Key Points:
The Grass 2 Crop project was set up to examine the influence of cultivation on the agronomic performance of crops following the grass phase in the rotation. In long term trials as part of the project, nutrient availability is also being monitored in order to assess the impact of different cultivation techniques. This work will be the subject of an Arable Extra at a later date. In this update we look at some of the yield results from project trials last season.
- There were no significant differences in milling wheat yields on a Wakanui silt loam or in feed wheat yields on a Mayfield stony silt loam (Methven) due to establishment method.
- The plough treatment recorded significantly higher plant establishment than top work and direct drill treatments.
- At the Wakanui trial site (Wakanui silt loam) in Mid Canterbury there were large differences in dry matter production and nitrogen uptake at stem elongation, with direct drilled crops having lower N uptake and dry matter at GS31, but this had no effect on yield.
- There were large differences in grass weed pressure (ryegrass volunteers) due to establishment method on a Wakanui silt loam and in radish volunteers at the long term trial site at Methven.
- At both sites ploughing resulted in the lowest levels of volunteers from the previous crop, with direct drilling producing the highest volunteer numbers, and top work treatments resulting in intermediate levels of weeds.
- Applying 30 kg N/ha at sowing with direct drilled crops following 12 months of grass did not increase yield, however it was noted to increase dry matter production and N uptake at early stem elongation.
- Whilst at sowing nitrogen was not noted to increase yield with direct drilled crops it was observed that these crops better competed with volunteer grass weeds, significantly reducing numbers to the levels recorded with the top work treatments.