Agronomy Journal of Nepal

Growth and Productivity of Cowpea (Vigna unguiculata L.) in Response to Seed Priming and Different Levels of Phosphorus

Asmita Amgai — 2023-07-10

Acidic soil generally has lower availability of phosphorus. Grain legumes respond positively to higher levels of phosphorus in acidic soil. Seed priming also enhances growth of the crops by activating various metabolic processes in plants. A field experiment was carried out to determine the influence of seed priming and phosphorus levels on growth and productivity of cowpea at Bhojad, Chitwan, Nepal. The experiment plot was laid out in two factorial randomized complete block design with three replications and the planting was done in spring season of 2022. The treatment consisted of two levels of seed priming (no priming and priming with 0.2 % Ca (NO₃)₂ for 24 hours) and four levels of P₂O₅ (20,30,40 and 60 kg ha^-1). The variations in different parameters of cowpea due to seed priming were significant (P < 0.05). Primed seed produced the highest grain yield (1.25 t ha^-1), which was followed by non-primed seeds (1.16 t ha^-1). Similar significant (p<0.001) differences in yield and yield-attributing (no. of grains/pods, test weight, biological yield, grain yield and harvest index) traits were found at different levels of P₂O₅, with the highest grain yield (1.44 t ha^-1) was obtained when applied with 40 kg P₂O₅ ha^-1. Significant (p<0.001) variations in grain yield were found as a result of the interaction between priming and P2O5 levels. The combination of priming and 40 kg P₂O₅ ha^-1 produced the highest grain yield (1.51 t ha^-1). The results showed that the use of primed seed with 40 kg P₂O₅ ha^-1 would be beneficial for the farmers in the Terai region of Nepal.

Growth and Yield of Cowpea (Vigna unguiculata L.) Under Different Levels of Phosphorous and Seed Inoculation with Rhizobium

Ankita Poudel — 2023-07-10

Cowpea (Vigna unguiculata L.) is a major source of protein and an important component of Nepal's cropping systems. However, yields are very low due to a lack of improved cultivars, poor management practices, and limited input use. The objective of this study was to evaluate the effects of rhizobia inoculant and P on cowpea growth and yield. A field study was carried out in Bharatpur-11, Chitwan, Nepal, during the spring season of 2022, using a randomized complete block design with three replications and eight treatments. The treatments included four different phosphorus doses (20, 40, 60, and 80 kg ha^-1) and seed inoculation (un-inoculated and inoculated). The rhizobium-inoculated plants produced significantly higher grain yield (1.27 t ha^-1) and various yield-attributing parameters than un-inoculated plants. Phosphorus fertilizer at 40 kg ha^-1 produced a higher grain yield (1.41 t ha^-1) than other phosphorus doses. The combination of rhizobium inoculation and application of phosphorus at the rate 40 kg ha^-1 yielded the highest grain yield (1.53 t ha^-1). The results show that phosphorus dose of 40 kg ha^-1 combined with Rhizobium inoculation with seed has the potential to improve cowpea grain yield.

Effect of Plant Density and Fertilizer Management Practices on Yield of Spring Maize

Binod Kumar Mandal — 2023-07-10

The grain yield of maize is lowered by an insufficient plant population and an unbalanced fertilizer application. An experiment was carried out in the spring to address these problems. The treatments were set up in a split-plot design with three replications and included factorial combinations of three planting densities and four fertilizer levels: 120:60:40 kg N, P₂O₅, K₂O ha^-1, 120% RBR, 150% RBR, and site-specific nutrient management (SSNM), 140:40:40 kg N, P₂O₅, K₂O ha^-1. Both the barrenness and sterility percentages were higher (p<0.05) for the highest planting densities and the lowest for the lowest plant densities. A higher (p<0.05) number of kernels per cob was recorded at the lowest plant density and the highest amount of fertilizer application. For the lowest and highest plant densities, the leaf area index increased the grain yield, whereas longer grain filling duration and less barrenness and sterility increased (p<0.05) the grain yield for all plant densities. The number of kernels per row or cob was the most crucial factor in increasing the yield of maize under a higher plant density, whereas the final plant population was the most crucial factor in increasing the yield under a lower plant density. Due to a higher number of final plant populations and comparable yield traits, the grain yield of the planting density with the highest grain production was significantly higher. The increased amount of fertilizer (144:72:48 N:P₂O₅:K₂O kg ha^-1, 180:90:60 N:P₂O₅:K₂O kg ha^-1) gave a higher grain yield. The plant densities of 66667 ha^-1 and 83333 ha^-1 were better, whereas the present recommended dose of N: P₂O₅:K₂O should be increased or need-based SSNM must be adopted to obtain more profits from spring maize.

