Comparative Vegetation Condition Report: August 15 - 21
The weekly Vegetation Condition Report maps below can be a valuable tool for making crop selection and marketing decisions.
The objective of these reports is to provide users with a means of assessing the relative condition of crops and grassland. The maps can be used to assess current plant growth rates, as well as comparisons to the previous year and relative to the 28-year average. The report is used by individual farmers and ranchers, the commodities market, and political leaders for assessing factors such as production potential and drought impact across their state.
The Vegetation Condition Report (VCR) maps were originally developed by Dr. Kevin Price, K-State professor emeritus of agronomy and geography, and his pioneering work in this area is gratefully acknowledged.
The maps have recently been revised, using newer technology and enhanced sources of data. Dr. Nan An, Imaging Scientist, collaborated with Dr. Antonio Ray Asebedo, assistant professor and lab director of the Precision Agriculture Lab in the Department of Agronomy at Kansas State University, on the new VCR development. Multiple improvements have been made, such as new image processing algorithms with new remotely sensed data from EROS Data Center.
These improvements increase sensitivity for capturing more variability in plant biomass and photosynthetic capacity. However, the same format as the previous versions of the VCR maps was retained, thus allowing the transition to be as seamless as possible for the end user. For this spring, it was decided not to incorporate the snow cover data, which had been used in past years. However, this feature will be added back at a later date. In addition, production of the Corn Belt maps has been stopped, as the continental U.S. maps will provide the same data for these areas. Dr. Asebedo and Dr. An will continue development and improvement of the VCRs and other advanced maps.
The maps in this issue of the newsletter show the current state of photosynthetic activity in Kansas, and the continental U.S., with comments from Mary Knapp, assistant state climatologist:
Figure 1. The Vegetation Condition Report for Kansas for August 15 – August 21, 2017 from K-State’s Precision Agriculture Laboratory shows the area of greatest vegetative activity continues to be in eastern Kansas, particularly in extreme northeast Kansas. The impact from the recent rains has begun to be visible, and the flooded areas of Wyandotte and Johnson counties show reduced photosynthetic activity. In central and south central Kansas the lower rainfall shows the continued stress on vegetation.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for August 15 – August 21, 2017 from K-State’s Precision Agriculture Laboratory shows the greatest change in vegetative activity is in the western third of the state, where rainfall has been more consistent this year. In contrast, much of the eastern half of the state has lower vegetative activity. Although August has been running cooler, this summer has been hotter and much drier than last year in this area.
Figure 3. Compared to the 28-year average at this time for Kansas, this year’s Vegetation Condition Report for August 15 – August 21, 2017 from K-State’s Precision Agriculture Laboratory above-average activity in the western parts of the state. Wetter-than-normal conditions have favored parts of the west, particularly Wallace County. Meanwhile continued dry weather has stressed vegetation in the central parts of the state.
Figure 4. The Vegetation Condition Report for the U.S for August 15 – August 21, 2017 from K-State’s Precision Agriculture Laboratory shows the highest NDVI values are centered in the Midwest, particularly in eastern Nebraska and western Iowa. A second area of higher vegetative activity is visible along the West Coast, where the recent warm weather has yet to have a visible impact. Extremely low NDVI values continue to highlight the severe drought in eastern Montana and western South Dakota.
Figure 5. The U.S. comparison to last year at this time for August 15 – August 21, 2017 from K-State’s Precision Agriculture Laboratory again shows the impact that the split in moisture has caused this year. Much lower NDVI values are visible in Montana and South Dakota, with slightly lower values in the Plains and into the Oklahoma Panhandle. In contrast, the desert Southwest and southern Texas have much higher NDVI values than last year at this time.
Figure 6. The U.S. comparison to the 28-year average for the period of August 15 – August 21, 2017 from K-State’s Precision Agriculture Laboratory shows the drought impacts in the Northern Plains are visible as below-average NDVI values. In Colorado, parts of Idaho, and the Sierra Nevada of California, the below-average NDVI values are due to clouds associated with monsoon moisture. Wetter-than-normal conditions continue in parts of Arizona.
Mary Knapp, Weather Data Library
Ray Asebedo, Precision Agriculture
Nan An, Imaging Scientist