International Journal of Horticulture 2026, Vol.16, No.4 http://hortherbpublisher.com/index.php/ijh © 2026 HortHerb Publisher, registered at the publishing platform that is operated by Sophia Publishing Group, founded in British Columbia of Canada. All Rights Reserved.
International Journal of Horticulture 2026, Vol.16, No.4 http://hortherbpublisher.com/index.php/ijh © 2026 HortHerb Publisher, registered at the publishing platform that is operated by Sophia Publishing Group, founded in British Columbia of Canada. All Rights Reserved. Publisher HortHerb Publisher Edited by Editorial Team of International Journal of Horticulture Email: edit@ijh.hortherbpublisher.com Website: http://hortherbpublisher.com/index.php/ijh Address: 11388 Stevenston Hwy, PO Box 96016, Richmond, V7A 5J5, British Columbia Canada International Journal of Horticulture (ISSN 1927-5803) is an open access, peer reviewed journal published online by HortHerb Publisher. The journal publishes all the latest and outstanding research articles, letters and reviews in all aspects of horticultural and its relative science, containing horticultural products, protection; agronomic, entomology, plant pathology, plant nutrition, breeding, post harvest physiology, and biotechnology, are also welcomed; as well as including the tropical fruits, vegetables, ornamentals and industrial crops grown in the open and under protection. HortHerb Publisher is an international Open Access publisher specializing in horticulture, herbal sciences, and tea-related research registered at the publishing platform that is operated by Sophia Publishing Group (SPG), founded in British Columbia of Canada. All the articles published in International Journal of Horticulture are Open Access, and are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. HortHerb Publisher uses CrossCheck service to identify academic plagiarism through the world’s leading plagiarism prevention tool, iParadigms, and to protect the original authors’ copyrights.
International Journal of Horticulture (online), 2026, Vol. 16, No.4 ISSN 1927-5803 http://hortherbpublisher.com/index.php/ijh © 2026 HortHerb Publisher, registered at the publishing platform that is operated by Sophia Publishing Group, founded in British Columbia of Canada. All Rights Reserved. Latest Content Effects of Different Mulching Materials on Growth, Bulb Development, and Yield of Onion (Allium cepa L.) at Bardiya Nepal Bipin Koirala, Aakriti Gautam, Shiva Chaudhary International Journal of Horticulture, 2026, Vol. 16, No. 4, 206-213 From Tunnels to Transformation: Evidence of Livelihood Enhancement through Protected Vegetable Farming in Meghang, Nuwakot Aayushma Poudel, Bishnu Prasad Bhattrai, Krish Rauniyar, Chandani Begam, Asmita Oli International Journal of Horticulture, 2026, Vol. 16, No. 4, 214-227 Evaluation of Fruit Characteristics of Major Varieties of Litchi in Sarlahi, Nepal Alisha Adhikari, Abhishek Pokhrel International Journal of Horticulture, 2026, Vol. 16, No. 4, 228-234 Effects of Organic Fertilization on Soil Health, Nutrient Uptake, and Fruit Quality of Grapevine Minghua Li, Zhen Li International Journal of Horticulture, 2026, Vol. 16, No. 4, 235-250 Effects of Potassium Fertilization on Fruit Size, Sugar Accumulation, and Quality of Citrus Bo Zhang International Journal of Horticulture, 2026, Vol. 16, No. 4, 251-268
International Journal of Horticulture, 2026, Vol.16, No.4, 206-213 http://hortherbpublisher.com/index.php/ijh 206 Research Article Open Access Effects of Different Mulching Materials on Growth, Bulb Development, and Yield of Onion (Allium cepa L.) at Bardiya Nepal Bipin Koirala1 , Aakriti Gautam1 , Shiva Chaudhary2 1 Agriculture and Forestry University, Rampur, Chitwan, 44209, Nepal 2 Shree Janata Secondary School, Bardiya, 21808, Nepal Co-corresponding authors: iambipin500@gmail.com; gautam.aakriti21@gmail.com; shivakumarchaudhary2021@gmail.com International Journal of Horticulture, 2026, Vol.16, No.4 doi: 10.5376/ijh.2026.16.0018 Received: 26 May, 2026 Accepted: 29 Jun., 2026 Published: 13 Jul., 2026 Copyright © 2026 Koirala et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Koirala B., Gautam A., and Chaudhary S., 2026, Effects of different mulching materials on growth, bulb development, and yield of onion (Allium cepa L.) at Bardiya Nepal, International Journal of Horticulture, 16(4): 206-213 (doi: 10.5376/ijh.2026.16.0018) Abstract Onion (Allium cepa L.) is a high-value bulb crop cultivated extensively across Nepal. However, yield is limited by suboptimal soil moisture and temperature regulation, particularly under subtropical conditions. A field experiment was conducted during the rabi season (November 2024-April 2025) using a randomized complete block design with five mulching treatments (control, black plastic, rice straw, banana leaf, and sawdust mulch), each replicated three times. Growth and yield parameters were recorded at regular intervals after transplanting and at harvest. Plastic mulch significantly increased bulb yield (35.27 t/ha), showing a 91.5% improvement over the control (18.42 t/ha), while rice straw mulch produced the tallest plants and longest leaves. Rice straw mulch is recommended as a cost-effective and ecologically sustainable alternative for smallholder onion production under Nepal's subtropical Terai conditions. Keywords Onion (Allium cepa L); Polyethylene mulch; Organic mulch; Bulb yield; Soil moisture conservation; Terai Nepal 1 Introduction Onion (Allium cepa L., family Alliaceae) is one of the most important vegetable crops cultivated worldwide because of its high economic value and widespread use in household consumption and the food industry (Griffiths et al., 2002; Khokhar, 2014). Global onion production is close to 100 million tonnes annually, with South and Southeast Asia accounting for a significant share (FAOSTAT, 2023). In Nepal, onion is grown on approximately 19,346 hectares, producing about 334,047 metric tonnes each year. However, the average productivity remains around 17-18 t/ha, which is lower than the global average of 20-22 t/ha (MoALD, 2023). Improving onion productivity is therefore an important priority for meeting domestic demand and reducing dependence on imports. One of the major factors limiting onion yield is its shallow and fibrous root system, which makes the crop highly sensitive to soil moisture stress and temperature fluctuations (Mutetwa and Mtaita, 2014). In the tropical Terai region of Nepal, high temperatures during the bulbing stage increase soil water loss, reduce nutrient uptake, and ultimately restrict bulb development (Brewster, 2008). Since many smallholder farmers have limited access to reliable irrigation, practices that conserve soil moisture are essential for sustaining onion production. Mulching is an effective agronomic practice for improving the soil environment. By covering the soil surface, mulch reduces evaporation, moderates soil temperature, suppresses weed growth, and minimizes soil erosion (Bhardwaj, 2013; El-Beltagi et al., 2022). Organic mulches, such as rice straw, banana leaves, and sawdust, also improve soil structure and fertility as they decompose, whereas black polyethylene mulch provides greater short-term moisture conservation and soil warming (Ham et al., 1993; Lamont, 2005; Ramakrishna et al., 2006; Nair and Ngouajio, 2012). Although the benefits of mulching have been reported for several vegetable crops, comparative studies evaluating different mulching materials for onion under the Terai conditions of Nepal are still limited. Most previous research has focused on crops such as garlic, potato, and leafy vegetables, with little information on the performance of locally available organic mulches compared with black polyethylene under the same field
International Journal of Horticulture, 2026, Vol.16, No.4, 206-213 http://hortherbpublisher.com/index.php/ijh 207 conditions (Tarara, 2000; Yimer, 2020). Therefore, this study was undertaken to evaluate the effect of different mulching materials on the growth and yield of onion under the agro-climatic conditions of Nepal's Terai region. This study was therefore designed to: (i) evaluate the effects of four mulching materials and an unmulched control on growth dynamics across four developmental stages; (ii) assess their influence on bulb yield components and total fresh yield; and (iii) identify the most suitable mulching strategy for onion production in Bardiya District, Nepal. 2 Materials and Methods 2.1 Experimental site The experiment was conducted at Shree Janata Secondary School, Bansgadhi Municipality, Bardiya District, Lumbini Province, Nepal (28.26° N, 81.52° E; approximately 150 m above sea level) during the rabi season from November 2024 to April 2025. The site has a subtropical monsoon climate with an average annual rainfall of approximately 1,600-1,900 mm, most of which occurs between June and September. During the crop-growing period, the mean monthly temperature ranged from approximately 11 °C in December to 35 °C in April. The experimental field consisted of sandy loam soil with good drainage and a slightly acidic to neutral reaction (pH 6.0-7.2), which is considered suitable for onion cultivation. Based on the regional soil characteristics of Bansgadhi, Bardiya, the cultivated soils generally contain 1.5%-3.0% soil organic matter, 150-300 kg/ha available nitrogen, 15-35 kg/ha available phosphorus, 180-350 kg/ha available potassium, and have a bulk density of 1.3-1.6 g/cm3. These soil properties indicate moderate fertility suitable for vegetable production. The experimental field had previously been cultivated with seasonal cereal crops and had not received any mulch treatment before the establishment of the experiment. 2.2 Experimental design and treatments The experiment was laid out in a Randomized Complete Block Design (RCBD) with five treatments and three replications, resulting in fifteen experimental plots, each measuring 5.0 m2. The treatments were as follows: T1: Control (no mulch); T2: Black polyethylene mulch (25 μm thickness); T3: Rice straw mulch (5 cm thick); T4: Banana leaf mulch (5 cm thick); T5: Sawdust mulch (5 cm thick). The organic mulching materials were collected locally and applied immediately after transplanting to maintain a uniform layer over the soil surface. Black polyethylene mulch was perforated at the designated planting positions before transplanting. Forty-five-day-old seedlings of the locally grown onion cultivar 'Nasik Red' were transplanted on 20 November 2024 at a spacing of 15 cm × 10 cm (between rows × within rows). An inter-plot spacing of 0.5 m and an inter-block spacing of 1.0 m were maintained throughout the experiment. 2.3 Crop management The field was ploughed twice to a depth of approximately 20 cm, followed by harrowing and leveling seven days before transplanting. Fertilizers were applied at the recommended rate of 80:60:60 kg N:P2O5:K2O/ha using urea, diammonium phosphate (DAP), and muriate of potash (MOP). The full doses of phosphorus and potassium and 50% of the nitrogen were applied as basal fertilizer at transplanting, while the remaining nitrogen was top-dressed in two equal splits at three and six weeks after transplanting (WAT). Flood irrigation was used throughout the experiment. All plots received the same amount of irrigation water at five-day intervals to ensure uniform water availability among treatments. Soil moisture was not monitored using soil moisture sensors, tensiometers, or the gravimetric method; therefore, the effects of mulching on soil moisture were inferred from crop growth and yield responses rather than direct soil moisture measurements. Manual weeding was carried out at three and six weeks after transplanting in the control plots, whereas no additional weeding was required in the mulched plots because the mulch effectively suppressed weed growth.
