From April to July, the main rice and maize crops were sown, and the harvest of the second rice was completed in June. According to the agroclimatic indicators, Thailand suffered rainy and cooler than usual weather in this monitoring period with above-average rainfall (RAIN, +36%) and sunshine (RADPAR, +5%), as well as decreased temperature (TEMP, -0.4°C). Sufficient rainfall mitigates water stress for crops, while enough sunshine ensures photosynthesis and benefits the accumulation of biomass. All of these indicators led to a favorable potential biomass (BIOMSS, +6%). As shown by its profile, rainfall was above average during the whole monitoring period. 

The NDVI development graph shows that crop conditions were above average in April and May. According to the NDVI departure clustering map, 29.9% of cropland was always slightly above average from April to July, mostly located in central and eastern areas. Crop conditions for 28.2% of the cropped area were slightly below average, except for the end of April, when they were slightly above average. Those areas were located in patches around most of Thailand, but predominantly in the south, including Surat Thani, Nakhon Si Thammarat, Krabi, Trang and northern areas including Chiang Rai, Phayao, Chiang Mai and Lampang. 30.4% of the cropped area, mostly located in central and eastern regions, fluctuated near the average level at beginning of the monitoring period and significantly improved to be above average after May. For the remaining 11.5% of the cropped area conditions were above average until June. The sharp negative departure at the end of this monitoring period was mostly likely due to cloud cover in the satellite image. 

At the national level, all arable land was cropped during the season (CALF +1%) and had favorable VCIx values of around 0.94. CropWatch estimates that the crop condition were favorable and above average.

Regional analysis

The regional analysis below focuses on some of the already mentioned agro-ecological zones of Thailand, which are mostly defined by the rice cultivation typology. Agro-ecological zones include Central double and triple-cropped rice lowlands (115), South-eastern horticulture area (116), Western and southern hill areas (117), and the Single-cropped rice north-eastern region (118).

The situation in the Central double and triple-cropped rice lowlands followed the same pattern as for the whole country: accumulated rainfall and radiation were above average (RAIN +91%, RADPAR +4%), and temperature was below average (TEMP -1.0ºC), which resulted in above-average biomass production potential (BIOMSS +6%). According to the NDVI development graph, crop conditions were slightly above the 5-year average. At the end of April, the crop conditions even reached the 5-year maximum level. Considering the favorable VCIx value of 0.91, the situation is assessed as slightly above average.

According to agro-climatic indicators for the South-eastern horticulture area, temperature was below average (TEMP -0.1 ºC), while accumulated rainfall and solar radiation were above average (RAIN +24%, RADPAR +4%), resulting in a slightly above-average biomass production potential (BIOMSS +5%). Crop conditions were slightly above average for most of the monitoring period, except for late June and July.  Considering the favorable VCIx value of 0.96, the crop conditions in this area were slightly above average. 

Agroclimatic indicators show that the conditions in the Western and southern hills were slightly above average: accumulated rainfall and radiation were above average (RAIN +22%, RADPAR +3%), and temperature was below average (TEMP -0.3ºC), resulting in a biomass production potential increase (BIOMSS +5%). As shown in NDVI development graph, the crop conditions were slightly above average before May but dropped to below-average levels in June and July.  According to the favorable VCIx value of 0.94, crop conditions are assessed as fair.

 Indicators in the  Single-cropped rice north-eastern region follow the same patterns as those for the country as a whole: accumulated rainfall and radiation were above average (RAIN +41%, RADPAR +7%), and temperature  was  below average (TEMP -0.3ºC), resulting in an increased biomass production potential (BIOMSS +8%). The crop condition was slightly above average as depicted in the NDVI development graph. According to the satisfactory VCIx value of 0.96, the crop conditions were above average.

Figure 3.39 Thailand's crop condition, crop calendar from April-July 2021

a) Crop phenology map of major crops

b) Crop condition development graph based on NDVI c) Maximum VCI

d) Spatial distribution of NDVI profiles

f) Rainfall profile                                               g) Temperature profile 

h) Crop condition development graph based on NDVI in the double and triple-cropped rice lowlands (left) and single-cropped rice North-eastern region (right) 

i) Crop condition development graph based on NDVI in the South-eastern horticulture area (left) and Western and southern hill areas (right)

Table 3.69 Thailand's agroclimatic indicators by sub-national regions, current season’s values and departure from 15YA, April - July 2021

Table 3.70 Thailand's agronomic indicators by sub-national regions, current season’s values and departure from 5YA, April - July 2021