60 research outputs found
Leaf area index and aboveground biomass estimation of Populus and its hybrids using terrestrial LiDAR
Short rotation woody crops (SRWC) eastern cottonwood (Populus deltoides) and hybrid poplar plantations were established in 2021 in Pontotoc and Oktibbeha counties of Mississippi to study the biomass potential of SRWC for biofuel production. We used a novel backpack LiDAR system to measure forest metrics and harvested sample trees to build aboveground biomass (AGB) and leaf area index (LAI) equations. The results showed that LiDAR-derived variables accurately estimated aboveground biomass (R2 =0.81 and 29.22 % RMSE). However, the LAI estimation results showed that the LiDAR metrics moderately explained field measurements of LAI (R2 =0.31 and 18.05% RMSE) for individual-trees and poorly explained plot-level LAI measured with the LAI-2200C (R2 =0.11 and 66% RMSE). The backpack LiDAR system can be valuable for forest managers and researchers, enabling non-destructive AGB and LAI estimation. However, further research is required to overcome its limitations and achieve precise measurements of AGB and LAI
Synthesis of Carbohydrate Based Macrolactones and Their Applications as Receptors for Ion Recognition and Catalysis
Glycomacrolactones exhibit many interesting biological properties, and they are also important in molecular recognitions and for supramolecular chemistry. Therefore, it is important to be able to access glycomacrocycles with different sizes and functionality. A new series of carbohydrate-based macrocycles containing triazole and lactone moieties have been designed and synthesized. The synthesis features an intramolecular nucleophilic substitution reaction for the macrocyclization step. In this article, the effect of some common sulfonate leaving groups is evaluated for macrolactonization. Using tosylate gave good selectivity for monolactonization products with good yields. Fourteen different macrocycles have been synthesized and characterized, of which eleven macrocycles are from cyclization of the C1 to C6 positions of N-acetyl D-glucosamine derivatives and three others from C2 to C6 cyclization of functionalized D-glucosamine derivatives. These novel macrolactones have unique structures and demonstrate interesting anion binding properties, especially for chloride. The macrocycles containing two triazoles form complexes with copper sulfate, and they are effective ligands for copper sulfate mediated azide-alkyne cycloaddition reactions (CuAAC). In addition, several macrocycles show some selectivity for different alkynes
Habitat Suitability and Conflict Zone Mapping for the Blue Bull (Boselaphus tragocamelus) across Nepal
Rapidly changing environmental conditions (bioclimatic, anthropogenic, topographic, and vegetation-related variables) are likely to alter the spatial distribution of flora and fauna. To understand the influence of environmental variables on the Blue bull’s distribution and to identify potential conflict zones, the habitat suitability analysis of the Blue bull was performed using ensemble modeling. We modelled the distribution of the Blue bull using an extensive database on the current distribution of the Blue bull and selected 15 ecologically significant environmental variables. We used ten species distribution modeling algorithms available in the BIOMOD2 R package. Among the ten algorithms, the Random Forest, Maxent, and Generalized linear model had the highest mean true skill statistics scores, ensuring better model performance, and were considered for further analysis. We found that 22,462.57 km2 (15.26%) of Nepal is suitable for the Blue bull. Slope, precipitation seasonality, and distance to the road are the environmental variables contributing the most to the distribution of Blue bull. Of the total predicted suitable habitats, 86% lies outside protected areas and 55% overlaps with agricultural land. Thus, we recommend that the future conservation initiatives including appropriate conflict mitigation measures should be prioritized equally in both protected areas and outside protected areas to ensure the species’ survival in the region
Decision to use herbicide in wheat production by the farm households in Nepal: A probit regression analysis
The use of herbicides in wheat production is increasing in Nepal mainly due to labor shortage and higher wage rates, even if available. However, little information is available on what factors determine the use of herbicides. This study explored the major factors that affect the decision to use herbicide by the wheat farmers. The semi-structured interview schedule was administered to 343 farmers from four major wheat-growing districts. The study employed a probit regression model to identify the factors that influenced the decision to use herbicides. Educations, membership, migration, wheat cultivated area, amount of urea use were identified as the significant factors influencing the decision of farmers to use herbicides. Herbicides user farmers produced 220 kg more wheat grain yield from one hectare of land compared to non-users. This study suggests that the wheat yield of Nepal could be increased through adopting better weed management techniques
Synthesis and Self-Assembling Properties of Carbohydrate- and Diarylethene-Based Photoswitchable Molecular Gelators
Carbohydrate-based low-molecular-weight gelators are interesting new materials with many potential applications. These compounds can be designed to include multiple stimuli-responsive functional groups. In this study, we designed and synthesized several chemically responsive bola-glycolipids and dimeric carbohydrate- and diarylethene-based photoswitchable derivatives. The dimeric glycolipids formed stable gels in a variety of solvent systems. The best performing gelators in this series contained decanedioic and dithienylethene (DTE) spacers, which formed gels in eight and nine of the tested solvents, respectively. The two new DTE-containing esters possessed interesting photoswitching properties and DTE derivative 7 was found to have versatile gelation properties in many solvents, including DMSO solutions at low concentrations. The gels formed by these compounds were stable under acidic conditions and tended to hydrolyze under basic conditions. Several gels were used to absorb rhodamine B and Toluidine blue from aqueous solutions. In this study, we demonstrated the rational design of molecular gelators which incorporated photoresponsive and pH responsive functions, leading to the discovery of multiple effective stimuli-responsive gelators
