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Depending on their origin, sedimentary phosphate rocks (PRs) may differ in their P solubility, and, as a consequence, in their agronomic effectiveness. The effect of six phosphate rocks (PR) -- originating from Algeria (ALG), North Florida (FLO), North Carolina (NCA), Senegal (SEN) Morocco (MOR) and Hyperphosphate (HYP) with various P solubility (evaluated by 2% formic acid, 2% citric acid, and neutral ammonium citrate) -- as well as single superphosphate (SSP) and superphosphate + lime (SSP + Ca) (each P source on 4 P levels, with doses of 0, 100, 400 and 1600 mg P2O5·kg-1 soil) on the shoot yield of tillering stage spring barley, soil available P (i.e. H2O, Olsen, Bray1, Lakanen-Erviö (LE) and ammonium lactate (AL) extractable P contents) were studied in pot experiments set up with acidic sandy soil (Nyírlugos, Hungary) and acidic clay loam soil (Ragály, Hungary), both with low P supplies. The average spring barley shoot yield at the beginning of shooting was 95% higher on the colloid-rich acidic (pHKCl: 4.5) clay loam soil than on the colloid-poor acidic (pHKCl: 3.8) sandy soil. The differences in the solubility of phosphate rocks showed close correlation to the differences in P responses. On both soils, the correlation between total PR-P added and P responses in spring barley shoot yield was much weaker than that between neutral ammonium citrate soluble PR-P added and P responses in spring barley shoot yield. When phosphate rocks were applied as P sources, the comparison of soil test P methods showed a different picture on the two soils. In the case of the acidic sandy soil (Nyírlugos), the strongly acid LE-P (r² = 0.83) and AL-P (r² =0.74) tests gave the highest correlation coefficients with spring barley responses to P, while on the acidic clay loam soil (Ragály) these were achieved by the Olsen-P (r² = 0.88) and Bray1-P (r² =0.88) methods. The presented study was financially supported by the Hungarian National Scientific Research Fund (OTKA) under Grant No. T 038046. [ABSTRACT FROM AUTHOR]

Five soil P-test methods were compared on the soils of the network of unified Hungarian P fertilization long-term field trials. The effect of P application on the soil P-test values was significant on the different P levels and sites. The average effect of the sites varied between 1.5-fold (H2O method) and 3.7- fold (AL-method). The amounts of extracted P increased in the order of H2O-P < Olsen-P < Pi- P < AERM-P < AL-P < Corrected AL-P. For studying the relationships between the P values extracted by the different methods, acidic, calcareous and all soils groups were taken into account as a basis. A good correlation was found between the Pi- and AERM-methods in each soil group. Within the acidic soil group, pH has a much less expressed effect on AL-P values, presumably this was the reason why the strongest correlation in this soil group was found between the AL- and the Corr. AL-P methods The next step in our research will be to calibrate these soil-P tests with plant P uptake and yield responses. [ABSTRACT FROM AUTHOR]

Hunger is one of the biggest global problems for humankind that has not been solved by the 21st century. Despite the satisfactory level of global food production, shortage of food is still a problem in some of the less-developed countries. Problems in food safety are the biggest in Africa, Asia, Latin America and the Near East. There are 795 million people who do not get enough calories and nutrients from food globally. President of American Association of Geographers Glen M. MacDonald (2016) named the question of food and famines as one of the key research agendas in geography. Depending on the future development trends, food problem may even get worse in the future due to steep population growth in the developing countries and negative effects of climate change on food production. One of the main reasons for the unequal distribution of hunger is socio-economic factors. In the future, climate change, population growth, increasing socio-economic differences, natural disasters and political conflicts are likely to increase the problem. To ease the food shortage (e.g. by developing agricultural policies, farming practices and food markets), we need timely and accurate information on global food accessibility. Regional balance between production and consumption, as well as differences in transport system conditions among regions, have a key role in satisfying demand. Aim of this study is to explore spatial mismatch between proxies of food grain production and consumption in accurately localised data. This study can plausible be executed thanks to rapid development in open-source geospatial data and its applicability in Geographic Information Systems (GIS)-based analyses. Analysis of the study include the distribution of population, food resources and accessibility by road and maritime transports at the same time. Data of the study consists of food grain supply and demand (Kinnunen et al. 2020) and multimodal global transport network model consisting of road network by NASA gROADS 2010, major ports by World Port Index 2019 and maritime connections by CIA Map of the World Oceans 2012 enhanced by raster (Figure 1). [ABSTRACT FROM AUTHOR]

Rainwater tanks are being introduced into urban areas in Australia to supplement centralised potable supply systems. A pilot scale tank study and a full-scale field tank study found that heavy metal concentrations in water samples taken from the tank's supply point can, in some cases, exceed levels recommended by guidelines. Both studies also found very high concentrations of heavy metals in the sediments accumulated at the base of rainwater tanks. Laboratory experiments are underway to investigate sediment transport processes within a full-scale tank. Preliminary results demonstrate the effect of sediment resuspension on the quality of water released from the tank outlet. Improved tank designs that reduce sediment resuspension and mitigate impacts on water quality are the focus of future work. [ABSTRACT FROM AUTHOR]

A response from the author of the article "Influence of roofing materials and lead flashing on rainwater tank contamination by metals" by MI Magyar and collegues in the previous issue is presented.