Stream Bars For Uniform Liquid Fertilizer Application
Since its introduction in the late 1980's, Intensive wheat management has contributed to a doubling of the Kentucky average state yield (reference USDA state wheat statistics) while states such as Kansas remain almost stagnant. When asked, many Kentucky producers suggest that there are at least 3 factors which contributed to the majority of the yield increases, these include the following:
Head populations of 550-650 per square yard allowed this 220 acre Kentucky field to average over 100 bu/ac with 3 plots entered in a yield contest which all exceeded 115bu/ac. Prior to the introduction of intensive wheat management, most fields yielded from 30-60 bu/ac.
Improved seeding equipment and greater attention to detail with regards to varieties, seeding rates, seed treatments etc. Many producers have now switched to no-till, a practice which can boost profits by trimming equipment costs, but it took a number of years of co-operative research in conjunction with the University of Kentucky to prove the viability of the system and to establish which management practices needed to be changed when a producer switched from conventional tillage to no-till.
Insect and Disease Management.
Prior to the adoption of intensive wheat management, many producers planted their crop in the fall and fertilized it one time in the spring. If weeds were a problem, many producers even mixed liquid nitrogen and a herbicide together to save a pass across the field, a practice which was unheard of in many European countries on account of crop damage and antagonism, especially at critical grain site initiation stages in the early spring. No fungicides or insecticides were utilized to manage these yield reducing problems.
Nitrogen Forms, Rates and Timings:
There is a now a significantly higher understanding of tiller densities and specific nitrogen timings at the grower level. In this regard, producers now understand how much N should be applied at which stage, to manipulate tiller populations and manage final head populations at harvest. Also improved nitrogen delivery uniformity has become very important (almost all KY producers utilize liquid nitrogen for their wheat nitrogen applications, especially for the 2nd application in the spring). Properly equipped liquid nitrogen application equipment allows almost perfect uniformity of nitrogen, which is difficult to match with other N sources. Many producers have found that liquid nitrogen provides the highest yields, and research from Ontario reinforces this observation. Ontario:
Nitrogen Sources For Wheat.
Liquid nitrogen was sprayed on this field of wheat early in the spring with flat-fan nozzles. Plant health was significantly compromised at a time when yields are being determined.
Some producers still apply liquid nitrogen to wheat in the spring with flat fan or flood-jet nozzles. Even when the wheat is small in the early spring, significant levels of leaf injury can occur. Leaf scorch causes infection sites for foliar diseases and reduces early spring plant health which is critical to the grain site formation process. Yield reductions of sprayed liquid nitrogen applications vary by conditions and nitrogen rates, but 5-10 bu/ac yield losses have been frequently documented. Additional plant injury and yield losses occur when liquid nitrogen and herbicides (especially SU herbicides) are tank mixed and sprayed on cereals in the spring. This practice should be avoided, in fact many producers should consider applying their herbicides in the fall to remove weed pressures before they begin competing with the crop in the spring.
Applying Liquid Nitrogen To Wheat
Liquid nitrogen is an excellent method of accurately and evenly applying nitrogen to wheat crops, in fact The Ministry Of Agriculture And Rural Affairs in Ontario recommends liquid N over urea. Their research (over multiple years) concludes that higher yields result from liquid N applications compared to urea at the same use rates per acre. They do make a point of saying that all of the liquid N was applied with stream bars however, stating clearly that if you want to use liquid N, you should use stream bars.
Some growers still apply liquid N with flat fan or flood nozzles which frequently causes significant leaf injury and yield reductions. An example is provided right. This field had 30 gallons of 28% nitrogen sprayed over the top with flat fan nozzles. Many growers will state the wheat will soon green back up, but the damage is already done and yield is lost.
How Much Yield Is Lost When Liquid N Is Broadcasted?
Lots of yield data is available from many different independent and University research trials to illustrate differences between nitrogen application methods.
One 2008 Kansas State University research trial is illustrated right. This study shows a 9 bushel per acre yield increase when liquid N was applied with stream bars, compared to broadcasting the same N rate (60 lb/ac) with spray nozzles. With $5.00 wheat (for example) that's a $45.00 per acre difference in profit and the nitrogen costs were the same!
