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Open Access
Carbon storage potential of intensive silvopasture systems in humid tropics of kerala
(Academy of Climate Change Education and Research, Vellanikkara, 2015) Varsha, K M; KAU; Asha, K Raj
The research project entitled “Carbon storage potential of intensive silvopasture systems in humid tropics of Kerala” was carried out at Instructional Farm, College of Horticulture, Vellanikkara during 2013-2015, in existing 2 year old intensive fodder production systems, to assess their carbon storage potential and associated soil fertility changes. Comparative carbon storage efficiency of six different fodder production systems viz; 3-tier hybrid napier (HN)+ mulberry+ stylosanthus system, 2-tier HN+ mulberry/ stylosanthus systems and HN/ mulberry/ stylosanthus monoculture systems and one open plot with natural grass vegetation as absolute control was assessed in randomized block design replicated thrice. The 3- tier silvopastoral system consisted of grass, trees and herbaceous legumes in 3:1:1 ratio, 2- tier systems contained grass + tree/ legume in 3: 2 ratios on area basis, whereas the entire area contained either grass or legume or tree for monoculture treatments. Trees were planted at a high density (11111 trees ha-1) at 60 cm x 60 cm spacing and maintained as hedges of 1m height by harvesting at 3 months interval. All other crops were planted and harvested as per state recommendation. Fodder yields from various systems and carbon storage in plant biomass and soil was assessed for two years. Among various systems, mulberry monoculture captured the maximum carbon (211.23 Mg ha-1); 81% of which form permanent carbon stored in standing, root biomass and soil and 19% as labile carbon in harvested biomass. The second best system was 2-tier HN + mulberry (177.14 Mg ha-1), which captured 13 % more carbon than 3-tier silvopasture and HN monoculture systems. However, despite the higher carbon storage potential of mulberry monoculture, the fodder yields were significantly lower than HN+mulberry system. HN monoculture outyielded all other systems in fodder production, but carbon storage was comparatively poor. Hence, considering the fodder production efficiency and carbon storage capacity, 2-tier HN+mulberry system was found to be the most promising system for meeting both farmer needs and environmental services. Moreover, higher protein content in mulberry adds to the quality of the forage, which is an important factor in economic milk production. Variations in soil physical properties and nutrient status were assessed after two years. In general, soil physical properties were favourably influenced by tree based systems as compared to others.The least and comparable bulk density (1.45 g cm-3) was recorded in HN+mulberry and HN monoculture system. Soil pH and water holding capacity considerably improved in mulberry monoculture (7.283) followed by 2-tier HN+mulberry system (6.36). Soil temperature was also higher in tree based systems. The 3-tier systems were found to be superior to monoculture systems but inferior to 2-tier HN+mulberry system with respect to soil physical properties.Comparing the soil nutrient status, the total N, P, K and available P content was higher in stylosanthus based systems, whereas the available N and K content excelled in mulberry based systems. Hence, 3-tier HN+mulberry+stylosanthus system seemed more favourable for replenishing soil fertility as well as nutrient availability. However, stylosanthus being a poor fodder yielder, substituting it with a suitable high yielding leguminous fodder tree can take care of both the forage yields as well as the soil fertility aspects. To conclude,the current research brings out the suitability of intensive silvopasture systems with high yielding grass species (HN) and densely planted fodder tree hedges (mulberry @ 11111 trees ha-1), for maximizing quality fodder production and carbon sequestration and favourably influencing soil physical properties in humid tropics of Kerala. However, the above system could not contribute much to soil fertility owing to the non leguminous and exhaustive feeding behaviour of mulberry and HN. Hence, inclusion of a leguminous fodder tree along with mulberry and HN can take care of both the forage yields as well as the soil fertility improvement.
