Now in his second season with Hutchinsons at G.D.Jewers and Son, Wood Hall Farm, Rattlesden, Mid Suffolk, Tom Jewers says he believes the Helix Farm project will help him work with, rather than against, nature to achieve a more ‘agroecological’ farming system.
However, he adds the project, which is based on an ‘improve or remove’ approach to raising farm productivity and profitability, is posing as many questions as it is delivering answers.
A socially distanced farm walk on a cold but sunny April day provided an opportunity to catch up with some of the work underway this season.
Nitrogen response work at Helix Farm East is assessing the effects of a range of four N rates between zero and 240kg N per hectare, applied as AN, UAN and UAN plus urease and nitrification inhibitors.
This work will consider economic and environmental aspects of nitrogen use.
Hutchinsons trials and technical manager Dr Bob Bulmer says: “If we can use N more efficiently and maintain productivity, it saves cost. We are looking at ways of bridging the loss of income from BPS and fertiliser is about 30% of farm input costs and N probably about 70% of that. So, we’ve got an input that is very cost-effective but by using less there is an opportunity to reduce the farm’s carbon footprint and improve the economics.”
From a farm business perspective, nitrogen provides the best return on investment of crop inputs, says Tom Jewers.
“So we are always a bit hesitant to reduce rates as we know nitrogen will build yield.”
But equally there are occasions when N rates are reduced because areas of a field may look poor, but end up combining as well as the rest of the field, he adds.
“And you think, we used 60kg N/ha less on there, so we’ve wasted it elsewhere. But would it have been the same result in another season? These are the questions we need to answer.”
Technology support tools including tissue testing, N-Tester, chlorophyll meter measurements, grain nutrient analysis and NVDI image analysis are also being used to determine whether they can support decisions on more efficient nutrient use.
The Helix East team hopes the work will also help inform the debate around nitrification inhibitors’ positive impact on GHG emissions but detrimental impact on soil microflora.
Dr Bulmer says: “Inhibitors are good at reducing nitrous oxide GHG emissions, but we have a debate about what they are doing to soil life as they inhibit the activity of some bacteria in the nitrogen cycle, which convert ammonium into nitrate.”
“So, we’ve got a conflict between healthy soils and putting on a nitrification inhibitor. One of the things we are doing here is reviewing a new in-field soil biology test to find out what is happening to soil life in these plots. We can certainly see some opportunities with inhibitors but also potentially a bit of a dilemma in terms of a healthy soils approach.”
Inhibitor Tom Jewers adds: “A nitrification inhibitor allows you to put on a lot of nitrogen in one go and not lose it, but is this then killing everything in the soil and encouraging more disease? These things have to be weighed up.”
A baseline assessment of the soil health status of the field has been obtained using the Eurofins Soil Life Monitor soil test.
This recently launched test provides a detailed insight into a soil’s chemical, physical and biological properties.
Soil Life tests were done at the beginning of the season and will be repeated later in the season, once nitrogen applications are complete, says Hutchinsons fertiliser and crop nutrition specialist Rob Jewers.
The farm’s soils have also been mapped using Hutchinsons’ Terramap soil mapping service and components of yield, including plants/sq.m; tillers/sq.m; ears/ sq.m; grains/ear; thousand grain weight plus grain nutrient analysis will be measured.
Dr Bulmer adds: “Last season the soil test was predicting low nitrogen availability and the grain analysis also picked this up. This is something Tom is concerned about in the context of the dry spring/early summers we have been having.”