Trials with Agrii-Start Release in field vegetable crops show potential for reduced phosphorous applications, reports Don Pendergrast, Agrii technical manager for non-combinable crops

The use of Agrii-Start Release, a soil-applied cation complexing agent used to improve the availability of phosphorous, has improved marketable yields by at least 10% in carrots, bulb onions and white cabbage.

In field trials over the past three years, Agrii has investigated the contribution to performance of a pre-emergence application of Agrii-Start Release.

As a cation complexing agent, Agrii-Start Release breaks the bind between the metal ions in the soil and phosphorous molecules thereby improving the availability of the latter to the growing crop.

Many species of vegetable crops, especially alliums, are known to be highly responsive to phosphorous. As such, fertilisers high in phosphorous are often applied as starter fertilisers as an aid to establishment. However, many soils are already high in phosphorous, but crops are not always able to access it.

This apparent contradiction between nutrient status and nutrient availability coupled with the prospect of tighter application restrictions intent on protecting water courses, prompted Agrii to investigate technologies that might lead to a reduction in the fertiliser needed to be applied by improving access to what is already present.

Results to date are highly encouraging. Soil analysis performed post-application revealed increases in the available quantity of phosphorous. This served as confirmation of its potential.

Yield results support this hypothesis with increases in both gross yield and the percentage of crop meeting market specifications.

Agrii-Start Release increased marketable yield in bulb onions by 10%

Reference: Agrii, 2023. Agrii-Start Release applied pre-emergence.

Agrii-Start Release increased average head weight of white cabbage by 12%

Reference: Agrii, 2023. Cv. Kalorama. Agrii-Start Release applied 1 day before planting.

Agrii-Start Release increased gross yields in carrot by 20% and marketable yield by 11%

Reference: Agrii, 2022. Cv. Nazareth. Agrii-Start Release applied 1 day before sowing.