Open Access
Effect of growing environment and climate change on physiyology of tomato ( Lycopersicon esculentum Mill. )
(Academy of climate Change Education and research, Vellanikkara, 2015) Rajalakshmi, Radhakrishnan; KAU; Sunil, K M
The present world production of tomato stands at 100 million tons fresh fruits produced on 3.7 million hectares. Even though productivity levels of tomato have increased, it will not be sufficient enough to the increasing population. Global climate change is any significant long term change in expected patterns of weather over a region which may be naturally induced or anthropogenic. The effect of climate change on crop and terrestrial food production are evident in several regions of the world. Negative impacts of climate trends have been more common than positive ones. Objectives of the study were to study the effect of different growing environment and climate change on the physiological traits of tomato development of crop weather relationships for the selected rice varieties and assessment of possible change in yield due to climate change. The studies were conducted during December 2014- March 15at the Central Nursery, Vellanikkara in the bacterial wilt resistant variety Anagha by providing three different growing environments namely polyhouse, rainshelter and open field conditions with four dates of transplanting. The results showed that the dates of transplanting and growing environment had a significant effect on the physiology of tomato. The crop transplanted inside the polyhouse took the longest duration. Maximum leaf area index (3.8) was observed in in the crop transplanted in open field, polyhouse and rain shelter on different dates on different dates (1 December 2014 and 20 January 2015 respectively). The highest values of leaf relative water content was observed in the first week following transplanting and the lowest values appeared prior to the last harvest regardless of the dates of transplanting and growing environment. The lycopene content was consistently highest in the crops inside the Polyhouse. The highest value for the same was 1.52 mg gm-1 was recorded in crops inside the polyhouse transplanted on 10 January 2015.The fruit ascorbic acid content (2.06 mg gm-1) was highest in the crop inside rain shelter transplanted on 10 December 2014. The highest mean length of style was documented in the flowers of the crop transplanted inside rain shelter (8.08 mm) on 1 December 2014 whereas, the highest mean stamen length was recorded in the flowers of the crop transplanted inside polyhouse (8.28 mm) on 1 December 135 2014). The difference in the length of the style and stamen and its relative position significantly affected the total yield obtained. A difference of more than -0.05 mm considerably reduced the yield. The highest yield (111.5 tons ha-1) was recorded inside the polyhouse in the crops transplanted on 1 December 2014. The net photosynthesis rate was highest in the rain shelter crops regardless of the dates of transplanting. The highest values recorded was 19.7 in the rain shelter and poly house for the crops transplanted on 10 and 20 January 2015. The temperature prevalent was the most crucial factor determining the rate of photosynthesis followed by Carbon dioxide. Under the projected climate change scenarios i.e. RCP 2.6, 4.5, 6.5 and 8.0, the ascorbic acid content increased in the fruit owing to higher temperature and lower soil moisture availability. The lycopene content remained unaffected as the UV radiation concentration is will be changing negligibly for the region where the study is conducted. The duration of the crop will be reduced drastically from 2030 to 2080 under all the scenarios. The results also showed that the effect of minimum temperature would drastically reduce the yield. The increasing atmospheric CO2 concentration is likely to have some positive effect on yield, but the effect is not significant compared to the negative impact of rise in temperature.
Open Access
Phenology of medicinal snake gourd (Trichosanthes cucumerina L.) under different seasons
(Academy of climate Change Education and research, Vellanikkara, 2015) Harsha Satheesh; KAU; Kanakamany, M T
The present study entitled “Phenology of medicinal snake gourd (Trichosanthes cucumerina L.) under different seasons” was carried out at Academy of Climate Change Education and Research (ACCER), Vellanikkara during the period 2014-2015. Field experiments were conducted at All India Coordinated Research Project on Medicinal, Aromatic Plants and Betel Vine (AICRP on MAP & B), College of Horticulture, Vellanikkara. The objective of the study was to assess the influence of weather parameters on yield and yield attributing characters of medicinal snake gourd (Trichosanthes cucumerina L.) under open and rain shelter during winter, summer and rainy seasons. The experiment was laid out in a randomized block design with six treatments and four replications each in open and rain shelter during winter, summer and rainy seasons. Observations on meteorological, growth characters, floral biology, yield and quality parameters were recorded under open and rain shelter in all the three seasons. Significant difference was observed in number of flowers, number of fruits produced, pollen fertility, fruit yield per plant, herbage yield per plant, total yield per plant and per plant cucurbitacin content for plants grown under rain shelter as well as in open condition during the three seasons. During winter, summer and rainy seasons crops grown under rain shelter recorded highest vine length, number of branches, maximum leaf area and number of male and female flowers produced, herbage yield per plant and dry yield per plant than open condition. Whereas pollen fertility, pollen viability and fruit weight were found to be highest in open condition than in rain shelter during summer season and found more in rain shelter during winter and rainy seasons. Earlier anthesis of both male and female flower was recorded during summer season under open condition. Highest herbage yield per plant, fruit yield per plant and total yield per plant were recorded under open condition during summer season. But during rainy season it is higher under rain shelter when compared to open field.Per plant cucurbitacin content was highest for the plants that grown under open environment than in rain shelter. It was found to be maximum during summer season followed by winter and rainy season. Weather parameters such as canopy air temperature, daily minimum and maximum temperature were high under rain shelter during the three cropping seasons. Relative humidity and soil moisture were high under rain shelter during winter and summer and low during rainy season. Correlation analysis with the weather parameters and crop was studied. Relative humidity and soil moisture had a significant negative correlation with the number of male flowers produced, pollen fertility, herbage yield per plant, total yield per plant and per plant cucurbitacin content. Canopy air temperature, minimum and maximum temperature showed positive correlation with the number of male flowers, produced pollen fertility, number of fruits, fruit yield per plant, herbage yield per plant, total yield per plant and per plant cucurbitacin content whereas rainfall had a negative correlation.
