County Field size (acres) Grazing starting date Grazing ending date Animal units 108 (33 grain sorghum stubble, 75 wheat pasture)

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1 Number 362 August 03, Compaction from cattle grazing of cropland fields 1 2. Control weeds in wheat stubble before they set seed 2 3. Considerations when using soybeans for grazing, hay, or silage 3 4. North Central Kansas Experiment Fields to host field day August South Central Kansas Experiment Field to host field day August Kansas Climate Summary, July 2012: The drought worsens 7 7. Comparative Vegetation Condition Report: July Compaction from cattle grazing of cropland fields What amount of compaction, if any, should producers expect from cattle grazing row crop stalks this fall and winter? There was a K-State study on this topic, published in K-State s Cattlemen s Day 2000 Report of Progress: The study was conducted by Randy Taylor, former K-State Extension Biological and Agricultural Engineer. The study was conducted on two fields, one in Rice County (Crete silt loam and Smolan silty clay loam soil) and one in Smith County (Harney silt loam). The grazing practices were: County Field size (acres) Grazing starting date Grazing ending date Animal units Rice 108 (33 grain sorghum stubble, 75 wheat pasture) November 17 March stocker calves, about 600 lbs each Smith 45 (grain sorghum stubble) November 11 December (33 cows, 2 bulls, 2 yearlings) Soil samples were taken before grazing began, and analyzed for bulk density. At the conclusion of the grazing period, samples were again taken and analyzed for bulk density. The higher the bulk density reading, the denser the soil which can be the result of compaction. The samples were divided into two depths: 0-3 inches and 3-6 inches. The samples were also analyzed for water content. Bulk Density and Water Content of Grazed and Ungrazed Soils Bulk density (g/cm 3 ) Water content (g/g) County Depth (inches) Grazed Ungrazed Grazed Ungrazed Rice a 1.35b 0.189a 0.212b a 1.51a 0.220a 0.228b Smith a 1.41b 0.217a 0.249b a 1.60a 0.238a 0.244a Bulk density and water content values within each row followed by different letters are significantly different (P<0.01). 1

2 The gist of the report is that the compaction caused by cattle grazing is limited to the upper 3 inches of soil. The depleted water content is also confined to the upper 3 inches. Cattle have a decent amount of surface pressure, about psi, but since they don t weigh more than a ton, the compaction doesn t travel deeply into the soil profile. Research has found that with farm equipment, it takes weights of greater than 10 tons per axle to cause compaction to a depth of 6 or more inches. If the cattle are grazed in the winter on corn or grain sorghum stalks, the upper 2 inches will almost certainly be loosened by freeze and thaw most years, minimizing the effect of the cattle-induced compaction in the surface zone. As for what happens from 2-3 inches, that may be a concern. We ve been having mild winters and the frost just doesn t seem to penetrate the ground deeper than 2 inches very often during the winter anymore. If the soil has about 20% or more clay in the surface layer, it tends to loosen up in the summer from wetting and drying cycles, which may help reduce any compaction in the top 3 inches. The tillage history of a field will have an effect on how readily it may become compacted by cattle grazing. Research by Humberto Blanco, former soil scientist at the K-State Agricultural Research Center-Hays, found that no-till soils are less compactable than reduced- or conventional-till soils. (This research was published in 2008 in Agronomy Journal, volume 100, pages ) So if a field has good residue and has been no-tilled for a number of years, the risk of compaction is lower. -- DeAnn Presley, Soil Management Specialist deann@ksu.edu 2. Control weeds in wheat stubble before they set seed Some areas in Kansas have received just enough rainfall to have rather large broadleaf and grassy weeds actively growing in harvested wheat stubble at this time. These weeds are utilizing moisture and nutrients that would be available for a subsequent crop. It is a good idea to control these weeds before they set seed. Kochia and Russian thistle are daylength sensitive and usually begin flowering in late July and early August, and set seed shortly after that. Controlling kochia and Russian thistle now is very important to prevent seed production. Weeds growing now in wheat stubble fields, without crop competition, set ample seed -- which will be likely to cause a problem in following crops. It is especially important to prevent seed production from happening on fields that will be planted to crops with limited options for weed control, such as grain sorghum, sunflower, or annual forages. It is especially difficult to control broadleaf weeds in sunflower and grassy weeds in sorghum that emerge after crop emergence. Preventing weed seed production ahead of these crops is essential. Seed of some weed species can remain viable for several years so allowing weeds to produce seed can create weed problems for multiple years. If the field will be planted to Roundup Ready corn or soybeans, producers may decide they can just wait and control any weed and grass seed that form now and emerge next season with a postemergence application of glyphosate in the corn or soybeans. However, with the concerns over the development of glyphosate-resistant weeds, it would be far better to control these weeds and 2