International Journal of Horticulture, 2026, Vol.16, No.4, 206-213 http://hortherbpublisher.com/index.php/ijh 208 2.4 Observations and measurements Five representative plants were randomly selected from the central two rows of each plot and tagged after transplanting for recording growth observations. Plant height (measured from the soil surface to the tip of the longest leaf), leaf length (base to tip of the longest fully expanded leaf), and the number of leaves per plant were recorded at 30, 60, 90, and 120 days after transplanting (DAT). At harvest, stem diameter (measured 2 cm above the bulb neck), bulb fresh weight, bulb length, equatorial bulb diameter, and root length were measured using a digital Vernier caliper (±0.01 mm) and a digital balance (±0.1 g). Total bulb yield was determined from the fresh weight of all harvested bulbs in each plot and converted to tonnes per hectare (t/ha). 2.5 Statistical analysis The recorded data were subjected to analysis of variance (ANOVA) appropriate for a Randomized Complete Block Design (RCBD) using RStudio version 4.3.1. Before conducting ANOVA, the assumptions of normality and homogeneity of variance were verified using the Shapiro-Wilk and Levene's tests, respectively. Treatment means were compared using Duncan's Multiple Range Test (DMRT) at the 5% level of significance. The coefficient of variation (CV%) was calculated to assess the precision of the experiment. 3 Results and Analysis 3.1 Plant height Plant height increased progressively across all treatments from 30 to 90 DAT, with a characteristic decline at 120 DAT reflecting assimilate remobilization from foliar tissues to the developing bulb during senescence (Brewster, 2008). No significant treatment differences were detected at 30 DAT (Table 1). Significant effects were evident from 60 DAT onward. Table 1 Effect of mulching treatments on plant height (cm) of onion (Allium cepa L.) at 30, 60, 90, and 120 days after transplanting (DAT) Treatments Plant height (cm) 30DAT 60DAT 90DAT 120DAT Control 18.47b 35.62c 52.83d 48.91c Banana leaf mulch 19.53ab 38.74bc 58.16c 53.45bc Sawdust mulch 20.28ab 41.15b 61.42bc 58.07b Rice straw mulch 21.74a 44.58a 67.93a 63.41a Plastic mulch 21.19a 44.07a 65.28ab 61.83a LSD(p≤0.05) 2.94 3.51** 4.23** 4.01*** CV(%) 7.86 4.42 3.81 3.64 Grandmean 20.24 40.83 61.12 57.13 Note: Means in a column followed by different lowercase letters differ significantly at p ≤ 0.05 (DMRT). ** p ≤ 0.01; *** p ≤ 0.001. DAT: days after transplanting; LSD: least significant difference; CV: coefficient of variation Rice straw mulch recorded the tallest plants at 60 DAT (44.58 cm), 90 DAT (67.93 cm), and 120 DAT (63.41 cm), closely followed by plastic mulch (44.07, 65.28, and 61.83 cm, respectively). The control consistently produced the shortest plants across all stages. The superiority of rice straw mulch for plant height is attributable to its dual role in moisture retention and progressive release of nitrogen and other nutrients as decomposition proceeds, augmenting the inorganic fertilizer program (Baten et al., 1995; Ramakrishna et al., 2006). These findings are consistent with Islam et al. (2007) and Mutetwa and Mtaita (2014), who documented superior plant height responses under straw mulch compared with bare soil in Alliumcrops. 3.2 Number of leaves per plant Leaf count per plant was significantly influenced by mulching at all observation stages (Table 2). Plastic mulch consistently recorded the greatest leaf numbers: 4.73 (30 DAT), 7.00 (60 DAT), 9.27 (90 DAT), and 9.00 (120 DAT). The control produced the fewest leaves at every stage. Plastic mulch maintains stable, slightly elevated soil
International Journal of Horticulture, 2026, Vol.16, No.4, 206-213 http://hortherbpublisher.com/index.php/ijh 209 temperatures that accelerate meristematic activity and shorten plastochron intervals, thereby increasing leaf production rates (Tarara, 2000; Lamont, 2005). Rice straw mulch was statistically comparable to plastic mulch at 90 and 120 DAT, suggesting its nutrient-release profile increasingly supports rapid leaf development as the crop approaches the grand growth phase. These trends mirror findings of Kabir et al. (2013), who reported plastic mulch superiority for early-stage leaf development with straw mulch increasingly competitive at later stages. Table 2 Effect of mulching treatments on number of leaves per plant of onion (Allium cepa L.) at 30, 60, 90, and 120 days after transplanting (DAT) Treatments Number of leaves per plant 30DAT 60DAT 90DAT 120DAT Control 4.13b 5.67c 7.13c 7.47b Banana leaf mulch 4.27ab 6.00bc 7.87bc 7.93ab Sawdust mulch 4.20b 6.13b 8.07b 8.20ab Rice straw mulch 4.53ab 6.67ab 8.80ab 8.73a Plastic mulch 4.73a 7.00a 9.27a 9.00a LSD(p≤0.05) 0.51 0.57** 0.75** 0.84** CV(%) 6.32 5.14 5.51 6.87 Grandmean 4.37 6.29 8.23 8.27 Note: Means in a column followed by different lowercase letters differ significantly at p ≤ 0.05 (DMRT). ** p ≤ 0.01. DAT: days after transplanting; LSD: least significant difference; CV: coefficient of variation 3.3 Leaf length Leaf length increased from transplanting through 90 DAT before declining at 120 DAT as assimilates were redirected to bulb storage organs (Table 3). Rice straw mulch consistently produced the longest leaves at all stages (25.88, 46.32, 58.14, and 42.37 cm at 30, 60, 90, and 120 DAT). Plastic mulch was statistically at par at all stages. The enhancement under rice straw mulch is attributed to improved nitrogen availability from mineralizing organic matter, which elevates leaf chlorophyll content and photosynthetic efficiency, sustaining leaf expansion (Baten et al., 1995; Nair and Ngouajio, 2012). The control consistently produced the shortest leaves, reflecting competitive water stress and nutrient immobilization associated with soil crusting in unmulched plots. Table 3 Effect of mulching treatments on leaf length (cm) of onion (Allium cepa L.) at 30, 60, 90, and 120 days after transplanting (DAT) Treatments Leaf length (cm) 30DAT 60DAT 90DAT 120DAT Control 22.53b 38.91c 46.07d 30.44d Banana leaf mulch 23.94ab 41.72bc 49.53c 34.88c Sawdust mulch 24.27ab 43.46ab 52.71bc 37.08bc Rice straw mulch 25.88a 46.32a 58.14a 42.37a Plastic mulch 25.17a 45.53a 55.92ab 41.14ab LSD(p≤0.05) 2.21* 3.14* 3.88*** 4.31*** CV(%) 5.24 4.33 3.97 6.22 Grandmean 24.36 43.19 52.47 37.18 Note: Means in a column followed by different lowercase letters differ significantly at p ≤ 0.05 (DMRT). * p ≤ 0.05; *** p ≤ 0.001. DAT: days after transplanting; LSD: least significant difference; CV: coefficient of variation 3.4 Yield and yield-associated parameters All yield parameters except root length were significantly affected by mulching treatments (Table 4). The absence of a statistically significant mulch effect on root length (p > 0.05) likely reflects high intra-block variability and the sensitivity of onion root architecture to micro-scale irrigation uniformity (Larkin, 2020).