Direct Seeded Rice Might Be One of the Potential Climate Smart Agricultural Technologies in Nepal

Tika Bahadur Karki — 2023-07-10

The conventional system of puddled transplanting of rice (PTR) with intensive tillage is common practice of rice growing in Nepal. It has many negative impacts on soil, water, labor, climate change and gender equality. Therefore, an alternative production system has been explored. Direct seeded rice (DSR) has been one of the potential systems of rice production in Nepal. The results of various studies on DSR revealed that it saves labor, requires less water, less drudgery, less energy, early crop maturity, low cost of production, better soil physical conditions and less greenhouse gas emission. The grain yields in DSR are comparable with PTR. However, special attentions must be given in selection of suitable cultivars, appropriate time of sowing, optimum seed rate, proper weed and water management practices. Despite its promise, the rate of its adoption is not as expected. It might be due to some of the constraints associated it. In this paper an attempt has been made to highlight the works done in DSR within and outside of the country, its constraints and the possible solutions to scale-out it.

Storability of Different Hermetic Bags on Seed Quality Attributes of Maize in Khumaltar, Lalitpur

Gopal Bhandari — 2023-07-10

To evaluate the comparative superiority of exotic hermetic seed storage bags versus locally available bags supplemented with or without desiccants for on-farm seed storage of smallholders, an experiment was conducted in the National Seed Science and Technology Research Centre (NSSTRC) of Nepal Agricultural Research Council (NARC) from May 2017 to June 2019. Maize seed variety Manakamana-3 was allocated in 8 treatments based on storage devices with three replications in a completely randomized design (CRD). The 98% initial germinating seed was stored in eight different storage containers viz., S1, Super grain bag; S2, PICS bag; S3, Safe Grain bag; S4, 400-gauge plastic bag; S5, 400-gauge plastic double liner; S6, 400 gauge + metal bin; S7, 400 gauge + Zeolite beads; S8, 400 gauge + roasted wheat. All seed attributing data were taken in tri-monthly intervals for two and half years. In the first year, all seven treatments were found statistically at par results for germination above 85% by meeting the Nepalese maize seed standard except 400-gauze plastic bag-single liner. However, significant differences were seen in each treatment in the second year. Results on germination of storage structures with desiccants viz., 400 gauge + Zeolite beads, and 400 gauge + roasted wheat were found superior to any other storage structures such as PICS bag, Super grain bag, Safe grain bag, 400 gauge + metal bin, & 400-gauge plastic double liner. Whereas, the single liner of a 400-gauge plastic bag was found non-suitable and found vulnerable to fungal infestation in long-run storage in ambient storage conditions. Hence, it was concluded that the locally fabricated seed storage bags provided equal results to exotic hermetic bags for one season seed storage in Mid-hill, humid and sub-temperate condition of Nepal and hence, found economical modified atmospheric storage (MAS) option for small holder farmers.

