Kerry AgriBusiness and Munster Technological University (MTU) Kerry’s (formerly IT Tralee) agricultural engineering department recently joined forces to pinpoint the best approach to establishing clover with the help of an old Hunter strip-seeder machine, as farmers face ever increasing fertiliser prices and climate change challenges.
The seed for the idea was first sown by Sean McCarthy, Kerry AgriBusiness sustainability manager. With the aid of his dairy farming brother, James, they were determined to speedily seek solutions.
They had trialled and researched all the current known systems of grass harrows, disc type over seeding drills and fertiliser spreaders with watery slurry. There was mixed feedback from James’ farm and the many farmers they spoke with as there were many variables.
They spoke with well known Castleisland based agricultural contractor, Garrett McCarthy, about an old Hunter strip-seeder machine he used in the 1980s. It was lying idle in his machinery shed and so, the rejuvenation of a different kind began.
Beginning the process
Garrett outlined the pros and cons of the Hunter machine and ‘dos and don’ts’ were quickly learned. It was very clear to all that the base unit with its floating cutting flails was solid.
Its heritage can be traced back to a Scottish agricultural research university and this created a guaranteed till regardless of soil types and grass cover, they said.
The metering and accuracy of small seeds was not always reliable, according to Garrett.
“Farmers, regardless of the machine, needed to get soil fertility right in order to successfully over sow into grassland,” he said.
Some outside the box thinking was implemented by the McCarthys. They felt if the seed metering was rectified it might be worth reviving it and then doing comparisons with today’s equipment as the guaranteed till of the soil and natural scarifying action were a solid foundation to begin.
A plan was created where this machine would be redesigned and field tested whereby ongoing trials would feed invaluable data back to MTU staff, students and Kerry’s milk suppliers.
While the plough is a very successful establishment method, farmers are very aware of the pros and cons of this practice. Keeping carbon stored in the soil and not using glyphosate were lofty targets of the project.
“A low cost and more successful method is needed in today’s price sensitive world,” said James.
“Not taking parts of the grazing platform out of production for long periods during the growing season is the advantage of over sowing but strike rates of seed germination can be very poor and hard to quantify with current machines.”
Farmers, James said, must realise the machine they choose is only a piece of the puzzle as soil type and fertility such as P and K indexes are important.
“The correct soil pH is crucial so soil testing is critical to help establishment and persistence. Weather plays a role as seeds need rain to germinate so doing this process before dry spells is not a good idea,” he said.
“Also, good pre and post-grazing management is needed to get sunlight down to newly emerging seedlings.”
Peter Folan, a fourth year agri engineering from Nenagh, Co. Tipperary, who isn’t from a farming background, undertook the project under the supervision of MTU staff.
He became interested in this course when he started work placement in transition year in secondary school with a local agricultural contractor, John Kennedy, in Nenagh, who designs and builds a lot of his own machinery in-house.
The ‘buzz’ of the silage harvest
Peter loved the buzz of the silage harvest and the engineering witnessed firsthand in John’s yard and this is where and why he explored the MTU course.
“With Peter’s background, course knowledge, drive and energy the machine was stripped and gearboxes rebuilt,” said lecturer Adrian Locke.
“The project was a lot of work, but I learned loads during the process. What I liked most about the project was the mix of different skills needed and research areas covered during it,” said Peter.
“There was the mechanical aspect of fully rebuilding the original Hunter Rotary Seeder,” he added.
“Then we moved onto the design of the frame for the new air seeder being mounted to it and modifying some aspects of the original machine such as the coulters to now deal with an air pressure from the two fans.
“Then there was marrying the new air seeder to the rotary tiller mechanism as it was previously set up for a mechanical seeder box and then calibrating and setting up the seeder to accurately seed to the rates we wanted.
“Finally, seeing the machine working properly in the field and achieving what it was designed to do was very rewarding,” said Peter.
Most pneumatic seeders on the market have eight or 16 distribution spouts and a bespoke manifold was made and supplied by Doyle Engineering as the machine created 12 slots which are 3in wide on the ground.
While there were many engineering facets to this machine, the main design was based around the critical and accurate seed distribution tubes and to exhaust air pressure before seed to soil contact to prevent seed bounce and get precise seed placement for maximum germination success was the main engineering challenge.
Rubber tails were manufactured and added with special purpose floating guides to all aid with seed placement.
“This all took a lot of creative engineering as these are not parts you can order off the shelf,” said Adrian.
`”Making parts by hand was critical and working with engineering companies to modify their designs to meet the needs of the project are crucial. Strong communication skills are essential as is good planning as there are many variables when a tech manual is unavailable, and a new design is being created,” he said.
Joe Bannon of CBS Bearings in Athlone assisted with sourcing parts and Denis Doyle of Doyle engineering also helped. Currently, the machine is out testing with various trial plots set out by Kerry Agri and its performance will be monitored by a cut and weigh yield system.
Already plans for phase two are well advanced for this project using Topcon’s correction signal technology to enable intersowing between the strips and using ISObus technology to add greater machine functionality.
Plans to test coated clover, MSS seeds and slug pellets as well as granular lime are all topics that the project is aiming to tackle as the emphasis is on gathering information.
It’s now being followed up by an agricultural science student gathering information on various farms. The machine has a working width of 2.7m and the target of 5k/h was achieved and surpassed.
“Garrett’s advice of moving from 540 to 1000RPM on the driveline helped us gain field performance which was very pleasing,” said Peter.
“Even though we did some testing on-site it was invaluable the day Garrett arrived in the college as he had such a wealth of knowledge and he knew the machine inside out. This really helped to get the optimum settings and performance from the machine. You can’t beat experience and wisdom,” said Peter.
Some of the main advantages of strip seeding with a min-till system like this machine Peter worked on with KerryAgri, he said, are low soil disturbance, not burying the fertile top few inches of soil, no glyphosate and potentially very high germination rates.
A great advantage of a strip till system is that the pasture can remain in production, unlike the more conventional regime of spraying the grass off before ploughing and cultivating which removes the pasture from the rotation for several months at the most productive time of year.
By sowing the seed in strips, the main crop can be left to grow for a further grazing while the sown strips germinate and establish in between the undisturbed plants.
The benefits include much reduced machinery costs, less field traffic, conservation of soil nutrients, reduction in carbon emission from the soil reservoir and less loss to birds.
“It’s really great that the agricultural department in Tralee and Peter in particular took on this challenge,” said James.
“Third-level facilities now realise that farmers more than ever need practical boots on the ground help as we are choked up with webinars and research papers that often don’t apply to our actual needs.
“What Peter achieved since March of this year in such a short timeframe between teardown and rebuilding, and then to get the machine set up and ready, calibrating it to within 1 gram of its target sowing rate and field tested, was really phenomenal,” said project co-ordinator Adrain Locke.
“Kerry Agri Business is delighted to collaborate with MTU in addressing the challenge of incorporating clover into existing grass swards. Clover is proven to reduce our dependence on chemical nitrogen fertiliser, increase milk solids production per cow and increase farm profitability,” he said.
“Many different machines have been used with varying degrees of success depending on factors such as the density of the existing grass sward and soil conditions at the time of sowing.
“We will need to be flexible in our approach as one machine won’t suit all situations and having come across an old Hunter Rotary Strip seeder, we felt it had a place. It is now equipped with some of the latest technologies,” said Locke.
“Working together and harnessing the knowledge, expertise and experience of people, we will ensure farmers can successfully incorporate clover into their swards,” said Sean McCarthy.
“This will improve the environmental sustainability and economic viability of our farms.”