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CambodiaMain producing and exporting countries

Authors: 超级管理员 | Edit: tianfuyou

Cambodia gradually entered the rainy season during this monitoring period. Harvest of dry season early rice was completed in April. Harvest of dry season maize, which had been planted in March, was finished in July. Planting of both wet season early rice and wet season maize began in May, followed by the planting of floating rice and medium rice. Soybeans continued to grow throughout the monitoring period and began to mature at the end. According to the CropWatch indicators, crop growth in Cambodia during this period was slightly below average due to rainfall deficits in April and May.

During the monitoring period, Cambodia experienced drier and hotter weather. Compared to the average, precipitation was about 6% (RAIN) lower, with a temperature increase of about 0.7°C (TEMP) and a slight increase in radiation of about 1% (RADPAR). Potential biomass was near average (BIOMASS -1%). The NDVI remained consistently below average. At the end of June and beginning of July, however, the NDVI almost returned to the average level. This is mainly due to the increase in precipitation. The pronounced rainfall deficit in April and May have significantly delayed the planting of rainy season early rice and rainy season maize. However, the normal rainfall in June and July restored the crop's NDVI. Furthermore, the rainfall deficit also increased the proportion of fallow land, leading to a 2% decrease in the CALF. Generally, crop growth across the country can be categorized into three conditions:

1) Approximately 22.9% of the cultivated area (light green) showed a continuous increase in NDVI from slightly below average to above average. These areas are mainly located in the lower Mekong River valley, where crop growth remains normal due to adequate water supply. 2) About 40.5% of the cultivated area (blue and dark green) showed a deterioration in NDVI. By the end of the period, crop growth in these areas was well below average. These areas are mainly located along the Tonle Sap Lake and in the northwestern highlands and have been severely affected by rainfall deficits and declining lake levels. 3) Approximately 36.5% of the cultivated area (red and orange) experienced a decline followed by a recovery in NDVI. These areas are mainly located in the downstream Mekong River and the northwestern region of Tonle Sap Lake. The initial decline is likely due to delayed planting caused by insufficient rainfall, while the subsequent recovery corresponds to increased rainfall.

In a word, despite a high VCIx index value of 0.84, crop growth in the country during the period is estimated to be slightly below average.


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 which is influenced by the inflow and outflow from the Mekong River, the Mekong valley between Tonle Sap and Vietnam border, Northern Plain and Northeast, and the Southwest Hilly region along the Gulf of Thailand coast.

For the Tonle Sap region (agro-ecological zone 117), rainfall was deficient (RAIN -12%) and temperatures were slightly warmer than usual (TEMP +0.9°C), while radiation remained at normal (RADPAR) levels, resulting in a 6% (BIOMASS) reduction in potential biomass. The NDVI in this region was well below average before mid-June and showed a slight recovery after mid-June. The deficit of rainfall in April and May led to delayed planting in this region, and the drop in water level of the Tonle Sap Lake was also unfavorable for floating rice growing. Despite a subsequent rise in water levels after June, crop growth was still slightly below average.

The Mekong Valley region (agro-ecological zone 118) is the most important agricultural production zone in Cambodia. Precipitation in this region shows a deficit of 4% (RAIN), accompanied by an increase in temperature of 0.7°C (TEMP), while radiation remained normal (RADPAR) levels. The potential biomass is maintained at a normal (BIOMASS) level, as the negative effects of the slightly reduced rainfall seem to be compensated by the increased temperatures. Crop NDVI was also well below average before mid-June and gradually recovered to above average after mid-June. The CALF index shows a fall of around 2% (CALF) in this region.

In the Northern Plain and Northeastern region (agro-ecological zone 119), there is a 4% (RAIN) deficit in precipitation, coupled with a significant increase in temperature of about 0.7°C (TEMP) and an increase in radiation of about 4% (RADPAR). The potential biomass in this region remains at normal (BIOMASS) levels. Similar to the Mekong Valley region, crop NDVI was well below average before mid-June and gradually recovered to average levels after June. The negative impact of the dry conditions in April and May on crops has been alleviated by the subsequent increase in rainfall, and the area under cultivation remained at a normal (CALF) level.

For the Southwest Hilly region (agro-ecological zone 120), the precipitation was slightly higher than average by about 4% (RAIN), with a temperature increase of about 0.3°C (TEMP). However, there was a slight decrease in radiation by about 1% (RADPAR), resulting in a 3% (BIOMASS) decrease in potential biomass. Crop NDVI in this region gradually recovered from well below average to normal levels. Although there was a sharp drop at the end of July, this was mainly due to the cloud cover and precipitation interfering with the remote sensing images. The proportion of cultivated land in this region remained at normal (CALF) levels, with the VCIx index reaching as high as 0.90, indicating an overall healthy crop growth status.


Figure 3.26 Cambodia's crop condition, April - July 2023

(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) Time series temperature profile (left) and rainfall profile (right)


(g) Crop condition development graph based on NDVI (left) and time series rainfall profile (right) in Tonle Sap Lake region

(h) Crop condition development graph based on NDVI (left) and time series rainfall profile (right) in Mekong valley region

(i) Crop condition development graph based on NDVI (left) and time series rainfall profile (right) in Northern plain and northeast region

(j) Crop condition development graph based on NDVI (left) and time series rainfall profile (right) in Southwest hilly region


Table 3.41 Cambodia's agro-climatic indicators by sub-national regions, current season's values, and departure from 15YA, April- July 2023

RegionRAINTEMPRADPARBIOMSS
Current(mm)Departure from 15YA(%)Current(°C)Departure from 15YA(°C)Current(MJ/m2)Departure from 15YA(%)Current(gDM/m2)Departure from 15YA(%)
Tonle-sap775-1228.00.9118601385-6
Mekong valley946-427.90.71199015530
Northern plain and northeast1192-427.30.71209415520
Southwest Hilly region1081425.80.31194-11487-3


Table 3.42 Cambodia's agronomic indicators by sub-national regions, current season's values, and departure from 5YA, April – July 2023

RegionCALFMaximum VCI
Current(%)Departure from 5YA(%)Current
Tonle-sap90-30.79
Mekong valley91-20.87
Northern plain and northeast9800.87
Southwest Hilly region9900.90