Contaminated Water and an Indication of Risk: Examining Microbial Contamination in the Water Used by Consumers and Commercial Growers in Fresh Produce Systems in Nepal.

There has been limited research and understanding of the water quality in developing countries. Fresh produce consumed raw is nutrient-dense but is more susceptible to causing foodborne illness when contaminated water is used in production and consumption. There have been increasing reported incidences of foodborne outbreaks in Nepal linked to fresh produce contamination. However, water used in washing fresh produce by consumers and water used by growers or vendors is rarely tested. This research examines the source water used by consumers and growers in fresh produce systems in Nepal. To examine Escherichia coli (E. coli) detection as an indicator of contamination risk in water, we selected five major metropolitan cities for consumer households and ten districts representing commercial growers of vegetable growing areas of all seven provinces of Nepal. Altogether, we collected 394 water samples from randomly selected individual households: 156 from consumer households and 238 from growers or vendors. Results suggest that 59% of the water used in fresh produce systems is contaminated with E. coli in Nepal. On the water source used by consumers to wash fresh produce before consumption, we found that the dominant sources are the stored water in tanks or containers (46%) and municipal or communal supply water (39%)-which have E. coli prevalence rate of 66% and 57%, respectively. On the dominant sources of water used in fresh produce by growers or vendors, we found up to 88% of E. coli prevalence in the water they use. We also discussed the location or regional differences in contamination risks. This nationally represented study has implications for intervention policies and programs for safer food production and consumption practices in countries like Nepal where food safety is an emerging priority.

Field evaluation of slow-release nitrogen fertilizers and real-time nitrogen management tools to improve grain yield and nitrogen use efficiency of spring maize in Nepal.

Several innovative fertilizers and application methods, along with different decision support tools have been developed to improve nitrogen use efficiency (NUE) and crop yields, but their comparative study in maize is yet to be done in Nepal. Thus, we evaluated different slow-release N fertilizers and decision-making tools for real-time N management compared with the common urea on their effectiveness in increasing NUE, grain yield and economic return of spring maize (Zea mays L. cv. Rampur Hybrid-10). A field trial was conducted at Dang Valley of Nepal in a Randomized complete block design with three replications and seven treatments; N omission- (0 kg N ha-1), normal urea at 120 kg N ha-1 (recommended dose, N120), and 180 kg N ha-1(N180), Polymer Coated Urea (PCU- 90 kg N ha-1), Urea Briquette-deep placement (UDP- 90 kg N ha-1), GreenSeeker (GS- 143 kg N ha-1) and Leaf Color Chart based N management (LCC- 143 kg N ha-1). N application based on decision support tools (LCC and GS) and innovative fertilizers (UDP, PCU) yielded 17.35-45.81% more grain yield than recommended dose (RDF). The real time nitrogen application through LCC and GreenSeeker and slow release N fertilizer (PCU and UDP) resulted in higher agronomic efficiency of nitrogen- AEN (21.30-27.82 kg grain kg-1 N) compared to RDF (12.15 kg grain kg-1 N) and N180 (19.87 kg grain kg-1 N). UDP, with 25% less N compared to RDF, resulted in higher grain yield (5.25 t ha-1), partial factor productivity of N- PFPN (58.37 kg grain kg-1 N) and AEN (27.82 kg grain kg-1 N). Based on the economic return and ease in the application, both UDP and LCC based N application seem promising in Nepalese conditions. However, their effectiveness should be validated across diverse agro-ecologies, soil types and climatic conditions for a general recommendation.