During the monitoring period from January to April, the harvest of Thailand’s main (monsoon) rice was completed in early January, while the second season rice was ready for harvest in April. Monsoon crops (maize and rice) are in their very early stages. 

According to CropWatch agroclimatic indicators, Thailand experienced drier weather compared to the 15YA. The rainfall from January to April was significantly below average by 40%, while temperature (+0.7°C) and radiation (+4%) were up, which led to a decrease of biomass production potential (BIOMSS) by 4%. As shown in the development of NDVI graph, crop conditions at the country level were considerably below the 5-year average. According to the NDVI profiles, crop condition were above average in some patches in Nong Khai, Roi Et, Si Saket, Ubon Ratchathani, Surin and Sa Kaeo, covering  19.1% of total arable land. This was  confirmed by VCIx map. Crop conditions in 40.9% of the arable land, mostly located in the northeast and center of Thailand, were below average until mid-March. Subsequently, they improved to close to, but still below average levels in early April. The crop conditions in the remaining areas were always below average during the monitoring period. Due to the ongoing drought, the government had restricted irrigation, which in combination with far below-average levels of rainfall until mid-April, caused unfavorable conditions. A rather low VCIx of 0.70 and a CALF decrease by 5% in combination with generally below average NDVI levels, indicate poor conditions for second season rice production.

Regional analysis

The regional analysis below focuses on some of the already mentioned agro-ecological zones of Thailand, of which some 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 numbers correspond to the labels in the VCIx and NDVI profile maps. 

Indicators for the Central double and triple-cropped rice lowlands follow the same patterns as those for the country as a whole: temperature (TEMP +0.9C) and radiation (RADPAR +2%) were above average, and accumulated rainfall was significantly below (RAIN -34%), resulting in an average biomass production potential (BIOMSS, +1%). According to the NDVI development graph, crop conditions were below the 5YA. Overall, the situation was below average considering the unfavorable VCIx value of 0.57 and a large decrease in the fraction of cropped arable land (CALF) by 22%.

The rainfall of the South-eastern horticulture area suffered a decrease of 12%, while temperature (TEMP +0.7°C) and radiation (RADPAR +5%) experienced the same changes as the whole country, which led to an increase of biomass production potential by +10%. However, according to the NDVI development graph, crop conditions were below average. Fair VCIx value of 0.78 and slightly lower fraction of cropped arable land (CALF -2%) confirm that crop conditions were unfavorable during this monitoring period.

Crop condition in the Western and southern hill areas were unfavorable according to the agroclimatic indicators (TEMP +0.6°C, RADPAR +3%, and BIOMSS -9%), mainly due to the deficit of rainfall (-48%). According to the NDVI development graph, crop conditions were below average. 

Finally, the situation in the Single-cropped rice north-eastern region was also unsatisfactory. According to CropWatch indicators, rainfall (RAIN -35%) was below average, while temperature (TEMP +0.9°C) and radiation (RADPAR +5%) were above average, leading to a slightly subnormal production potential (BIOMSS -1%). According to the NDVI development graph, crop conditions were slightly below average. However, they improved slightly in early April.

Figure 3.28a. Thailand phenology of major crops

Figure 3.28b. Time series temperature profile in Thailand

Figure 3.28c. Time series rainfall profile in Thailand

Figure 3.28d. Thailand national level crop condition development graph based on NDVI, comparing the January-April 2020 period to the previous season and the five-year average (5YA) and maximum

Figure 3.28e. Thailand maximum VCI for January-April 2020 by pixel

Figure 3.28f. Thailand spatial NDVI patterns up to April 2020 according to local cropping patterns and compared to the 5YA (left) and (e) associated NDVI profiles (right)

Figure 3.28g Central double and triple-cropped rice lowlands (Thailand) crop condition development graph based on NDVI

Figure 3.28h.Western and southern hill areas (Thailand) crop condition development graph based on NDVI

Figure 3.28i. South-eastern horticulture area (Thailand) crop condition development graph based on NDVI

Figure 3.28j. Single-cropped rice north-eastern region (Thailand) crop condition development graph based on NDVI

Table 70. January-April 2020 agro-climatic indicators by agro-ecological region, current season values and departure from 15YA

Table 71. January-April 2020 agronomic indicators by agro-ecological region, current season values and departure from 15YA/5YA