By Jacqueline Maclaurin
Viticultural Technician, Wither Hills
As the season warms up so too does the shoot, weed and grass growth.
The buckwheat and Phacelia are showing signs of growth. This year we sowed at a rate of 35 kilograms per hectare of buckwheat and 3 kilograms per hectare of Phacelia.
This season we are also trying to open up the compacted soil, with the aim of allowing more root penetration throughout the soil to access more water and nutrients, and to help the fertiliser to work its way through the soil instead of remaining in the top surface layers. We used a para plough down the middle of the inter-row on both the organic and conventional Pinot Noir blocks. We did try to plough the wheel tracks but they were too compacted and we couldn’t get the plough into the ground without extra weight on the implement. Alternate rows were ploughed as we felt doing every row may disturb the root system too much on young vines that are already underperforming.
We decided to only do the Pinot Noir blocks as we did not want to bring up more rocks in the Sauvignon Blanc blocks.
The tractor driver found little difference between the organic and conventional blocks in terms of the speed he was able to achieve and driving the implement into the ground. As the conventional block is fully herbicide sprayed off in the winter as a tool in frost protection, I envisaged this to be more compacted soil, but there appeared to be little difference.
The ploughing did cause a shatter effect on the soil in the conventional block as it broke through the ‘crust’, whereas the soil was held together by the sward roots in the organic blocks. As a permanent sward had been sown in every alternate row two years ago in the organic Pinot Noir, we decided to plough the alternate rows that were still in volunteer sward.
A light roller was put over the ploughed rows, just heavy enough to put the topsoil back to ground level.
Looking forward we are going to watch the crop levels on both blocks more closely, and monitor the nitrogen levels of the organic Pinot Noir as feedback from the winemakers on the past vintage were not very positive on this block.
The Sauvignon Blanc is showing little difference in growth between the organic and conventionally managed blocks.
Video of the para plough in action. Grassy area = organic block, bare soil = conventional: