The sun has been welcomed and crops are rapidly growing in South Central Nebraska! Corn right now is between V6-V8 (6-8 leaf) for the most part. Quite a few farmers were side-dressing and hilling corn the past two weeks. It never fails that corn looks a little stressed after this as moisture is released from the soil and roots aren’t quite down to deeper moisture.
Installing watermark sensors for irrigation scheduling, we’re finding good moisture to 3 feet in all fields in the area. The driest fields are those which were converted from pasture last year and we want to be watching the third foot especially in those fields. Pivots are running in some fields because corn looks stressed, but there’s plenty of moisture in the soil based on the watermark sensor readings I’m receiving for the entire area. So we would recommend to allow your crops to continue to root down to uptake deeper moisture and nitrogen.
The last few weeks we observed many patterns from fertilizer applications in fields but as corn and root systems are developing, they are growing out of it. We’ve also observed some rapid growth syndrome in plants. This can result from the quick transition we had from cooler temperatures to warmer temperatures, which leads to rapid leaf growth faster than they can emerge from the whorl. Plants may have some twisted whorls and/or lighter discoloration of these leaves, but they will green up upon unfurling and receiving sunlight. This shouldn’t affect yield.
Damping off has been a problem in areas where we had water ponded or saturated conditions for periods of time. We’ve also observed some uneven emergence in various fields from potentially a combination of factors including some cold shock to germinating seedlings.
We began applying sugar to our on-farm research sugar vs. check studies in corn. We will continue to monitor disease and insect pressure in these plots and determine percent stalk rot and yield at the end of the season.
Leaf and stripe rust can be observed in wheat fields in the area and wheat is beginning to turn. We had some problems with wheat streak mosaic virus in the area again affecting producers’ neighboring fields when volunteer wheat wasn’t killed last fall. Alfalfa is beginning to regrow after first cutting and we’re encouraging producers to look for alfalfa weevils. All our crops could really use a nice slow rain right now!
It’s wonderful receiving the rain we did, seeing how quickly planting progress came along, and how quickly corn is popping out of the ground! Being mid-May, it’s time to get our Evapotranspiration (ET) gages out. A reminder to only use distilled water in the gages, make sure to fill up the ceramic top portion of the gage before inserting the stopper, and gently dust off the ceramic top and replace the white membrane and green canvas cover. We recommend replacing those membranes and covers each year so if you need a new one, please let the Natural Resources Districts (NRDs) or me know and we’ll get you a new one! For those of you recording ET information online, please be sure to do so consistently each week to help your neighbors and crop consultants.
Early after crop emergence is the best time to install watermark sensors. For those of you with watermark sensors, read them to ensure they read 199 kpa (dry). Then “prime” them first by soaking them for 24 hours in water to ensure all the air bubbles have been released. The sensors should have a reading of 10 kpa or below to be considered good. If they read higher than that, either continue soaking them another 24 hours and read them again, or plan that they no longer are reading correctly and replace them with others from the NRDs. Remember after soaking sensors that water moves up into the PVC pipe via capillary action, so be sure to dump the water out of the pipe as well.
When installing the sensors, be sure to install them wet, drain excess water, and look for areas that are not compacted, avoid tractor wheel tracks, and look for even spacing of plants. Carefully install without breaking off any plants (thus easier when plants are small!). It’s also important not to install sensors into extremely wet fields. What we have found is that a thin soil layer can cover the sensor when pushing it into the soil of very wet fields. When that soil layer dries, it can provide a reading of 199 saying the sensor is dry when it truly isn’t. If this happens to you, simply remove the sensor, rewet for one minute and re-install. It should be acclimated to field conditions within 48 hours. If you have any questions regarding the installation process, please let the NRDs or your local Extension Educator know. You can also view videos of the installation process and receive additional information to answer your questions.
Well, August has begun and so has the season for field days. Here are a few I hope you mark on your calendars and plan on attending. Also a reminder, for all drought information from UNL Extension including crop, livestock, water, lawn, and garden, please check out http://droughtresources.unl.edu.
With the drought and a shortage of forages, if you are considering harvesting or grazing crops for forage, it is important to consider the herbicide restrictions applied to these fields. Check the labels of these herbicides to confirm that grazing restrictions or forage harvesting restrictions have been met before you turn livestock into the fields or cut the crop for hay or silage. Check out this link for more information.