Research conducted in 2006 and 2008 by Edwards, Arnall and Zhang at Oklahoma State University states "Plots receiving UAN produced statistically greater yield than those receiving urea. This was likely because sufficient rainfall to move N fertilizer into the soil did not occur for approximately two weeks following application in 2008. This might have created a favorable environment for N volatilization from urea which would have favored the N use efficiency of UAN treatments".
Bill Mullen from Ohio "Do not broadcast UAN solutions past Feekes Stage 5 due to leaf burn. The leaf burn can lead to lower yields, delayed plant growth and possible disease infections later. Instead, use a stream jet bar to apply the solution. Also avoid adding herbicides to UAN solutions because the mix can delay plant growth and reduce yields".
Full story can be found
Tank Mixing Herbicides With Liquid Nitrogen?
Tank mixing liquid nitrogen and herbicides should be discouraged, as significant plant injury and yield losses can result when they are applied through spray nozzles.
Yield reductions in the order of 5-10% frequently occur as a result of the increased leaf scorch and the accumulated plant stresses during critical grain initiation stages.
Most weeds can be controlled in the fall, which enable straight liquid N applications to be made with stream bars in the spring.
The HRWW research (right) was conducted by Dr. Bob Klein at the University of Nebraska. This data correlates yield loss to percentage leaf injury within a replicated trial environment when liquid nitrogen was tank mixed with a SU herbicide and applied to wheat on April 23rd and May 2nd 1991.
Stream Bars Help Reduce Nitrogen Losses
Loss of nitrogen (N) as ammonia gas (NH3) is known as volatilization. Nitrogen Fertilizers containing ammonia or urea can be lost through volatilization as ammonia gas to the atmosphere. Ammonia volatilization increases with increasing soil pH and pH of the applied fertilizer. These types of losses are greater with urea (46-0-0) than with UAN solutions (28-0-0 or 32-0-0, but losses can still be significant.
There are a number of ways to decrease volatilization of UAN applications:
For Example. Wheat is to be top dressed with 100 lb N/acre using UAN solution applied with stream bars. 50% of the UAN solution contains urea, so in this example only 50 lb N can be potentially lost as NH3. Streaming liquid N results in less potential loss than surface broadcast applications, so under severe conditions (where high volatilization rates are expected), 25% of that 50 lb of N might be lost as NH3. So total N loss under these conditions could be expected to be 12-13 lb N/acre. IF the fertilizer cost is $0.50/lb of N then this relates to a loss of $6-7/acre and this is the figure that should be used to help determine the most appropriate nitrogen application techniques. Remember that this is a "high loss" scenario and that if rainfall greater than ¼ inch occurs within 3 days of N application, losses would probably not be this significant.
Urease inhibitors such as Agrotain, may also be added to UAN solutions (or dry urea) to reduce volatility losses when no rain is forecasted after application. Peer reviewed wheat research conducted by Slaton (et al.) – 2011, includes a statement which reads “Based on these results, averaged across all sites and N application times, the urease inhibitor Agrotain provided a significant, albeit small yield advantage to wheat”.
Another statement within the same research paper states:
“Agronomically, the use of Agrotain to minimize NH volatilization losses from surface-applied urea in winter wheat appears most practical when a suboptimal N rate would be applied or when an optimal N rate is applied under conditions that are known to be favorable for NH volatilization. From an economic viewpoint, the cost of Agrotain is estimated to be $0.065/lb urea N or $4.88 to 6.50/acre assuming 75 to 100 lb N/acre is applied, which makes the input cost recoverable if an average yield benefit of 2 bu/acre is realized”.
Get the full research paper.
While 3 hole nozzles are an improvement over flat fan spray tips, they do not apply nitrogen as evenly or accurately as a stream bar.
3 hole caps produce a triangular shaped distribution pattern that's very height sensitive. As the boom raises up, two streams come together to deliver a 2X N rate as illustrated in the image to the right. As the boom is lowered (either intentionally on unintentionally on rolling ground), there may be areas that don't receive any N, as illustrated in the second image to the right. With N prices at record levels, you need to apply the nutrient evenly so each plant receives a consistent quantity, 3 hole caps don't allow this to happen.
Three hole nozzles are also influenced by forward speed and/or wind speed. As producers buy larger and more powerful sprayers, they want to run faster. The pattern produced from the 3 hole caps narrows as effective forward speed increases, so constant changes in boom height are required to compensate for the changing distribution angles.
The photo left, illustrates a wheat field which had liquid nitrogen applied using three hole fertilizer caps.