International Journal of Horticulture, 2026, Vol.16, No.4, 206-213 http://hortherbpublisher.com/index.php/ijh 210 Table 4 Effect of mulching treatments on yield and yield-related parameters of onion (Allium cepaL.) at harvest Treatments Stem Dia. (cm) Bulb Wt. (g) Bulb length (cm) Bulb Dia. (cm) Root length (cm) Total yield (t/ha) Control 0.89c 61.72e 4.28c 5.21d 10.38a 18.42d Banana leaf mulch 1.11b 80.93cd 4.73bc 5.79cd 9.76a 22.14c Sawdust mulch 1.06b 76.58d 5.19a 5.91bc 10.09a 23.87c Rice straw mulch 1.28a 95.84b 4.97ab 6.53ab 10.68a 29.54b Plastic mulch 1.41a 111.47a 4.83b 7.08a 11.14a 35.27a LSD(p≤0.05) 0.19*** 9.7*** 0.33*** 0.61* 1.97ns 2.9*** CV(%) 5.92 6.24 3.82 5.17 10.91 5.86 Grandmean 1.15 85.31 4.80 6.10 10.41 25.85 Note: Means in a column followed by different lowercase letters differ significantly at p ≤ 0.05 (DMRT). * p ≤ 0.05; *** p ≤ 0.001; ns: not significant. LSD: least significant difference; CV: coefficient of variation; Stem Dia.: stem diameter; Bulb Wt.: bulb weight; Bulb Dia.: bulb diameter 3.4.1 Stem diameter Plastic mulch produced the widest stem diameter (1.41 cm), followed by rice straw mulch (1.28 cm), while the control recorded the smallest (0.89 cm). Pseudostem girth is closely correlated with overall plant vigor, vascular bundle density, and capacity for water and solute transport to the bulb (Ahmad et al., 2022). Banana leaf and sawdust mulches produced intermediate values (1.11 and 1.06 cm, respectively), reflecting their lower thermal insulation and slower nutrient contribution relative to plastic and straw mulches. 3.4.2 Bulb weight Fresh bulb weight differed significantly among treatments (p < 0.001). Plastic mulch achieved the highest value (111.47 g), followed by rice straw mulch (95.84 g), banana leaf mulch (80.93 g), sawdust mulch (76.58 g), and the control (61.72 g). The 80.7% increase in bulb weight under plastic mulch relative to the control underscores the critical importance of consistent moisture supply and thermal regulation during the bulbing phase. These results corroborate Islam et al. (2007) and Najafabadi et al. (2012), who documented substantial bulb weight advantages under polyethylene mulch. The competitive performance of rice straw mulch reflects the combined benefit of moisture conservation and gradual nitrogen supply during storage organ filling. 3.4.3 Bulb length and diameter Sawdust mulch produced the longest bulbs (5.19 cm), though statistically at par with rice straw mulch (4.97 cm). Elongated bulb form under sawdust is attributable to its high porosity and low bulk density when applied as mulch, improving aeration and reducing mechanical resistance to radial bulb expansion (Haque et al., 2003). Bulb diameter was greatest under plastic mulch (7.08 cm), followed by rice straw mulch (6.53 cm), and was lowest in the control (5.21 cm). Equatorial diameter is a primary determinant of commercial grade in onion markets, making the plastic mulch advantage economically significant (Najafabadi et al., 2012). 3.4.4 Total yield Total fresh yield showed the strongest treatment differentiation (Table 4). Plastic mulch yielded 35.27 t/ha 91.5% advantage over the control (18.42 t/ha)—and was significantly superior to all other treatments. Rice straw mulch (29.54 t/ha) was the next highest, statistically distinct from banana leaf mulch (22.14 t/ha), sawdust mulch (23.87 t/ha), and the control. The superior yield under plastic mulch is a cumulative outcome of consistently higher leaf area index, improved photosynthetic duration, enhanced nutrient uptake efficiency, and reduced weed competition across the entire growth cycle (Lamont, 2005; El-Beltagi et al., 2022). The yield hierarchy plastic > rice straw > sawdust > banana leaf > control is consistent with reports from comparable subtropical environments (Ramakrishna et al., 2006; Mutetwa and Mtaita, 2014).
International Journal of Horticulture, 2026, Vol.16, No.4, 206-213 http://hortherbpublisher.com/index.php/ijh 211 4 Discussion 4.1 Effect of mulching on vegetative growth The results clearly showed that mulching improved vegetative growth compared with the unmulched control. Rice straw mulch produced the tallest plants and the longest leaves, while plastic mulch resulted in the highest number of leaves. These improvements suggest that mulching created a more favorable environment for onion growth during the growing season. Mulch generally reduces water loss from the soil surface and suppresses weed growth, allowing plants to use available water and nutrients more efficiently. Since soil moisture and temperature were not measured in this experiment, these factors cannot be confirmed directly, but they are likely to have contributed to the observed differences. The better performance of rice straw mulch may also be related to its gradual decomposition during the cropping period. As the mulch breaks down, it can improve the soil surface environment and provide a small amount of nutrients to the crop. Similar responses have been reported by Ramakrishna et al. (2006), who found that straw mulch improved crop growth by conserving soil moisture and enhancing soil conditions. Likewise, Mutetwa and Mtaita (2014) reported improved vegetative growth of onion under organic mulching compared with bare soil. 4.2 Effect of mulching on bulb development and yield The improvement in vegetative growth was reflected in bulb development and final yield. Plastic mulch produced the highest bulb weight, bulb diameter, stem diameter, and total bulb yield, whereas the control consistently recorded the lowest values. Onion bulb development depends largely on the plant's ability to produce and transfer photosynthates from the leaves to the bulb. Therefore, treatments that supported better leaf growth were also able to produce larger bulbs and higher yields. Rice straw mulch also performed well and produced significantly higher yield than the control. Although its yield was lower than that of plastic mulch, the difference was relatively small considering that rice straw is an inexpensive and locally available material. This suggests that rice straw can be a practical alternative for farmers who wish to improve onion production without relying on plastic mulch. Root length was not significantly affected by the treatments. This indicates that the increase in yield was more closely related to improvements in above-ground growth and bulb development than to changes in root elongation. 