Greater consistency in meeting market specifications for grain can be achieved by employing crop-specific nitrogen management techniques, according to Terra Nitrogen's Mike Slater speaking at Cereals 2003.
He illustrated this point with reference to the company's winter wheat monitoring sites at the event at Vine Farm, Wendy in Hertfordshire, where the varieties Malacca and Access are being grown under varying regimes in accordance with yield potential, end market specification, and information from biomass sampling and tissue analysis.
"Both varieties have very high yield potential, but we are growing Malacca as a bread making wheat and Access for the feed market," explained Mr Slater. "We've targeted the yield potential in each case, based on our historical knowledge of the site and what we know about these varieties. This provides the basis for broad fertilizer recommendations, but the difference between success and failure in hitting end market specifications comes in the detail of actual rates and timings.
"We've based our final recommendations on information gleaned from biomass sampling and tissue analysis, plus an understanding of the relationships that we now know exist between the nitrogen content of the plant at different stages and final grain nitrogen content.
"An understanding of the variety is also important. In the case of Malacca, for example, we know there is great yield potential, but as this dilutes the protein content fertilizer rate and timing is even more critical."
Terra Nitrogen runs over 30 other monitoring sites similar to the facility at Vine Farm. The information gathered from these sites over the past four years has been used to establish key relationships that are used increasingly by Terra in its fertilizer recommendations.
Nitrogen recommendations for Malacca and Access based on soil and tissue sampling, Vine Farm, Herts (2003)
Malacca: Vine Farm, Wendy, Herts
Target: 10 tonnes/ha, grown for bread making
Total N recommendation: 252 kgN/ha (202 unitsN/acre)
Splits:
Late February - 125 kg/ha (1bag/acre) Nitram
Growth Stage 31 - 250 kg/ha (2 bags/acre) Sulphur Gold
Growth Stage 32 - 265 kg/ha (2.1 bags/acre) Nitram
Growth Stage 37 - 125 kg/ha (1 bag/acre) Nitram
Access: Vine Farm, Wendy, Herts
Target: 12 tonnes/ha, grown for feed
Total N recommendation: 285 kgN/ha (228 unitsN/acre)
Splits:
Late February - 125 kg/ha (1bag/acre) Nitram
Growth Stage 31 - 225 kg/ha (1.75 bags/acre) Nitram
Growth Stage 32 - 476 kg/ha (3.8 bags/acre) Nitram
