The period from January to April covers the late harvesting of wet season rice, the harvesting of medium, late and floating rice, the late sowing, growing and harvesting of dry season rice, the growing and harvesting of dry season maize and the early growing period of soybean in Cambodia. Dry season rice relies on irrigation and contributes about 20% to total production.  Compared to average, Cambodia suffered from a sharp drop in rainfall (RAIN, -46%) but experienced higher temperatures (TEMP +0.8℃) and a slight increase in radiation (RADPAR +5%), which resulted in a 4% decrease in potential biomass production (BIOMSS -4%). Moreover, the fraction of cropped arable land (CALF -18%) was below the 5YA. At the same time, the maximum VCI value for the whole country was at 0.64, which indicates poor crop conditions.

The nationwide NDVI profile showed unfavorable levels as compared with the 5YA.  According to the maximum VCI profile, a large fraction of the crop land had a relatively low Maximum VCI index (VCIx<0.8). The Mekong valley, where the main rice growing area in Cambodia is located, suffered from a severe drought (RAIN 175mm  -49%). Record low water levels of the Mekong river and in the Tonle Sap lake area hindered irrigation. As a result of that, growth of dry season early rice, dry season maize and soybean were negatively affected.

Regional analysis

Based on cropping systems, climatic zones and topographic conditions, four sub-national regions are described below: the Tonle-sap lake area where the seasonally inundated freshwater lake and especially temperature are influenced by the lake itself, the Mekong valley between Tonle-sap and Vietnam border, Northern plain and northeast, the Southwestern Hilly region along the Gulg of Thailand coast.

In the Tonle Sap lake area, NDVI was below average during the reporting period. Compared to average, the temperature and sun shine were relatively higher (TEMP +1.0℃; RADPAR +4%). However, rainfall (RAIN -43%) and the potential biomass production (BIOMSS, -7%) for the region were below average. The fraction of cropped arable land was below the 5YA (CALF -26%).

The Mekong valley between Tonle-Sap and Vietnam border, the main rice growing area of Cambodia, was affected by low precipitation (RAIN -49%) with relatively higher temperature (TEMP +0.8℃) and above-average radiation (RADPAR +3%). However, the biomass potential  for the region was close to average (BIOMASS -1%). The fraction of cropped arable land was below the 5YA (CALF -16%) and the maximum VCI value (VCIx) was at 0.61. According to the NDVI profile, the NDVI of this region was below the 5YA, but it improved in April when the NDVI values started to gradually recover.

The Northern plain and northeast recorded a great drop of rainfall. It was 56% below the 15YA. Temperature (TEMP +0.7℃) and radiation (RADPAR, +7%) were higher than the 15YA. This region experienced a lower biomass potential (BIOMASS -9%) and the CALF was below average by 6%. The regional maximum VCI value was at 0.61, which means  poor crop conditions. The NDVI profile showed that the regional NDVI was below average for the entire reporting period.

The Southwest Hilly region had a deficit of rainfall (RAIN -35%) accompanied by above average temperatures (TEMP +0.9℃) and radiation (RADPAR +3%). The biomass potential production for the region was slightly higher than the 5YA (BIOMASS +3%). The region suffered from a decrease of crop land utilization and the CALF was below average by 5%. The maximum VCI value was at 0.73, which was higher than for the other regions. Like the Mekong valley, the NDVI was below average during the whole reporting period, but it improved in late April when the departure from the average became smaller.

Cambodia’s crop condition, January - April 2020

(a) Phenology of major crops

(b) Crop condition development graph based on NDVI        (c) Maximum VCI

(d) Spatial NDVI patterns compared to 5YA           (e) NDVI profile

(f) Crop condition development graph based on NDVI_Tonle-sap (left) and NDVI_Mekong valley (right)

(g) Crop condition development graph based on NDVI (Northern plain and northeast (left), Southwest Hilly region (right))

(h) Time series temperature profile          (i) Time series rainfall profile

Cambodia's agro-climatic indicators by sub-national regions, current season's values and departure from 15YA, January - April 2020

Cambodia's agronomic indicators by sub-national regions, current season's values and departure from 5YA, January - April 2020