Better soil health and consistent yields through accurate manure applications

A Bunning Lowlander 175HBD is helping Cambridgeshire arable grower James Sapsed to reduce his reliance on bought-in fertiliser and maximise the nutrient values from a variety of manures.

In 2014, James Sapsed set out on a mission to increase the accuracy of organic fertiliser applications across his 1,500ha of contract and owned land, west of Cambridge. Owning no livestock himself or having regular access to manure, the change in approach to crop nutrition required significant investment in buying the manure and hauling it to the farm.

At the time, D&A Sapsed and Sons were in the minority, as the demand from arable growers for organic manures was small. Mr Sapsed applied small amounts of manure but with rear discharge machines that weren’t accurate enough to monitor how the manures were improving the soils. He could see the benefits increasing accuracy could bring not only in fertiliser savings, but better crop health and improving moisture retention on his heavy clay soils, as he explains.

“I felt our crops were droughting out quicker than they should have been on our soil type. We started buying in manure before 2014, but our contractor’s application method wasn’t very accurate before the cultivations, with basic spreaders unable to spread to the accuracy we required for us to calculate what effect the manure was having.”

This meant the farm investing in one machine that could precisely spread all types of solid manure. After a trip to LAMMA, he settled on a Bunning spreader due to build quality and technology options, such as weigh cells, and the traceability for individual customers and fields. He also preferred to deal with a local company that was easily contactable for back up.

His first Bunning Lowlander 150 HBD (horizontal beater and spinning disc) arrived in 2014 and was predominately applying his own manure that was bought-in on a per tonne cost, so getting it spread with weigh cells was essential. Since then, the farm has moved to a brace of Lowlander 150 HBD machines when the contracting work increased and has now upgraded to a single larger Lowlander 175 HBD.

Establishing a system

After nearly a decade of manure applications under his belt, Mr Sapsed says you must want to do it and be committed to the long-term project. “With the investment in machinery and added logistics at an already busy time of year, a clear plan about where manures are being spread allows the cultivations team to be ready once the spreader is finished. There must be a desire to improve crops through long-term applications of organic manures, it isn’t a quick-fix option to reduce the cost of nitrogen.”

Mr Sapsed began with compost and farmyard manure (FYM) moving it onto field edges throughout the winter for application after harvest or before spring crops, but to make the system stack up financially, and release cash to buy higher value manure such as sewage sludge and poultry litter, he began selling the straw in the swath to a couple of local contractors. Although Mr Sapsed admits it was a bit backwards in the early stages, the long-term plan has now evolved to a regime of consistent applications of the right manures for following crops, all funded for by straw sales.

“Selling the straw may appear counter-intuitive, but over the course of a 4-year rotation we will remove an estimated 15t/ha of straw. However, we will be applying on average 30-40t/ha of organic materials back onto the soil depending on the crops. The straw helps pay for the manure and eases cashflow, but, with the shallower cultivations we are doing, there are less issues with trash flow as we aren’t chopping vast quantities of straw.”

The farm spreads compost after a break crop as reserves of nitrogen and phosphorous will remain in the soil for the next crop. Mr Sapsed looks to apply sewage sludge or poultry litter into a second- or third-year cereal when N and P reserves will have been used from the compost and the nutrients in the high N manures will directly influence crop growth. Application timings begin at harvest through to late September and then in the spring, where Mr Sapsed has seen a significant increase in demand from his contracting customers.

Crop and soil benefits

The overall aim has been to improve soils though accurate application of manures and reduce use of artificial N and P sources. Mr Sapsed says after nearly a decade of consistent use, his crops are healthier coming out of the winter, with bigger green areas helping them kick on earlier. This has also been highlighted in the last two seasons with the weather variability and he says in these years the manure has come through to influence end yield.

Being able to precisely apply all types of manure is key to these benefits. “We can see from the record on the Bunning spreader exactly where we have applied products for comparisons with yield data at harvest. I believe our yields have been more consistent in recent years, we aren’t breaking any records, but we don’t experience the variability in the end results like we used to.”

The Lowlander 175 HD HBD is powered by a Fendt 939 and although this may seem overkill for a 17.5t spreader, it means that the limiting factor is never the tractor, and the spreader can always operate at its most efficient by maintaining forward speed, PTO speed and, most importantly, spread width and pattern when going up hills.

With fertiliser prices high, bought-in nutrition costs are significantly lower than they would have been if the manures weren’t accurately applied. “We don’t buy any TSP (Triple Superphosphate) anymore, which used to equate to 110t/year, as the soil reserves are maintained by the organic fertilisers. Our nitrogen use is down on average 40kg/ha so the applications are having a consistent effect on our soil nutrition requirements.”

He has also cut out a cultivation pass as the soil quality and friability is better. The farm’s cultivator of choice is a Sumo Quattro and previously it would have been followed by up to two passes to get a suitable seedbed to drill into, whereas latterly only one pass is needed, saving both time and cost.

Consistent spread is key

Mr Sapsed’s latest spreader is top spec, with weigh cells, Isobus and field mapping all part of the package, and Bunning’s knowledge of how the spreader integrates with the tractor’s software has meant any teething issues are quickly sorted and this has helped to refine the application of different products.

Going from two spreaders back to one has also increased work efficiencies as turnaround times are quicker as there is never a queue to be loaded, and the best day saw 1,500t put through the machine. “We are now doing with one spreader what we could do with the two smaller ones. This is down to the extra power of the tractor allowing for quicker cycle times and the preferential loading.”

Running a bigger tractor also means that it feels in control of the spreader, and it won’t be bossed around when fully loaded. Additions to Mr Sapsed’s machine include rubber strips along the top edge of the side walls, allowing an extra 5/6m3 when loading lighter materials such as compost.

“Bunning have also been willing to work with us to get the machine we wanted. As we load the spreader with a Hitachi Zaxis 130 excavator, as opposed to a loading shovel or telehandler, the slew over the rear of the machine caused a build-up of material above the beaters that was dangerous to clear off by hand and could drop off when on the road. Bunning designed a flipper that raises as the slurry door reaches full height and allows the loose material to slide off.”

The continual investment in manures, and the precision technology to apply them, has allowed Mr Sapsed to reduce his reliance on bought-in fertiliser and improve soil and crop health through accurate applications.