Soybean Management Field Days Planned: Please mark the dates of the upcoming Soybean Management Field Days on your calendar. They are planned for August 14-17 with sessions planned for Lexington, O’Neill, Platte Center and David City. Registration for each of the Field Days starts at 9:00 a.m. with four one hour programs from 9:30 a.m. to 2:30 p.m. Topics include: Soybean Seed Treatments and Foliar Fungicides Growth Enhancement Interaction with Herbicides, Managing Land Leases and Soybean Marketing, Herbicide Carrier Rate Study and Quest for the Holy Grail in Soybean Production! Check out the sessions by going to http://ardc.unl.edu/soydays. The David City date and location is August 17th and it’s located from the Jct of 92 & Hwy 15, 1 mile east on 92 and ¾ mile north on county road.
South Central Ag Lab Field Day: Some of you have been asking about the next field day at South Central Ag Lab near Clay Center. Please mark your calendars for August 22 from 9:00 a.m.-2:00 p.m. with registration beginning at 8:30 a.m. Topics include: Weed control, timing, resistant weeds; Emerging diseases of corn and corn rootworm management options; Impacts of corn stover harvest on soil quality and greenhouse gas emissions; Variable rate nitrogen and irrigation management according to landscape variation; and Use of Soy-Water for managing soybean irrigation. There is no charge but please RSVP for a meal count by Friday, August 17 to (402) 762-4403. Hope to see you there!
York County Corn Grower Plot Tour: The York County Corn Growers Annual Plot tour will be held Thursday, August 23, 2012 from 5:30 – 7:30 p.m. This year’s cooperators are Ray and Ron Makovicka and the plot is located west of York on the Dwight Johnson farm. The plot is located ¾ miles north of Hwy 34 on Road I. Those attending will be able to check out the various corn varieties and visit with the seed company representatives. Supper will be served after the tour. Then there will be a report on 2012 practices, products used and irrigation update.
Also this year they have several different types of irrigation equipment in the field to monitor soil moisture and estimate crop ET. Systems in the field include: AquaCheck USA provided an AquaCheck soil moisture sensor system; Servitech provided the Profiler Watermark soil moisture sensor system; McCrometer provided an EnviroPro soil moisture sensor system; and AquaSpy provided AquaSpy soil moisture sensor system. Several of you have asked about wireless irrigation scheduling systems-here’s your chance to compare them all in one place!
While farmers may be tired of irrigating right now, I think all who have irrigation are thankful for it in such a dry year. Honestly, thankfully with our irrigation we have some of the best looking crops in the Corn Belt right now. Even so, with corn that hasn’t been replanted nearing dent or stages of starch fill, you may be wondering how to schedule for your last irrigation.
For those of you in our Nebraska Ag Water Management Network using watermark sensors, the goal is to use them to determine when the soil profile reaches 60% depletion (for silty-clay soils in our area aim for an average of 160 kpa of all your sensors). You may be thinking, “An average of 90kpa was hard enough!” but as Daryl Andersen from the Little Blue Natural Resources District points out, you’re only taking an additional 0.30 inches out of each foot. So if you’re averaging 90kpa on your three sensors, you have depleted 2.34 inches in the top three feet so you still have 0.96 inches left (see the Soil Moisture Depletion Chart). If you add the fourth foot (using a similar number from the third foot), it would bring the water available to the plant up to 1.28”.
At beginning dent corn you need 24 days or 5 inches of water to finish the crop to maturity. If you subtract 1.28 from 5 you will need 3.72” to finish out the crop. Corn at ½ milk line needs 13 days or 2.25” to finish the crop to maturity-so subtracting it from 1.28 would be only 0.97”.
Soybeans at the beginning of seed enlargement (R5) need 6.5”. Soybeans in R6 or full seed which needs 3.5 inches yet for maturity. Subtracting off the 1.28” in the four foot profile would lead to 2.22”. The UNL NebGuide Predicting the Last Irrigation of the Season provides good information on how determine your last irrigation in addition to showing charts on how much water the crop still needs at various growth stages.
Several people I’ve talked to who have been irrigating using watermark sensors aren’t replenishing the second foot, so you may have a few rounds yet to go on corn and beans. For a quick way to know where you’re at, think about irrigating this way as explained by Daryl Andersen at the Little Blue Natural Resources District:
One way to look at this is by the numbers of days left. At 1/4 starch, there are about 19 days before maturity so you can let your sensors average 130kpa on the first week and 150kpa on the next week. If these targets are met during the week, you would put on about 1 inch of water. By going to these numbers, it might give you a higher probability for rain in the next couple of weeks. I’m hoping for many answered prayers that we will see rain in August!
Water use efficiency (or crop water productivity) is important in crop production. The seed Industry has invested scientific efforts and financial resources into developing hybrids and varieties that can better tolerate environmental stresses such as water stress.