3 grasses now in wheat stubble. That way, other herbicides with a different mode of action can be tank-mixed with glyphosate to ensure adequate control. Producers should control weeds in wheat stubble fields by applying the full labeled rate of glyphosate with the proper rate of ammonium sulfate additive. As mentioned, it is also a good idea to add 2,4-D or dicamba (unless there is cotton in the area) to the glyphosate. Do not apply the growth regulator herbicides around cotton. Tank mixes of glyphosate and either 2,4-D or dicamba will help control weeds that are difficult to control with glyphosate alone, and will help reduce the chances that glyphosate-tolerant weed populations will develop. Several have asked about the addition of atrazine for residual weed control in fallow. Although atrazine provides residual control of weeds, it is best applied later in the fall. At this time of year, atrazine residual is quite short and will not provide adequate control of fall emerged weeds/winter annuals. An application of atrazine needs to be made in the fall (early October into November), depending on the weeds being targeted. Also, keep in mind that atrazine antagonizes glyphosate. Do not apply atrazine with reduced rates of glyphosate. Atrazine can be synergistic with Gramoxone; however, the spectrum of weeds controlled with this combination will be less than with glyphosate. An application of atrazine may limit subsequent crop selection. -- Curtis Thompson, Weed Management Specialist cthompso@ksu.edu 3. Considerations when using soybeans for grazing, hay, or silage (Editor s note: An article in the July 20, 2012 issue of the Agronomy e-update, No. 359, discussed how to make the decision of whether to keep stressed soybeans for seed harvest or to cut the plants for forage. The following information, from a fact sheet published by North Carolina State University in 2007, discusses in more detail how to best manage and utilize the soybeans for forage if that s the way you want to go. I ve deleted most direct references to North Carolina in the article below because the information can apply anywhere drought has affected soybeans. The fact sheet can be found at: This information concerns the feeding value and harvesting methods of the different options for using soybeans as forage. Steve Watson, Agronomy e-update Editor) Soybean fields that will not make a profitable bean crop, may still have significant value as a forage crop. Soybean forage can definitely help livestock producers who are short on feed because of the drought. If producers have soybean herbage, making hay or silage for their own stock or for sale is an economic calculation. Remember, a field should have at least enough forage to pay for the fuel to harvest it. As a general rule, a yield of 2 tons dry matter (DM) per acre (five to six 700 lb round bales) is possible with waist-high beans if most of the leaves are still intact. If there is not enough forage to pay for the harvesting and handling, grazing is another option. Two cautions before salvaging soybeans as forage: 1. The label for any pesticides used on the soybeans should state that use as forage is permitted. Some herbicides and insecticides forbid using soybeans treated with that pesticide for forage. 3

