After a brief overview of the agro-climatic and agronomic conditions in China over the reporting period (section 4.1), Chapter 4 describes the situation by region, focusing on the seven most productive agro-ecological zones (AEZs) of the east and south (4.2): North-east China, Inner Mongolia, Huanghuaihai, Loess region, Lower Yangtze, South-west China, and Southern China. Additional information on the agro-climatic indicators for agriculturally important Chinese provinces are listed in table A.11 in Annex A.

4.1 Overview

During the current monitoring period, winter wheat and rapeseed were still growing while most of other crops (i.e., maize, early rice, single season rice and soybean) were at sowing. Overall, agroclimatic condition were favorable and beneficial for crops growth. At the national scale rainfall and temperature increased respectively 20% and 0.6°C compared to average, whereas RADPAR declined by 4%. Consequently, BIOMSS was 10% above average and VCIx was relatively high, with a value of 0.90.

Spatially, 86.8% of arable land experienced average precipitation throughout the reporting period. Remaining areas (13.2% of crop land) in the south-eastern region, underwent rainfall fluctuations over time. The most  pronounced high rainfall anomalies (more than 210 mm above average) affected 2.9% of agricultural areas from mid-April in the border area of Guangdong, Guangxi, Hunan and Jiangxi provinces.  In contrast to rainfall, temperature anomalies were very variable over time especially in North-east China, including Heilongjiang, Jilin and Liaoning Province, where the anomalies ranged between -2.5 and +9.0°C, and exceptional value. Fortunately, the dramatic variations in temperature anomalies in North-east China might have little effect on crops because they occurred before the start of the growing season, as shown by the graph of cropped and uncropped land in China (Figure 4.4). In addition to North-east China, uncropped areas were also occurred  in the North-west and northern parts of China.

The cropping season is well underway  in southern and central China. According to the  spatial VCIx patterns (Figure 4.5), southern and south-east China enjoy favorable crop condition (VCIx larger than 0.8); values between 0.5 and 0.8 appear in Central China. This is also where patches of extreme low values of VHIn (below 15; Figure 4.6) do occur, including central Anhui and Shaanxi Provinces and southern Jiangsu Province. High VHIn values (above 36) are widespread in China.

As for the main producing regions at the sub-national level, rainfall was significantly above average in all the regions, ranging between +15% and +43%, except for North-east China (-28%). Temperatures were close to average in Huanghuaihai, Loess region, Lower Yangtze, Southern China and South-west China, with the departures between -0.3°C and +0.6°C. In contrast, North-east China and Inner Mongolia experienced warm weather  (+3.0°C and +1.6°C). RADPAR in all regions was close to average, except for Lower Yangtze, where it dropped 15% below average. BIOMSS increased in almost all the regions compared to average, with the anomalies ranging from +8% to +25%. CALF markedly fell below average in the Loess region (20%) and North-east China (66%), but was close to average in other regions. VCIx was relatively high for all the regions values between 0.80 and 0.98.

Table 4.1. CropWatch agroclimatic and agronomic indicators for China, January-April 2019, departure from 5YA and 15YA

Figure 4.1. China crop phenology

Figure 4.2. China spatial distribution of rainfall profiles, January-April 2019

Figure 4.3. China spatial distribution of temperature profiles, January-April 2019

Figure 4.4 Cropped and uncropped arable land by pixel, January-April 2019

Figure 4.5. China maximum Vegetation Condition Index (VCIx), by pixel, January-April 2019

Figure 4.6. China Vegetation Health Index Minimum(VHIm), by pixel, January-April 2019