Leaf Color Chart Can Increase Productivity and Foster Climate Smart Agriculture in Rice: A Case Study

Ashmita Lamsal — 2023-07-10

Optimum nitrogen application has been a major challenge to enhance agricultural productivity and sustainability in rice cultivation of Nepal. Nitrogen fertilizer must be applied only when necessary and must be based on the crop’s nitrogen requirement. Losses of nitrogen from rice field can cause air pollutant production, global warming and climate change. Leaf Color Chart (LCC) poses potential climate smart practice in rice field. The use of LCC is a low cost and viable method for managing nitrogen in real time, enhancing the nitrogen use efficiency. To demonstrate the effectiveness of LCC based urea application for nitrogen management in rice, a field experiment was conducted at Masala Bali Bikash Kendra, Panchkhal from June to November, 2022. Variety selected for field experimentation was Makawanpur-1. The experiment compared government-recommended urea application with LCC-based application for which field was divided into two equal plots (300 sq m). Morphological growth was measured at different stages of rice and yield was taken at maturity. In rice, LCC-based urea application led to taller plants (128.5 cm) compared to blanket urea application (115.56 cm) at harvest. LCC-based urea application also had 34% more leaves (126) and 54.5% higher effective tiller count (17). Despite the same rate of nitrogen application, yield was 35% higher in LCC based practice (4694.73 kg ha^-1) than government recommended practice. Real time nitrogen application in splits based on LCC management led to better plant growth and yield, while fixed-time nitrogen application regardless of crop need in conventional blanket application resulted in nitrogen loss and lower yield. Considering the effect of nitrogen application through LCC management on rice productivity, it's clear that LCC offers valuable chances to enhance nitrogen use efficiency, rice yield, and farmers' profits.

Nitrogen Levels Effects on Different Maturity Duration Hybrid Rice at Parwanipur, Bara, Nepal

Pradeep Shah — 2023-07-10

Two years field experiments were conducted at Directorate of Agricultural Research, Parwanipur, Bara, Nepal from 2016 to 2017 to assess the effect of different hybrid rice varieties and nitrogen levels on yield attributes, yield and economics of rice. The experiment was arranged in two factorial Randomized Complete Block Design with three replications. The experiment comprised 12 treatment combinations of three different maturity duration hybrid rice varieties (Arize 6129 Gold, Arize Tej Gold and Arize 6444 Gold) and four nitrogen levels (0, 60, 120 and 180 kg ha^-1). The two years combine analysis revealed that the hybrid varieties Arize 6444 Gold (4313 kg ha^-1) and Arize Tej Gold (4274 kg ha^-1) recorded significantly higher grain yield over Arize 6129 Gold (3731 kg ha^-1). These two hybrid varieties (Arize 6444 Gold and Arize Tej Gold) also recorded significantly higher plant length and grains panicle^-1. The nitrogen level of 180 kg ha^-1recorded significantly the highest grain yield at 6357 kg ha^-1. Effective tiller m^-2 and grains panicle^-1 were significantly higher with nitrogen level of 180 kg ha^-1. The thousand grains weight was found significantly higher with 180 kg N ha^-1, which was statistically similar with 60 and 120 kg ha^-1. Moreover, interaction effect between nitrogen levels and varieties revealed that Arize 6444 Gold and Arize Tej Gold equally produced the highest mean grain yield with 180 kg N ha^-1. The highest gross return, net return and B:C ratio were observed with 180 kg N ha^-1 with Arize 6444 Gold and ArizeTej Gold. Therefore, 180 kg N ha^-1 could be optimum dose for Arize 6444 Gold and Arize Tej Gold for Parwanipur, Bara, Nepal.

Effects of Crop Geometry and Split Nitrogen Application on Spring Maize Growth, Yield Components and Yield in Digam, Gulmi, Nepal

