This project used information from three previous studies which attempted to no-till brassicas to the existing swards of pastures for grazing ruminants. With the results from this study we formed the conclusion that no-til brassicas can not compete with a growing pasture sward, even one burnt back with acetic acid. A second conclusion of this study was that daikon radishes can be no-tilled into compacted areas of the pasture where the existing sward was killed from trampling ie. water troughs and feed ring areas, and provide a nutrient dense forage and improve the physical component of soil health.
An interesting comparison of soil health, including physical, chemical and biological measures, between the pasture sod and the sward underneath the fenceline showed a difference of 63 score (medium soil quality) vs 73 score (high soil quality) from the Cornell Soil Health test for a loam soil.
- Fay Benson, the PI on this project, at his farm in Groton NY. He’s holding a Daikon Radish which grew 4 foot from a water trough where the soil was heavily compacted.
- Pasture Sward burned by Acetic Acid prior to no-tiling of brassicas
It is common to see brassicas included in pasture rotations in Northern European countries and New Zealand. Their high protein and energy, along with their low fiber content, make them a good fit for cooler season grazing. When Northeastern grazing farmers were asked whether they used brassicas, the response was that many had used them as a catch crop when reseeding a pasture back to a pasture sward. Farmers were impressed by the forage quality yet they did not use them regularly. Many of the farmers questioned had only used them once. The reason given was that the cost of tilling and planting did not justify the one season of feeding that the brassicas provided. The idea of introducing brassicas into existing stands through no-till methods would allow a cheaper way to capture brassicas’ nutritional benefits without the cost of establishing them through tilling.
The compaction busting ability of daikon radish also called “Bio-Drill” or “Groundhog” prompted the addition of this variety to this study, not only to capture the benefit of their nutrition but also to improve the soil health of pastures which are often compacted. As reported in the Annual Report for this project test plots were planted in 2014 at Bob Zufall’s all grass dairy, Lisbon NY, Morrisville State College for the July 2014 Grasstravaganza Conference , and Peggi Clarke’s grazing dairy, Lowman NY. The results of these three sites plus five other tests sites planted over the past 5 years did not provide a reliable method of establishing brassicas through no-till methods in existing swards. There was additional knowledge gained which prompted the planting of 6 acres of pasture at Fay Benson’s (PI and author) Custom Grazing Farm, Groton NY in 2015.
The extra year of planting was not part of the budget for this SARE project but funding was obtained from a NIFA – OREI project that Benson was part of titled: “Assisting Organic Dairy Producers to Meet the Demands of New and Emerging Milk Markets Objectives and Performance Targets” Part of that project was to explore alternative pasture forages that would lengthen the grazing season. With this funding, 6 acres of established pasture were planted in July of 2015. The planting used the accumulated knowledge gained from all the previous test plots to provide the best possible conditions to no-till brassicas into existing swards of pasture.
The 2015 planting was designed using the knowledge aquired during the first year of this project as well as earlier attempts to no-till brassicas into pasture swards. This knowledge included:
- The drills seed bed preparation made a difference in seed establishment. Of the earlier tests, 4 were planted with an Atchison No-till drill and 4 were planted with a single disk opener drill. The plots planted with the Atchison drill had better performance than the single disc opener drills. It was theorized that the more aggressive hoe used on the Atchison reduced the mechanical friction for the seed to emerge. To incorporate this technique into the 2015 planting, a Tye Drill was selected that had scalloped coulters ahead of the disc openers which left a ¾” slit for the seed to emerge from, see photo #1.
- Nutrients for the emerging brassica seed are tied up by the existing pasture sward which resulted in the starvation of the seedlings once emerged. It was suggested to band an organic fertilizer source near the emerging seeds. The 2015 planting used two methods to accomplish this: 1. Using Chilean Nitrate or composted poultry pellets in the first seed box which placed the fertilizer below the seedlings. 2. Mix seed and one of the fertilizers together to have the desired amount of seed to come out in the same placement. A modification of the drill was required to have two seed boxes. See photo #2
- Accurate seeding rates and planting depths are important for brassicas to grow to full size. Drill calibration is important prior to planting different species of brassicas.
- Organic burn-back of the sward was done in 4 inch bands with acetic acid (seeding rows were 7 inches apart).
- Previous test plots showed that a 10% solution sprayed at 20 gallons per acre (over the 4 inch band not entire field) was sufficient to control grasses and broad leaves in sward. If sward was higher than 8 inches additional burn back was required. This could be achieved by increasing the rate to 25 gallons per acre or by the addition of 2 lbs of salt and 8 oz. of a surfactant per acre to the original rate of spray.
