Studies to focus on nitrogen, phosphorus and sulfur
Commencing this autumn and focusing on nitrogen (N), phosphorus (P) and sulfur (S), the four research projects are being conducted by ADAS in collaboration with 12 industry partners who will contribute a further £250,000 cash/in-kind funding.
James Holmes, research manager for crop nutrition at HGCA, stated: “The Fertiliser Manual (RB209) is a crucial source of information. But as farming practices move on, it is essential that nutrient management recommendations keep pace with change. This new work will play a valuable role in updating nutrient management information.”
The first project extends current research to help growers maintain an appropriate level of phosphorus in the soil.
Holmes said: “In the last 30 years, fewer fields have received P treatment as growers take ‘P holidays’. This, together with the increasing cost of P fertilizers and environmental pressures, has stimulated a lot of debate on the management of P.
“Recent research has shown how P management may need to be adapted in certain soils and has confirmed that growers running down soil P to below Olsen P Index 2 could be approaching a ‘cliff edge’ of P deficiency and risk not achieving optimum yields, especially when conditions are less than ideal.”
The new research will refine understanding of critical soil phosphorus levels and how to satisfy crop demand across a range of soil types, which could include applying ‘fresh phosphorus’ during the season.
“The use of fresh P applications is particularly interesting and HGCA work has already demonstrated that fresh P fertilizer can be effective in raising winter wheat and oilseed rape yields in plots below Olsen P Index 2. Further P-response trials will be conducted on farms to calculate when fresh P applications could be beneficial,” commented Holmes.
Two further projects will focus on the management of nitrogen.
Holmes said: “Current recommendations for N management are based on averages which fail to adequately reflect the diversity in soil types and the large variations in actual field nutrient requirements. There is also increasing evidence that N is being under-applied on some farms.”
In the first nitrogen project, a series of on-farm trials will be set up to test a novel ‘strip trial’ approach, where a standard nitrogen rate is applied along with 50kg/ha more and 50kg/ha less applied nitrogen to alternate tramlines.
Allison Grundy, from GrowHow, one of the project’s industry partners, commented: “We are supporting this work with soil analysis and helping growers to set up strip trials. We will help develop a robust data set to produce a better picture of N variability and the proportion of fields that require more or less N fertilizer than predicted by RB209.”
The second nitrogen project will look at the nitrogen requirements for winter barley.
Holmes said: “RB209 recommendations for winter barley have not been updated for around 30 years and varieties have changed significantly over that period.
“This project will review N management data and conduct experiments on application rate and timing for two-row, six-row and hybrid winter barley varieties.”
The final project takes a look at sulfur management.
Holmes said: “The recent HGCA ‘yield plateau’ work found that many winter wheat and oilseed rape crops may not be receiving enough S and this could be limiting yield.
“This new research will extend S-response trials, as well as quantify the S supply from applications of manures and biosolids.
Dr. Pete Berry, principal research scientist at ADAS, concluded: “The nutrient research projects have been designed with RB209 in mind. The projects, which will deliver findings over the next five years, will be made available to Defra to assist with future revisions of RB209.”