Praju Ghimire — 2023-07-10

Maize (Zea mays L.) is a heavy nutrient feeder that needs optimum spacing and appropriate time to apply nitrogen to get maximum yield. A field study was carried out at Digam, Gulmi, from February to June 2022 to examine the impact of crop geometry and split application of nitrogen on spring maize in two factorial randomized complete block design (RCBD) with four replications. Factor A was the split application of nitrogen; (120 kg ha^-1N at the time of sowing) and (60 kg ha^-1N at the time of sowing + 30 kg ha^-1N at knee height stage + 30 kg ha^-1N before tasseling stage) and factor B included the three levels of spacing (75 cm x 25 cm, 60 cm x 25 cm and 50 cm x 25 cm). Plant height , stem girth , leaf number, cob girth, thousand grain weight, number of kernel rows per ear, number of kernels per row, and grain yield (3.45 MT ha^-1) were all highest for treatment (60 kg ha^-1N at sowing + 30 kg ha^-1N at knee height + 30 kg ha^-1N before tasseling). Likewise, plant height, leaf area index, cob length, cob girth, cob weight, thousand grain weight, number of kernels per row, grain yield (3.04 MT ha^-1) and harvest index were highest in plant spaced at (75 cm x 25 cm), while the number of kernel rows per ear was highest in plants spaced at (60 cm x 25 cm). The lowest value of all parameters was found in plants at treatments; (120 kg ha^-1N at the time of sowing) and (50 cm x 25cm). Similarly, the treatment (60 kg ha^-1N at the time of sowing + 30 kg ha^-1N at knee height stage + 30 kg ha^-1N before tasseling stage) combined with spacing of (60cm x 25cm) was found to have a significant effect on grain yield (3.99 MT ha^-1) which was statistically at par to the treatments, (60 kg ha^-1 N at the time of sowing + 30 kg ha^-1 N at knee height stage + 30 kg ha^-1 N before tasseling stage) combined with spacing of (75 cm x 25 cm) (3.95 MT ha^-1 ) . Thus, for the optimum and sustainable production of the spring maize, crop geometry of (75 cm x 25 cm) or (60 cm x 25 cm) can be recommended with three splits application of nitrogen at Digam, Gulmi.

Yield and Seed Quality of Wheat as Affected by Seeding Dates and Boron Levels at Rampur, Chitwan

Bishwo B. Chhetri — 2023-07-10

Yield and seed quality of wheat is affected by sowing dates through its impacts on growing environment, soil moisture content and terminal heat stress. Boron fertilization also impacts on number of seed per spike and quality of the seed. A field experiment was laid out in split-plot design with four sowing dates (15 November, 30 November, 15 December and 30 December) in main plot and four boron levels (0, 1, 2 and 3 kg ha^-1) on sub-plot, replicated thrice to assess the effect of sowing dates and boron levels on yield and seed quality of wheat at Rampur, Chitwan during winter season of 2019. The results revealed that significantly highest grain yield was obtained on November sown wheat compared to December sowing. Highest grain yield was obtained with the application of boron at 3 kg ha^-1, significantly higher than 0 and 1 kg ha^-1boron application. Significant interaction among sowing dates and boron levels was found on grain and seed yield. Seed quality parameters viz; seedling root and shoot length, vigour indices I and II were better in the earlier sown wheat and with 3 kg ha^-1boron application. The germination was also higher in earlier sown wheat but not affected by boron levels. Therefore, wheat with high seed quality can be sown from 15 to 30 November with 3 kg ha^-1boron application in Chitwan and under similar environments.

Effects of Nitrogen Levels on Growth and Yield of Some Newly Released Wheat Genotypes under Bhairahawa Condition

Narayan Khatri — 2023-07-10

The newly released wheat varieties with different nutritional demands and their yield potential hinder generalized recommendations for nitrogen (N) fertilization. Field experiments were carried out during 2018/19 and 2019/20 growing seasons to evaluate the response of varying N fertilizer rates on growth and yield parameters of two newly released wheat varieties (Borlaug 2020 and Zinc Gahun-1), one promising line (NL 1179) and Vijay as a check variety. Five N levels (i.e. 0, 50,100,150 and 200 kg N ha^-1) were applied in the experiment designed in split plot with three replications. Nitrogen levels and genotypes were allocated as main plot and sub plot treatments, respectively. The combined analysis of both growing seasons indicated that, all newly released and promising genotypes performed better than check variety. NL 1179 recorded the highest grain yield followed by Borlaug 2020 and Zinc Gahun-1. A linear increase of grain yield was observed with increased rate of N from 0 to 200 kg ha^-1, while 200 kg N ha^-1showed significantly (p<0.001) highest grain yield which was statistically at par with 150 kg N/ha. Similarly, gross margin (Rs. 148933 ha^-1) was highest with the application of N @ 150 kg ha^-1. Interaction effect of genotypes and N levels was not found significant. Thus, it can be concluded that for higher grain production of improved wheat varieties, 150 kg Nha^-1could be recommended under Bhairahawa condition.

