Reappraisal of methods of application of nitrogen and phosphorus at sowing on the yield, grain protein content and nitrogen economy of malting barley in Sweden

To compare the relative efficiency of different fertilisation strategies, malting barley was fertilised with calcium ammonium nitrate (CAN) or compound ammonium nitrate with phosphorus (NP) applied in two ways: broadcast and harrowed into the seedbed before seeding or banded using the Scandinavian combi-drill design, with the fertiliser between every second seed row, and 40 mm below. A fixed nitrogen level (120 kg N ha(-1)) was used, giving four fertiliser treatments. Eleven experiments were carried out the years 1992-1994, with latitudes 55 degrees 55' N as southern and 59 degrees 36' N as northern limit. Fertiliser-use efficiency, defined as grain yield, or grain nitrogen yield, per unit of applied N, was strongly affected by the treatments: values for combi-drilled were higher than for broadcast fertiliser and higher for NP than for CAN, with the effects being additive. The best treatment, using both banding and NP, resulted, as a mean of all trials, in a grain yield increase of 939 kg ha(-1) at 15% moisture content, or a nitrogen yield increase of 18 kg nitrogen ha(-1) compared with the poorest, using broadcast CAN. The N combi-drill effect was expected to be dependent on water availability, but this could not be confirmed when accumulated rainfall during crop establishment was used as test variable. The combi-drill effect was strongest in places where major extractable cations were abundant, possible explanations for this are discussed. Application of P to the crop and the use of combi-drill are recommended for malting barley fertilisation in Sweden.