4 2. Contact a crop insurance agent before harvesting for forage. They will advise each producer on how harvesting a crop for forage may affect insurance payments. The status of the crop may need to be documented for possible disaster payments before haying or grazing. Insurance adjustors may require leaving some unharvested strips to allow later bean yield estimation. Grazing Grazing is the most efficient means of harvesting the forage. Strip grazing soybeans will result in less waste due to trampling, fouling with manure etc. Grazing is the best option, especially if the beans made very little growth, but the field must be fenced, and water needs to be provided to the animals. If there are still animals grazing perennial pastures, use the beans to get the animals off the permanent pastures. This may allow pastures to survive the drought and recover for next season. Soybean silage In some states, silage is recommended as the best preservation option for soybean forage. But silage is not as portable/movable (nor therefore) saleable as hay. For those who have experience with silage, beans will work. Chop at 3/8 inch. For silage the plants need to be more than 50% green, at 35-40% DM. This may require wilting many beans in their current stage of growth. Peak digestibility is at beginning to late pod (R3-R4) stage. The fat in more mature beans may interfere with fermentation. Dry matter testing (using the microwave method) is advisable, since most of us don t have experience estimating soybean forage DM. Soybean hay Soybean hay is routinely produced in the northeast and north central areas of North Carolina. Here are some guiding comments from experienced North Carolina producers of soybean hay: It is best to harvest at early pod stage. It makes a high quality feed. We have not experienced feeding problems associated with soybean hay. Feeding one round bale of soybean hay and two round bales of grass hay at the same time makes a good system. Yield is usually approximately half of first cutting fescue hay. If soybean hay is stored outside, use netwrap. String is o.k. inside shelter but loss could be as much as 35% when stored outside with string. Soybean hay is worse than peanut hay about leaf shatter, so minimize the number of times it s mechanically handled (raked, tedded). I have had lots of experience with soybeans for hay. It works great if the beans are cut with a mower-conditioner. If not, it takes forever for them to dry. Also, stage of maturity has a big effect on the final quality of the hay. The beans should be cut early for optimal quality. The best stage to cut is when the pods are not filled out and there are still a lot of leaves. The biggest issue is when to bale, too soon and they will mold, too late and the leaves shatter. I try to bale in the evening to cut down on leaf loss and the dust while baling is not so bad. They will change color and look brown not green after baling. The cattle consume them well and I typically cut some every year to stretch my other grass resources. Soybeans are difficult to get cured, and a tedder will do a lot of damage to them even when they are green. The best method is to just swath them leaving about a 4-inch stubble, and then let them get almost totally dry before doing anything else. Then, rake them before they get crispy dry in the morning and don't make the windrows too big. Once they are raked they will dry very slowly, so 4

5 raking too soon is often a problem. Once they dry in the windrow for at least several more hours, you can invert the windrows to continue the drying process. It is very sensitive to shattering so rake slow and gentle. Tedding after the leaves dry will knock most of the leaves off and reduce yield and quality. It is best if it is rolled in the late evening. Be aware that the leaf will get crispy after only one day of drying, but the stems take more like 3 or 4 days to cure, especially if they are big and if there is a high yield. Myself, along with several other producers in our area have fed soybean hay. The only thing you should be aware of is that cattle have an increased tendency to bloat on this hay. You can limit the risk by mixing it with grass type hay. Ironically, at least three dry days are needed for making soybean hay. The key with making good soybean hay is limiting leaf loss; don t be tempted to bale too quickly after cutting because the stems need time to dry down, or you will have heating, mold, and spoilage losses. Storage: Soybean hay, even round bales, will need protection from rain. Bales need to be put in a shed or covered with a tarp or plastic. Soybean round bales will not shed rain as does unprotected grass hay, and moisture will penetrate the bales. A high level of spoilage will result. Feed value: If you are able to use soybeans for forage they can provide excellent feed. The best soybeans for forage are in the beginning pod stage (harvested at R3 - when one of the top four nodes with a fully developed leaf has a 3/16-inch long pod). Less mature soybeans have lower protein and digestibility. Soybean silage runs % protein. Soybean hay is high protein (averaging around 15%), and beef cattle fed soybean forage should also be fed a lower quality forage. Feed the soybean hay or silage (or pasture) as 20-30% of the ration. This will stretch the higher quality feed and balance the lower quality forage. It will also avoid problems with bloat. Bloat has been reported so use good bloat management. Most importantly, don t feed soybean hay to very hungry cattle; fill them up on grass hay before offering soybean hay. Horses can consume soybean hay safely if it is put up properly. Timeliness: Given the condition of the crop and possible damage by rain or wind, we suggest you begin the forage harvest as soon as you have followed the procedures necessary for crop insurance and disaster payments. Harvesting before leaves start to drop, even if the plants are still flowering, is advised to get the best value from the crop. Baling soybean stalks or stover after soybean harvest is not recommended. The feed value of soybean stover is reportedly very low; making it uneconomic to bale or feed. Conservation: Remember to leave some residue and cover in the field to protect the soil when the rain finally arrives. Consider planting a cover crop to help reduce soil erosion after you harvest the hay. -- Sue Ellen Johnson, NCSU Crop Science Forage Specialist -- Jim Dunphy, NCSU Crop Science Soybean Specialist -- Matt Poore, NCSU Animal Science Beef Specialist 5