4.3 Comparison with previous studies The findings of this study agree with several earlier reports showing positive effects of mulching on onion production. Islam et al. (2007) and Najafabadi et al. (2012) also reported higher bulb yield under plastic mulch than under bare soil. Similarly, Ramakrishna et al. (2006) found that organic mulches improved crop performance by reducing evaporation and creating more favorable soil conditions. However, the magnitude of yield improvement observed in the present study differs from some previous reports. Such differences are expected because crop response to mulching depends on several factors, including climate, soil type, irrigation method, cultivar, and mulch characteristics. In this experiment, onion was grown under the subtropical conditions of western Nepal using flood irrigation, whereas many previous studies were conducted under different environmental conditions and irrigation systems. These differences may explain the variation in yield response among studies. 4.4 Agronomic implications Among the tested mulching materials, plastic mulch was the most effective for maximizing onion yield. Nevertheless, its use also raises concerns about the disposal of polyethylene after harvest and the possibility of plastic residues remaining in agricultural fields. Rice straw mulch offered a good balance between productivity and sustainability. Although it produced a lower yield than plastic mulch, it substantially outperformed the control and other organic mulches. Because rice straw
International Journal of Horticulture, 2026, Vol.16, No.4, 206-213 http://hortherbpublisher.com/index.php/ijh 212 is readily available in the Terai region and decomposes naturally, it can serve as a practical and environmentally friendly option for smallholder farmers. Therefore, farmers seeking maximum yield may prefer plastic mulch, whereas those aiming for a low-cost and sustainable production system may find rice straw mulch to be a suitable alternative. 4.5 Limitations and future research The findings of this study should be interpreted in light of several limitations. The experiment was conducted at a single location during one growing season, and soil moisture, soil temperature, nutrient dynamics, and weed biomass were not measured directly. Consequently, the mechanisms responsible for the beneficial effects of mulching could not be verified experimentally. Future research should evaluate these mulching materials across different locations and growing seasons to determine whether the observed responses remain consistent under varying environmental conditions. Measuring soil moisture, soil temperature, and nutrient availability would help explain the processes responsible for improved crop performance. In addition, economic analyses and assessments of the environmental impacts of plastic mulch would provide useful information for developing practical recommendations for onion growers in Nepal. 5 Conclusion This study provides comprehensive evidence that mulching materials significantly influence the growth trajectory, bulb development, and marketable yield of onion under subtropical conditions in Chitwan, Nepal. Plastic mulch consistently maximized yield parameters, achieving a total fresh yield of 35.27 t/ha nearly double the control yield of 18.42 t/ha with the highest bulb weight (111.47 g), bulb diameter (7.08 cm), and stem diameter (1.41 cm). Rice straw mulch emerged as the strongest-performing organic alternative, particularly for plant height and leaf elongation, with a total yield of 29.54 t/ha representing a 60.4% improvement over the control. Sawdust mulch demonstrated a specific advantage in promoting bulb elongation (5.19 cm), potentially valuable in markets favouring elongated bulb forms. Banana leaf mulch and the unmulched control consistently underperformed across all parameters. Given documented concerns regarding microplastic accumulation, soil contamination, and disposal challenges associated with long-term polyethylene mulch use, rice straw mulch is recommended as the preferred sustainable option for smallholder onion production in Nepal’s Terai region. Where maximum productivity is the primary objective and plastic waste is responsibly managed, plastic mulch remains the most effective single intervention. Future research should investigate the economic feasibility and cost-benefit ratios of mulching systems at different farm scales, long-term effects of organic mulches on soil health and microbial communities, performance across multiple onion varieties, and the potential of biodegradable plastic mulches as transitional alternatives to polyethylene. Authors’ contributions BK conceived and designed the study, conducted the research, interpreted the results, and prepared the original manuscript. AG performed the data analysis, assisted with data interpretation, and critically reviewed the manuscript. SC managed the experimental field, supervised field operations, and collected the experimental data. All authors read and approved the final manuscript. Conflict of Interest Disclosure The authors affirm that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest. References Ahmad A., Yaseen M., Hussain H., Tahir M.N., Gondal A.H., Iqbal M., Aziz A., Irfan M., and Ahmad Z., 2022, Effects of mulching on crop growth, productivity and yield, In: Mulching in Agroecosystems: Plants, Soil and Environment, Singapore: Springer, pp. 215-229. https://doi.org/10.1007/978-981-19-6410-7_14
International Journal of Horticulture, 2026, Vol.16, No.4, 206-213 http://hortherbpublisher.com/index.php/ijh 213 Baten M.A., Nahar B.S., Sarker S.C., and Khan M.A.H., 1995, Effect of different mulches on the growth and yield of late planted garlic (Allium sativumL.), Pakistan Journal of Scientific and Industrial Research, 38: 138-141. Bhardwaj R.L., 2013, Effect of mulching on crop production under rainfed condition: A review, Agricultural Reviews, 34(3): 188-197. https://doi.org/10.5958/j.0976-0741.34.3.003 Brewster J.L., 2008, Onions and other vegetable alliums, 2nd ed., Wallingford, UK: CABI Publishing. El-Beltagi H.S., Basit A., Mohamed H.I., Ali I., Ullah S., Kamel E.A.R., and Ghazzawy H.S., 2022, Mulching as a sustainable water and soil saving practice in agriculture: A review, Agronomy, 12(8): 1881. https://doi.org/10.3390/agronomy12081881 FAOSTAT, 2023, Crop production data: Onions (dry), Rome: Food and Agriculture Organization of the United Nations. https://www.fao.org/faostat/en/#data/QCL Griffiths G., Trueman L., Crowther T., Thomas B., and Smith B., 2002, Onions—a global benefit to health, Phytotherapy Research, 16(7): 603-615. https://doi.org/10.1002/ptr.1222 Ham J.M., Kluitenberg G.J., and Lamont W.J., 1993, Optical properties of plastic mulches affect the field temperature regime, Journal of the American Society for Horticultural Science, 118(2): 188-193. Haque M.S., Islam M.R., Karim M.A., and Khan M.A.H., 2003, Effects of natural and synthetic mulches on garlic and onion (Alliumspp.), Asian Journal of Plant Sciences, 2(1): 83-89. https://doi.org/10.3923/ajps.2003.83.89 Islam M.J., Hossain A.K.M.M., Khanam F., Majumder