Rainfed corn has increased in acres, replacing sorghum year after year. This trend may be partly due to the basis price, herbicide options, and newer corn hybrids bred with root systems to better withstand water stress. In 2009 the question was posed, “Is sorghum still the most crop-water-use-efficient crop, given newer corn hybrids in rainfed fields are providing decent yields and more herbicide options?” To answer the question the Nebraska Grain Sorghum Board funded a project in south-central Nebraska.
On-farm research was conducted for three years in rainfed production fields near Lawrence with the most adapted and high-yielding corn, sorghum, and soybean hybrids and varieties for that area. The research was conducted in no-till fields where the previous crop had been sorghum. A randomized complete block design with three replications was used.
Corn and soybean were planted between May 5 and May 7; sorghum planting ranged from May 19 to May 28. Corn was planted at 20,000 seeds/acre, soybean at 135,000, and sorghum at 65,000. Rainfall in this area varied greatly from 2009 to 2011: 2009 was dry with only 10 inches of rain during the growing season; 2010 had 16 inches, and 2011 had 20.5 inches from May 1 to October 15.
To monitor soil moisture, Watermark sensors were placed at 1-, 2-, 3-, and 4-foot depths in each plot and the readings were recorded hourly throughout the growing season via Watermark dataloggers. Data were compiled and analyzed to determine crop water use efficiency (CWUE) values. The CWUE values were determined from the Watermark soil moisture data, actual crop water use (evapotranspiration), and grain yield for each crop.
Results: Table 1 shows actual crop evapotranspiration (ET) in inches, grain yield, and crop water use efficiency for each crop in each year. Corn was the most water use efficient of the three in 2009. Sorghum results in 2009 might have been different if rainfall had occurred to activate the sorghum herbicide as grass pressure was heavy in the sorghum plots that dry year. In 2010-2011, sorghum yielded the most, had good weed control, and had the best crop water use efficiency value.
|Table 1. Crop water use efficiencies in on-farm field trials conducted near Lawrence, Nebraska, 2009-2011.|
Overall in this study, sorghum had a crop water use efficiency of at least 5.5 bu/inch; corn, at least 4.3 bu/inch, and soybean, at least 2.0 bu/inch. These results show sorghum’s continued value as a crop that efficiently uses water. Sorghum produced more grain per unit of water used than corn or soybean, an important benefit in water-limited environments. On a three-year average, sorghum resulted in 1.2 bu/inch and 3.5 bu/inch more grain production per inch of water used than corn and soybean, respectively. This study did not compare sorghum or soybean with new “drought-tolerant” corn hybrids. Graphs, charts, and production information can be found here.
Acknowledgements: Special thanks to John Dolnicek of Lawrence, Nebraska for allowing this research to be conducted on his farm and for all his help and efforts to make it a successful study and to the Nebraska Grain Sorghum Board for funding this study.
Crazy? Perhaps! Which according to one of my farmer friends is a little typical of me when I put my mind to figuring out something. So I had been analyzing my crop water use data from my dryland corn, sorghum, soybean crop water use comparison study. It’s the one where we had coon problems this year and ended up trapping a skunk! I noticed how much the soil moisture profile had been depleted and knowing we’ve received minimal precip during fall and winter, I wondered what our soil moisture profile would be for dryland fields by planting. During a meeting yesterday I thought it would be good to install some watermark sensors to determine soil moisture profile recharge with the pending storm. Problem was I was at a meeting over 100 miles from my equipment and the pending storm was starting today. But I was still determined to get them in the ground as early as possible in order to measure the soil moisture status. So I woke up at 4:00 a.m. to heavy rain. Great! It was such a gorgeous day yesterday, and the past week…past month… The first thing my colleagues had asked me when I told them my idea was “Why didn’t you think of this sooner?” Answer: “Guess I needed a precipitation event!”
So I drive to the field in the rain, get the gear together and start installing the sensors. First foot went in easy with the rain that had soaked in. Then it seemed like I tried for 20 minutes (although probably not near that long) putting all my weight on the soil probe to get the 2nd foot in. Wind-driven rain soaked my jeans since I didn’t have rainpants on…fingers were numb from the cold. I kept telling myself this will still hopefully be worth it! On the research data from this field, the second foot was driest of all the crops (was depleted well above plant available water). I got the third foot in and John, the man who farmed the field appeared.
While he thought it was crazy he graciously volunteered to help as he always does. He put in the rest of the sensors while I
hooked everything up.
