January to April covers the growing period and early harvesting stage of  maize, and the harvesting time of rainy season rice. Compared to average, CropWatch agro-climatic indicators show a sharp drop in rainfall (RAIN -26%), no change for air temperature and a slight increase in radiation (RADPAR, +3%), resulting in a sharp drop in biomass production potential (BIOMASS, -17%). Moderate VCIx is observed around the Tongle Sap (<0.8), with lowest values below 0.5 in the western part of the country.

The nationwide NDVI profile displays an obvious deficit compared with 5-year average but spatial NDVI clusters only partially confirm the VCIx distribution. In March and April, 45.4 % of cropped areas display above or near average condition, with 46.2% slightly below average by 0.05 NDVI units and only 8.4% with NDVI 0.2 units below average. No clear spatial patterns emerge although the poorest crops seem to be located along the tributaries of Tonle Sap. 

Regional Analysis

Based mostly on climate differences and topography four agro-ecological regions can be distinguished, starting with the Tonle Sap lake area where rainfall and especially temperature are influenced by the lake itself. The second and the third area , referred to as the "Mekong valley between Tonle-sap and Vietnam border"  and "Northern plain and northeast" covers agriculturally less important regions east of the Lake. In the last zone, the  "South-western Hilly region" monsoon plays a larger part than in the other regions where the Mekong supplies most water to farming.

All four regions suffered a reduction in rainfall compared with average in the range of 10% (Tonle Sap) to 43% in the Mekong valley between Tonle Sap and the Vietnam border. All regions had about average temperature and a positive RADPAR departure (2 to 3%) which, however, reached 6% in the northern plain and North-east. Drought caused an 8% drop in BIOMSS near Tonle Sap but larger departures from -9% to - 25% in other regions. NDVI profiles also display unsatisfactory crops in all four regions. NDVI was persistently below average except in January in the Tonle Sap basin and the Mekong valley between Tonle Sap and the Vietnam border and at the end of April in the south-western Hills.

Considering, in addition, that VCIx values are fair with CALF variations between -7% and +8%, overall crop condition in Cambodia appears to be below average to average.

Cambodia agroclimatic indicators by sub-national regions,current season's values and departure from 15YA, January 2019 - April 2019

Cambodia agronomic indicators by sub-national regions, current season's values and departure from 15YA/5YA, January 2019 - April 2019

图.X phenology

图.X Maximum VCI

图.X Crop condition development graph based on NDVI_Cambodia

图.X Spatial distribution of NDVI profiles

图.X Crop condition development graph based on NDVI_Tonle-sap

图.X Crop condition development graph based on NDVI_Mekong valley between Tonle-sap and Vietnam border

图.X Crop condition development graph based on NDVI_Southwest Hilly region

图.X Crop condition development graph based on NDVI_Northern plain and northeast