This reporting period covers the monsoon season in Cambodia. The sowing period of early rice (wet season) and floating rice started before July, followed by the medium rice and late rice, which started in July and August respectively. The harvesting period of soybean started in July, followed by the wet season maize and early rice (wet season), which started in August and September respectively.

Cambodia generally experienced normal weather conditions, which were close to the respective averages of the previous 15 years. The precipitation (RAIN) was 2% below average, while the temperature (TEMP) rose by 0.2℃ and the radiation (RADPAR) increased by 1%, which resulted in a slightly increased estimate of biomass (BIOMSS, +1%). At the same time, the cropped arable land fraction (CALF, +1%) for the country was 98% and the maximum VCI value was at 0.93.

According to the NDVI profile for the country, the NDVI value was close to the average before August and near the 15 year maximum in early September. During this period, the deficit in precipitation had a small influence on the crop conditions. In late October, the NDVI dropped to below average as a result of excessive rainfall in that month. A large negative anomaly of NDVI was recorded in early October, which was presumably due to cloud cover in the satellite images.

Considering the spatial patterns of NDVI profiles, about 10.9% of crop land, mainly located in the lower Mekong River, experienced an above-average NDVI during the monitoring period. This high NDVI value shows that the crops benefitted from irrigation from the Mekong river. On the contrast, over 16% of the crop land had  lower NDVI values than average, which  was mainly located around the Tonle Sap Lake. The low NDVI values may have been caused by lower-than-average water levels of Tonle Sap due to water supply deficits from the Mekong River.  Around 73% of the crop land had a stable NDVI, which is close to the average. All in all, the prospective production of maize and early rice is close to or slightly higher than average. 

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, and the Southwestern Hilly region along the Gulf of Thailand coast.

In the Tonle Sap lake area, NDVI was close to or higher than average before the middle of September, while it dropped to below average subsequently. Compared to average, the rainfall (RAIN, +8%) and temperature (TEMP, +0.2℃) were higher. However, the radiation (RADPAR, -2%) and biomass (BIOMASS, -2%) for the region were below average. The fraction of cropped arable land (CALF, +1%) was above 5YA. This region is cultivated with a mixture of single and double cropping systems, and cropping intensity was below the 5-year average (CI, -2%).

The Mekong valley between Tonle Sap and Vietnam border, the main rice growing area of Cambodia, recorded a slight increase of precipitation (RAIN, +4%) and a rise of temperature (TEMP, +0.3℃). Both the radiation (RADPAR) and the biomass (BIOMSS) were near average. However, the NDVI profile for the region shows that the NDVI was higher than average before October and then dropped to below average. At the same time, this region is cultivated with a mixture of single and double cropping systems, and cropping intensity was lower than the 5-year average (CI, -1%). As a result, the soybean and wet season maize harvested there seems to have a good production.

The Northern plain and northeast had a deficit of rainfall (RAIN, -12%) accompanied by above-average radiation (RADPAR, +3%) and biomass (BIOMSS, +4%). The temperature (TEMP) was at average. Moreover, this region is cultivated with a mixture of single and double cropping systems, and cropping intensity was below the 5-year average (CI, -11%). The regional NDVI was slightly higher than average in middle August. Otherwise, it was below average, which indicates that the crop conditions for the region were unfavorable.

The Southwest Hilly region experienced an increase of rainfall (RAIN, +8%) and a rise of temperature (TEMP, +0.4℃), while the radiation (RADPAR) and biomass (BIOMSS) were near average. This region is cultivated with a mixture of single and double cropping systems, and cropping intensity was lower than the 5-year average (CI, -22%). At the same time, the cropped arable land remained very close to average (CALF, -0%) and the maximum VCI value was at 0.92. However, the NDVI for the region was higher than average before September. It subsequently dropped to below average, which means that the crop conditions for this region were unfavorable at the end of this monitoring period.

Cambodia’s crop condition, July- October 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, July- October 2020

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