This reporting period covers the end of maize and soybean harvest, as well as the sowing and early growth phase of winter wheat (Figure 1). Favorable crop growth and production of summer crops in 2020 was reported in the last bulletin. This bulletin pays more attention to major winter wheat production regions of the United States. In general, the crop conditions were mixed. 

Nationwide, drier-than-usual weather conditions were observed. According to the agro-climatic indicators of CropWatch, rainfall (291 mm) was 12% below the 15YA. Temperatures (TEMP 6.4°C) were higher (+0.7°C) and RADPAR (548 MJ/m²) was slightly below the 15YA (-1%). Regions with insufficient precipitation were mainly concentrated in the western US. Some important winter wheat producing states received significantly below-average rainfall, such as California (-40%), Colorado (-37%), Idaho (-21%) and Texas (-22%). In the early growth and over-wintering stages, the water demand is limited so that the precipitation deficit had limited impact on winter wheat. Above-average temperatures were observed in all states. Significantly above-average RADPAR was observed in western US, such as California (+5%) and Idaho (+2%) coinciding with low precipitation. Insufficient rainfall resulted in below-average potential biomass in California (-5%) and Texas (-8%). For the two important winter wheat producing states, Kansas and Oklahoma, normal agro-climatic conditions were observed.  

The rainfall deficit led to a delay of the emergence and early development of winter crops in the western states, as observed by below-average crop conditions in the NDVI departure cluster maps and the corresponding profiles in California. The drought development and its impact on crop conditions needs to be watched closely in the next reporting period, as dry conditions were observed for the Southern plain and the northwest region of the United States. Winter wheat will enter into the tillering and heading stages with an increased demand for water. In short, mixed conditions for winter wheat were observed by CropWatch for this period.

Figure 1. Phenology of United States from October 2020 to January 2021

Figure 2. Crop condition development graph based on NDVI

Figure 3. Time series rainfall profile

Figure 3. Time series temperature profile

Figure 4. Spatial distribution of NDVI profiles

Regional Analysis

This analysis focuses on the Agro-climatic and agronomic indicators of the three major winter wheat growing zones: Southern Plain, Northwest region and California. The sowing of winter wheat was completed and it entered into the early growth and over-wintering stages.

Southern Plain

This region is the most important winter wheat production zone of the United States. It includes Kansas, Oklahoma, Texas and Colorado. In general, mixed crop conditions were observed in this region. Precipitation was 9% below average, temperatures were 0.4°C above average and RADPAR was 1% below the 15YA. Rainfall shortages were most severe in Texas (-22%) and Colorado (-37%), whereas near-average precipitation occurred in Oklahoma (+9%) and Kansas (-5%). Above-normal temperatures continued in this reporting period. Rainfall shortage and above-normal temperatures led to a decline of soil moisture and had a negative impact on winter wheat growth in Texas and Colorado. If rainfall shortages for Texas and Colorado continue, crop growth conditions would turn unfavorable.

Figure 5. Crop condition development graph based on NDVI of South plain

Figure 5. Time series rainfall profile of South plain

Figure 6. Time series temperature profile of South plain

Northwest

This region is another important winter wheat production area. Winter wheat is mainly grown in the Columbia River basin located in Washington State and Oregon. The NDVI development profile indicates that the crop conditions improved from poor in October and November to favorable in January. According to the agro-climatic indicators of CropWatch, dry agro-climatic conditions were observed in the entire region with precipitation 13% below average, temperatures 0.7°C above average and RADPAR 1% above average. In mid-November, significantly above average precipitation occurred in this region, which helped the crops get well established. Starting from mid-December, close-to-average precipitation and warmer temperatures helped further improve the conditions for winter wheat. If the normal weather continues in the next reporting period, prospects for winter wheat are favorable.

Figure 7. Crop condition development graph based on NDVI of Northwest

Figure 8. Time series rainfall profile of Northwest

Figure 9. Time series temperature profile of Northwest

California

In this reporting period, California suffered a serious shortage of rainfall with precipitation 41% below average, temperatures 0.7°C above average and RADPAR 5% above average. Except for mid-November and late January, this region was dominated by dry weather conditions. The long-term severe rainfall deficit has accelerated the depletion of soil moisture and affected the growth of winter crops. The poor crop growth conditions were reflected by the NDVI development profile, as the NDVI values were significantly below average from October to January. Additional rainfall is needed to ensure normal crop growth and development.

Figure 10. Crop condition development graph based on NDVI of California

Figure 11. Time series rainfall profile of California

Figure 12. Time series temperature profile of California

Table 3.73 Agro-climatic indicators from October 2020 to January 2021 compared to 15YA

Table 3.74 Agronomic indicators from October 2020 to January 2021 compared to 5YA