6 4. North Central Kansas Experiment Fields to host field day August 21 The North Central Kansas Experiment Fields Fall Field Day will be held August 21 at the field approximately 2 miles west of Belleville on U.S. Highway 36. The Field Day will start at 6 p.m. Field Day Topics: * Planting Wheat After Summer Row Crops * Micronutrients in Wheat * Soybean Inoculation * Drought Tolerant Corn and Phosphorus A meal, compliments of K-State Research and Extension, will follow the tour and presentations. -- Randall Nelson, Agronomist-In-Charge, North Central Kansas Experiment Fields jrnelson@ksu.edu 5. South Central Kansas Experiment Field to host field day August 23 Crop growers in south central Kansas will be updated on the latest corn, sorghum and wheat information when Kansas State University hosts its Fall Field Day at the K-State Research and Extension Redd Foundation Irrigation Field near Hutchinson on Thursday, Aug. 23. The field is located at the intersection of Kansas Highway 61 and Red Rock Road (about two miles south of Partridge on Highway 61, then 1,000 feet east on Red Rock Road). A map is available at The field day begins at 6 p.m. and ends with a meal and beverages at 7:30 p.m. Presentations will include: Wheat Planting Considerations Corn Root System Architecture and P Uptake Managing Sorghum Before Planting Wheat Chloride on Corn and Sorghum More information is available by calling Kraig Roozeboom, Crop Production and Cropping Systems Specialist kraig@ksu.edu 6

7 6. Kansas Climate Summary, July 2012: The drought worsens The continued heat and dryness has resulted in deterioration in the drought situation. No division had normal or above-normal precipitation. The Northwest Division fared best, but only saw 84 percent of normal precipitation. East Central and Southeastern Divisions had the greatest shortfall. Both divisions average 0.83 inches, which was 23 and 24 percent of normal respectively. There weren t as many temperature records broken this month, but temperatures continued well above average, putting the January through July period as the warmest on record. This was also the warmest August to July period, and the second warmest 2-year period. The highest temperature was 111 degrees F at Wichita on July 29 th and Leavenworth on July 30 th. Even with these readings, July was the 7 th warmest on record. The average temperature was 84.degrees F, which was 5.5 degrees above normal. The warmest July was recorded in 1934, when the average temperature was 86.7 degrees F. The coldest July on record occurred in 1950, when the average temperature was 72.7 degrees F. The lowest reading this month was 47 degrees F at Greensburg, Kinsley, and Larned on the July 3rd. Preliminary statewide average precipitation was 1.19 inches, which was only 37% of normal. This makes it the 10 th driest July since The Northwest Division was the wettest in overall precipitation at an average of 2.54 inches or 84% of normal. The East Central and Southeastern divisions tied as driest, with an average precipitation of 0.83 inches or 23 and 24% of normal. Eight days saw no reports of precipitation, and on 10 days the state-wide average was zero, with only isolated reports of moisture. Only three days had an average precipitation greater than 0.25 inches. The heaviest rains occurred on July 9 th. A narrow area of north central Kansas had the heaviest amounts. Drought conditions worsened across the state. The latest Drought Monitor showed the entire state in severe drought or worse. Extreme drought now covers 88 percent of the state, with over 17 percent of the state in exceptional drought. Despite the rain over the last several days, the area of exceptional drought is likely to expand. The latest Drought Outlook indicates drought conditions are expected to continue through October. The La Niña has ended and conditions favor the development of an El Niño by fall. For August, drier-thannormal conditions are expected statewide. Temperatures are expected to continue above average. 7

8 Table 1 Jul-12 Kansas Climate Division Summary Precipitation (inches) Temperature ( o F) July 2012 Jan. through July 2012 Monthly Extremes % % Dep. Division Total Dep. 1 Normal Total Dep. 1 1 Normal Ave Max Min Northwest West Central Southwest North Central Central South Central Northeast East Central Southeast STATE Departure from normal value 2. State Highest temperature: 111 degrees F at Wichita on July 29th; Leavenworth on July 30th. 3. State Lowest temperature: 47 degrees F at Greensburg, Kinsley, Larned on July 3rd. 4. Greatest 24-hr rainfall: 5.50 inches at Lenora; 4.79 inches at Protection. Source: KSU Weather Data Library 7. Comparative Vegetation Condition Report: July 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 21-year average. The report is used by 8

