The period from January to April falls into the dry season in Thailand. It is the growing and harvest season for the second rice crop. Maize planting started in April. The proportion of irrigated cropland in Thailand is 23% and agro-meteorological conditions play an important role in the growth of most crops. During this monitoring period, the rainfall was significantly above average (+34%), while the temperature was below the 15YA (TEMP -0.2°C) with below-average radiation (RADPAR -7%).

Sufficient rainfall led to above-average potential production (BIOMSS, +17%). According to the profile of the NDVI development graph, the crop conditions were favorable, even reaching the five-year maximum. The maximum vegetation condition index (VCIx) was relatively high at 0.94. The crop condition in 71.6% of cropped area was above average, while only 28.4% of the cropped area was below average, mainly in Chumphon, Prachuap Khilikhan, Surat Thani, Nakhon Si Thammarat, Kampaeng Phet and Udon Thani. Considering the cropped arable land fraction during the growing season was also above average (CALF, +12%), the CropWatch anticipated production for second rice is favorable.

Regional analysis

The regional analysis covers  four main agro-ecological zones (AEZ) of Thailand: Central double and triple-cropped rice lowlands,  North-eastern single-cropped rice region, South-eastern horticulture area, and Western and southern hill areas. The characteristics of rice planting are dependent on rice cultivation topology.

Central double and triple-cropped rice lowlands is the major region for the second rice. Indicators for this region show a similar pattern as for the whole country: Temperature and radiation were below average  (TEMP -0.1°C; RADPAR -2%) whilst the rainfall was higher than the 15YA by 22%. These weather factors led to a biomass increase (+15%). The fraction of cropped arable land (CALF) increased by 8% and the maximum VCI was 0.88. According to the NDVI profile, the NDVI values exceeded the 5-year maximum from February to March 2022. In April, crop condition was close to the 5YA.  The second rice production is forecasted to be favorable.

In the North-eastern single-cropped rice region, temperature was below average (-0.2ºC) and rainfall and radiation had increased by 31% and 2%, respectively. Estimated biomass was 14% above the 15YA.  VCIx was 0.94  and CALF increased by 3% compared with the 5Y average.  

Crop conditions in the Western and southern hill areas experienced wetter than average conditions (RAIN +30%). Temperature and solar radiation were close to average (TEMP -0.2ºC; RADPAR -1%). Estimated biomass was higher by 16%.  VCIx was 0.93.

The South-eastern horticulture area experienced above-average rainfall (RAIN +48%) while the temperature was below average (TEMP -0.5℃) with averaged solar radiation (RADPAR 0%), leading to a biomass increase (BIOMSS 21%). 

Figure 1 Thailand's crop condition, crop calendar from January-April 2022

a) Crop phenology map of major crops

b) Phenology of major crops                                   c) Maximum VCI

d) Crop condition clustering map based on NDVI graph      

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 1 Thailand's agroclimatic indicators by sub-national regions, current values and departure of 15YA

Table 2 Thailand's cropped arable land fraction (CALF) and current maximum VCI values, January-April 2022