Integrated Soil and Water Management at Farm Level in Honam Sub-Catchment(Part I: Determination of Homogeneous Soil and Water Management Units)

This study expresses the steps of achievement to the indigenous-executive framework of integrated soil and water management at farm level through a mega project with 19 sub-projects. The projects were carried out during 2013-2020 with active participation of international, national and regional experts as well as local farmers in Honam Sub-basin, Lorestan Province, Iran. To understand the soil and water management problems for agriculture in the same homogeneous units (HSWMUs), farmlands were classified regarding physical, chemical and biological characteristics of soil, making it possible to convert soil maps into thematic maps. In this research, the fertility capability classification (FCC) method that integrates surface and sub-surface soil textures with modifieres was used. In addition, several modifieres were revised for soils of semi-arid regions and new modifieres were introduced for Irrigation Capability Classification (ICC). The required information was collected from 119 soil profiles and 101 surface soil samples in detailed scale of 1:25000 and the corresponding measurements were made. Accordingly, different data layers including detailed soil map were produced via geopedological method icluding land limitation, land suitability, and land production potential (LPP) of major crops, land degradation, location of water withdrawal, land use and agricultural cadastre of 2395 farms were prepared. To evaluate the current soil and water behavior of farmers within HSWMUs, the multidisciplinary team recorded the issues through field visits and open semi-structured questionnaire of 84 selected farmers in 24 villages who were interviewed during 2018-2019. The results showed that 23 and 30 HSWMUs that covered, respectively, 93% and 90% of the irrigated and rainfed areas were delineated on the map. Investigations showed that the sub-basin suffers from problems such as plow pan, phosphorus and zinc deficiencies, poor irrigation scheduling, and three types of farmers. Finally, recommended packages were prepared and validated for each HSWMU, which will be discussed in the part 2.