Identification of Optimum Plant Population and Nitrogen Dose in Maize for Mid Hills Conditions of Nepal

Bhimsen Chaulagain — 2023-07-10

An experiment was conducted in the summer seasons of 2021 and 2022 at the National Agronomy Research Centre's Farm Khumaltar to find out the appropriate row spacing and optimum nitrogen dose for maize. The experiment was laid out in a split plot design where nitrogen levels were allocated in the main plot and row spacing was assigned in subplots. The four different nitrogen levels were 120:60:40 N:P₂O₅:K₂O kg ha^-1, 150:60:40 N:P₂O₅:K₂O kg ha^-1, 180:60:40 N:P₂O₅:K₂O kg ha^-1 and 210:60:40 N: P₂O₅:K₂O kg ha^-1. Four different rows spacing were 75 cm, 60 cm, 50 cm and 43 cm. Seeds were sown at 25 cm apart. The individual plot size was 4m x 3m. Maize variety BGBY POP was used in the experiment. The sowing dates were 6 May and 19 May in 2021 and 2022 respectively. In the combined analysis of two-year data, days to 50% tasseling was found significant in 150:60:40 N: P₂O₅:K₂O kg ha^-1 while other traits were found non-significant. The mean grain yield was 4.29 t ha^-1. Few traits were found significant in subplot factor i.e., cob diameter (4.38 cm), cob length (16.72 cm), ear height (107.1 cm) and seed per row (28.84) were found superior to other treatments within traits while all other traits in subplot factor were non-significant in pool analysis. Late maize sowing in the second year and rainfall during earthing up affected maize performance and gave lower maize yield. From the experiment, we could say that sowing of maize should be done within the second week of May and more experiments need to be done to conclude nitrogen optimization.

Impact of Age of Seeding and Varieties on Yield and Yield Attributing Characters of Rice in Central Terai Region of Nepal

Mitali Kumari Sah — 2023-07-10

The objective of this study was to evaluate the response of age of seedling and varieties on yield and yield attributing characters of rice. A field experiment was conducted at Directorate of Agriculture research, Parwanipur in two main season from 2018-2019. The experiment was designed in split plot with two factors; seedling age 20, 30, 40, 50 days and varieties Chaite-5, Radha-14 and Bahuguni-1 as main and sub-factors, respectively. The result was analyzed using Zen-stat ver.15. The results revealed there were no significant impact of all varieties in term of yield in pooled condition (Chaite-5, Bahuguni-1 and Radha-14 yielded 5376 kg ha^-1, 4943 kg ha^-1, 4357 kg ha^-1, respectively), whereas age of seedling significantly influenced the yield and yield attributing characters in both years and in pooled condition. The yield of rice was significantly higher for twenty days aged seedling (6080 kg ha^-1) in 2018 and 4628 kg ha^-1 in 2019 and 5354 kg ha^-1 in pooled and followed by consecutive old aged seedling. In conclusion, twenty days aged seedling would be the best option for the optimum production in Central Terai Region of Nepal.

