This study was carried out during the period 2011–2010 for 12 months. 110 species
of phytoplankton in Al-Kabir Al-Shamali River were identified including 4 species of
Euglenophyta, 15 species of Cyanophyta, 49 species of Chrysophyta, 40 species of
Chlorophyta and 2 species of Pyrrophyta.
Some physicochemical parameters of water were determined. Some of them were the
temperature which ranged between 10.8–28°C, the pH 7.76–8.2 and the BOD 1.6–10mg/l,
while the concentrations of NO3
- ranged between 1.10-250 mg/l, nitrate 0.13-0.01mg/l, and
PO4
- ions 0.015–1.05 mg/l. The highest value of ammonium ions was 6.25mg/l and the
lowest was 0.011 mg/l. BOD concentrations ranged between 6.06-12.07mg/l.
During the last decades a large area of irrigated lands in Syria has been
shifted from extensive cropping to intensive agriculture. Many kinds of soils
became incapable to supply high yield crops by their micronutrients
requirements. Therefore, th
e deficiency of Zn, B, Mn and Fe was mentioned in
this soil. Humic substances influence micronutrients availability through
chelating, which can either increase or decrease the availability of the
micronutrients (MN). In this framework, two pot experiments were carried out
in a greenhouse at the University of Plymouth (2006) to investigate the effect of
a commercial humic substance (HS) on the micronutrients availability of: Fe,
Mn ,Zn & Cu in two composite surface soil samples collected from Vertic
Cambisols ,southwest of Syria & from Dystric Cambisols, southwest of England.