- In test plots using conventional methods, glyphosate was sprayed in a 3 inch band (seeding rows were 7 inches apart)
- To achieve the spray pattern required for proper widths and spray pressures low flow fan type nozzles were used. The nozzles were turned 90 degrees and the height of the boom was adjusted to get the desired band width.
Prior to the planting of the Zufall, Morrisville, and Benson plots Cornell Soil Health tests were completed. The results are included below. It was not expected that our planting would impact soil health. The testing was included in the grant for the purpose to educate farmers about the concept of the three components of soil health: chemical (which the traditional soil testing measures), physical (such as compaction) and biological (possibly the most important and least understood of the three components). Part of the soil health testing is done with a penetrometer. At pasture walks penetrometer readings were taken in the pasture and under the fence line to compare compaction. The difference was surprising to many farmers and the discussion highlighted the obstacle that compaction plays on pastures with heavy clay soils in the Northeast.
The July 16th 2015 plantings at Benson’s included the most extensive measures to improve the populations of brassicas in the grazing sward through no-till planting: Precise seeding depth of ¼ to ½ inch. Planting rates varied from 5 lbs/ac for the smaller seed varieties (Graza and Winifred) and 10 lbs/ac for the larger seed (Daikon). Banding of either Chilean Nitrate (donated by Allganic) or organic poultry compost (donated by Kreher Poultry) was done to provide 10% of their required Nitrogen, and burn-down of the sward was administered with 10% acetic acid at 20 gallons/acre. The populations and uniformity results were better than other tests but still did not provide a uniform population that could be recommended to farmers.
The plots were distributed over a 6 acre paddock area. The area had seen three previous grazings prior to planting and received up to three additional grazings after planting. During the three grazings prior to the planting the soil was soaked with unseasonable high rainfall to the point that the cows left hoof prints any place they stood for long, such as around the feeder or water tank. The grazing sward was killed in these areas. Without the brassica planting these areas would have remained bare for the rest of the season and most of the next season.
Daikon Radish for Soil Compaction Remediation
Benson’s custom grazing operation is home to 80 bred dairy heifers during the grazing season. As mentioned, the 2015 season included a wetter than average spring and an early summer followed by dry periods in the early fall. Pasture is the only feed during this time so daily grazing is mandatory. The herd is moved to a new paddock each day to reduce compaction and improve grazing efficiency. A mobile feeder is moved to each new 1 acre paddock with the heifers. It contained 2 molasses mineral lick tubs, salt blocks and fly control rubs. Even with the daily and sometimes twice daily moves of the feeder, the animals’ compaction during the wet times created bare spots in the paddock (Photo #1). In the 6 acres of the brassica trial fields there were 6 bare areas. The brassicas grew in a uniform and robus fashion in those areas. The brassica planting provided forage during the rest of the grazing season and in addition the daikon it also helped reduce compaction through the growth of its tuber.
In the animal compacted areas, the daikon radish grew well either with fertilizer or without, probably due to the increased amount of animal waste deposited from the time the animals spent in the compacted area. The largest daikon turnip grew in an unfertilized area close to a water tank. This is another area where compaction killed the existing pasture sward. (Photo #2) The radish was dug up to determine how far into the compacted area it grew. The tap root broke off at 24 inches (Photo #3).
- Photo #1 Compacted area around movable feeder in pasture. These areas were particularly compacted in the 2015 grazing seson due to increased rainfall. The sod was killed even though feeder was moved every 12 hours.
- Photo #2 Water trough compaction. Upper side of trough was a brassica test plot. The largest Daikon Radish grew 4 feet from the water trough. Lower portion of the photo was how the area remained with out the brassica planted.
- This Daikon Radish grew in an unfertilized plot just 4 feet from a water trough where the grazing sward had been killed due to compaction.
The original goal of this project was to explore methods to establish brassicas into existing grazing swards for the increased nutritional value through no-till planting. Plots were established on 9 farms over this project and the 3 previous projects. Only one of those small plots resulted in a substantial brassica population in the resulting sward. It is the author’s conclusion that brassicas are not able to compete with an actively growing pasture sward even when burned back prior to planting. There was a successful finding of this project which was that the brassicas could be established in areas where the grazing sward was killed due to compaction through the use of no-till drilling. Further, that if the Daikon Radish was planted the tuber would aid in repairing the compaction.
To measure compaction a penetrometer is used to register the force required for a root to move through a soil. The units of this is in lbs/sq.inch. Included below is a 3 dimensional graph of a 50 foot semi-circle radiating from a water trough. When the resistance reaches 400 lbs/in2 all plants were killed. The reading of 400 cannot be used as an absolute since resistance goes down as soil moisture goes up. The relationship between the graph’s points is what is important. In the case of this graph the pasture was dry so the readings were high. From 0-12 feet from the trough the readings were higher than what our penetrometer could measure. There was no pasture sward within 20 feet of the trough. In our plots all three of the brassicas did well within that zone but did not persist in the area 20 feet and greater.
