The reporting period covers the harvesting stages of wet-season early rice, medium rice, late rice and floating rice. The sowing of dry-season early rice was completed by the end of January, and the harvest was accomplished by the end of April, when the harvest of dry-season maize was concluded as well. Soybean had been planted in December and will be harvested in June/July. 

Rainfall was generally below average (RAIN, -29%). It reached average levels by mid April only. Temperature was below average as well (TEMP -0.2ºC). The radiation was higher than the average (RADPAR +4%). As a consequence, the potential biomass was below average (BIOMSS -7%). At the same time, the cropped arable land fraction (CALF) was at 75%, with a 3% decrease. The national maximum VCI value was at 0.80.

According to the NDVI profile for the country, the NDVI values were below average in January, which was caused by the colder weather as shown in the temperature profile. Warmer temperatures in February helped increase NDVI. However, the deficit in precipitation, especially in the late March and early April, seems to have negatively influenced crop conditions. With the start of above-average rainfall in mid April, the NDVI values improved to average levels by the end of this reporting period. The spatial patterns of the NDVI profiles show that for 15.8% of crop land, mainly located in central Kampong Cham, NDVI departure values reached -0.2. These were the largest departures among all regions. Above-average NDVI was observed for 8.5% of the crop land mainly located in the lower reaches of Mekong River and the entrance of the tributaries of Tonle-Sap. All in all, the conditions for crop production in Cambodia were slightly unfavorable.

Regional analysis

Based on cropping systems, climatic zones and topographic conditions, four sub-national regions are described below: The Tonle Sap lake area, a seasonally inundated freshwater lake, 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, rainfall was 31% below average and the temperature was slightly below average as well (TEMP, -0.1℃), which resulted in an lower biomass compared with the 15YA (BIOMSS, -21%). Additionally, both the NDVI values in January and in the middle of March and early April were lower than average. The former resulted from the cold weather in January and the latter was the consequence of a lack of water.

In the Mekong valley, the NDVI values trended below the 5YA until late April. Rainfall was below average by 32% and the temperature was 0.2℃ below average. Although the radiation was higher (RADPAR, +3%), the potential biomass was 18% slightly below average. Additionally, the cropped arable land fraction (CALF) in this region was at 78%, with a 6% decrease , which means the production conditions in this region were unfavorable.

In the Northern plain and northeast, this season's NDVI values were always lower than the corresponding averages as well. As for the agro-climate indicators, the precipitation was below average (RAIN -21%) and the temperature was lower (TEMP -0.2℃). Although the radiation was 6% higher than average, the potential biomass was less than average (BIOMSS -19%). The cropped arable land fraction (CALF) was 91%  and the maximum VCI value was at 0.75.

In the Southwest Hilly region, rainfall was below average (RAIN -39%) and the temperature was 0.1℃ lower. The resulting biomass was 21% lower than the average although solar radiation was higher (RADPAR +3%). The maximum VCI value was at 0.82. The NDVI for the region was always lower than average as well, which indicates unfavorable conditions.

Figure 3.26 Cambodia’s crop condition, January - April 2021

(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

Table 3.41 Cambodia's agro-climatic indicators by sub-national regions, current season's values and departure from 15YA, January - April 2021

Table 3.42 Cambodia's agronomic indicators by sub-national regions, current season's values and departure from 5YA, January - April 2021