This report summarizes the rice production conditions over Vietnam and in its main agro-ecological zones including North Central Coast, North East, Red River Delta, South East, South Central Coast, North West, Central highlands and Mekong River Delta from April to July, 2020. This monitoring period fully covers the duration from sowing to harvesting of summer rice in the Central Part, while the north and the south were in the last stages of their winter-spring rice and summer-autumn crops, respectively. Spring-winter rice production in the Mekong Delta and Southest region started in July.

Precipitation over the nation decreased nearly 21% as compared to the 15-year average. Shortages of rainfall occurred in May, early June, early and late July. The North Central Coast (-39%) and Red River Delta (-37%) are the two regions encountering the highest lack of precipitation. Apart from precipitation, temperature (+0.3 °C) and radiation (+5%) were slightly above average. The moderate climate conditions led to a 4% gain in biomass at the national scale. 

Crop condition development based on NDVI was significantly lower than the 5YA. The NDVI trend in the northern part of Vietnam tended to be below average levels, while the region from central to southern Vietnam (nearly 57% area) had a similar pattern of NDVI, which was close to the average. When it comes to VCIx, most parts of Vietnam had a value over 0.8, except for South Central Coast and the coastal provinces of the Mekong Delta where VCIx was very low. According to prior knowledge of the research team from Vietnam Academy for Water Resources, these two zones suffered from drought and salinity intrusion. This considerably affected the health of the crops. The CALF was stable as compared to the recent five-year average.

Overall, the output of rice production from April to July is estimated as poor, due to unfavorable weather conditions.

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).

During this reporting period, the summer-autumn rice crop cultivation in the North Central Coast passed through 3 phases: sowing, growing and harvesting. The average rainfall was about 571 mm, 39% below average, while the temperature was 25.3℃, an increase by 0.5℃ as compared to the 15YA. RADPAR was above average (+7%). Despite the substantial reduction in rainfall, BIOMASS was above average (+ 6%). The crop conditions were below average from April to July. Overall, VCIx was 0.95 and CALF was close to average, indicating moderate conditions in this region. The output of summer and autumn rice in this region is estimated to be slightly lower than in 2019.

The period from April to May is the last stage of rainy season rice in the North West. In this region, the average rainfall was 4% above average while temperatures dropped 0.2℃ compared to the 15YA. Radiation was also slightly higher than average (+6%). In general, the climate condition pattern had a small departure from the 15-year baseline. The potential biomass was above average (+ 2%) and the VCIx was in the range of 0.8 -1. The NDVI profiles in the region showed temporal variations, and the values of this indicator decreased between June and July. The CALF reached 100% and was stable compared the to 5 year average. Generally, the output of the rainy season crop  in the North West would be average thanks to good weather conditions.

In the Red river Delta, the average rainfall was 674 mm and it was 37% lower than the 15YA. The temperature was up by 0.1°C and the VCIx was 0.95. RADPAR (1%) and BIOMSS (0%) did not change significantly from the 15-year average. The crop condition development graph based on NDVI fluctuated greatly from 0.3 to 0.7. CALF increased by 1%. Overall, this region has moderate prospects for summer-autumn rice.

During this reporting period, the summer-autumn rice crop in the South East entered the growing and harvesting phases. It was followed by the planting of the spring-winter rice crop in July.  Total rainfall in this reporting period was about 902 mm,  24% below 15YA. Temperature was 27.2℃, up by 0.7℃ as compared to the 15YA.  RADPAR was higher than average (+5%). BIOMASS was above average (+3%). The crop condition graph based on NDVI presented below-average values. Rainfall deficit might be the reason for negative NDVI departure. Overall, VCIx (0.9) and CALF (94.11%) indicated moderate conditions in this region. The outputs of summer-autumn rice and spring-winter rice crop can be expected to be slightly lower than in 2019.

During this reporting period, the summer-autumn rice crop in the South Central Coast passed through 3 phases: sowing, growing and harvesting. The average rainfall was about 721 mm, 24% below average while TEMP  was 24.6℃, up by 0.3℃ over the 15YA. RADPAR was above average (+7%). Despite the big reduction in rainfall, BIOMASS was above average (+2%). The crop condition was below average from April to July.  VCIx (0.86) and CALF (+1%), in combination with the other CropWatch indicators, presented a generally unfavorable yield prospect for summer-autumn rice.

The summer-autumn rice crop in the Central Highlands passed through all  3 phases: sowing, growing and harvesting. The average rainfall in the Central Highlands was about 884 mm and it was 26% below average, while TEMP was  24.4 ℃, an increase by 0.6℃, as compared to the 15YA. RADPAR was above average (+12%). Despite the big reduction in rainfall, BIOMASS was above average (+10%). The crop conditions were below average from April 1 to early July, and then  above average in late July. Overall, high VCIx (0.94) and stable CALF indicated moderate conditions in this region. The output of summer-autumn rice is estimated to be poor.

During this reporting period, the summer-autumn rice crop in Mekong River Delta had completed the growing and harvesting phases. Spring-winter rice planting started in July. Total rainfall in this reporting period was about 944 mm, and it was 11% below the 15YA. Average temperature was 28.5℃, 0.6℃ higher than the 15YA. PAR (RADPAR) was slightly higher than average (1%). BIOMASS was above average (+2%).  The crop condition graph based on NDVI presented below-average values over the entire monitoring period. Rainfall deficit as well as record-low flow levels of the Mekong river are the likely causes for the negative NDVI departure. VCIx (0.87) and CALF (83%)  indicated moderate conditions in this region.  The outputs of summer-autumn rice and spring-winter rice crop are forecasted to be lower than in 2019. 

Figure 3.44 Vietnam's crop condition, April-July 2020

(a). Phenology of major crops

(b) Crop condition development graph based on NDVI in Vietnam

(c) Spatial distribution of NDVI profiles of all zones in Vietnam

(d) Maximum VCI in Vietnam

(e) Time series rainfall profile in Vietnam

(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 3.79 Vietnam’s agro-climatic indicators by sub-national regions, current season's values and departure from 15YA, April-July 2020

Table 3.80 Vietnam’s agronomic indicators by sub-national regions, current season's values and departure from 5YA,  April -July 2020