Authors: Mary Knapp, Ray Asebedo, Nan An

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 27-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. 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 March 1 – 7 from K-State’s Precision Agriculture Laboratory shows increasing vegetative activity in the south central and central areas of the state. The highest NDVI values are still in Sumner and Harper counties. In the Northwest Division, the area of very low vegetative activity has been eliminated, as the impacts from the early February snow is replaced by warmer soil temperatures. This area still has the coolest average soil temperatures.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for March 1 – 7 from K-State’s Precision Agriculture Laboratory shows much higher photosynthetic activity in the western two thirds of the state. There is also a pocket of higher NDVI values in southeast Kansas where warm temperatures and recent rains have favored plant development.
Figure 3. Compared to the 27-year average at this time for Kansas, this year’s Vegetation Condition Report for March 1 – 7 from K-State’s Precision Agriculture Laboratory shows that the area of above average photosynthetic activity continues to increase. The areas with the greatest increase are in central and south central Kansas. Temperatures continue above normal across the state, with the warmest departures in the southwest. Increased activity at this time of the year brings concerns about increased water demand and the potential for freeze damage to wheat, with even a normal last freeze date.
Figure 4. The Vegetation Condition Report for the U.S for March 1 – 7 from K-State’s Precision Agriculture Laboratory is missing part of California, due to satellite data issues. For the rest of the continental U.S. it shows that the highest photosynthetic activity is along the Gulf Coast. Early melt of the snow pack, particularly in Idaho and Montana, bring concerns of reduced water supplies in the spring. Lingering impacts of the December flooding are still visible in the reduced vegetative activity in the lower Mississippi River Valley, although that continues to lessen. Impacts of this week’s rainfall won’t be visible yet in these maps.
Figure 5. The U.S. comparison to last year at this time for the period March 1 – 7 from K-State’s Precision Agriculture Laboratory shows that lower NDVI values are most evident along the Pacific Northwest while much higher NDVI values are visible from the Great Lakes to New England. Snow continues to be the major influence in both cases. The Ohio River area continues to see a low-snow season, while the Pacific Northwest has a higher snow pack than last year.
Figure 6. The U.S. comparison to the 27-year average for the period March 1 – 7 from K-State’s Precision Agriculture Laboratory shows much above average photosynthetic activity across much of the continental U.S. The increased vegetative activity in eastern Montana and North Dakota is of particular concern. Snow pack in these areas is below average and abnormally dry conditions continue to expand in the region. Warmer-than-average winter temperatures across the Northern Plains is also spurring plant development.

Mary Knapp, Weather Data Library

Ray Asebedo, Precision Agriculture

Nan An, Imaging Scientist