• Energy Research

Today, the global food security is one of the most pressing issues for humanity, and, according to Food and Agriculture Organisation (FAO), the increasing demand for food is likely to grow by 70% until 2050. In this current condition and future scenario, the agricultural production is a critical factor for global food security and for facing the food security challenge, with specific reference to many African countries, where a large quantities of rice are imported from other continents. According to FAO, to face the Africa’s inability to reach self-sufficiency in rice, it is urgent “to redress to stem the trend of over-reliance on imports and to satisfy the increasing demand for rice in areas where the potential of local production resources is exploited at very low levels” The present study was undertaken to design a new method for land evaluation based on soil quality indicators and remote sensing data, to assess and map soil suitability for rice crop. Results from the investigations, performed in some areas in the northern part of the Nile Delta, were compared with the most common approaches, two parametric (the square root, Storie methods) and two qualitative (ALES and MicrioLEIS) methods. From the qualitative point of view, the results showed that: (i) all the models provided partly similar outputs related to the soil quality assessments, so that the distinction using the crop productivity played an important role, and (ii) outputs from the soil suitability models were consistent with both the satellite Sentinel-2 Normalize Difference Vegetation Indices (NDVI) during the crop growth and the yield production. From the quantitative point of view, the comparison of the results from the diverse approaches well fit each other, and the model, herein proposed, provided the highest performance. As a whole, a significant increasing in R2 values was provided by the model herein proposed, with R2 equal to 0.92, followed by MicroLES, Storie, ALES and Root as R2 with value equal to 0.87, 0.86, 0.84 and 0.84, respectively, with increasing percentage in R2 equal to 5%, 6% and 8%, respectively. Furthermore, the proposed model illustrated that around (i) 44.44% of the total soils of the study area are highly suitable, (ii) 44% are moderately suitable, and (iii) approximately 11.56% are unsuitable for rice due to their adverse physical and chemical soil properties. The approach herein presented can be promptly re-applied in arid region and the quantitative results obtained can be used by decision makers and regional governments.

: One of the latest updates on the soil cover of the mountain regions of Uzbekistan is contained in the “Atlas of the Soil Cover of the Republic of Uzbekistan”, published in 2010. It contains soil maps of the regions of the country at the scales of 1 : 350 000 to 1 : 2 500 000 and provides brief charateristics of the soils. The Atlas was compiled on the basis of traditional methods of soil mapping. As a result, its contour part is typical of maps of the mentioned scales and rather schematic. The aim of the research was to update the contour part of the soil maps of mountain territories of Uzbekistan, contained in this Atlas, by means of the analysis of Landsat 8 satellite data. The contour part of the map was updated for the territory with absolute terrain altitude exceeding 900 m. Updating of the map contours was based on the methods of interactive indirect interpretation, when the boundaries of the contours were specified in the GIS using as a substrate the color composites of satellite data obtained at the optimal time of survey. Map correction, mountainous area delineation, and area counting were performed using the GIS ILWIS v.3.3 software package. About 18% of all soil mapping units were divided into several subunits. For 37% of the soil mapping units the boundaries changed significantly (the area of the units changed – by more than 30% with an average change in the length of the boundary of 15–38%). For 45% of soil mapping units the boundaries had changed less significantly (the area of the units had changed by no more than 30% and the boundary length had changed by no more than 20%). No cases of merging of soil mapping units were recorded. As a result, the contour part of the corrected map, compared to the original one, became much more detailed with more indented boundaries. The updated map shows the natural soil cover, excluding the anthropogenically changed soils. But the approach used for updating the original soil map may be also applied to expand the information on anthropogenical load as well. Moreover, this information can be obtained by interpretation of the same satellite data that were used for the map updating.

The ‘4 per mille Soils for Food Security and Climate’ was launched at the COP21 with an aspiration to increase global soil organic matter stocks by 4 per 1000 (or 0.4 %) per year as a compensation for the global emissions of greenhouse gases by anthropogenic sources. This paper surveyed the soil organic carbon (SOC) stock estimates and sequestration potentials from 20 regions in the world (New Zealand, Chile, South Africa, Australia, Tanzania, Indonesia, Kenya, Nigeria, India, China Taiwan, South Korea, China Mainland, United States of America, France, Canada, Belgium, England & Wales, Ireland, Scotland, and Russia). We asked whether the 4 per mille initiative is feasible for the region. The outcomes highlight region specific efforts and scopes for soil carbon sequestration. Reported soil C sequestration rates globally show that under best management practices, 4 per mille or even higher sequestration rates can be accomplished. High C sequestration rates (up to 10 per mille) can be achieved for soils with low initial SOC stock (topsoil less than 30 t C ha− 1), and at the first twenty years after implementation of best management practices. In addition, areas which have reached equilibrium will not be able to further increase their sequestration. We found that most studies on SOC sequestration only consider topsoil (up to 0.3 m depth), as it is considered to be most affected by management techniques. The 4 per mille number was based on a blanket calculation of the whole global soil profile C stock, however the potential to increase SOC is mostly on managed agricultural lands. If we consider 4 per mille in the top 1m of global agricultural soils, SOC sequestration is between 2-3 Gt C year− 1, which effectively offset 20–35% of global anthropogenic greenhouse gas emissions. As a strategy for climate change mitigation, soil carbon sequestration buys time over the next ten to twenty years while other effective sequestration and low carbon technologies become viable. The challenge for cropping farmers is to find disruptive technologies that will further improve soil condition and deliver increased soil carbon. Progress in 4 per mille requires collaboration and communication between scientists, farmers, policy makers, and marketeers.