U.K., Rahman M.M., and Rahman M.S., 2007, Effect of mulching and fertilization on growth and yield of onion at Dinajpur in Bangladesh, Asian Journal of Plant Sciences, 6(1): 98-101. Kabir M., Rahim M., Majumder D., and Iqbal T., 2013, Effect of mulching and tillage on yield and keeping quality of onion (Allium cepa L.), Bangladesh Journal of Agricultural Research, 38(1): 115-125. https://doi.org/10.3329/bjar.v38i1.14858 Khokhar S., 2014, Onion flavonoids and organosulfur compounds: A review, In: Phytochemicals: Biosynthesis, Function and Application, Cham: Springer. https://doi.org/10.1007/978-3-319-04045-5_3 Lamont W.J., 2005, Plastics: Modifying the microclimate for the production of vegetable crops, HortTechnology, 15(3): 477-481. https://doi.org/10.21273/HORTTECH.15.3.0477 Larkin R.P., 2020, Effects of selected soil amendments and mulch type on soil properties and productivity in organic vegetable production, Agronomy, 10(6): 795. https://doi.org/10.3390/agronomy10060795 MoALD, 2023, Statistical information on Nepalese agriculture 2079/80 (2022/23), Kathmandu, Nepal: Ministry of Agriculture and Livestock Development. Mutetwa M., and Mtaita T., 2014, Effects of mulching and fertilizer sources on growth and yield of onion, Journal of Global Innovations in Agricultural and Social Sciences, 2(3): 102-106. Nair A., and Ngouajio M., 2012, Soil microbial biomass, functional microbial diversity, and nematode community structure as affected by cover crops and organic mulches in an organic vegetable production system, Applied Soil Ecology, 58: 45-55. https://doi.org/10.1016/j.apsoil.2012.03.008 Najafabadi M.B.M., Peyvast G., Hassanpour Asil M., Olfati J.A., and Rabiee M., 2012, Mulching effects on the yield and quality of onion as second crop in rice fields, International Journal of Plant Production, 6(3): 315-328. Ramakrishna A., Tam H.M., Wani S.P., and Long T.D., 2006, Effect of mulch on soil temperature, moisture, weed infestation and yield of groundnut in northern Vietnam, Field Crops Research, 95(2-3): 115-125. https://doi.org/10.1016/j.fcr.2005.01.030 Tarara J.M., 2000, Microclimate modification with plastic mulch, HortScience, 35(2): 169-180. https://doi.org/10.21273/HORTSCI.35.2.169 Yimer O., 2020, Different mulch material on growth, performance and yield of garlic and onion: A review, International Journal of the Science of Food and Agriculture, 4(1): 38-42. https://doi.org/10.26855/ijfsa.2020.03.005
International Journal of Horticulture, 2026, Vol.16, No.4, 214-227 http://hortherbpublisher.com/index.php/ijh 214 Research Article Open Access From Tunnels to Transformation: Evidence of Livelihood Enhancement through Protected Vegetable Farming in Meghang, Nuwakot Aayushma Poudel 1 , Bishnu Prasad Bhattrai 1, Krish Rauniyar2, Chandani Begam1, Asmita Oli 1 1 Himalayan College of Agricultural Sciences and Technology (HICAST), Kathmandu, 44600, Nepal 2 Southern Illinois University, Carbondale, Illinois, 62901, USA Corresponding author: aayushma.ag@gmail.com International Journal of Horticulture, 2026, Vol.16, No.4 doi: 10.5376/ijh.2026.16.0019 Received: 16 May, 2026 Accepted: 15 Jul., 2026 Published: 28 Jul., 2026 Copyright © 2026 Poudel et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Poudel A., Bhattrai B.P., Rauniyar K., Begam C., and Oli A., 2026, From tunnels to transformation: evidence of livelihood enhancement through protected vegetable farming in Meghang, Nuwakot, International Journal of Horticulture, 16(4): 214-227 (doi: 10.5376/ijh.2026.16.0019) Abstract This study was carried out from March 2025 to June 2025 to assess the contribution of tunnel based vegetable farming in household income and livelihood enhancement in Meghang Rural Municipality, Nuwakot. The data was taken from five wards namely Panera (ward No.6), Samari (ward No.5), Kimtang (ward No.4), Deurali (ward No.3), Bungtang (ward No.2). A total of 100 farmers were selected through simple random sampling, and data were collected using household surveys and interviews. According to the study, farming community was dominated by male farmers (68%) and the majority were between the ages of 30 to 50. The majority of respondents were involved in vegetable farming as prime occupation and source of income. Tomato was the dominant crop grown under tunnels, and most farmers adopted improved practices such as drip irrigation and mulching. Majority of farmers relied on agro vets for hybrid seeds, applied FYM with chemical fertilizers, and had built medium sized, 6*12 m tunnel covered with 90 GSM plastic sheets. About 38% of the farmers who produced vegetables in tunnels earned more than NRs. 3 lakhs annually. About 23% of income was saved and was mostly used for health, education, and food. However, farmers faced challenges such as high initial investment, limited access to inputs, and market dependency. Overall, plastic tunnel farming has the potential to support household income generation and livelihood improvement in the study area. Keywords Farming; Income; Livelihood; Tunnel; Vegetable 1 Introduction Vegetable farming is an important income generating activity for smallholder farmers in Nepal. It plays significant role in Nepal’s agricultural economy as a valuable cash crops and provides quick cash, improves household income, food security and livelihood conditions among smallholder farmers. As compared to traditional and cereal based farming systems, vegetable production provides opportunity for higher economic return within short production cycle and limited land resources while having higher demand in the market. Vegetables are considered important for both nutrition and economic reasons. Vegetables are abundant in nutrients, minerals and vitamins. Vegetables consist of phytochemicals which are antioxidant and anti-inflammatory in nature, these properties help reduce the risk of chronic diseases such as diabetes, cancers, obesity or cardiovascular diseases (Abobatta, 2021). Vegetable production, yield, and cultivation area have all steadily increased in Nepal's agriculture sector during the last ten years. While production climbed by 21% in the fiscal year 2020-21, the cultivated area increased by nearly 16% between 2011-12 and 2020-21. But in the last year, productivity has only gone up by 4.38%. With the exception of the fiscal years 2016-17, 2019-20, and 2020-21, the cultivated area, production, and productivity were all steadily rising overall (Ghimire et al., 2023). According to the Food and Agriculture Organization (FAO’s) 2024 data, global fruit and vegetable production reached 2.1 billion tonnes in 2023, which represents a 1% rise compared to 2022 (FAO, 2024). In Nepal, the vegetable industry is the largest subsector, accounting for 80.09% of the country's total horticultural produce and 9.7% of its overall Agricultural Gross Domestic Product (AGDP). Over the past 20 years, Nepal's total per capita
