<P> Whilst the earliest Egyptians simply laboured those areas which were inundated by the floods , some 7000 years ago , they started to develop the basin irrigation method . Agricultural land was divided into large fields surrounded by dams and dykes and equipped with intake and exit canals . The basins were flooded and then closed for about 45 days to saturate the soil with moisture and allow the silt to deposit . Then the water was discharged to lower fields or back into the Nile . Immediately thereafter , sowing started , and harvesting followed some three or four months later . In the dry season thereafter , farming was not possible . Thus , all crops had to fit into this tight scheme of irrigation and timing . </P>
<P> Whilst the earliest Egyptians simply laboured those areas which were inundated by the floods , some 7000 years ago , they started to develop the basin irrigation method . Agricultural land was divided into large fields surrounded by dams and dykes and equipped with intake and exit canals . The basins were flooded and then closed for about 45 days to saturate the soil with moisture and allow the silt to deposit . Then the water was discharged to lower fields or back into the Nile . Immediately thereafter , sowing started , and harvesting followed some three or four months later . In the dry season thereafter , farming was not possible . Thus , all crops had to fit into this tight scheme of irrigation and timing . </P>
when the nile river flooded what did it leave behind
when the nile river flooded what did it leave behind
silt
silt