biochemical changes in the products of understorey crops were also studied. Growth parameters of understorey fodder crops varied remarkably among these land use systems. The fodder grasses grown in coconut plantations showed an increased plant height, leaf area index, leaf area ratio, and leaf weight ratio as compared with treeless open plot. However, the number of tillers per clump and number of leaves per clump showed a decreasing trend when grown as understorey crops in mature coconut and rubber plantations. Rubber grown fodder grasses expressed substantially poor performance both in growth and yield attributes. Regarding fodder production, open grown fodder grasses consistently showed maximum biomass dry weight throughout the harvests. On comparing with the open, the rubber plot showed a substantial reduction of 91.35% in the total biomass dry weight from all harvests whereas the reduction was only 39.02% under coconut plantations. Mean mid day (12–1p.m) understorey photosynthetic Photon Flux Density (PPFD) were 1342.5 moles μ m -2 sec -1 in rubber and 1575 μ molesm -2 sec -1 in coconut, with respective understorey PAR transmittance of 39.84 % and 56.08% of full sunlight. The understorey crops in coconut and rubber showed an increased chlorophyll-a, chlorophyll-b, and total chlorophyll content and leaf moisture content over treeless control. The maximum crude protein value was noticed in the rubber (11.97%) grown fodder grasses and was on par with open while 124 coconut (9.29 %) accounted the least crude protein content. The understorey crops showed a decreased crude fibre content as compared to open. The maximum leaf nitrogen content was observed in the rubber plot (1.92%) and this was followed by open plot (1.87%). The lowest nitrogen content was observed in the coconut plot (1.49%). No noticeable changes were observed in foliar phosphorus and potassium content across both land use systems. The soil analysis revealed that the organic carbon and available nitrogen content of the top soil were increased under both the tree based cropping systems as a result of understory intercropping. However, on comparing with the initial values of different soil properties studied, only modest changes were observed in the soil properties in general across both the land use systems and treeless open plot. It is concluded that the coconut based fodder production systems with these grasses are almost comparable, in terms of growth and yield, to the open areas and hence recommended for farmers adaption. This practice of integrating fodder grasses in coconut plantations gains immense importance in Kerala, where mature coconut plantations forms one of the extensive and prominent land management system. Thus, judicious use of the vast area of interspaces under these matures coconut plantations for fodder production is very ideal especially in the state of Kerala. The best proven combination of land use system and the fodder grass in a coconut based intercropping scenario was the cultivation of CO-3 fodder grass under matured coconut plantations. However, the rubber based fodder production system is not at all feasible and further conclusive studies may be done for affirming more reasons for such a substantial reduction of growth and yield in rubber based system.

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