Response of Wheat Genotypes to Different Levels of Nitrogen

A field experiment was conducted using six genotypes of wheat (Triticum aestivum L.) for response to different levels of nitrogen (N) use. The experiment was laid out in split plot design with four levels (0, 50, 100 and 150 kg N ha-1) as main plots and six wheat genotypes (BL 3623, BL 3629, BL 3872, NL 1008, NL 1055 and Vijay, a check variety) as sub-plots. Grain yield and other yield components increased linearly in response to N concentrations in both seasons. Only two parameters: days to heading (DOH) and days to maturity (DTM) varied significantly (p ≤ 0.05) among wheat genotypes in both the years. None of the parameters showed interaction effects in both seasons. Vijay showed highest grain yield of 3.12 t ha-1 in 2013 with the application of 100 kg N ha-1, and 3.23 t ha-1 in 2014 with 150 kg N ha-1. Spike length, productive tillers m-2, number of spikes m-2 and test weight were greater with higher N rates. The straw yield of wheat fertilized with 150 kg N ha-1 was the highest in Vijay (4.35 t ha-1) and BL 3872 (4.33 t ha-1), respectively. Vijay with 100 kg N ha-1 produced the highest number of productive tillers m-2 (276.33) in 2013 and 296.00 with the application of 150 kg N ha-1 in 2014

Mapping historical and contemporary agrarian transformations and capitalist infiltration in a complex upland environment: A case from eastern Nepal

The relationship that mountain communities have with global capitalism are complex, being mediated by a diverse topography and ecology, both of which provide opportunities for capital accumulation, while also isolating older, “pre-capitalist” modes of production. This paper takes a case study valley from Nepal's eastern hills, tracing over two centuries of agrarian change and evolving interactions between “adivasi” and “semi-feudal” economic formations with capitalism. In recent years, the expansion of markets, rising demand for cash, and climate stress have solidified migrant labour as a core component of livelihoods, and the primary mechanism of surplus appropriation from the hill peasantry. Through a focus on three altitudinal zones, however, it is demonstrated how the trajectory of this transformation, including the interactions with persisting pre-capitalist formations, is mediated by both political–economic processes and the local agro-ecological context

Sensitivity of WRF Cloud Microphysics to Simulations of a Convective Storm Over the Nepal Himalayas

Background:This paper investigates sensitivity of bulk microphysical parameterization (BMP) schemes within the Weather Research and Forecasting (WRF) model to simulate a convective storm that generally evolves during pre-monsoon season (March – May) across the foothills of the Himalayas.Method:Four mixed-phase BMP schemes (Morrison, Lin, WDM6, and WSM6), which are parameterized with an increasing complexity from single to double moments of particle distribution to represent cloud processes, are used with an explicit convection permitting grid resolution (3 km x 3 km). Experiments are set up to simulate a convective storm that occurred in the late afternoon of 18thMay 2011 and compared with i) Satellite-based tropical rainfall measuring mission (TRMM) 3B42 v7 data, and ii) Ground-based observations at Nagarkot (27.7°N, 85.5°E), Nepal.Result:Our results show that the simulated storm characteristics are not overly sensitive to the chosen BMP schemes. In general, all the BMP schemes produce similar rainfall characteristics and compares reasonably well with the observations across Siwalik Hills and Middle Mountains, which act as a topographic barrier to low level circulations and receive more rain. The schemes, however, show negative bias across central Nepal including the Kathmandu Valley, albeit the magnitude and spatial distribution of bias are different between the schemes. In contrast, upper level total water condensate and cloud fraction show a strong sensitivity to the BMP schemes.Conclusion:Overall, the Morrison scheme, in addition to warm clouds which also predict double moment distribution of all hydrometeors in the cold-cloud processes, a dominant cloud forming process in the Himalayas, accurately represents the mechanism and outperforms the simplified schemes based on root mean square error (RMSE) analysis.</jats:sec

The influence of soils on heterotrophic respiration exerts a strong control on net ecosystem productivity in seasonally dry Amazonian forests

Net ecosystem productivity of carbon (NEP) in seasonally dry forests of the Amazon varies greatly between sites with similar precipitation patterns. Correctly modeling the NEP seasonality with terrestrial ecosystem models has proven difficult. Previous modelling studies have mostly advocated for incorporating processes that act to reduce water stress on gross primary productivity (GPP) during the dry season, such as deep soils and roots, plant-mediated hydraulic redistribution of soil moisture, and increased dry season leaf litter generation which reduces leaf age and thus increases photosynthetic capacity. Recent observations, however, indicate that seasonality in heterotrophic respiration also contributes to the observed seasonal cycle of NEP. Here, we use the dynamic vegetation model CLASS-CTEM (Canadian Land Surface Scheme–Canadian Terrestrial Ecosystem Model) – without deep soils or roots, hydraulic redistribution of soil moisture, or increased dry season litter generation – at two Large-Scale Biosphere–Atmosphere Experiment (LBA) sites (Tapajós km 83 and Jarú Reserve). These LBA sites exhibit opposite seasonal NEP cycles despite reasonably similar meteorological conditions. Our simulations are able to reproduce the observed NEP seasonality at both sites. Simulated GPP, heterotrophic respiration, latent and sensible heat fluxes, litter fall rate, soil moisture and temperature, and basic vegetation state are also compared with available observation-based estimates which provide confidence that overall the model behaves realistically at the two sites. Our results indicate that representing the effect of soil moisture on heterotrophic respiration in terms of soil matric potential and constraining heterotrophic respiration when absolute soil matric potential is both low (wetter soils) and high (drier soils), with optimum conditions in between, allows %appropriately representing the influence of soil texture and depth, %through soil moisture, on seasonal patterns of GPP and, especially, % heterotrophic respiration is important to correctly simulate NEP seasonality

MARKET PRICE COINTEGRATION OF TOMATO: EFFECTS TO NEPALESE FARMERS

Market price cointegration is a critical issue in Nepalese vegetable industry. This study intended to analyze the market price cointegration of tomato and its effect on Nepalese farmers, using secondary monthly time series of wholesale price data (since 2000 to 2010) of the Government of Nepal. The results of error correction model (ECM) showed that the series were stationary, and Kathmandu market was well cointegrated with source markets (Chitwan and Morang). Meanwhile, the vector error correction model (VECM) revealed that price adjustment process was much faster in source markets especially in negative price shocks in response to Kathmandu market, which affected the farmers for speedy price adjustment that leads to be hurt and discouraged. The study recommend policies to establish alternative vegetable markets that reduce the price dependency of farmers on Kathmandu market, encourage traders in involving vegetable marketing, and enhance effective market information services