The study was carried out to determine soil organic matter content (SOM) using loss on ignition (LOI) and titrant methods. Eighty-four composite soil samples were collected from surface soil of randomly different locations in four governorates of northern parts of Iraq. The percent mean values of SOM recorded were 2.34, 2.399 and 1.821, respectively for Erbil, Sulaymaniyah, Kirkuk, and Duhok soil samples for the LOI method, while lower values were obtained 1.39, 1.595 and 0.98% respectively by using the titrant method for the same soil samples. A low relationship between two SOM procedures was obtained (r2=0.462, 0.585 and 0.241) respectively for the same governorates soil samples. Current results revealed that the titrant method is more accurate and convenient to be used for SOM determination of soils in our area, and further studies must be done by using other methods to find the more suitable procedure for this purpose.

This study was conducted during 2008-2009 ,which included calcium carbonate determination from 84 locations (40 soil samples from Erbil, 24 samples from Sulaimani and Kirkuk in addition to 20 samples from Duhok) using calimetric and titration method. The results indicated to significance correlation coefficient between the studied methods or it means that the results of both methods are similar.

to study the effect of different concentration of dill plant residue (added to soil at ratio 0, 2, 4, and 6% W: W mixed and incubated for four weeks) on some vegetative growth characters and chemical composition of leaves and grains of two barley cultivars (C 1 = Tedmor, C 2 =Barbara). The results indicated that the different concentration of dill plant residue were affected significantly (P≤ 0.05) on most growth characters except number of tiller/plant. The highest values for all studied growth characters were recorded at 2% of dill plant residue for both cultivars. On the other hand, statistical analysis showed significant (P≤ 0.05) differences between two cultivars on nutrient content of leaves and seeds. In general, increasing level of dill plant residue led to significant increase of nitrogen, protein percent, proline, phosphorus, Fe, K + , and Na + content of the leaves in both cultivars.

Soil, plant, and water (Kasnazan impoundment and well water) samples were monthly collected from Kasnazan (10 Km north east of Erbil city) during August 2004 to February 2005. Chemical and statistical analysis indicated that the irrigation with well water resulted to decreases EC from 0.87 dS.m -1 to 0.49 dS.m -1 , because of leaching and dilution effects. Statistically there is a positive significant correlation (P< 0.05) between SAR value of well water and irrigated soil with it, whereas, a negative correlation of Mg +2 concentrations observed between well water and soil irrigated with it. On the other hand, there was high content of Mg +2 and low content of K +1 for eucalyptus plant irrigated by well water in comparison to that irrigated with impoundment water.