The last several years we have been blessed to have a fully charged profile going into planting. Even with this rain/snow event, I’m not sure we will have that in dryland fields in this area of Nebraska. So I thought it would be interesting to know where we stood before planting and figured the farmers may want to know that as well. Perhaps a little crazy regarding installing the sensors on such a bad weather day but hoping the data in the end will benefit our farmers and be worth it!
Last week was fun and somewhat exhausting teaching with my colleagues in Extension and several area Agencies at the Water Jamboree at Liberty Cove in Lawrence. Water Jamboree started over 15 years ago to teach 5th and 6th graders about the importance of water and water-related subjects. Nearly 800 youth learned about where water goes when it goes down the storm drain, about irrigation and siphon tubes, the aquifer, life inside and outside of the lake, mosquitoes, water movement, and much more. Holli Weber and I utilized the nature trails through the tallgrass prairie to teach a session on life outside the lake focusing on the importance of plants as buffers to filter chemicals and allowing youth to run through the trails doing a photo ID scavenger hunt of the area plants (also to burn off energy!). While I’ve done this session the past 5 years, this year I took time to show the youth specific characteristics to ID grasses. God created each plant unique and I was showing them how Indiangrass has rabbit ears when you pull the leaves back from the stem…or the M/W on the smooth brome leaves. It was fun watching the youths’ faces light up and then try to find these and other characteristics for themselves while on the trails. It was a great day, although I really don’t know how teachers do it day in and out! I wish I could’ve attended something like this when I was young! A special thanks goes to Marlene Faimon at the Little Blue NRD for coordinating this each year.
After Water Jamboree, I headed to my research plot at Lawrence. It’s been a trying year of coon damage and most recently a skunk inside our traps instead of the coons (and it still smelled like skunk out there!). Anyway, I was pulling watermark sensors and the 1st and 2nd foot ones were really rough but the 3rd and 4th feet came out easily. So just a reminder, when pulling watermark sensors, clamp a vice grip below the cap, twist and pull up. I’ve taken out hundreds of these and have only pulled apart four. If your sensor won’t pull up, simply take a spade and dig around the sensor and also bring a jug of water with you. This is the first time I’ve had to dig sensors out but the water really helped as I got it to run down the tube, it eventually loosened at the base to pull out easily without removing the sensor from the pvc pipe. Sensors can be gently washed with a hose or in a bucket of water using your fingers to gently clean them-don’t use a brush. Allow to dry and store in your shed, garage, basement, etc. Also a reminder (although I should’ve done this during the cold of Husker Harvest Days), to get your ET gages inside. Pour out the water and empty the ceramic top by pulling out the tube and then store that inside where it won’t freeze during the winter.
Combines have been rolling in the area soybeans and dryland corn. This is a busy time for farm families, but don’t let the rush to get the crop in compromise safety. Farming is one of the most hazardous occupations in the U.S. Here is a quick list of reminders for a safe harvest season.
It’s important to teach children these safety tips so they learn safety by habit as they live and work on the farm. Keep children and grandchildren away from equipment and machinery. Children who are involved in operating machinery and equipment should be properly trained by an adult on each piece they operate. It is always fun for kids to ride in the combines, or on the tractor fenders, but if there is not an extra seat and a seatbelt, it’s not a good idea. Tractor operators can be distracted by these extra riders and not keep their full attention on operating the equipment. All it takes is a sudden stop or swerve for the extra passengers to be thrown off or more serious injuries to occur. Keep kids out of grain wagons and bins and always be watchful for children and adults when moving machinery.
Double check to make sure all machinery is working properly and that safety shields are in place. When moving equipment, especially grain augers, watch for power lines, keeping equipment at least ten feet from them. Don’t get into grain wagons or bins while the grain is moving. Many people have seen the demonstrations of how quickly a person can be sucked under the grain and suffocated. Probably the hardest one to follow, yet easiest safety tip to do is to shut down moving equipment when it gets plugged. It only takes a few extra seconds and is well worth it to save a limb. People who think “nothing will happen to me” are those at the greatest risk for something to happen because they do not practice safety as they should. Farm accidents happen so quickly; don’t let them happen to you or your family!
Try to move equipment during the daylight hours. If you must move equipment at night, make sure tractor lights are working properly and slow moving vehicle signs are visible. It may even be helpful to put lights on grain wagons or on equipment you are pulling for other drivers to see them in time. You may have someone follow you in a vehicle with flashers to warn others of a slow moving vehicle ahead. Be cautious of other drivers as they get anxious to pass, especially if they try to pass while you intend on turning. For all of us on the road, it’s important to slow down and stay alert when we encounter harvest equipment on the road. During this Farm Safety Week, I’m wishing everyone a safe and bountiful harvest!