Open Access
Impact of heat and nutritional stress on rumen fermentation characteristics and metabolic activity Bucks
(Academy of climate Change Education and research, Vellanikkara, 2015) Chaidanya, K; KAU; Girish, varma
A study was conducted to assess the combined effect of heat stress and nutritional restriction on rumen fermentation characteristics and metabolic activities in Osmanabadi Bucks. Twenty four adult Osmanabadi bucks (average body weight (BW) 16.0 kg) were used in the present study. The bucks were divided into four groups viz., C (n=6; control), HS (n=6; heat stress), NS (n=6; nutritional stress) and CS (n=6; combined stress). The study was conducted for a period of 45 days. C and HS bucks had ad libitum access to their feed while NS and CS bucks were under restricted feed (30% intake of C bucks) to induce nutritional stress. The HS and CS bucks were exposed to solar radiation for six hours a day between 10:00 h and 16:00 h to induce heat stress. The data were analyzed using repeated measures analysis of variance. The carboxy methyl cellulase (CMCase) Extracellular activity (EC), CMCase Intracellular activity (IC) and CMCase total activity (TA) of rumen liquor differed significantly (P<0.01) between the groups. The highest concentration of ammonia nitrogen (P<0.05) was recorded in C while the lowest in CS group. There were significantly (P<0.01) higher levels of trichloroacetic acid (TCA) in ad libitum (C and HS) fed groups as compared to restricted fed (NS and CS) groups. There were significantly (P<0.01) higher levels of total nitrogen in ad libitum (C and HS) fed groups as compared to restricted fed (NS and CS) groups. There were significantly (P<0.01) higher levels of propionic acid, butyric acid, and valeric acid in ad libitum (C and HS) fed groups as compared to restricted fed (NS and CS) groups. Further, the acetate and propionate ratio was significantly (P<0.01) higher in CS and NS groups as compared to C and HS groups. There were significantly (P<0.01) higher levels of plasma alkaline phosphatise (ALP) in ad libitum (C and HS) fed groups as compared to restricted fed (NS and CS) groups. However, plasma Aspartate amino transferase (AST) and alanine amino transferase (ALT) showed reverse trend (P<0.05) to plasma ALP. The highest (P<0.01) plasma Triiodothyronine(T3) and Thyroxine(T4) was recorded in C group as compared to stress groups (HS, NS and CS). Further, the highest leptin concentration was recorded in C group while the lowest level in CS group. The higher expression of rumen heat shock protein 70(HSP70) messenger Ribonucleic acid(mRNA) was reported in CS goats. Further, the higher expression of intestinal HSP70 mRNA was reported in HS goats. The thyroid alveoli showed significantly lower thyroglobulin activity in HS group. The length of rumen villi and thickness was reduced more in CS, whereas rumen keratinization was observed highest in CS group. It can be concluded from this study that when two stressors occur simultaneously, they may have severe impact on rumen fermentation characteristics and metabolic activities of bucks as compared to that would occur individually. Further, the study established the adaptive capability of Osmanabadi bucks to the detrimental effects of environmental stresses to alter their fermentation and metabolic activities. This is evident from the significant influences of interaction between treatment and experimental days on majority of the parameters studied.
