Comparative Vegetation Condition Report: April 25 - May 1

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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, 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 April 25 – May 1, 2017 from K-State’s Precision Agriculture Laboratory shows a continued increase in vegetative activity eastern Kansas. The recent cold weather has slowed vegetative activity in the west, while persistent clouds have masked activity in the extreme northeast.

Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for April 25 – May 1, 2017 from K-State’s Precision Agriculture Laboratory lower NDVI values are present in scattered areas of western and central Kansas. The winter wheat is less advanced this year than last, particularly in western Kansas, where dry fall conditions hampered establishment and recent cold weather has slowed development. The greatest increase in vegetative activity is in the eastern portions of the state, where moisture has been more plentiful this April and mild temperatures have been more consistent.

Figure 3. Compared to the 27-year average at this time for Kansas, this year’s Vegetation Condition Report for April 25 – May 1, 2017, from K-State’s Precision Agriculture Laboratory the eastern two-thirds of the state has near-normal vegetative activity. In the extreme northeastern corner, persistent cloud cover has masked activity. The western third of the state is showing below-average activity. The poor establishment of winter wheat last fall, coupled with the recent cold, snowy weather has hampered plant activity.

Figure 4. The Vegetation Condition Report for the U.S for April 25 – May 1, 2017 from K-State’s Precision Agriculture Laboratory shows an area of high NDVI values in the Southern Plains, particularly in east Texas and Louisiana. A second area of higher vegetative activity is also visible along the West Coast, where the wet conditions continue. Low NDVI values are visible along the central Mississippi River Valley. Intensifying drought conditions are slowing plant activity in the south from South Carolina through southern Georgia into Florida.

Figure 5. The U.S. comparison to last year at this time for April 25 – May 1, 2017 from K-State’s Precision Agriculture Laboratory again shows the impact that the split in the snow cover has caused this year. Much lower NDVI values prevail in the Pacific Northwest. The Northern Rockies are showing higher NDVI values as the snow pack is rapidly retreating. The South has much lower NDVI values due to persistent clouds in the area this year.

Figure 6. The U.S. comparison to the 27-year average for the period of April 25 – May 1, 2017 from K-State’s Precision Agriculture Laboratory shows an area of below-average photosynthetic activity in the Pacific Northwest, where continuing cloud cover has masked NDVI values. Below-average NDVI values are also present in the South from the Ohio River Valley, where continued cloud cover has also masked NDVI values. Higher-than-average vegetative activity is present in the Northern Plains and Northern Rockies as the snow pack continues to retreat rapidly.


Mary Knapp, Weather Data Library

Ray Asebedo, Precision Agriculture

Nan An, Imaging Scientist