Phosphorus availability as influenced by different application rates of elemental sulphur to soils [electronic resource].

Includes references.

This paper aims to monitoring waterlogged areas through linking terrain condition with ETM spectral characteristics images of West Delta in Egypt.. The agriculture development in the area is facing with human-induced degradation mainly waterlogging and salinity problems. Those are due to seepage from irrigation canals, inadequate drainage systems, conversion of pressurized irrigation system to surface-flooding irrigation, direct use of low quality drainage water in irrigation, and mixing drainage and wastewater with irrigation water system. The area is subjected to national extensive land improvement program throughout 1998 to 2004. The study involves: - (1) Digital terrain analysis, (2) TM Analysis (Bands 1, 2, 3, 4, 5, 7 and 6), (3) field observations, (4) Test the relationship of the terrain condition with the different spectral classes, (5) Evaluate the effectiveness of the land improvement program throughout the temporal variability of the waterlogged areas. The materials used were topographic maps scales 1 :50000, and Landsat 7 of ETM September 1997, December 1999, and December 2001. The integrated land and watershed management system (IL WIS 3.2) has been used as the main software. The contour lines and ground control points of the topographic maps with 1000 meters grid system were used to create DTM using the geostatistical analyses. - Physiographic mapping units was compiled from overlying and analyzing the classified DTM, slope aspect map, hills shadow map, geomorphologic information, ancillary information and geological map. Multi-spectral image classification is used to extract thematic information from satellite images in a semi-automatic way. The thermal band was stretched to re-distributes values of an input map . over a wider range of values in an output map. The results show that terrain analysis is a powerful tool to identify the major physiographic mapping units. There is a good relationship between the physiographic mapping units and distribution of water logged areas. Also, there is a highly significant relationship between the two techniques of ETM analysis of using supervised maximum likelihood of the map list and thermal analysis of the band 6 of years 1997, 1999, and 2001 to determine the water logged areas. In general both techniques show that, there is dramatic increase in surface water; waterlogged area with shallow water, and waterlogged areas with poorly drained soils with high water table through 1997, 1999, and 2001. There is significant increase 'of the water logged areas in Sugar Beet and West Nubanya areas through 2001 due to the intensive flooding irrigation practices and the lack of appropriate drainage programs. The improvement of EI-Bustan 1&2 is clear, due to the activities of Bustan Agricultural Development Project (1998-2004). The deterioration of some areas in Branch 20 and El-Bustan 3 reflects the recent intensive Banana cultivation.

Summary in Arabic.

1