Browsing by Author "Dharmakeerthi, R.S."
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Item Adoption of Eco-Friendly Technologies in Paddy Farming in Sri Lanka as an Alternative to Chemical Fertilizer: Exploring the Farmer Perceptions(Uva Wellassa University of Sri Lanka, 2019) Lakmali, C.D.A.; De Silva, L.H.N.; Mudalige, U.K.J.; Dharmakeerthi, R.S.; Dandeniya, W.S.; Balasooriya, W.K.There is a greater interest among scientists to develop Eco-Friendly Technologies (EFTs) for paddy farming, from one hand, to reduce chemical fertilizer usage, and to safeguard food supply and ecosystem health, on the other. This paper explores the attitudes and perceptions of farmers that trigger them to use certain EFTs produced such as (‘slow release fertilizer’, ‘organic carbon’, and ‘microbes’) produced through a multi-phased project funded by National Research Council of Sri Lanka. These EFTs were incorporated into the root ball of the rice plant at the nursery stage and then healthy seedlings were planted in the field by using the ‘Parachute Technique’ method (i.e. alternative technology to other modes of seed establishment including ‘broadcasting’ and ‘transplanting’). Farmers from Anuradhapura and Kurunegala districts (n=80) were selected to collect data in terms of farmer attitudes and perceptions linked with six key criteria related to these EFTs including: (1) ‘Regulation’; (2) ‘Cost’; (3) ‘Environment’; (4) ‘Performance’; (5) ‘Services’, and (6) ‘Acceptance’. The possible effects of each criterion were written in the form of attitudinal statements and supported by a 10-point likert-scale. The scores provided by farmers on each statement were subjected to the tests on Scale Reliability and Unidimensionality and then used to derive Aggregate Mean Scores. Results suggested that, ‘Parachute Technique’ was better than broadcasting with respect to Regulation (1.44), Environment (-2.49) and Performance (-1.57). The farmer perception on parachute technique was ‘poor’ only for Service (0.19) when compared to transplanting. The outcome of the analysis highlights the importance of generating private and market-based incentives for farmers as potential end-users to encourage adoption of EFTs in paddy cultivation. Further, availability of related services and facilitative institutional framework will have a direct impact on the adoption of such EFTs.Item Effect of Biochar Application on pH and pH Buffering Capacity of Rubber Growing Soils(Uva Wellassa University of Sri Lanka, 2013) Rathanayaka, R.A.G.S.; Herath, H.M.S.K.; Dharmakeerthi, R.S.Rubber (Heveabrasiliensis L.Muell. Arg.) growing soils in Sri Lanka are less fertile and characterized by low cation exchange capacity (CEC), very high acidity, and low organic carbon (OC). This has resulted low fertilizer use efficiency and low productivity in rubber growing soils. In order to increase soil fertility effectively, amending these soils with biochar (BC) are being evaluated (Dharmakeerthi et al., 2012). Biochar, is a solid material produced from pyrolysis of biomass, is a highly alkaline material with high CEC and higher percentage of stable OC (Sohi et al., 2010). Amending soils with BC may change soil pH and pH buffering capacities (Xu et al., 2012). However, there is no data available on changes of soil pH after BC addition in rubber growing soils not only in Sri Lanka, but also anywhere else in the world. Therefore, this study was conducted to investigate the effect of rubberwood BC on pH and pH buffering capacity of some contrasting rubber growing soilsin Sri Lanka. Methodology Two soils from traditional rubber growing areas i.e. Red Yellow Podsol (RYP) from Paiyagala Estate, Dodangoda, Reddish Brown Latasol (RBL) from Parambe Estate, Parambe, and one soil from dry zone, Reddish Brown Earth (RBE) from Thanamalwila ,representing contrasting agro - ecological conditions were selected for the study. Those soils were mixed with BC made from rubber wood with two different rates, 0 and 2% by weight andincubated at 70% water holding capacity at room temperature 25±2ºC for 12 weeks. The change in pH was measured at 0, 1, 4, and 12 weeks after the biochar amendment. pH buffering capacity was measured in another set of amended soils, incubated for 40 days as above, using the methods given by Liyanage et al. (2012) with certain modifications. All treatments were replicated four times. Results and Discussion Application of biochar increased pH in all three soils; the increase was very small in Thanamalwila soil while the greatest observed in Payagala soil. Week after incubation, the pH increase in the three soils were 0.4, 0.9 and 0.9 for Tanamalwila, Parambe and Payagala soils, respectively (Figure 1). As incubation time increased from 1 to 12 weeks, the pH did not increase significantly (p<0.05) in Thanamalwila and Payagala soils, and the gap decreased in significantly (p<0.05) Parambe