Nutrient and irrigation assessments benefit Geographe growers
Funded by Wine Australia through their Regional Program initiative, this program enabled viticulture consultant Jim Campbell-Clause to visit 17 grape growers in the Geographe Region with the aim to:
- Demonstrate best practice when collecting soil, water and petiole samples for laboratory analysis
- Collect irrigation and nutrition records
- Collate the laboratory analyses with irrigation and nutrition records and compare results to industry standards; and provide feedback to the grower on their management practices.
A range of soil types and varieties were included in the study that involved vineyards in Harvey, Donnybrook and the Ferguson Valley. The most notable findings in regard to soil tests was a high proportion of sites with low pH, high soil copper levels and low sulphur levels. There was discussion about cation ion exchange capacity and the use of lime and gypsum to ameliorate problem soils.
The water analysis was surprising in that several sites had high chloride and/or high sodium levels.
Petiole levels of most nutrients were within expected ranges. Most of the discussion was around the levels of nitrate and nitrogen.
Nutrition application rates varied significantly across sites. Some growers applied little or no nutrition while others were applying up to 80kg/ha of nitrogen, 50kg/ha of phosphorus and 44kg/ha of potassium. There was discussion about natural nutrition sources and availability of nutrients.
Irrigation applied through the season was also variable with some growers applying no irrigation while some used up to 4700Kl/ha. On average growers used 1270Kl/ha annually. Growers were interested to learn about new more cost effective soil moisture monitoring technology and the applicability of this to their fertiliser and irrigation management practices.