Key Points
- Headlands in maize crops are used for turning during drilling and post emergence crop operations such as spraying and side-dressing. Growers often observe lower yields in headlands.
- Maize grain yield, plant population, plant standard deviation and soil bulk density were measured in the headland and paddock of eleven Waikato maize crops
- On average, the headlands yielded 1.8 t/ha or 15% less than the paddock, as much as $150/ha loss in yield in a 4ha paddock.
- Plant population was lower in the headland by 14 000 plants/ha. This would have reduced yields by 1.2 t/ha or 10% of the paddock yield.
- The balance of 0.6 t/ha (or 5% of paddock yield) is probably due to a combination of factors such as higher plant spacing deviation, soil compaction and weed pressure.
- To reduce yield loss in headlands, crop management techniques that reduce the amount of pre and post-emergence traffic in the paddock should be considered. Options include broadcasting fertiliser rather than side-dressing, or in regions of low leaching risk, applying all fertiliser before or at sowing.
- Precision agriculture provides the option of sowing headlands last reducing pre-emergence traffic.