By the end of 2020, Chloe Turner’s Rylington Park trial (above) showed stark contrast in crop growth and development with P treatments.

Superior seed quality has a number of crucial factors such as; trueness to variety, germination rate, purity (absence of contaminants), seed chemical composition, early seedling vigour and general appearance.

For Chloe Turner, Summit Fertilizers Kojonup based Area Manager, the impact of crop nutrition on the performance of retained seed is a fascinating area of study. Chloe has field trials at Rylington Park near Boyup Brook which are designed to investigate the impact of varying rates of phosphorus (P) and trace elements on seed quality.

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Chloe’s trials have extended across 2020 and 2021, with the high P fixing forest gravel soils at Rylington Park adding a layer of complexity to this research.

“The 2020 trial was sown using Planet barley seed from Rylington Park silos,” said Chloe.

“The soil type at the trial site that year had a very high Phosphorus Buffering Index (PBI) of 416. PBI is a measure of the soil’s ability to bind P. Soils with a high PBI require more P, because more of what is applied becomes bound to soil particles.

“The four P treatments were low (P = 0kg/ha), modest (P = 8kg/ha), adequate (P = 16kg/ha) and luxury (P = 32kg/ha), each applied with or without copper, zinc and manganese.

“Given the relatively lower rainfall of the 2020 season and the high PBI soil type, there was stark contrast in crop biomass and growth rate between treatments.

“For example, the luxury P treatment had started grain-fill when the low P treatment was still at the mid-booting growth stage.

“Harvest results (Figures 1 and 2) from 2020 showed that increasing the P rate increased yield and reduced screenings.

“Grain protein dropped off slightly with each increase in P, although all treatments would have achieved Malt 1 receival grade,” said Chloe (view results from this trial here).

Barley seed from the 2020 trial was analysed, retained, and sown this year to assess the performance of the various nutrition regimes. Two Summit trials were established. The first trial again received varying P rates with and without trace elements, similar to 2020. In the second trial, all plots received the same basal level of fertiliser across the retained seed treatments.

“The 2021 site has delivered some logistical issues for the Summit Field Research team.

“Frequent weather events meant herbicide, fungicide and nitrogen applications were not able to be applied at the optimal timings.

“Hence treatment variations are not as clear cut as 2020, although harvest may offer some surprising results,” said Chloe.

For more information on her trials, growers can contact Chloe Turner on 0447 469 245.