Developing a sustainable agro-system for central Nepal using reduced tillage and straw mulching

In Nepal, soil erosion under maize (Zea mays) agro-ecosystems is most critical during the pre-monsoon season. Very few field experiments have been conducted on reduced tillage and rice straw (Oryza sativa) mulching, although these conservation approaches have been recommended. Thus, a five replicate field experiment was established in 2001 at Kathmandu University (1500 m above sea level) on land with 18% slope to evaluate the efficiency of reduced tillage and mulching on soil and nutrient losses and maize yield. The results showed non-significant differences among conservation approaches on runoff and maize yield. Mulching and reduced tillage significantly lowered annual and pre-monsoon soil and nutrient losses compared to conventional tillage. Soil organic matter (SOM) and nitrogen losses associated with eroded sediment were significantly higher in conventional tillage. However, due to limited availability and high opportunity cost of rice straw, reduced tillage would be a better option for soil and nutrient conservation without sacrificing economic yield in upland maize agro-ecosystems.     

Distribution of health costs of pesticide use by household economy

We observed skewed distribution across household of benefits of pesticide use in vegetable farming in Nepal. However, economic burden or harm of pesticide use and exposure by household economy is poorly studied. It is hypothesized that exaggerated and incompetent pesticide use is likely to affect human health that may lead to decline in human productivity, and economic loss––that may further marginalize farmers. Thus, a study was conducted in the Ansi khola watershed of Kavrepalanchowk District of central Nepal. The primary aim of the study was to value risks of pesticide use and to estimate health costs of exposure by household category. We grouped household into “large-scale” who owns more than 1 ha of agricultural land, “small-scale” having <0.5 ha and “medium-scale” in between >0.5 and <1 ha. Data were collected through (1) an initial household survey conducted from May to June 2008, (2) monthly visit surveys accomplished from June to November 2008 and (3) a final household survey conducted during November to December 2009. The cost of pesticide use and exposure was highest for medium-scale household; however, the economic burden in relation to incomes was the highest for small-scale household. On the basis of area under vegetables, small-scale household incurred 23 % higher economic burdens compared to the large-scale household. Overall, the cost of pesticide use and exposure amounted 15 % of agricultural income and/or 5 % of gross household income. For small-scale households, the cost was equivalent to 18 % of agricultural income and 6 % of gross income. Small-scale households are not only deprived from benefits of agriculture intensification, but also incurred highest burden of pesticide use.     

New Proof-of-Concept in Viral Inactivation: Virucidal Efficacy of 405 nm Light Against Feline Calicivirus as a Model for Norovirus Decontamination

The requirement for novel decontamination technologies for use in hospitals is ever present. One such system uses 405 nm visible light to inactivate microorganisms via ROS-generated oxidative damage. Although effective for bacterial and fungal inactivation, little is known about the virucidal effects of 405 nm light. Norovirus (NoV) gastroenteritis outbreaks often occur in the clinical setting, and this study was designed to investigate potential inactivation effects of 405 nm light on the NoV surrogate, feline calicivirus (FCV). FCV was exposed to 405 nm light whilst suspended in minimal and organically-rich media to establish the virucidal efficacy and the effect biologically-relevant material may play in viral susceptibility. Antiviral activity was successfully demonstrated with a 4 Log₁₀ (99.99%) reduction in infectivity when suspended in minimal media evident after a dose of 2.8 kJ cm^?2. FCV exposed in artificial faeces, artificial saliva, blood plasma and other organically rich media exhibited an equivalent level of inactivation using between 50–85% less dose of the light, indicating enhanced inactivation when the virus is present in organically-rich biologically-relevant media. Further research in this area could aid in the development of 405 nm light technology for effective NoV decontamination within the hospital environment.     

Study of chromium immobilization behavior in unbound and concrete bound ferrochromium slag

Journal of Material Cycles and Waste Management - Disposal of ferrochromium slag, a major industrial solid waste generated during production of ferrochromium alloy has been a serious problem owing...