Open Access
Tree growth climate relationship in plantation teak (Tectona grandis L.f.) grown in Thrissur district, Kerala
(Academy of climate Change Education and research, Vellanikkara, 2015) Gayathri, Asok; KAU; Anoop, E V
The present study ―Tree growth climate relationship in plantation teak (Tectona grandis L. f.) grown in Thrissur District, Kerala‖ was conducted to develop tree-ring chronologies from plantation teak (Tectona grandis ) at the site Vazhani in Thrissur forest division, Kerala, to understand the relationship between climate and tree growth. The work was carried out at the Department of Wood Science, College of forestry, KAU, Vellanikkara, Thrissur. The study samples were selected from the sample collection in the Department of Wood Science, College of Forestry. The collected samples are thinned and sanded with different grades of sand papers to expose the growth rings. Statistical parameters like SNR (Signal to Noise Ratio) and EPS (Expressed Population Signal) showed a good dendroclimatic potential. Weather parameters such as rainfall, temperature and moisture index showed significant positive and negative correlation with Ring Width Index. Summer temperature, showed significant positive correlation and annual temperature showed negative correlation. South West monsoon rainfall showed significant positive correlation. Correlation between Ring Width Index and Moisture Index showed positive correlation during previous year North East monsoon.
Open Access
Impact of climate change on water availability across Western Ghats
(Academy of climate Change Education and research, Vellanikkara, 2015) Anjali, B Nair; KAU; Prasad, Rao G S L H V
The present study entitled “Impact of climate change on water availability across Western Ghats” was taken up at the Energy and Wetlands Research Group, Indian Institute of Science, Bangalore during 2014-‘15 with the objectives of analyzing the changes in surface air temperature and rainfall across the Western Ghats along the Coast, Ghat and Plain regions and visualizing the likely scenario in land use and water availability in two selected basins viz., Karamana Basin (Thiruvananthapuram, Kerala and Sita Basin, Udupi, Karnataka) under the projected climate change scenario. The data required for the study were obtained from the Directorate of Economics and Statistics, Government of Karnataka, website of NOAA, website of Hydrology Department, University of Princeton and from the publications of the Central Government Department and the concerned State Departments. The study revealed that the rainfall over the Western Ghats as a whole doesn’t reveal any trend from 1901-2010 while it is not so at the regional level. However, the maximum and minimum temperatures along the Western Ghats showed an increasing trend from 1948- 2010. The trend was similar at regional level except in the plains of the Northern Western Ghats which showed a marginal decrease in the mean maximum temperature. Both the representative river basins viz., Karamana in Thiruvananthapuram district and Sita in Udupi district have undergone changes in the land use pattern which altered the water balance of the basin along with the change in population since last two decades from 1990 to 2010. The Karamana Basin suffered a deficit in the available water owing to the low rainfall received in the basin in comparison to the huge demand of water and the situation tend to aggravate with an increase in water demand and decrease in rainfall over the basin. But, Sita basin receives abundant rainfall which caters to the needs of the basin which rules out the water deficit in the basin unless in case of occurrence of moderate to severe drought.