soils. types. Thanamalwila soil had the highest pH buffer capacity (7.3mmol/kgpH) while Payagala soil had the lowest value (4.7mmol/kgpH) Parambe soil had (5.5mmol/kgpH) in between value. The pH buffering capacity was highly significantly correlated with CEC of the soils ( R =0.92 ,p< 0.001), indicating that CEC was an important factor determining soil pH buffering capacity.Item Effect of Biochar on Phosphorus Availability and Fixation in Some Rubber Growing Soils of Sri Lanka(Uva Wellassa University of Sri Lanka, 2013) Nandasena, M.A.G.H.; Herath, H.M.S.K.; Dharmakeerthi, R.S.In most rubber growing soils in Sri Lanka, Phosphorus (P) availability is very low and added P fertilizer becomes unavailable to the rubber plant due to strong fixation into Fe and Al oxide minerals prevalent in these soils (Dissanayake et al., 1994). Biochar (BC) may significantly improve soil fertility in acid and highly weathered soils (Lehmann and Rondon, 2006). With respect to soil chemical fertility, Dharmakeerthi et al. (2012) observed a significantly high P uptake in some BC amended rubber growing soils. BC have high P concentration than in other organic materials (Brown 2009). However, no experiment has been so conducted so far on dynamics of soil P (availability and fixation) in BC amended rubber soils, both in Sri Lanka and other rubber growing countries. Therefore, objectives of the present study were: (i) to study the changes in P availability with time in three contrasting soil types in rubber growing areas when they were amended with rubber wood biochar (RWBC), and (b) to determine the effect of RWBC on P fixation in those soils. Methodology Two factorial experiments with two factors; three soil types and three BC rates were conducted under laboratory conditions at Rubber Research Institute of Sri Lanka. . Biochar was produced from rubber wood (RW) at 350°C and added in to the three soils: Reddish Brown Latasolic soil from Parambe (PR), Reddish Brown Earth soil from Thanamalwila (TW), and Red Yellow Podsolic soil from Payagala (PY). Three BC rates were 0, 2 and 5% (w/w) from RW BC. Soils and BC samples were characterized for some important chemical properties using standard methods. In the first experiment each soil type was amended with the 3 BC rates and incubated in four replicates at 80% of water holding capacity (WHC), for 4 weeks. Available P contents were measured at 0, 1, and 4 weeks after incubation. In the second experiment, P fixation capacity of the three soils amended with three different BC rates was assessed, in triplicate, using the Portch and Hunter (1998) method with slight modifications. Five ml solution containing 0, 20, 40, 60 and 80 ppm of P were added to BC amended and unamended soils after air-drying of 3-5 days. Available P from these two experiments were extracted according to the Bray II (Bray and Kurtz, 1945) method and determined by using a SKALAR San++auto analyzer. Data were analyzed using PROC GLM program of the SAS software packageItem Paddy Farmers’ Willingness-To-Pay towards Eco-Friendly Farming Technologies: Case of Adoption of Parachute Technology(Uva Wellassa University of Sri Lanka, 2019-02) De Silva, L.H.N.; Lakmali, C.D.A.; Jayasinghe-Mudalige, U. K.; Dharmakeerthi, R.S.; Sirisena, D.N.The controversial issue of an excessive usage of chemical fertilizers in paddy farming led scientists to investigate on and invent environmentally-friendly production technologies (EFTs) such as ‘Parachute Technology’ that enhances the efficiency of fertilizer uptake. What factors trigger farmers to adopt EFTs in the field, and more importantly, the “role of economics” in adoption of such technologies is, however, not yet fully disclosed. This study, in particular, explores the outcome of an economic analysis carried out to determine the Willingness-To-Pay (WTP) of farmers, as potential end-users, for Parachute Technology. Data were collected by way of face-to-face interviews supported by a structured- questionnaire from a set of farmers (n=120) registered with a multi-stage multi-criteria project on production and promotion of EFTs in Kurunegala and Anuradhapura districts. Choice experiment method was employed to elicit their Marginal WTP for individual attributes. The estimates from Conditional Logit model revealed that certain attributes, including ‘low environmental damage’ (i.e. the highest value of Rs. 7,872), ‘requirement of training’ (Rs. 5,183), ‘integration ability with other EFTs at the beginning’ (Rs. 4,099) and ‘low fertilizer wastage’ (Rs. 2,488) possess a significant relationship with farmer’s WTP. These imply that the farmers, in general, exhibits positive attitudes and willing to pay relatively high prices for eco-friendly attributes associated with EFTs like Parachute Technology, but needs to expose them to a facilitative process along with financial packages to offset short-term benefits of chemical fertilizer use.