Clac

Different forms of nitrogen fertilizer are applied to cultivated soil with the ultimate goal for
maximizing productivity and economic return, but it is known to affect CO2 and N2O emissions. A field
experiment was carried out in 2012/2013 season at Agric. Res. Station, Giza, Egypt, to study the capability of
cyanobacteria to sustain their viability in mitigate N2O and CO2 gases emitted from soil fertilized with different
nitrogen fertilizer forms and their effects on some soil properties and barley yield. The nitrogen fertilizers were
namely: ammonium nitrate, compost and urea-form (UF); which applied separately or in combinations to barley
field; where no nitrogen fertilizer was applied to the control. Results showed that application of compost
fertilizer either alone or in combination with other fertilizer forms resulted in significant increases in
dehydrogenase activity, soil respiration, organic matter, cyanobacterial population, CO2 and N2O emissions as
well as nutrients availability in soils after harvest. While, less amounts of CO2 and N2O emission were
monitored due to application of urea-form comparing to either compost or mineral fertilizers. Diminishing
percent in N2O and CO2 emission ranged from 14.50 to 23.65 % over all treatments due to addition of
cyanobacteria, where the highest beneficial effect of cyanobacteria was attained with application of ½ compost
+ ½ UF. It was also demonstrated that cyanobacteria have the potential to significantly improve soil microbial
activities, soil properties and nutrients availability, which in turn reflected on crop productivity increases. The
results indicated that the application of ½ mineral nitrogen + ½ urea-form treatment preferably to attain the
highest plant productivity, which increased grains and straw yield by 19.12 and 36.53 %, respectively due to
application of cyanobacteria. High grains and straw yield and environmental efficiency could be achieved by
applying ½ mineral nitrogen + ½ urea-form and cyanobacteria
Key words: Nitrogen fertilizers, cyanobacteria, N2O and CO2 emission, urea-form, compost, soil productivity

Cucumber (Cucumis sativus L.) is considered one of the most important vegetable crops, under greenhouse conditions in Egypt. Application of black and white nets and polyethylene sheet affect on environmental factors under greenhouse conditions where as environmental factors (temperature and relative humidity) were higher with application of polyethylene sheet comparing with application of black and white nets. There was positive relationship between environmental (temperature and relative humidity) factors and population of aphids, spider mites, thrips and whitefly by using black and white nets and polyethylene sheet. Population of different pests were increased as well as increasing temperatures and decreasing relative humidity. Maximum population of aphid and whitefly were observed during May, but maximum population of spider mites and thrips were observed during June. Population of aphid was most frequent with using different shading nets, while population of spider mites and thrips were more frequent, While whitefly pests was less frequent. Populations of insects were more high when using polyethylene sheet than black and white nets.

This study aims to investigate the buffalo geographical distribution, developmental pattern and the relationship between developmental pattern and drought in Egypt throughout 2001/ 2010. Geographic Information system (GIS) and remote sensing were used as a tool to create buffalo distribution maps and monitor drought conditions from 2001 to 2010. The results indicated that the buffalo census was increasing steadily from 2001 to 2008 and decreased from 2009 to 2010.This drop was highly at lower and Middle Egypt. There is an adverse relationship between buffalo census developmental and drought waves. However, drought is not the only factor that affects the buffalo developmental pattern but it could be one of the most critical ones. In conclusion, drought waves may buffalo's developmental pattern. Therefore, monitoring and forecasting drought waves each year are needed to overcome the expected risks.