Authors: Mary Knapp, Kevin Price, Nan An
K-State’s Ecology and Agriculture Spatial Analysis Laboratory (EASAL) produces weekly Vegetation Condition Report maps. These maps can be a valuable tool for making crop selection and marketing decisions.
Two short videos of Dr. Kevin Price explaining the development of these maps can be viewed on YouTube at:
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 26-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.
NOTE TO READERS: The maps below represent a subset of the maps available from the EASAL group. If you’d like digital copies of the entire map series please contact Nan An at firstname.lastname@example.org and we can place you on our email list to receive the entire dataset each week as they are produced. The maps are normally first available on Wednesday of each week, unless there is a delay in the posting of the data by EROS Data Center where we obtain the raw data used to make the maps. These maps are provided for free as a service of the Department of Agronomy and K-State Research and Extension.
The maps in this issue of the newsletter show the current state of photosynthetic activity in Kansas, the Corn Belt, and the continental U.S., with comments from Mary Knapp, assistant state climatologist:
Figure 1. The Vegetation Condition Report for Kansas for April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that photosynthetic activity is greatest in southeast Kansas, where temperatures and moisture have been most favorable. Pockets of increased vegetative activity are beginning to be visible in the eastern portions of central Kansas, where significant moisture was received over the period. Activity in northwest and west central Kansas continues to be limited.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows largest areas of much lower biomass production in Smith and Osborne counties. The continued rainfall deficit in these areas has hindered plant development.
Figure 3. Compared to the 26-year average at this time for Kansas, this year’s Vegetation Condition Report for April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that a large portion of Kansas from the Northwest Division through the Central Division has below-average biomass production. Smith and Osborne counties show particularly low biomass production. For much of these areas, this reduction in biomass production is a combination of winterkill, freeze damage, and drought. Only portions of the Southwest and western South Central Divisions have higher-than-average photosynthetic activity.
Figure 4. The Vegetation Condition Report for the Corn Belt for April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that the greatest photosynthetic activity is concentrated in the south central portion of the region, extending north to the Ohio River in the east. Some increased photosynthetic activity is also visible in northeastern Minnesota and northern Wisconsin. This increase is mainly due to the quick loss of snow cover in the area. Much lower NDVI values are visible in eastern North Dakota, where drought conditions are deepening. Impacts from rainfall this week have yet to be seen.
Figure 5. The comparison to last year in the Corn Belt for the period April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows a pocket of much higher NDVI values in the Black Hills of South Dakota and the Upper Great Lakes region of eastern Minnesota, northern Wisconsin, and the western Upper Peninsula of Michigan. These areas saw much lower snowfall totals this season, and thus have higher photosynthetic values this spring compared to last. In southern Iowa, northern and eastern Missouri, and through the Ohio River Valley, mild and wet spring conditions have favored photosynthetic activity.
Figure 6. Compared to the 26-year average at this time for the Corn Belt, this year’s Vegetation Condition Report for April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows an area of below-average photosynthetic activity in northern and central Kansas, and central South Dakota. Below-average precipitation continued to be a problem in these areas through this two-week composite period.
Figure 7. The Vegetation Condition Report for the U.S. for April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that an area of low photosynthetic activity continues along the central Mississippi River Valley, where flood conditions are finally falling. In the West, moderate biomass production continues along the coast from central California to Washington. Photosynthetic activity remains limited from the Northern Plains to the Panhandle of Texas and westward toward the Rockies, as the impact of recent rains is not yet visible.
Figure 8. The U.S. comparison to last year at this time for the period April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows increased photosynthetic activity in the Pacific Northwest, the Northern Great Lakes, and west Texas. For the northern areas, this increase is due mainly to lower snow amounts. In Texas, this increase is due to recent moisture. That moisture has favored rapid green-up. In all cases, the question is how quickly the available moisture will be depleted. Chances for continued favorable moisture are better in the Southern Plains than in the Northern Plains, or in the Pacific Northwest. Lower NDVI values are becoming visible along the coast of Washington. Lower NDVI values are also present in the New England area, as cool conditions have delayed spring development.
Figure 9. The U.S. comparison to the 26-year average for the period April 21 – May 4 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows pockets of below-normal photosynthetic activity in the Central Plains and the Central Valley of California, due mainly to drought. The small band of below-normal photosynthetic activity in northern Colorado and southern Wyoming is more the result of recent snow events, while the low biomass production in New England is mainly the product of slow spring growth.
Mary Knapp, Weather Data Library
Kevin Price, Professor Emeritus, Agronomy and Geography, Remote Sensing, GIS
Nan An, Graduate Research Assistant, Ecology & Agriculture Spatial Analysis Laboratory (EASAL)