STATISTICAL STUDY OF IRRIGATION AND DRAINAGE NETWORKS EFFECTS ON SOIL PHYSICO-CHEMICAL PROPERTIES

摘要

Soil resources management is necessary for increasing productivity and efficiency of irrigation and drainage networks. Therefore, soil physico-chemical changes against climate, cultivation, operation and maintenance of canals and drains should be monitored carefully. Soil property changes of the 1238.5 km~2 Doroudzan project region, located 50 km northeast of Shiraz in Fars province have been studied and assessed. Based on the studies in 1344~4, 1353 and the synchronized studies of 1389, there are 16 soil series with heavy and very heavy soil texture and have the limitation of lime, salinity, alkalinity and etc. it was classified based on (U.S.D.A Soil Taxonomy 1999(Revised 2010)) in four categories such as Alfisols, Aridisols, Entisols and Inceptisols. Various phenomena over the last 35 years have affected the physic-chemical characteristics of these soils. Studying soil information statistically using SPSS (Statistical Package for the Soil Sciences) software specified that 74% of saline and alkaline lands with severe drainage problems (soil class VA and VW) and those with soil class IIIW, IIIAW and IIIA have improved to II or III soil classes. Considering the poor quality and improper use of water for agriculture, salinity has caused gradual reduction in soil quality of these regions.