Effect of Herbicide Application on Weed Density and Yield of Wet Direct Seeded Spring Rice at Sundarpur, Nepal

Chudamani Pant — 2023-07-10

Weeds are the major challenges for Direct Seeded Rice (DSR). A field experiment was carried out to evaluate the effect of herbicide application on weed density and yield of wet-direct seeded spring rice using Randomized Complete Block Design (RCBD), each treatment replicated thrice. The treatments consisted of three sole applications of pre-emergence herbicides (Pendimethalin @1000g a.i per ha, Pretilachlor @600g a.i ha^-1and Butachlor 1500 g a.i ha^-1at 3 DAS), six sequential applications of herbicides pre (at 3 DAS) and post emergence herbicides (at 22 DAS) (Pendimethalin fb Bispyibac Na @1000 fb 25 g a.i. ha^-1, Pretialchlor fb Bispyibac Na @ 600 fb 25 g a.i. ha^-1, Butachlor fb Bispyibac Na @ 1500 fb 25 g a.i. ha^-1, Pendimethalin fb 2,4-D EE @1000 fb 500 g a.i. ha^-1, Pretialchlor fb 2,4-D EE @600 fb 500 g a.i. ha^-1, Butachlor fb 2,4-D EE @1500 fb 500 g a.i. ha^-1) and two controls (weed free and weedy check). Result revealed that herbicide application significantly reduced the weed density (35.15-86.28%) compared with weedy check. Sequential application of pre and post emergence herbicides were more effective in reducing weed density and dry weight compared to sole application of herbicide. And among all sequential application, Pendimethalin fb Bispyribac sodium (119.3 m^-2 and 124.33 m^-2) and Butachlor fb Bispyribac sodium (129.3 m^-2 and 148.0 m^-2) were better and reduced weed density higher than other sequential application at 30 DAS and 90 DAS, whereas at 60 DAS, the highest reduction in total weed density was observed in Pretilachlor fb 2,4-D EE (90.0 m^-2) and Butachlor fb Bispyribac sodium (93.0 m^-2). The higher grain yield was observed in sequential application of pre-emergence herbicides followed byBispyribac sodium and was statistically similar with weed free plot. Up to 55.70% yield reduction was observed due to weeds. Therefore, sequential application of pre and post emergence herbicides: Pendimethalin fb Bispyribac sodium, Butachlor fb Bispyribac sodium and Pretilachlor fb Bispyribac sodium seems better in terms of reducing weed density and producing higher grain yield in wet-direct seeded spring rice.

Effect of Different Sowing Dates and Row Spacing on Growth and Yield of Faba Bean under Khumaltar Environment

Reshama Neupane — 2023-07-10

Faba bean (Vicia faba L.) is an annual minor grain legume locally known as Bakulla. An experiment on sowing dates and different row spacing was conducted at the National Agronomy Research Centre (NARC) Khumaltar from 2019/20 to 2021/22 to identify suitable sowing dates and row spacing. Three sowing dates (October 24, November 7, and November 21), row spacings (30 cm, 45 cm, and 60 cm), and plant-to-plant spacing of 10 cm were evaluated in a split plot with four replications. Plot size was maintained at 7.2 m²(2 m x 3.6 m), the variety used was local, and the fertilizer dose applied was 20:40:20 N: P₂O₅:K₂O kg ha^-1. At physiological maturity, five plants per plot were sampled randomly for measurements of plant height, number of pods per plant, unfilled pods/plant, and 100 seed weight. Data on 50% flowering, days to 90% maturity, plant height, number of pods per plant, green pod yield, biological yield, and hundred seed weight were recorded. Combined analysis showed that sowing dates significantly influenced days to 50% flowering, final stand/m², plant height, number of branches per plant, and number of pods per plant. The final stand/m², plant height, straw dry matter, seed yield, and hundred seed weight were affected significantly by various row spacing. There was no significant interaction effect between sowing dates x row spacing, and all three factors (sowing dates x spacing x year) also had no significant interaction. The year they have significantly influenced all the parameters except 90% maturity and number of pods per plant. Sowing dates x year and spacing x year did not significantly influence all the parameters. Crop sown on October 24 produced the highest grain yield (1571 kg ha^-1), followed by November 21 (1354 kg ha^-1). Grain yields were significantly higher in 30 cm row spacing (1825 kg ha^-1), mainly due to higher plant population per m²than in 60 cm row spacing. It was concluded that the last week of October and 30 cm row spacing is suitable for faba bean production.

