Agroclimatic Suitability Assessment for Rain Fed Chickpea (Cicer arietinum L.) Based on Growth Period and Precipitation Indices in Kurdistan Province

Rainfall is a predominant climatic element that affects the density and location of agricultural systems as well as the choice of farming operations. The distribution, intensity, duration, and type of rainfall are very important at different stages such as cultivation, emergence, tillering, stem formation, and flowering. Kurdistan province has regular rainfall with an average rainfall of more than 500 mm per year. Therefore, Kurdistan province is one of the most prone rain-fed areas in Iran. As well his province with an area under cultivation of 120,000 hectares is one of the most important areas of chickpea growing in the country. However, the distribution of rainfall is not the same in all regions of this province, and therefore it is necessary to study the potential risk of chickpea production in Kurdistan province.

Long-term climatic data were collected from 15 stations for a period of 20 years from 1991 to 2011. The results of spatial and temporal analysis determined the climatic-agronomic indices of the suitable region and the amount of dryland chickpea production. Kurdistan province was divided into three climatic regions; High-risk or unsuitable climatic-agro-area (0.23% of the total area), medium-risk area or with relative proportion for production (59.71% of the total area), low-risk or suitable climatic-agro-area (37.96%) From the whole area).

The results of spatial and temporal analysis determined the climatic-agronomic indices of the suitable region and the amount of dryland chickpea production. Kurdistan province was divided into three climatic regions; High-risk or unsuitable climatic-agro-area (0.23% of the total area), medium-risk area or with relative proportion for production (59.71% of the total area), low-risk or suitable climate-agro-area (37.96%) From the whole area). The results of the study on the relationship between rainfall of vegetative stage and the potential of cultivation of dryland chickpeas in the region show except for a small part of Qorveh, Bijar, and Sarvabad cities which are in a weak degree. The whole region is in a very good degree in terms of supplying the required moisture, which is also due to the necessary rainfall at this time and the humidity of the storage capacity stored from the winter rains. The occurrence of suitable precipitations for the vegetative period in the whole region had the highest value compared to other developmental stages. The results of the study between the relationship between reproductive stage rainfall and cultivation potential of rainfed chickpeas in the region showed that Zarrineh station in the north of the region is weak due to unfavorable weather conditions at the beginning of the growing season and the developmental stages of the growing season in this region are delayed. At Zarrineh station, the critical reproductive stage occurs at a time of year when the probability of precipitation in Kurdistan has actually decreased and a part of the southeast of Qorveh city is one of the weak and critical areas. The rest of the province in terms of moisture supply for this stage of dryland chickpea development is in a suitable degree, which is due to the necessary rainfall in this period of development.

The results of the study show the relationship between rainfall of vegetative stage and cultivation potential of dryland chickpeas in the region, except for a small part of Qorveh, Bijar and Sarvabad counties, which are in a weak degree. The whole region is in a very good degree in terms of supplying the required moisture, which is also due to the necessary rainfall at this time and the humidity of the storage capacity stored from the winter rains. Occurrence of suitable precipitations for the vegetative period in the whole region had the highest value compared to other developmental stages.