International Journal of Horticulture, 2026, Vol.16, No.4, 214-227 http://hortherbpublisher.com/index.php/ijh 215 vegetable intake has grown from 60 kg to 128.04 kg (Gyawali et al., 2022). An estimated 3,243,521 households cultivate vegetables, with women leading 17% of these households (CASA, 2020). Despite the growing significance of vegetable farming in Nepal, production is highly influenced by seasonal climate changes, particularly in the mid-hills and high-hills of Nepal. Farmers often face challenges such as disease and pest outbreaks, heavy rainfall, frost, low temperature and limited production opportunity during off-seasons. These challenges impact crop yield, market supply and profitability. Therefore, the adoption of protected cultivation technology including plastic tunnels has emerged as a potential approach to mitigate climatic constraints and boost vegetable production. Growing out of season crops in a controlled environment within plastic tunnels is generally referred as tunnel farming. Usually, this kind of farming is employed to grow summer vegetables during the off seasons (Sarmah et al., 2022). With the use of these protected cultivation technologies, farmers can design controlled environments that are suited to the unique requirements of their crops, increasing crop quality, productivity, and resource efficiency. The most popular type includes shade houses, polyhouses, greenhouses, and others (Rana and Sahu, 2024). These structures help regulate temperature, conserve soil moisture, protect crops from frost, excessive rainfall and wind damages. These structures reduce the impact of adverse weather conditions and provide favourable environment, improves crop quality, fetch higher market price and extend production periods. According to Atreya et al. (2020), Nepal's estimated 1,000 hectares of protected farming, 70% are used for vegetable production and 30% are used for fruit and flower cultivation. Protected vegetable cultivation is especially important for small holder’s farmers in the mid-hill areas of Nepal, where restricted land and climate uncertainties hinder year round yields. Tunnel production allows farmers to cultivate high value vegetable crops like tomatoes, cucumbers, leafy greens with optimum utilization of land and resources. Studies have shown that tunnel technology contributes to improved crop productivity and supports livelihood improvement by increasing production opportunities and strengthening income generation among smallholder farmers (Kc et al., 2021). Meghang Rural Municipality in the Nuwakot district is emerging as a significant area for vegetable production under tunnel technology. Due to favourable agro-climatic conditions and the growing farmers interest in protected vegetable cultivation, the area has been recognized as a vegetable production zone under the National Agriculture Modernization Program (NAMP). However, few studies have investigated the socio-economic impacts of plastic tunnel vegetable farming at a local level, particularly regarding farmer’s production practices, marketing systems, and how they utilize the income generated for their livelihoods. Therefore, this study aimed to assess the contribution of tunnel based vegetable farming to household income and livelihood improvement among smallholder farmers in Meghang Rural Municipality, Nuwakot. This study examined farmer’s socioeconomic characteristics, tunnel production practices, vegetable marketing channel, income generation and major constraints affecting vegetable production. 2 Materials and Methods 2.1 Study area The study was carried out in Meghang Rural Municipality, Nuwakot (Figure 1). Meghang is a Rural Municipality located in Nuwakot District of Nepal, it has total 6 wards and 98 square kilometers of geographical area, according to 2011 census, it had total population of 13,479 (Karki, 2019). The data was taken from 5 different wards namely, Panera (ward No.6), Samari (ward No.5), Kimtang (ward No.4), Deurali (ward No.3), Bungtang (ward No.2). The research area represents a mid-hill agro ecological setting ideal for commercial vegetable cultivation. The area has a temperate climate with seasonal changes, where cold winter temperature and significant rainfall during the monsoon season frequently impact open-field vegetable cultivation. These climatic constraints lead farmers to utilize protected methods like plastic tunnels to prolong the growing season and enhance crop yield.
International Journal of Horticulture, 2026, Vol.16, No.4, 214-227 http://hortherbpublisher.com/index.php/ijh 216 Agriculture serves as the primary source of livelihood in Meghang Rural Municipality, where farmers primarily engage in vegetable cultivation (tomato, cabbage, cauliflower, cucumber, potato as primary crops), livestock rearing, and diverse farming practices. The grown vegetables are sold via local collection systems, cooperatives, and middleman to nearby urban areas such as Kathmandu which is around a distance of 80 km. The study area was selected purposively because the region has developed into a growing hub for vegetable production as part of the National Agriculture Modernization Program (NAMP) with a rise in the use of plastic tunnels for commercial vegetable farming. Figure 1 Map of Meghang Rural Municipality, Nuwakot, Nepal 2.2 Sample size A household was considered as the sampling unit for the study. A total of 100 households were selected using a simple random sampling technique and the data were recorded from the respective farmers involved in vegetable production under plastic tunnels. The sample size was selected considering the availability of tunnel based vegetable growers, feasibility of household level data collection, time constraints and available resources while maintaining adequate representation of farmers involved in protected vegetable cultivation. Due to the absence of a complete publicly available database, 100 households were selected using simple random sampling based on the available list of active tunnel vegetable growers and the feasibility of household level data collection. The chosen sample consisted of farmers with various socioeconomic status and farming sizes to reflect differences in tunnel structures, production methods, income generation, and marketing strategies. 2.3 Data collection Primary data were acquired by direct personal interview and household survey using semi-structured questionnaires. An objectively prepared survey questionnaire was created to collect necessary primary data and information on the socioeconomic profile of vegetable growers under plastic tunnels, demographic information about family members, farmer landholdings, farming practices, and income status.