Performance of Promising Rice Genotypes as Affected by Different Nitrogen Levels in Central Terai of Nepal

Chetan Gyawali — 2023-07-10

Application of appropriate level of nitrogen (N) for rice is a key to increase nitrogen use efficiency thereby yields. Six rice genotypes under six N levels were evaluated in a split plot design with three replications under irrigated conditions in National Rice Research Program, Dhanusha during 2020 with the objective of determining the high yielding variety and the best dose of N for obtaining higher yield. The six rice genotypes were NR 2168, NR 2158, NR 2157-122, NR 2175, NR 2182 and PR 126 while various N levels were 0. 75, 100, 125, 150 and 175 kg N ha^-1. The results indicated that NR 2182 recorded the highest grain yield of 5.28 t ha^-1 while PR 126 recorded the lowest grain yield 3.98 t ha^-1. A linear increase in grain yield was observed with a continuous increase in N level from 0 to 150 kg ha^-1 while it decreased thereafter. The grain yield was significantly higher with the application of 150 kg N ha^-1 as compared to control. Agronomic N use efficiency for studied rice genotypes varied significantly and ranged from negative to 12.63 kg grain yield per kg of N applied. NR 2182 recorded the highest value of agronomic nitrogen use efficiency for the N level of 150 kg ha^-1. It can be concluded that increasing nitrogen levels resulted in significant variations in the response of different varieties, with all varieties consistently recording lower yields at highest N levels. Thus, opting for an intermediate N level appears both economically prudent and environmentally sustainable.

Effect of Different Herbicides in Weed Management in Transplanted Rice

Rajendra Kumar Bhattarai — 2023-07-10

Weed is one of the major yield-limiting factors in rice cultivation. It causes yield losses of around 40-90%, depending on the situation. Manual weeding is the dominant weed management method in rice and limited farmers use herbicides in Nepal. Selecting effective herbicides for different weed species is a crucial task for farmers. So, an experiment with 9 treatments consisting of 5 herbicides was conducted in RCB Design with 3 replications during 2020 and 2021 to find effective herbicides. The recommended agronomic practices were followed. Rice variety Khumal 11 was transplanted in a 4m x 3m plot with a spacing of 20 cm between rows and 15 cm between plants. Pooled data of two years showed the lowest weed density (14.2 m^-2) and highest (73.2 m^-2) in the treatment pretilachlor @ 0.5 kg ha^-1 (pre) as sand mix and in the weedy check. Similarly, the lowest weed dry biomass (7.4 g m^-2) and the highest (42.4 g^-2) were recorded in the same treatments. The grain yield was the highest (7253 kg ha^-1) in pretilachlor applied at 0.5 kg a.i ha^-1 as pre-emergence spray and the lowest (4339 kg ha^-1) in the control. The treatment pretilachlor @ 0.5 kg a.i ha^-1 (pre) applied as spray was superior in managing weed and resulting in the highest grain yield, so it is recommended for mid-hill ecologies under transplanted rice.

Rice Self-Sufficiency Model to Enhance the Food Security Status in Nepal

Mukunda Bhusal — 2023-07-10

The study focuses on the slow growth of rice production in Nepal and the country's heavy reliance on rice imports to meet its food demand. The government has been spending a significant portion of its budget on imports, and it aims to reduce this dependence by increasing domestic production and achieving food security goals. To understand the dynamics of this issue, system dynamics modelling steps were employed. The key variables considered in the model testing were domestic production, imports, per capita consumption, productivity per hectare, and average area expansion rate. The study utilized time series data from 1991 to 2020 and projected the analysis up to 2050 using Stella Architect, a computer-based software program. The findings reveal that both the population and imports have exhibited exponential growth over the years. The model also indicates goal-seeking behaviour, with the government setting targets for yield increment based on available harvest areas. However, the policies implemented thus far have mostly been quick-fix approaches focusing input subsidized programs. According to the model, an increase of 70-100% in rice production will be required by 2050 to meet the growing population's demand. The study presents three policy options for achieving rice self-sufficiency: 1) a 2% annual increase in average area expansion, 2) raising productivity from 3700 kg ha^-1 to 5000 kg ha^-1 and 3) increasing productivity to 3900 kg ha^-1 while reducing per capita rice consumption from 200 kg to 130 kg. The study suggests that adopting the recommended policy implications can help increase rice production in Nepal. Decision-makers should adopt a dynamic approach to the rice production system to address the issue of slow growth and achieve national self-sufficiency and food security goals.

