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 15 – 21 from K-State’s Precision Agriculture Laboratory shows little expansion of the area of highest plant production. The highest NDVI values are still in Sumner and Harper counties. Some higher activity is also visible in the Arkansas River Valley in Southwest Kansas.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for March 15- 21 from K-State’s Precision Agriculture Laboratory shows much higher photosynthetic activity continues 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 15 – 21 from K-State’s Precision Agriculture Laboratory shows that the area of above-average photosynthetic activity continues to increase. The largest 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. There is a small area in Finney and Scout counties of below-average vegetative activity. We will be watching for the impact of the recent freezing temperatures across these areas.
Figure 4. The Vegetation Condition Report for the U.S for March 15 – 21 from K-State’s Precision Agriculture Laboratory shows higher NDVI values across central California, where recent rains have been plentiful. For the rest of the continental U.S. it shows that the highest photosynthetic activity is in east Texas through central Oklahoma. Heavy rains last week have reduced vegetative activity in the lower Mississippi River Valley. Impacts from the flooding rains along the Gulf Coast are also visible in Louisiana, Mississippi, and Alabama.
Figure 5. The U.S. comparison to last year at this time for the period March 15 – 21 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, and in the Central and Southern Plains. Along the northern tier, the snow continues to be the major influence. The Northeast continues to see a low snow season, while the Pacific Northwest has a higher snow pack than last year. In the Plains, warmer temperatures than last year have fueled early progress in the vegetation, despite recent cold weather.
Figure 6. The U.S. comparison to the 27-year average for the period March 15 – 21 from K-State’s Precision Agriculture Laboratory shows continued above-average photosynthetic across the Plains. 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. The below-average vegetative activity in the Southeast is largely due to last week’s heavy rainfall, while the below-average NDVI values in the Pacific Northwest are indicative of the current snowpack conditions.

Mary Knapp, Weather Data Library

Ray Asebedo, Precision Agriculture

Nan An, Imaging Scientist