Rice is the main crop in the Nile delta, Egypt. However the salt was accumulating in the agricultural field, and is affecting the rice cultivation, recently. The objective of the present study was to find out the salt tolerance level of Egyptian rice varieties in germination, vegetative and reproductive stages. Seeds of Egyptian rice varieties (Oriza sativa L. vars. Sakha 104, Giza 178, and EHR 1) and seeds of Japanese variety (Koshihikari) were selected for our germination tests. One hundred of seeds were put in petri dishes (9 cm diameter) with 10 mL of distilled water as a control, or salty solutions as treatments (0.35, 0.7, 1.0, 1.5, 2.0, 2.5 and 3.0% NaCl) under 25°C in a growth chamber. As a result, Sakha 104 and Giza 178 were germinated earlier than Koshihikari under 0.35, 0.7, 1.0, 1.5 and 2.0% NaCl treatments. All varieties could not germinate under 3.0% NaCl treatment. In the field research, Rice varieties (Giza 177, Giza178, Sakha102, Sakha 104, Sakha 105, Sakha 106 EHR 1 and HER 2) were cultivated at the low EC field (6.5 mS cm^–1) and rice varieties (Giza178, Sakha 104 and EHR 1) were cultivated under the high EC (11.8 mS cm^–1) at Damietta. Photosynthetic rates of EHR 1 increased with the increase of EC, and was the highest of 4 varieties under high EC treatment. SPAD of Egyptian varieties under low and high EC treatments were 31.6-42.0 and 37.3-38.4, respectively. On the day of photosynthesis measurement, plant lengths of Egyptian varieties were 56.7-71.7 cm under EC 6.5. Plant length of EHR 1 increased with increase of EC, while that of Giza 178 and Sakha 104 did not show significant differences between low and high EC treatments. Salt tolerance mechanism of Egyptian rice varieties were estimated that Egyptian varieties have kept growth under high EC condition because they could keep high photosynthetic rates and SPAD.

According to the newest IPCC sixth assessment report, arid regions, which occupy about 46% of the total land area (excluding Antarctica) and host over a third of the current population, are likely to be faced with more extreme weather phenomena as global warming advances. To develop sustainable land management in drylands, it is essential to gather information by monitoring changes in environmental conditions such as land degradation. In this report, the current climatic aridity situation and the actual arid conditions based on an analysis of satellite data are presented.

Human-induced climate change is already affecting many weather and climate extremes, and changes in extremes will become larger with additional global warming. Precipitation changes associated with global warming are expected to be spatially concentrated with wetter areas becoming wetter and drier areas becoming drier, as well as temporally concentrated with increased frequency and intensity of heavy rainfall and increased periods of no or little rainfall. The IPCC Special Report on Climate Change and Land summarizes the latest findings on desertification and land degradation through land-climate interactions, and on land-related risk management and sustainable development. It points out that most of the land area is affected by humans, that land is important for humans, ecosystems, and the climate system, that climate change can exacerbate land degradation, and that various factors are interacting to contribute to desertification. This paper outlines the effects of global warming on the world’s water cycle and the relationship between climate change and desertification.