Residue Management and Nutrient Dynamics in Conservation Agriculture: A Review

Sangita Kaduwal — 2023-07-10

Conservation tillage significantly influence the physico-chemical properties of soil that makes microclimate conducive for crop growth and productivity. The use of chemical fertilizers alone to sustain high crop yield has not been successful due to its effects on soil acidity, nutrient leaching, degradation of soil’s physical properties and organic matter. Higher levels of soil organic carbon, microbial biomass of carbon and nitrogen, nitrogen mineralization, total nitrogen and extractable phosphorus are directly related to crop residues under conservation tillage management. Conservation agriculture (minimum or no tillage with residue retention and crop rotation) practices has potential for increasing the nutrient supply to crops through changes in the mineralization and immobilization of nutrients by microbial biomass and provide an eco-protective environment for sustainable production. Conservation agriculture reduces nutrient percolation/leaching from the soil profile, can redistribute the soil profiles thus affects nutrient supply, and its storage. Entire soil-plant continuum changes after the conversion from conventional agriculture to conservation agriculture. The review therefore highlights the nutrient dynamics under crop residue management with no or minimum tillage.

Modified Nursery Structures: An Approach to Grow Rice Seedlings in Winter for Early Spring Planting

Puspa Raj Dulal — 2023-07-10

Raising rice seedlings in cold winter months for subsequent early spring transplanting has a great challenge in rice-rice cropping system in Nepal. An essential technological intervention involves modifying the rice nursery structure to create an optimal environment that supports proper germination and seedling growth during the cold season. Hence, a field experiment was conducted to evaluate the impact of different nursery structures on the germination and growth of rice seedlings in the farmer’s field at Sunwal-12, Bhumahi, Nawalparasi West, from 21^st of January- 19^th of February, 2021, 2021. The experiment was executed in randomized complete block (RCB) design with 8 different raised bed (1m × 1m) structures as treatments, namely T₁: open uncovered beds, T₂: plastic tunnel covered beds, T₃: mat bed under plastic tunnel, T₄: plastic trayunder plastic tunnel, T₅: Plastic tray under open condition, T₆: Open bed with removal of dew, T₇: Ash covered beds and T₈: Plastic sheet covered beds. Each treatment was repeated three times. The spring rice variety Chaite-5 was sown at the rate of 60 g m^-2, with dry seeds being evenly distributed in rows spaced 10 cm apart. The beds were fertilized at the rate of 1 kg N, 0.8 kg P₂O₅ and 0.8 kg K₂O 100 m^-². Soil temperatures at a depth of 5 cm were monitored regularly at two time points each day, specifically at 8 am and 4 pm, until 30 days after sowing (DAS). The results revealed that the germination index, average height, and above ground weight were significantly higher (40.57, 9.81 cm and 78.67 gm^-2, respectively) for the beds under tunnel (T₂). Seedlings grown in trays under tunnel exhibited statistically similar plant heights. The highest seedling population m^-2(288% more compared to open beds) was obtained in trays (both open and under tunnel). Trays and mat beds under tunnel recorded higher soil temperature in the morning and evening, as well as higher air temperatures and relative humidity. These favorable conditions were met approximately 16-17 days earlier compared to the uncovered beds. Therefore, the practice of covering seedling beds with plastic tunnels, growing rice seedlings in plastic trays and utilizing mat beds were the better ways for raising rice seedlings in cold environments for early spring transplanting.

DOI: https://doi.org/10.3126/ajn.v7i1.62269