9 individual farmers and ranchers, the commodities market, and political leaders for assessing factors such as production potential and drought impact across their state. The maps below show the current vegetation conditions in Kansas, the Corn Belt, and the continental U.S, with comments from Mary Knapp, state climatologist: Map 1. The Vegetation Condition Report for Kansas for July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that only a little photosynthetic activity continues across the state. Greatest activity is in the northeastern counties, where June and early July precipitation was more favorable. Some lingering biomass production can be seen along the Republican River Valley in north central Kansas. 9

10 Map 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that most of the state has lower biomass production. The southwestern and south central divisions show slightly better conditions than last year. This does not mean there is good photosynthetic activity this year, just that last year s conditions were extremely poor. 10

11 Map 3. Compared to the 23-year average at this time for Kansas, this year s Vegetation Condition Report for July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that most of the state has belowaverage photosynthetic activity. Only a very small portion of North Central Kansas currently has slightly aboveaverage photosynthetic activity. This is the area that saw several inches of rain in the last few weeks. 11

12 Map 4. The Vegetation Condition Report for the Corn Belt for July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that most active biomass production is occurring in the northern portions. Northern Iowa and northern Wisconsin have had the most favorable moisture and temperature conditions, and that is reflected in the photosynthetic activity. Some additional photosynthetic activity can be seen along the Platte River in Nebraska, but that is minimal. 12

13 Map 5. The comparison to last year in the Corn Belt for the period July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows only small areas are showing higher biomass production. In southwest Kansas this is a result of the lingering impact of winter moisture. In the Northern and Central Plains, the lower productivity values are highlighting the much drier and warmer conditions that prevail this summer. 13

14 Map 6. Compared to the 23-year average at this time for the Corn Belt, this year s Vegetation Condition Report for July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows western and central sections of the region are much below average in photosynthetic activity. The Northern Plains is experiencing more favorable conditions, as the drier spring conditions allowed for timely planting. Also, this region hasn t had the extreme heat that was recorded in the central portions of the Corn Belt. 14

15 Map 7. The Vegetation Condition Report for the U.S. for July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows the divide of greater photosynthetic activity in the eastern US and along the West Coast with lower values in the High Plains and Mountain West. Of note are the reduced values in the center of the country, particularly in Missouri and Illinois. 15

16 Map 8. The U.S. comparison to last year at this time for the period July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows how conditions have flipped. The Northern Plains, with the exception of North Dakota, has had much warmer and drier conditions this year. In contrast, the Southern Plains, while warm, has not reached the extremes seen last year. More favorable moisture has been present, particularly in east Texas and Alabama. 16

17 Map 9. The U.S. comparison to the 23-year average for the period July from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that much of the Central U.S. is well-below-normal in photosynthetic activity. The Southern U.S. is showing normal to slightly above-normal productivity, as is North Dakota and parts of Wisconsin. North and South Carolina, despite the above-average level of photosynthetic activity, continues to experience extreme to exceptional drought conditions this year. Note to readers: The maps above represent a subset of the maps available from the EASAL group. If you d like digital copies of the entire map series please contact us at kpprice@ksu.edu and we can place you on our 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. -- Mary Knapp, State Climatologist mknapp@ksu.edu -- Kevin Price, Agronomy and Geography, Remote Sensing, Natural Resources, GIS kpprice@ksu.edu -- Nan An, Graduate Research Assistant, Ecology & Agriculture Spatial Analysis Laboratory (EASAL) nanan@ksu.edu 17 These e-updates are a regular weekly item from K-State Extension Agronomy and Steve Watson, Agronomy e-update Editor. All of the Research and Extension faculty in Agronomy will be involved as sources from time to time. If you have questions or suggestions for topics you'd like to have addressed in the weekly updates, contact Steve Watson, swatson@ksu.edu, or Jim Shroyer, Research and Extension Crop Production Specialist and State Extension Agronomy Leader jshroyer@ksu.edu