Comparative Vegetation Condition Report: September 12 - September 18, 2017
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 September 12 – September 18, 2017 from K-State’s Precision Agriculture Laboratory shows very little vegetative activity this week. The greatest area of photosynthetic activity is in southeast Kansas. Recent warm, dry weather has increased crop maturity and reduced photosynthetic activity.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for September 12 – September 18, 2017 from K-State’s Precision Agriculture Laboratory shows lower vegetative activity across the eastern two-thirds of the state. Much of that is due to increased cloud cover rather than heavy rains, which was confined to the southeastern division.
Figure 3. Compared to the 28-year average at this time for Kansas, this year’s Vegetation Condition Report for September 12 – September 18, 2017 from K-State’s Precision Agriculture Laboratory shows above-average vegetative activity in the western third of the state. Increasing drought conditions has stressed vegetation in parts of central and northeast Kansas, particularly in Nemaha and Marshall counties.
Figure 4. The Vegetation Condition Report for the U.S for September 12 – September 18, 2017 from K-State’s Precision Agriculture Laboratory shows the highest NDVI values centered across the Great Lakes into upper New England. A second area of higher vegetative activity is also visible along the Carolinas, where the recent rainfall has reduced drought stress. Extremely low NDVI values continue to highlight the severe drought in eastern Montana and western South Dakota, while the excess rainfall along the Gulf Coast is beginning to show visible impacts, particularly in Florida which experienced Hurricane Irma. No data was available for much of the West Coast, which is blank.
Figure 5. The U.S. comparison to last year at this time for September 12 – September 18, 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 across the northern states with slightly lower values in the Plains. In contrast, the desert Southwest has much higher NDVI values than last year at this time. Pockets of low NDVI values in Colorado and Wyoming are the result of early mountain snows.
Figure 6. The U.S. comparison to the 28-year average for the period of September 12 – September 18, 2017 from K-State’s Precision Agriculture Laboratory shows the drought impacts in the Northern Plains are visible as below-average NDVI values. In Louisiana and the Ohio River Valley, below-average NDVI values are associated with cloud cover and rain from Hurricane Irma. Higher-than-average vegetative activity is most visible in west Texas, eastern New Mexico, and western Kansas where rainfall and temperatures have been favorable.
Mary Knapp, Weather Data Library
Ray Asebedo, Precision Agriculture
Nan An, Imaging Scientist