Cornell University has developed the “Cornell Soil Health Assessment” Which uses a number of tests to determine a soils’ Physical, Chemical and Biological health. Samples were submitted to Cornell for Zufall, Morrisville, and Benson pasture plots. The information contrasted what farmers have traditionally been told about “soil tests” which have only covered the chemical aspects of their soil. The first sample is of the pasture and the second was from 10 feet away but under the fence where there was no cow traffic. The first page (of the 11 page results) are shown for the two samples.
The pasture was part of the brassica plots. The brassicas germinated and then slowly turned yellow eventually disappearing after 2 – 3 weeks. Which was similar to the results of other plots. It was while doing a botanic composition after the disappearance of the brassicas that it was discovered that there was a wide variation between counts done in the pasture and the counts done under the fence. There was a number of sedges in the pasture and almost none under the fence. The samples were taken 10 feet away so we assumed the soil was the same. We could see the difference of the productivity of the soils since the sward under the fence was more productive and the cows consumed a greater percentage of the sward then what was in the pasture.
The first page shown for the two samples show “Value” and “Rating” for each soil health indicator. The ratings are based on 100 being excellent and going down to 0 for the least health. There is a color assigned to the rating to show whether it’s green for good, yellow for caution and red for extreme constraint. The indicators which showed the largest difference were in the physical components of the soil, particularly the Surface Hardness and the Sub Surface Hardness. Both of these measurements are done in the field with a penetrometer. The readings from under the fence can be used as an example of what the soil could be and the readings from in the pasture is a representative of how the management has affected the soil. More work needs to be done on different textured soils to understand how management can be used to minimize compaction in pasture soils.
- 3 Dimensional Graph showing soil compaction radiating from a water trough.
- This is the first page of the soil health report from Cornell. The sample was taken from Zufall’s pasture. It can be used to compare to the soil sample from Zufall’s fence line which was just 10 feet away.
- Cover sheet to the Cornell Soil Health Assessment. The sample was from under the fence at Zufall’s farm
Education & Outreach Activities and Participation Summary
July 17th – 19th 2014, Grasstravaganza was a grazing conference was held at Morrisville State College. The focus of the conference was soil health. The PI applied to plant 3 test plots in May at the fields where other demonstrations were held. There were 150 in attendance at “Grasstravaganza,” all of whom came to the field site to see the brassica trial. The interaction while looking at the trial and then in conversations during the event provided many opportunities for farmers and educators to learn more about using radishes/brassicas in pastures.
Dec 4th 2014, E-Organic Webinar “ No-tiling Brassicas into Pastures”
Of the 150 who enrolled, 90 (60%) people participated in the webinar.
March 6th&7th 2015, “North Country Grazing School” Two one hour presentations on what has been learned about establishing brassicas into pastures. Total in attendance at the two days- 68 people.
August 24th 2015, “Soil Health on Pastures”, At Fay Benson’s custom Grazing farm. 12 people.
Dec 13th – 16th 2015, National Grazinglands Coalition, Dallas Texas, Poster presentation on SARE brassica project. 700 in attendance.
- This article was written after the author viewed the webinar through E-Organic. The author followed up with an interview to get more information.
- This manuscript of the SARE Brassica Project will be published in the National Grazinglands Coalition’s 2015 proceedings.
- Poster displayed at National Grazinglands Coalition Conference, Dallas Texas Dec 2015
The issue of soil compaction in pastures has gained interest, partly because of this project and also due to the increased conversations about soil health in agriculture in general. Bob Zufall has asked for recommendations for his pastures once he became aware of the different penetrometer readings within his pastures. One reading taken under the fence line where cows do not walk and the other reading taken from just 10 feet away in the pasture. The difference was visible (see photo below) but he did not notice it since he visits the pastures so regularly and compaction takes years to show up. We are trying to develop plot trials to determine how best to impact the affected area and what management factors can prevent it from getting worse.
Areas needing additional study
How to alleviate soil compaction in pastures with an actively growing grazing sward is a question that more farmers will be asking. The possible answers may include:
- Letting the sward grow taller before grazing which would allow the roots to grow more extensivly in the soil helping to add carbon to the soil.
- Use mechanical means such as an aerway or a yeomans plow.
In areas of pasture where there is compaction sufficient to kill existing sward this project proved that brassicas could be used but more work needs to be done to determine the least costly ways to establish them.