The photo below left, also illustrates a field that had a single application of N delivered with the 3 hole nozzles just prior to green-up. The N was the only application that was made at a 90 degree angle to the drill rows, so the streaks could be easily traced back to the 3 hole nozzles on the 120' boom.
The photo below illustrates a couple of the main stem wheat heads which came from the previously discussed photo. The one on the left came from one of the yellow N deficient streaks and the larger head on the right came from one of the green streaks. Look at the difference in head size and flag leaf health. Based upon spikelet counts, we suggested that yields were halved in the streaks where little to no N was applied.
There are lots of opportunities to increase wheat yields, don't let poor N distribution be one of the weak links.
When applying liquid nitrogen with multi-hole nozzles, most producers have found they are extremely susceptible to wind. Wind can be caused directly from fast forward speeds, or the combination of driving into head winds.
Applying nitrogen within either (or both) of these conditions frequently results in the streams not spreading out sideways, causing a concentrated band of nitrogen to be applied under each nozzle cap, as illustrated within the photo to the left.
The photo left illustrates another producer who used 3 hole nozzles to apply the second application of spring N around the jointing stage. In this example, the pass was made at an angle to the planted rows.
Close inspection revealed significantly increased scorch where the streams narrowed as a result of the combination of wind and forward speed. The final result appeared to be most of the liquid N was delivered to about 1/3 of the surface of the crop.
Multi-hole caps produce smaller droplets than a stream bar, this results in more leaf retention on the wheat and additional leaf tissue injury. Research shows that leaf injury translates into yield loss. As illustrated in the photo to the right, streams of nitrogen also collide when using the multi-hole caps, which further adds to the leaf injury problems.
Multi-hole caps are height dependant. When operating on rolling ground, it's difficult to hold the boom at a consistent height above the crop. Height variations can result in 2-3 streams hitting the ground in the same area, which also results in 10-15" areas of the ground which receive no nitrogen at all. As expensive as nitrogen is, it must be applied accurately and uniformly. A set of multi-hole caps don't achieve this goal.
Learn more about stream bars – watch our youtube videos below
Most producers or dealers own mounted, trailed or self-propelled sprayers. Most of these sprayers can be equipped with stream bars to allow accurate and uniform liquid fertilizer application. We sell stream bars for many different brands and configurations of sprayers around the world and some are illustrated below. If you have questions regarding specific configurations, please call or email us.
When you order stream bars, we will need to know the following information to help us determine the optimal configuration and maintain the ideal application rate and pressure range.
(15" or 20" for example)
(We need an approximate operating speed range, for example 10-12mph)
Application Rate Range:
(For example, 12-20 gallons per acre of 28% nitrogen)
Sprayer Plumbing Brand:
(For example, Spraying Systems, Hardi, etc)
Benefits Of Stream Bars
Stream bars are designed to evenly apply liquid fertilizers such as 28%, 30% or 32% nitrogen to wheat and other crops. Each of the four outlets on the stream bars are ported to ensure consistent delivery of fertilizer over the range of operating pressures.
Excellent for no-till
Stream bars deliver concentrated streams at equal distances, minimizing the amount of N tied up on residue, compared to the 3 hole nozzles (and especially flat fan nozzles) which increase the coverage on surface residue (in addition to the wheat leaves). 3 hole nozzles (and flat fan nozzles) also increase the amount of N which is tied up on surface residue and also potentially increase the N losses via volatilization.
Unaffected by boom height
Stream bars produce vertical streams of fertilizer with no overlap, so product application is unaffected by boom height.
Minimal leaf scorch
Stream bars deliver streams of fertilizer, so contact with the crop is minimized. High rates of nitrogen can be applied in one pass with minimal leaf injury, even on windy days.
Available for 15" and 20" spacing
Stream bars are available to fit most sprayers around the world and are available in 15" and 20" spacing.
Adaptable for different product rates
By using orifices, the operating sprayer pressure can be maintained within the 25 to 50psi range.
See the Chafer stream bars in action and watch how uniformly they apply nitrogen to a wheat crop later in the spring
Stream bars provide uniform delivery of fertilizer despite windy conditions or rolling ground.
Growers with wet soils in the early spring, should consider wider tires or floater tires to enable them to apply nitrogen in a timely fashion.
Stream bars are available in 15" or 20" spacing to maximize yields.
For more information, together with pricing – please click the link below.