This monitoring period covers the growing period and harvest of winter rice, followed by planting of summer rice in the central part. The winter-spring rice in the Mekong Delta and southeast of Vietnam was harvested in February. It was followed by summer-autumn rice in March. The planting of winter-spring rice in the north had started in January. It will be harvested in May.

The proportion of irrigated cropland in Vietnam is 32% and agro-meteorological conditions play an important role in the growth of most crops. Rainfall is not the major influential factor on irrigated cropland. CropWatch agro-climatic indicators showed average radiation (975 MJ/m2, +0%) and temperature (20.7°C, -0.1°C). Because of higher precipitation (381 mm, +24%), the BIOMSS (+11%) showed an increase compared to the 15YA. The VCIx (0.93) was high, and the CALF (96%, +0%) was close to the 5YA.

Based on the NDVI development graph, the crop conditions were below the 5YA in the first half of this monitoring period. The large negative departures in January and February were presumably caused by cloud cover in the satellite images. The crop conditions rose to near the 5YA in early March and exceeded the maximum in late March. From January to April the precipitation was generally near the 15YA and surpassed the fifteen-year-maximum in mid-February and late March. While the temperature was above the 15YA, except for late February and early April, when it was below the 15YA. As to the spatial distribution of NDVI profiles, crop conditions on 54.2% were near average, located in the northwest and the south of Vietnam. Overall, the crop conditions were favorable. The winter rice in the north, which will be harvested in May, experienced above-average conditions.

Regional analysis

Based on cropping systems, climatic zones, and topographic conditions, several agro-ecological zones (AEZ) can be distinguished for Vietnam: Central Highlands, Mekong River Delta, North Central Coast, North East, North West, Red River Delta, South Central Coast and South East.

In the Central Highlands, due to the significant increase of RAIN (309 mm, +20%), the BIOMSS increased by 12%. CALF was 99% and VCIx was 0.96. According to the NDVI development graph, crop conditions were higher than the 5YA since February and exceeded the five-year-maximum at the end of the monitoring period. Based on the agroclimatic indicators, the crop conditions were expected to be above average.

In the Mekong River Delta region, TEMP (27.5°C, +0.1°C) was close to the 15YA, and RADPAR (1235 MJ/m2, +3%) was above the 15YA. The RAIN (432 mm, +39%) and the BIOMSS (+20%) were significantly increased. CALF was same as the 5YA and VCIx was 0.89. According to the NDVI development graph, crop conditions were slightly below the 5YA. Overall, the winter crop production was slightly below average.

In the region of North Central Coast, the RADPAR was same as the 15YA, and the TEMP was 19.0°C with a decrease by 0.4°C. RAIN (471 mm, +34%) showed a significant increase, and BIOMSS increased (+12%). CALF was same as the 5YA, and VCIx was 0.96. The crop condition development graph shows that NDVI fluctuated greatly. Crop condition in this region were expected to be near average.

In the North East region, RAIN (393 mm, +18%) increased，while RADPAR (697 MJ/m2, -2%) decreased. The BIOMSS increased by 7%. CALF was 99% and VCIx was 0.94. According to the NDVI development graph, crop conditions fluctuated widely, and in March showed a high value exceeding the five-year-maximum. The crop conditions were expected to be above average.

In the North West region, RAIN (314 mm, +24%) showed a markable increase, and the TEMP (17.3°C) was same as the 15YA. RADPAR decreased by 2%. The BIOMSS significantly increased (+12%). CALF was 100% and VCIx was 0.97. According to the NDVI development graph, except in early January and February, NDVI values were near the 5YA and peaked in late March. Crop conditions in this region were expected to be above average.

In the region of Red River Delta, RAIN (350 mm, +13%) and BIOMSS (803 gDM/m2, +4%) increased significantly. TEMP (18.7°C, -0.6°C) was below average. CALF was 95% and VCIx was 0.87. According to the crop condition development graph, the NDVI was below the 15YA, except at the end of March, NDVI exceeded the five-year-maximum. Based on the agroclimatic indicators, the crop conditions in this region were above the average.

In the South Central Coast, with the increased of RAIN (486 mm, +16%), TEMP (20.7°C, +0.2°C) and RADPAR (1070 MJ/m2, +4%), BIOMSS (969 gDM/m2, 10%) significantly increased. CALF was 98% and VCIx was 0.95. According to the crop condition development graph, the NDVI fluctuated widely until in March. Thus, crop conditions in this region were close to the average.

In the South East region, RADPAR (1189 MJ/m2) was same as the 15YA, TEMP (26.2°C, +0.2%) and RAIN (270 mm, +83%) were both above the 15YA, BIOMSS (828 gDM/m2, +8%) increased. CALF was 94% and VCIx was 0.88. According to the crop condition development graph, the NDVI values were near the 5YA According to the agroclimatic indicators, crop conditions in this region were about average.

Figure 3.45 Vietnam's crop conditions, January – April 2022

(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) Rainfall profiles                                                             (g) Temperature profiles

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

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

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

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

Table 3.83 Vietnam's agroclimatic indicators by sub-national regions, current season's values and departure from 15YA, January – April 2022 

Table 3.84 Vietnam's agronomic indicators by sub-national regions, current season's values and departure from 5YA, January – April 2022