Despite being a major domain of global food supply, rice-wheat cropping system is questioned for its contribution to carbon flux. Enhancing the organic carbon pool in this system is therefore necessary to reduce environmental degradation and maintain agricultural productivity. A field experiment (November 2002-March 2006 evaluated the effects of soil management practices such as tillage, crop residue, and timing of nitrogen (N) application on soil organic carbon (SOC) sequestration in the lowland of Chitwan Valley of Nepal. Rice (Oryza sativa L.) and wheat (Triticum aestivum L.) were grown in rotation adding 12 Mg ha -1 y -1 of field-dried residue. Mung-bean (Vigna radiata L.) was grown as a cover crop between the wheat and the rice. Timing of N application based on leaf color chart method was compared with recommended method of N application. At the end of the experiment SOC sequestration was quantified for five depths within 50 cm of soil profile. The difference in SOC sequestration between methods of N application was not apparent. However, soils sequestered significantly higher amount of SOC in the whole profile (0-50 cm soil depth) with more pronounced effect seen at 0-15 cm soil depth under no-tillage as compared with the SOC under conventional tillage. Crop residues added to no-tillage soils outperformed other treatment interactions. It is concluded that a rice-wheat system would serve as a greater sink of organic carbon with residue application under no-tillage system than with or without residue application when compared to the conventional tillage system in this condition.

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Organic farming is increasingly popular among the farmers of Kathmandu valley. However, the organic growers have been facing issues in production, organic certification, and product marketing. To date, little is known about the challenges faced by the organic growers in Kathmandu valley. This study aimed to explore the status of organic farming, attitudes of farmers towards organic farming, their suggestions for improvement, and strengthening the value chain of organic products. Face-to-face interviews were conducted at Agriculture Knowledge Centre, Lalitpur, Nepal during December 2019 with 37 organic growers directly or indirectly involved in organic farming. The results showed that organic growers face challenges in marketing and institutional recognition. Challenges in product certification and marketing were reported by 45.95% of the total interviewed organic growers while they are following organic practices (transitional organic). Our study suggested that reducing the cost of production through easy access to organic inputs like organic seeds, fertilizers, and biopesticides are highly desired by the growers. Participatory Guarantee System (PGS) or group certification along with collective marketing could be the policy implications to address the issues. Organic farming in Kathmandu valley is limited to a niche market; however, due to increasing consumer demand for safe, fresh, and local food the popularity of organic products is increasing to other regions within the country.

A field experiment on different maize cultivars planted at different sowing dates were accomplished at Kawasoti-5, Nawalparasi during spring season of 2013 to find suitable sowing date and maize cultivar for the location. Along with this, effect of sowing dates and maize cultivars on different agro-climatic indices were also calculated using formulas. Result showed that RML- 4/RML-17 produced higher kernel rows ear-1 (13.77), kernel per row (30.42) and test weight (244.9 g). Significantly higher grain yield was also found for RML-4/RML-17 (6.03 tha-1) compared to Poshilo makai-1 (4.73 t ha-1), Arun-2 (3.55 t ha-1) and Local (2.92 t ha-1). Earlier sowing date (7th April) produced higher kernel row-1 (27.97), kernel rows ear-1 (12.89) and 1000 grain weight (230 g). Significantly higher grain yield (5.13t ha-1) was obtained in earlier sowing date (7th April). Although the mean ambient temperature during research period was increasing with delayed sowing, days to attain different phenological stages decreased with late sowing. The statistically similar GDD was recorded for different sowing dates and higher PTI values were noticed with delay in planting. Similarly, heat use efficiency (HUE) was found higher in early sowing date. Arun-2 had small reduction in HUE so, it can be considered stable and best cultivar among the tested cultivars.

A field experiment was conducted at National Maize Research Program (NMRP) in Rampur, Chitwan, Nepal during May-Nov 2013. The experiment was laid out in strip-split design with twelve treatments and three replications. Treatments consisted of two different tillage methods namely conventional tillage (CT) and zero tillage (ZT) as vertical factor, two different levels of residue (residue kept and residue removed) as horizontal factor and three different levels of cropping systems namely sole maize, sole soybean and maize + soybean intercropping system as sub plot factor. Manakamana-3 and Puja were the variety of maize and soybean used for the experiment respectively. The results revealed that the grain yield and yield attributing components of maize and soybean was significantly influenced by cropping systems but not by tillage methods and residue levels. The grain yield of maize obtained under sole cropping (4.76 t ha-1) was significantly higher than maize + soybean intercropping system (4.27 t ha-1). Similarly, the grain yield of sole soybean was significantly higher (1.99 t ha-1) than that of maize + soybean intercropping system (1.26 t ha-1). Moreover, the total grain yield equivalent of 6.45 t ha-1 obtained from sole soybean system was significantly higher and was followed by maize and soybean intercropping system with 4.99 t ha-1. Whereas, sole maize produced significantly the lowest maize grain yield equivalent of 3.47 t ha-1. Significantly, higher LER (1.38) was recorded with maize and soybean intercropping system over sole system (1.0). Tillage and residue levels did not affect the gross and net return and B: C ratio but the effect was found obvious due to intercropping system. Significantly higher net return (NRs.140.49 thousands ha-1) was recorded in intercropping of maize with soybean as compared to sole soybean (NRs. 89.85 thousands ha-1) which was at par with sole maize system (NRs. 80.91 thousands ha-1). Maize and soybean intercropping system produced significantly the higher (2.47) B: C ratio than sole soybean (2.28) and was at par with sole maize (2.18).