Good agricultural practices in mandarin (Citrus reticulata Blanco); Perception and factors affecting awareness among farmers in Gulmi, Nepal
Citrus, in general, and mandarin, in particular, has long been one of Nepal's most important fruit crops. However, in recent years, a lack of good cultivation procedures and negligence has resulted in a significant reduction in its productivity. The declining situation cannot be controlled without the transfer of science-based knowledge and skills where Good Agricultural Practices have been linked to higher output. A study was carried out in 2020 to assess the perception of farmers towards Good Agricultural Practices and factors affecting awareness of GAP among mandarin growers. Altogether 100 households from Dhurkot and Chhatrakot Rural Municipalities, and Resunga Municipality from Gulmi district, were purposively chosen for the study in the command area of the PMAMP PIU Citrus Zone, and sampling was carried out using a simple random sampling technique. Data were collected with the use of a semi-structured questionnaire, entered, and analyzed using SPSS and STATA software. The farmers were categorized into GAP aware and unaware based on the criteria made by the focus group discussion carried out with the leading farmers, mandarin experts, and government agriculture officers. The findings revealed that 39% of the total respondents knew about GAP for mandarin. The entire respondents agreed that GAP-produced fruit has a nicer appearance and better quality and fruits meet national and international standards and enhance exportability of fruits, however, 61.5% of respondents didn’t agree that GAP helps in providing subsidies from governmental organizations. The output of the binary logit model suggested that an increase in participation in training and contact with extension agents has a significant effect on awareness of GAP. Participatory GAP training, regular extension services to smallholding farmers could be beneficial for mandarin farmers leading to commercialization
Technical efficiency of wheat growing farmers of Nepal
Wheat is a major staple food crop of Nepal, so it is necessary to increase its productivity. However, the national average wheat productivity of Nepal is low as compared to other neighboring countries. This study employed a Cobb-Douglas stochastic production frontier model to examine the technical efficiency and its determinants using randomly selected household data from 343 wheat farmers from four districts of Nepal. Maximum likelihood estimation results showed that wheat production responded positively to an increase in the quantity of inorganic fertilizer, whereas it was detrimental to seed rate. Likewise, the study found that farmers were not technically efficient with a mean technical efficiency of 81%. The result showed irrigation, herbicides, sowing time, Farm Yard Manure (FYM), and wheat varieties were statistically significant factors that affect the technical efficiency of wheat farmers. Furthermore, to increase wheat productivity, farmers should use better irrigation, appropriate weed management practices, optimum sowing time, and adoption of recent improved varieties. Findings suggest that the technical efficiency of wheat farmers could be enhanced by practicing optimum use of inputs and improving the inefficiency factor
Zero till in wheat from the gender perspective in Nepal
Different tillage practices such as zero-till direct-seeded rice (ZTDSR), zero-till maize (ZTM), and zero-till wheat (ZTW) were implemented in the farmer's field of Sunsari district were evaluated. However, the focus was on ZTW because of high its competitiveness with cheaper wheat from abroad. Focus Group Discussion (FGD), Famers households keeping records, field monitoring, key informant interviews were the primary source of data whereas literature and desktop review were done for secondary data. Zero till wheat operation scale out of the machine use had been increased, by 61.25% out of 109.63ha land in Bhokraha and 66.49 % out of 55.3ha of land in Kaptangunj. Whereas, a new node Chitaha was established with the initiation of non-respondent farmer's where the area occupied 26ha in the year of 2019 respectively as compared to the base year that of 2014. Yield advantage was not much higher with ZTW, the additional benefit of almost 34% over conventional till wheat (CTW) was sufficient enough for the farmers to decide to adopt zero tillage technology. Farmers perceived about 17% saving in seed requirement, 13% saving in irrigation amount and time, and 44% saving in total labor cost with ZTW to make it more profitable as compared to CTW. Among different methods of extension, farmers’ field day with 63% and field trial with 48% with women's participation shows the most effective method to create awareness. Although the percentage of the working hour for the female worker is higher the number of the total hour has been decreased for both the man and women and the total 303.64hr/ha has been saved
Technical efficiency of hybrid maize production in eastern terai of Nepal: A stochastic frontier approach
Maize is the second most important crop after rice in terms of area and production in Nepal. This article analyzes the technical efficiency and its determinants of hybrid maize production in eastern Nepal. Using a randomly selected data from 98 farmers (41 from Morang and 57 from Sunsari) in eastern Nepal, the study employed a stochastic frontier production model to find the production elasticity coefficients of inputs, determinants of efficiency and technical efficiency of hybrid maize farmers. The results showed that maize production responds positively to increase in amount of urea, DAP and the area planted, where as it is negative to seed quantity. The study indicate that farmers are not technically efficient with a mean technical efficiency 79 %. Socioeconomic variable age had a negative and significant while the household size had a positive and significant related to maize output. The younger farmers were observed more technically efficient than older farmers. Larger the members in the household higher the maize production. It is recommended that farmers should increase their fertilizer dose and farm size while they should decrease their seed rate for efficient production
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