Open Access
Impact of heat and nutritional stress on adaptive capability of bucks
(Academy of climate Change Education and research, Vellanikkara, 2015) Shilja, Shaji; KAU; Girish, Varma G
A study was conducted to assess the combined effect of heat stress and nutritional restriction on growth and reproductive performances in Osmanabadi Bucks. Twenty four adult Osmanabadi bucks (average body weight (BW) 16.0 kg) were used in the present study. The bucks were divided into four groups viz., C (n=6; control), HS (n=6; heat stress), NS (n=6; nutritional stress) and CS (n=6; combined stress). The study was conducted for a period of 45 days. C and HS bucks had ad libitum access to their feed while NS and CS bucks were under restricted feed (30% intake of C bucks) to induce nutritional stress. The HS and CS bucks were exposed to solar radiation for six hours a day between 10:00 h to 16:00 h to induce heat stress. The data was analyzed using repeated measures analysis of variance. There were significantly (P<0.01) higher standing time in ad libitum (C and HS) fed groups as compared to restricted fed (NS and CS) groups. However, the highest (P<0.01) lying time was recorded in CS group. The highest (P<0.01) drinking frequency was recorded in CS group while the lowest in NS group. The highest (P<0.01) defecating frequency was recorded in C group while the lowest in CS group. The highest (P<0.01) water intake was recorded in both HS and CS groups. The animals exhibited different physiological adaptive behaviour in morning and afternoon. The respiration rate (RR), pulse rate (PR) and rectal temperature (RT) were higher (P<0.01) in ad libitum fed groups in morning while in the afternoon it was higher (P<0.01) in both HS and CS groups. Both skin temperature of head and scrotum in afternoon differed significantly (P<0.01) between the groups. The highest plasma total protein (P<0.01) and total cholesterol (P<0.05) was established in NS groups as compared to other groups. Plasma triglycerides, plasma urea and plasma urea nitrogen also differed significantly (P<0.01) between the groups. Further, the higher plasma cortisol (P<0.01) and aldosterone (P<0.05) was recorded in CS group as compared to othergroups. The higher expression of adrenal Heat Shock Protein 70 (HSP70) messenger Ribonucleic acid (mRNA) was reported in CS goats. However, the higher expression of hepatic HSP70 mRNA was reported in HS goats. The highest degree of degenerative changes and hyperactivity of endocrine cells was recorded in CS group liver and adrenal gland respectively. It can be concluded from this study that when two stressors occur simultaneously, they may have severe impact on adaptive capabilities of Osmanabadi bucks as compared to that would occur individually. This is evident from the significantly higher behavioural, physiological responses and endocrine responses in CS group. Further, the study indicated that Osmanabadi bucks possess the capability to adapt to the detrimental effects of environmental stresses which is evident from the significant interaction of treatment and experimental days on majority of the parameters studied.
Open Access
Spatiotemporal distribution of aquatic invasive plants in Kuttanad wetland ecosystem
(Academy of Climate Change Education and Research, Vellanikkara, 2015) Krishnaveni, R Y; KAU; Vishnu, B
A study of aquatic invasive plants of Vembanad Lake south of Thannermukkam bund and AC (Alappuzha-Changanassery) canal in the Kuttanad wetland ecosystem using multispectral imageries was undertaken to assess the spatiotemporal variation in the aquatic weed area, its distribution, extent and trends in variation. The study also aimed to analyse the contribution of climatic factors in explaining the changes in the spatiotemporal distribution of aquatic invasive plants. The study employed medium resolution LANDSAT imageries for mapping and monitoring the aquatic weed distribution. The digital image processing software used for classification of the multispectral satellite imageries to estimate the area of aquatic weeds was ILWIS 3.31 Academic version (Integrated Land and Water Information System) by ITC. The supervised classifications of the multispectral imageries were carried out with the help of the ground truth data collected from several Ground control points (GCPs). The study revealed the usefulness of multispectral satellite imageries obtained from satellites like LANDSAT in studying the spatiotemporal changes in the aquatic invasive plant distribution. However, the effects of cloud cover in obscuring the spectral reflectance data limits the availability of usable imageries. The study utilised cloud free imageries for the determination of the areal distribution of the aquatic invasive plants and cloud free imageries were not available for the rainy period. The spatiotemporal variations in aquatic invasive plants showed a cyclic trend in its distribution. The mean area of the aquatic invasive plants distribution during the period under consideration was 3.25 km2. Among the months taken for the study, monthly mean aquatic weed distribution was maximum in the month of September with a value about 5.4 km2. In the seasonal distribution, the southwest monsoon season (5.4 km2) had the maximum aquatic weed distribution, followed by the winter season (4.0 km2), Northeast monsoon season (3.4 km2) and summer season (2.3 km2). Factor analysis and stepwise regression analysis was performed to understand the effect of climatic parameters on the spatio-temporal distribution of aquatic invasive plants. The dependent variable considered in the analysis was the aquatic weed area and the independent variables were maximum temperature, minimum temperature, average temperature, relative humidity, total