This monitoring period covers the grain filling period and harvest of winter wheat, as well as the planting and early establishment of the rice crop. According to the NDVI based crop condition development graph, the conditions in Iran during this whole monitoring period were below the 5-year average. The cumulative rainfall was 91 mm, which was 1% below average. The average temperature was 22.8°C (1.4°C above average), whereas the photosynthetically active radiation was 1628 MJ/m2 (at average). The potential biomass was 1% lower than the 15-year average. The national maximum vegetation condition index (VCIx) was 0.58, while the cropped arable land fraction (CALF) was 31% lower than the average of the past 5-years. 

The NDVI spatial patterns show that from April to July, crop conditions on 8.8% of the cropped areas were above the 5-year average (marked in blue). 29.4% of the cropped areas (marked in dark green) and 21.4% of the cropped areas (marked in red), mainly located in the provinces of West Azaibaijan, East Azarbaijan, Gilan, Mazandaran and Khuzestan, experienced close to average crop conditions almost throughout the monitoring period. The two remaining clustered regions, accounting for 40.4% of the cropped areas, both suffered from significantly below average crop conditions (negative NDVI anomaly more than -0.1) from early to middle June (light green marked regions) and from middle April to middle June (orange marked regions), mainly located in the provinces of Kordestan, Zanjan, Kermanshah, Hamadan, Ilam, lorestan, Golestan, North Khorasan and Razavi Khorasan. The severe lack of rainfall in April caused very unfavorable conditions for rice and wheat, as confirmed by the NDVI profiles. The spatial pattern of maximum Vegetation Condition Index (VCIx) was in accord with the spatial distribution of the NDVI profiles. 

The proportion of NDVI anomaly categories, as compared with the 5-year average, shows that in the first and third 16-day phases, almost 10% of the cropped area  had slightly below or below average crop conditions. From the 3rd to the 6th 16-day phases, about 20% of the cultivated areas experienced above average crop conditions. The proportion of VHIm categories shows that more than 20% of the cultivated regions suffered from severe droughts from the 6th to the 16th weekly phases. Overall, lack of rainfall caused unfavorable crop conditions for Iran.

Regional Analysis 

Based on farming system, climate, and topographic conditions, Iran can be subdivided into three regions, two of which are the main production areas for crops, namely the Semi-arid to the subtropical hilly region in the west and the north and the Coastal lowland and plain areas of the arid Red Sea. 

In the Western and northern semi-arid subtropical hilly areas, the cumulative precipitation during the monitoring period was 99 mm, 8% below the average, the temperature was 21.0°C (+1.5°C), and photosynthetically active radiation was at average. The potential biomass was 2% lower than the average. Crop conditions were below the 5-year average throughout the monitoring period. The proportion of cultivated land was 25%, which is 31% lower than the 5YA average. The average VCIx for this region was 0.61, indicating unfavorable crop conditions.  

In the Coastal lowland and plain areas of the arid Red Sea, the temperature was 1.2°C above average, the accumulated precipitation was 36% above average and the photosynthetically active radiation was also slightly above average (+1%). The potential biomass was at the 15-year average. Crop conditions were below to near the 5YA average. During the monitoring period, CALF was 20% below the average of the last 5-years, and the VCIx was 0.51, also indicating poor crop prospects.

Figure 3.21 Iran's crop condition, April-July 2021

(a) Phenology of major crops

(b) Crop condition development graph based on NDVI

(c) Maximum VCI

(d) Rainfall time series profile

(e) Temperature time series profile

(f) Spatial NDVI patterns compared to 5YA                  (g) NDVI profiles

(h) Crop condition development graph based on NDVI (Semi-arid to sub-tropical hills of the west and north region)

(i) Crop condition development graph based on NDVI (Coastal lowland and plain areas of the arid Red Sea)

(j) Proportion of NDVI anomaly categories compared with 5YA

(k) Proportion of VHIm categories compared with 5YA

Table 3.33 Iran's agroclimatic indicators by sub-national regions, current season's values and departure from 15YA, April-July 2021

Table 3.34 Iran's agronomic indicators by sub-national regions, current season's value and departure from 5YA, April-July 2021