Potassium for quality hay

In association with Meridian Agriculture (Andrew Speirs) and with support from the local growers and Canpotex, three field demonstration K strip trials have been established in the Victorian Western District. The focus of the strips is to assess the effects of K on the production and quality of fodder produced from pastures. T a new series of K strip trials focused on fodder producers in the southern cropping zones. These are not replicated experiments but purely demonstrations, and will be linked to field walks in the spring.

Three sites and the soil tests are:

Analyte	Hamilton	Condah	Mepungah
Texture	Sand	Sand	Sandy Loam
pH (CaCl2)	6.1	5.7	4.9
EC (1:5)	0.08	0.09	0.08
Olsen P mg/kg	18	25	16
Colwell K mg/kg	170	53	160
CEC cmol(+)/lkg	7.3	5.7	7.7
Avail. K mg/kg	120	44	110

Based on the Better Fertilizer Decsions soil test critical values for pastures (see downloads), the critical Colwell K range for sands is 109-142 for 95% of maximum pasture production. Two of these sites are marginally above this critical value, but even so, a response to added K is expected under good conditions.

This work is supported by Canpotex P/L (through Agrow P/L) and the International Plant Nutrition Institute. The demonstration was designed and arranged by Meridian Agriculture P/L (Andew Speirs). Thanks are due to the landholders for their co-operation.