Investment Requirements in Extension to Achieve Zero Hunger and Adapt to Climate Change

The study reflects on previous World Bank and FAO reports that made the general recommendation to set both research and extension investment targets in developing countries at 1% of agricultural gross domestic product （AgGDP）. In order to define proxies for country-specific extension investment targets, authors developed an extension investment model （EIM） based on socio-economic macro-indicators （poverty, undernourishment, access to information and population density） and a method to define estimates for cost increases related to climate change. These parameters helped estimating the demand for agricultural extension and investments required for it. Results showed that about half of the 94 developing and emerging countries should spend more than 1% of their respective share of GDP derived from agriculture and about a quarter of the countries, mostly in Africa and South East Asia, need to spend more than 2% of their AgGDP. The paper reveals significant differences in average investment requirements in different regions and shows the additional extension costs related to climate change and other areas that currently lack investment.     

Multiple introductions determine the genetic structure of an invasive species population: American mink Neovison vison in Poland

Genetic diversity of feral and ranch American mink was studied in order to understand the processes of invasion and the possible influence of multiple introductions on the feral mink population in Poland. Tissue samples obtained from feral mink taken from 10 sites across Poland (196) and from ranch mink at nine mink farms (147) were genotyped at 14 microsatellite loci. Genetic differentiation among the separate regions and sites indicated some restriction in gene flow among them (pairwise F_ST values), and greater variation at microsatellite loci for feral mink was attributed to differences among sites rather than among regions (AMOVA). A Mantel test demonstrated a positive association of pairwise genetic and geographic distances. A total of five clusters of feral mink were identified and their spatial distribution partially reflected regional distribution, but also suggested that there were other factors (human-mediated propagule pressure) shaping mink genetic structure. Feral and ranch mink belong to two genetically separate clusters and an assignment test showed that 34 feral mink (17%) were assigned to the ranch mink clusters. The proportion of feral mink assigned to ranch mink clusters correlated with the size of the farm breeding stocks in the districts where sampling sites were located. High human-mediated propagule pressure (particularly in western Poland) increases feral population genetic diversity and overwhelms genetic structure and potential management units, making the control of mink populations less successful. Our results indicate that reducing number of escapees from farms should be required management action.     

Nitrogen leaching from tile-drained fields and lysimeters receiving contrasting rates and sources of nitrogen

Leaching of nitrogen from arable land can lead to pollution of groundwater and surface water. Various measures have been implemented in agriculture to reduce leaching, but there is still potential to do more. To find the best agricultural management regime to limit the problem, leaching from soils under different management must be measured. Different methods to estimate leaching are available, but they have not been thoroughly evaluated. This study compared (a) leaching of nitrogen from five different fertilizer treatments differing in amount and source (mineral and organic) of nitrogen and (b) two different methods for measuring leaching (tile-drained field plots and lysimeters). Nitrogen leaching from five different fertilizer treatments was studied for three years in a tile-drained field facility and for three of the treatments also for 16 months in a lysimeter facility. Leaching from organic and mineral nitrogen sources was similar in the three-year field study. Mineral nitrogen input above the economic optimum tended to give greater leaching (by 24%–43%) than nitrogen input at the expected optimum. Measurements in lysimeters and tile-drained field plots gave similar results, although leaching values tended to be slightly higher (by 18%–25%) in the tile-drained field. Overall, both facilities give reliable estimates of nitrogen leaching and are suitable for leaching studies.