Upland rice is typically grown under slash-and-burn systems in the mountainous regions of northern Laos by resource-poor farmers for subsistence. Upland rice cultivars are all traditional and no fertilizer inputs are used. In these systems, grain yields average only 1.7 t/ha. A multi-site experiment was conducted in Luang Prabang province to examine cultivar and fertilizer effects on grain yiel...

This study investigated the influence of nitrogen (N) fertilizer and straw on intact amino acid N uptake by soil microorganisms and the relationship between amino acid turnover and soil properties during the wheat growing season. A wheat pot experiment was carried out with three treatments: control (CK), N fertilizer (NF) and N fertilizer plus rice straw (NS). We used stable isotope compound-sp...

As part of an effort to assess the influence of cultural practices on bruising in potato tubers, this work was a preliminary study to determine whether the pattern of early-season nitrogen fertilizer application influences impact sensitivity (bruise threshold and bruise resistance) in Russet Burbank tubers. Tissue sample impact failure stress, strain, and shock wave speed, and whole-tuber bruis...

In this study, poultry manure compost and organic fertilizer were added to soils derived from basalt, granite, and river alluvial deposits for use as soil parent materials. Following incubation periods of 30 or 60 days at 25 °C, the physical and chemical properties and adsorption characteristics of the soils were studied. The results indicated that the application of poultry manure compost or o...

Increased phosphorus (P) fertilizer use and livestock production has fundamentally altered the global P cycle. We calculated spatially explicit P balances for cropland soils at 0.5° resolution based on the principal agronomic P inputs and outputs associated with production of 123 crops globally for the year 2000. Although agronomic inputs of P fertilizer (14.2 Tg of P·y(-1)) and manure (9.6 Tg ...

Traditionally, sulfur responses have been limited to coarse textured or other soils low in organic matter that have little potential for sulfur mineralization. In the past, the burning of fossil fuels has contributed a significant amount of sulfur through deposition in rain. Also, many phosphorus fertilizers contained sulfur as impurities, which lessened the need for the application of sulfur t...

abstract in order to investigate the effects of nitrogen fertilizer levels on the yield and quality of potato, (solanum tuberosum l.) a field experiment was conducted based on randomized complete blocks design with 3 replications in the research field of the college of agriculture, ferdowsi university of mashhad. nitrogen topdress fertilizer was applied in two levels of 100 and 150 kgn.ha-1 and...

This paper assesses the origins of and changes to fertilizer policy in Nepal over a period of time. It assesses farmers’ awareness of the recent changes to the subsidy policy and examines their perceptions of the extension services. This paper looks at the environmental implications of the concentrated application of chemical fertilizer, particularly as far as food security is concerned. Questi...