Vietnam is the world’s second largest exporter of rice. The monitoring period covers the sowing and growth of spring and winter rice in both the north and south of the country. Most of the rice cultivation regions are concentrated in the northern Red River Delta and the Mekong Delta in the south.

Crop condition development trends based on NDVI were significantly below average. The spatial NDVI patterns compared to the five-year average indicated that 35.6% of the country was slightly above average, while the rest was below average. CropWatch indicators showed that RADPAR (+1%), CALF (96%) and temperature (+0.4°C) were above the long-term average, but total rainfall (274 mm) was below average by 7% which led to a BIOMSS decrease of about 8%. VICx was only 0.89. In the north, rainfall was above average, while in the south, it was about 50% below average. The drought conditions in the south were exacerbated by record low water levels of the Mekong River, causing intrusion of saline water into the delta. Hence, crop conditions  were very poor in the south and close to average in the north.  Overall crop conditions in the country were unsatisfactory.

Regional analysis

Based on cropping systems, climatic zones, and topographic conditions several agro-ecological zones (AEZ) can be distinguished for Vietnam: North Central Coast (202), North East (203), Red River Delta (204), South East (205), South Central Coast (206), North West (207), Central highlands (208), Mekong River Delta (209).

In the Central Highlands, both TEMP and RADPAR were above average (0.3°C and 8%, respectively), while RAIN was only 84 mm (-68%). Crop condition development trends based on NDVI were consistently below average. Although cropped arable land fraction was 0.97, scarce rainfall caused a BIOMSS decrease by 8% compared to average and VCIx was only 0.77. Crop conditions were bad in this region

The situation in the Mekong River Delta was conditioned by low precipitation (RAIN -48%) and average temperature (TEMP +0.6°C) and sunshine (RADPAR +3%). BIOMSS was slightly below average (-1%). But VCIx (0.83) and CALF (84%) indicated bad conditions. The crop condition development graph based on NDVI showed that crop conditions were consistently below the 5-year average. Output is likely to be far below the average.

Favorable climatic conditions dominated the North Central Coast over the reporting period. Rainfall was 3% above average. Temperature (+0.3°C), CALF(+1%) and RADPAR (+2%) were higher, and BIOMSS was below average by 5%. CALF (+1%) and high VCIx (0.97) value  confirmed the average conditions in this region.

North East recorded 448 mm of rainfall over four months (RAIN +47%). Temperature (+0.5°C) and CALF (0.99) was average. A significant decline in BIOMSS (-18%) compared to the 5-year average was calculated, due to lack of light (RADPAR -12%). However, VCIx and NDVI trends were high. Close to normal crop conditions are expected.

North West recorded high RAIN (+46%), above average TEMP (0.5°C) and temperature (+0.8°C). VCIx (0.9) and CALF (1.0) were high. With the decrease of 3% in RADPAR, the biomass also decreased by 6%. The NDVI profile also confirmed that the crop conditions were below average from January to March, but they recovered to average levels in April.

In the Red River Delta, rainfall was 38% above the average and the temperature was up by 0.3°C. The VCIx (0.94) and CALF (+4%) were slightly above average. Both RADPAR and BIOMSS declined sharply (-16% and -18% , respectively). This region is known for the wide cultivation of rice. The crop condition development graph of NDVI fluctuated greatly, which might have been due to atmospheric anomalies and may not have accurately reflected the conditions on the ground. Crop conditions were close to normal. 

In the South Central Coast, the average rainfall was 52% below average and TEMP was unchanged. RADPAR was above average (+10%). Despite the high reduction in rainfall, BIOMSS was below average (-6%) and the crop condition was below the average from February to April. Overall, VCIx(0.93) and CALF(+1%) indicated moderate conditions in this region.

In the South East of Vietnam, crop conditions were below average from January to April. The agro-climatic conditions showed that rainfall was (-47%), TEMP (+0.5°C) and RADPAR (+6%), resulting in a BIOMSS decrease by (-12%). VCIx (0.74) and CALF(-1%) were close to average. Crop conditions were unsatisfactory.

Figure 3.43 Vietnam’s crop condition, January 2020-April 2020

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(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 profiles

(f) Crop condition development graph based on NDVI Central Highlands Vietnam (left), and Mekong River Delta (right).

(g) Crop condition development graph based on NDVI North West Vietnam (left), and Red River Delta (right).

(h) Crop condition development graph based on NDVI South Central Coast Vietnam (left), and South East Vietnam (right).

(i) Crop condition development graph based on NDVI North Central Coast Vietnam

Table 3.77 Vietnam’s agro-climatic indicators by sub-national regions, current season's values and departure from 15YA, January -April 2020

Table 3.78 Vietnam’s agronomic indicators by sub-national regions, current season's values and departure from 5YA,  January -April 2020