International Journal of Horticulture, 2026, Vol.16, No.4, 214-227 http://hortherbpublisher.com/index.php/ijh 217 The secondary data were gathered from a variety of published and unpublished materials from different sources. These materials contain annual reports from Ministry of Agriculture and Livestock Development (MoALD), Nepal Agriculture Research Council (NARC), and District Agriculture Development Office (DADO), as well as research papers, articles, and journals. 2.4 Data analysis The gathered data were organized, coded and analyzed using Microsoft excel. Descriptive statistical tools were used to summarize the characteristic of respondents and their production practices. Frequency and percentage analysis were used to describe the socioeconomic characteristics, tunnel structures, irrigation methods, marketing channel and income categories. Results were presented using tables, figures, and graphical representations. The study mainly used descriptive analysis because the objectives was simply to assess the current status, production practices, income patterns, and perceived livelihood contribution of tunnel based vegetable farming among surveyed households. 3 Results and Analysis 3.1 Socio-demographic information of the respondents The socio-demographic information of the respondents is presented in (Table 1). Among the 100 respondents, 68% were male and 32% were female farmers. The majority of the respondents (40%) belonged to active age group of 30-50 years followed by those between 50-70 years (30%), 20-30 years (20%), and above 70 years (10%). Table 1 Socio-demographic information of the respondents Demographic characters Category Percentage (%) Gender Male Female 68 32 Age group 20-30 30-50 50-70 70 above 20 40 30 10 Literacy status Illiterate Literate Below SLC (School Leaving Certificate) Plus 2 Graduate 22 18 34 19 7 Occupation Farming Business Service Wage labour Others 60 10 9 13 8 Total land under plastic tunnel cultivation 0.05-0.25 ha 0.25-0.50 ha More than 0.50 ha 37 40 23 Regarding educational status, most respondents had basic education. About 34% had education below the School Leaving Certificate (SLC) level, 19% had completed higher secondary education, 7% had a university degree, while 22% were illiterate. In terms of occupation, a significant 60% of the population were engaged in farming activities as primary occupation while a relatively smaller percentage were engaged in wage work, businesses, and services, at 13%, 10%, and 9%, respectively. In terms of land allocation for tunnel cultivation, 40% of farmers cultivated vegetables on small to medium-sized plots (0.25-0.50 ha), while 37% cultivated on less than 0.25 ha and 23% cultivated on
International Journal of Horticulture, 2026, Vol.16, No.4, 214-227 http://hortherbpublisher.com/index.php/ijh 218 more than 0.50 ha. These findings indicate that the tunnel vegetable farming in the study area is mainly practiced by small and medium scale farming households. 3.2 Plastic tunnel structures 3.2.1 Types of tunnel used by the respondents Farmers used different types of plastic tunnels based on their farm size, investment capacity and crop to be planted. Among the respondents, 84% used medium sized tunnel with a height of 2-2.5 m, while 10% used high tunnel (4-5 m) and 6% used low tunnels (up to 1 m) (Figure 2). Figure 2 Types of tunnels used by the respondents The most common structure respondents used were medium tunnels as they are suitable for crops like tomato and cucumber. Protected structures such as walk-in tunnels are common for cultivating commercial vegetables as they provide a controlled environment and allow efficient crop management (FAO, 2013). 3.2.2 Grams per Square Meter (GSM) of plastic used by the respondents The majority i.e. 60% of the farmers used 90 GSM plastic sheets, followed by 120 GSM (25%), 200 GSM (7%), and 8% of the other farmers used others GSM (50 GSM, 70 GSM, 150 GSM) and microns plastic (100 micron, 200 micron) (Figure 3). Figure 3 GSM of plastic used by the respondents
International Journal of Horticulture, 2026, Vol.16, No.4, 214-227 http://hortherbpublisher.com/index.php/ijh 219 The thickness of plastic is important factor in durability of tunnel especially in areas exposed to rain, strong wind and hailstorm. Plastic materials ranging from 70-120 GSM are commonly used for protected structures in Nepal (Bhusal et al., 2022). 3.2.3 Size of the plastic tunnel used by the respondents Different tunnel sizes were observed among farmers. The most common tunnel size was 6*12 m, adopted by 35% of respondents. Other tunnel sizes included 6*18 m (20%), 6*10 m (15%), 6*15 m (12%), and other sizes (18%) include 12*15 m, 15*18 m, 18*24 m of plastic tunnels (Figure 4). Figure 4 Size of the plastic tunnel used by the respondents 3.3 Vegetable production practices 3.3.1 Major vegetables grown by respondents Tomato was the dominant vegetable cultivated under tunnels, grown by 70% of respondents. Beside tomato, other vegetables grown in the field were cauliflower, cabbage, leafy greens, cucumber, others (peas, beans, chilli, eggplants) which holds 8%, 4%, 6%, 10%, 2% respectively. The dominance of tomato shows its commercial importance and suitability for protected cultivation. According to MoALD (2024), tomato is among the major commercial vegetable crops cultivated in Nepal. The most recent district level statistics (2022/23) indicate that Nuwakot has approximately 3049 ha, 39741Mt and 13034 kg/ha of total area, production, and productivity of vegetables respectively and the major vegetables grown in Nuwakot district are radish, cabbage, cauliflower, pumpkin, broad leaf mustard, cucumber, peas etc (Pokhrel et al., 2022). 3.3.2 Major varieties of vegetable crops grown for commercial farming The major varieties of tomato were Sirjana and Sarbashrestha. They were the highest yielding varieties as per the farmers with a maximum reported yield of around 120 t/ha for Sirjana, and around 70 t/ha for Sarbashrestha (Table 2). White Top was most common variety of cauliflower. The variety of cabbage planted was Green Coronet, while Bhaktapur Local was the major variety of cucumber. 3.3.3 Types of seed used by the respondents The majority of the respondent 60% people used hybrid seeds, (such as Sirjana and Sarbashrestha, for tomato, White Top, Snow Grace for cauliflower, Green Coronet, Futoski F1, for cabbage and Madhu F1, for cucumber). 10% of the respondents used local seeds (such as Kathmandu Local for cauliflower, and Bhaktapur Local for cucumber). While 18% used both local and hybrid seeds, and 12% of them used improved seeds (such as
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