Soil map density and a nation's wealth and income

Little effort has been made to link soil mapping and soil data density to a nation’s welfare. Soil map density in 31 European countries and 44 low and middle income countries is linked to Gross Domestic Product (GDP) per capita and the number of soil scientists per country

The invasive shrub Piper aduncum in Papua New Guinea: a review

HARTEMINK AE. 2010. The invasive shrub Piper aduneum in Papua New Guinea: a review. Piper aduncum is a shrub native to Central America. It is found in most Central and South American countries and also in the Caribbean and southern Florida (USA). In Asia and the Pacific, P aduncum occurs in Indonesia, Malaysia, Philippines, Papua New Guinea, Solomon Islands, Vanuatu, Fiji, Micronesia, American Samoa, Niue, the Marianas, Tonga, Samoa, the Cook Islands, Palatt and Hawaii (USA). Piper aduncum arrived in Papua New Guinea before the mid-1930s. From the 1970s, it started to dominate the secondary fallow vegetation in many parts of the humid lowlands. It invaded grassland areas and also appeared in the highlands up to 2100 in asl. The seeds are dispersed by birds, bats and wind, as well as by logging equipment and in some localities, by migrating people. The combination of its vigorous generative characteristics (small and abundant seeds), high growth rate and the accidental or intentional spreading has resulted ill its presence in most provinces of Papua New Guinea. In the 1990s, awareness of the spread of P aduncum grew and there was a corresponding increase in research interest. from a range of disciplines, e.g. pharmacology, agronomy, quarantine, forestry and taxonomy. The invasion of P aduncum has affected the farming system and livelihood of many rural people. Future research should focus on mapping its extent, and studying its agronomic, socio-economic and ecological effects, particularly its effect on biodiversity

Growing Sugarcane for Bioenergy – Effects on the Soil

An increasing area of sugarcane is being growing for the production of bioenergy. Sugarcane puts a high demands on the soil due to the use of heavy machinery and because large amounts of nutrients are removed with the harvest. Biocides and inorganic fertilizers introduces risks of groundwater contamination, eutrophication of surface waters, soil pollution and acidification. This paper reviews the effect of commercial sugarcane production on soil chemical, physical and biological properties using data from the main producing areas. Although variation is considerable, soil organic C decreased in most soils under sugarcane and, also, soil acidification is common as a result of the use of N fertilizers. Increased bulk densities, lower water infiltration rates and lower aggregate stability occur in mechanized systems. There is some evidence for high leaching losses of fertilizer nutrients as well as herbicides and pesticides. Eutrophication of surface waters occurs in high-input systems. Sugarcane cultivation can substantially contribute to the supply of renewable energy, but that improved crop husbandry and precision farming principles are needed to sustain and improve the resource base on which production depends

Soil profiles: the more we see, the more we understand

The aesthetics of soils have fascinated soil scientists in all times. Since the late 1800s soil profile drawings, paintings and photographs have been depicted in hundreds of text books. The first soil profile depictions were simple diagrams illustrating different layers and soil processes. Photographs started to appear in textbooks at the end of the nineteenth century. In the 1950s, several books contained water paintings and from the 1970s onwards text books had colour photographs. Soil profile depictions were merely used to illustrate different orders in a classification system. Since the 1990s, efforts have been made to depict the soil profile in 3D. The depiction of soil profiles follows the understanding of the key properties and processes that have formed a soil

Nutrient deficiencies in export tree and food crops: literature review and field observations

This paper reviews nutrient deficiencies in agricultural crops of PNG using the literature of agronomic trials and field observations made throughout the country. Nutrient deficiencies have been investigated systematically since the mid-1950s, but research has mainly focused on export tree crops and relatively little information is available on food crops. Literature analysis and field observations showed consistent trends, with deficiencies of boron and phosphorus in large parts of the PNG highlands. The review has been useful in delineating areas where nutrient deficiencies occur and these findings could be used for planning nutrient management research and extension activities in food crop