rain, average rain, evaporation and sunshine hours. Among the climatic factors, temperature has got a negative relationship with the aquatic weed area i.e., as temperature increases the aquatic weed area decreases. From the correlation analysis, it was seen that the maximum temperature has got the maximum negative correlation (-0.63) with the aquatic weed area among the variables considered. The regression analysis revealed that there is a statistically significant relationship between the maximum temperature and aquatic weed area as the p-value is less than 0.001. It was found that 39.67 per cent of the variation in aquatic weed distribution can be explained by the regression model. The regression equation obtained is AWA = 27.93 - 0.757 Tmax where AWA = Aquatic weed area (km2) Tmax. = Temperature maximum (°C) The forward and backward step wise regression analysis also showed that the maximum temperature has got more effect on the aquatic weed distribution than the other climatic variables considered. The aquatic weed area was more during the rainy season as nutrient rich sediment from the agricultural lands is swept into the lake by the rains and floods, which lead to the proliferation of the aquatic invasive plants. The areal spread of aquatic invasive plants is not only influenced by the temperature, but also by other factors such as dissolved oxygen, nutrient load, light intensity and pH. The intrusion of saline water from the sea into the fresh water lake also plays an important role as salinity has a detrimental effect on the growth of these aquatic invasive plants. The regions with the menace of aquatic invasive plants in Kuttanad wetland ecosystem need sustainable management. The study of the spatio-temporal distribution of aquatic invasive plant area using remote sensing techniques provided useful information about the aquatic weed growth in the study area and this method can be utilized for mapping and monitoring the areal spread of aquatic invasive plants.
Open Access
Impact of climatic parameters on watershed management practices using GIS techniques
(Academy of Climate Change Education and Research, Vellanikkara, 2015) Sandra, George; KAU; Sathian, K K
Water is one of the most important natural resources supporting all forms of life on earth and the sustainable use and conservation of this resource has to be planned on watershed basis. Watershed is a land area which drains water received through precipitation to a common outlet, usually a small drainage channel to a river. Changes in weather parameters will lead to cascading effects on watershed hydrology, biomass production and many other natural processes. The changes in precipitation pattern with changes in intensity and frequency will give rise to corresponding changes in the surface runoff, lateral flow, base flow, evapotranspiration and soil erosion. Quantifying these hydrological processes are very important from the point of view of sustainable use of land and water and their conservation planning and implementation. Since the various watershed processes are interdependent, highly variable with respect to time and space, measurement of these natural processes at different spatial location is not an easy task. Watershed models are a solution to meet the challenge of estimating watershed processes to reasonable level of accuracy. Among the watershed models, physically based watershed models will be yielding better results as they are designed to simulate the physical processes more close to reality by considering maximum number of parameters governing those processes. In the present study, Kurumali sub basin of Karuvannur river in Thrissur district, Kerala was selected for the estimation of surface runoff using the widely used SWAT model. The study envisaged to determine the impact of climate changes on various watershed processes using SWAT model. Secondary data on climate, river flow, DEM, soil map have been used and landuse map has been prepared from satellite imagery procured from NRSA. The river flow prediction efficiency of the calibrated watershed model has been tested by Nash Sutcliff efficiency (NSE) and Coefficient of Determination (COD). A very high Nash Sutcliffe Efficiency (NSE) of 0.88 and Coefficient of Determination (COD) 0.96 have been obtained for the calibration period. Corresponding NSE and COD of 138 the model simulation for the validation period were 0.90 and 0.99. The very high NSE and COD for both calibration and validations periods are the clear indication of the good model prediction of the river flow. The study revealed that average annual rainfall of the area was 2829 mm with a standard deviation of 748. For the existing climatic scenario (year 1993 to 2012), water balance components including the surface runoff, lateral flow, base flow and evapotranspiration of the basin were 306 mm, 339 mm, 1649 mm and 337 mm respectively. The predicted mean annual rainfall for the basin for the years 2021 to 2030 was 3655 mm and the water balance components including the surface runoff, lateral flow, base flow and evapotranspiration of the basin were 756.92 mm, 407.56 mm, 1802.78 mm and 456.02 mm respectively. Future rainfall was 29 percent greater than the existing rainfall and the river flow predicted for the basin for the changed climate was 46 per cent higher than the existing one. Similarly, surface runoff, lateral flow and base flow also showed considerable increase in the changed climatic scenario. Study highlights that soil and water conservation measures, presently being practiced in the area, will have to be modified and augmented as rainfall and surface runoff showed remarkable increase for the future time period.

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