Abstract
The study aims at evaluating the impact of precipitation variance on the productivity of wheat in Nineveh under various rainfall levels during the wheat planting season 2008 - 2009. Large areas of land in this region depend on rain for their irrigation and thus affecting the income of a large number of farmers. The standard of living of those farmers approaches poverty during the dry seasons. This means that there is no strong correlation between the average rainfall and the production of wheat but between the distribution of rainfall patterns and the production a fact assured by the statistical distribution. The increase of rainfall in the lands which are classified as rainfall assured by 1% will lead to the increase in production by 29% while in the same level of increase the productivity will increase by 35% and 55% respectively under a statistical significant accepted level, while the variances in semi-assured land were not significant. Thus, the land use, for this purpose, must rely solely on rainfall, especially in the lands that are classified as rainfall assured, but complementary irrigation must also be used and in this case will increase the productivity per unit of land planted with wheat and may increase the well beings of these lands. .
