Shortlands Station - Fertiliser Trials

Peter Espie has carried out a large number of experiments testing the effectiveness of non-standard (alternative) fertilisers and comparing them with conventional recommended fertiliser applications. The experiments have shown that some alternative products give significant production advantages. Some large-scale tests have been done on Shortlands Station with very positive results. 

Any fertiliser company should be able to demonstrate to their clients or anyone else that their products perform as claimed and have the content that is claimed. This applies to “alternative” fertiliser producers just as much as any mainstream fertiliser company, according to Dr Peter Espie, a scientist specialising in soil/plant relationships who has carried out considerable research over many years in grassland ecology and fertiliser performance.

“My company runs many research trials in various locations for different fertiliser companies that require an independent assessment of their products,” says Peter.

“This is the third year of trials at Shortlands Station testing fertiliser products and we have shown that they work in a way that is statistically verifiable and meet the criteria of the science community, and the results generally support the use of those products.”

Major experiments have been carried out on the lower “flats” in two areas, each 1 ha in size. One area had never been fertilised in 150 years of pastoral farming; the second was on a site that had been developed into high fertility pastures. Experiments have been replicated on each area to highlight any differences between low and high fertility sites. Because of the drought the visual differences are subtle.

Trials have included:

• Comparing guano with that of acidulated superphosphate as a source of P
• The efficacy of foliar fertilisers
• The effects of lime and dolomite
• The interaction of foliar and solid fertilisers
• The effects of adding humates 

The results are from scientific trials, not anecdotal, and potentially confounding factors have been excluded. They confirm that the results Shortlands Station has been getting from the application of biological fertilisers are genuine and not wishful thinking.

P supplied in guano has given higher yields to P supplied in superphosphate.

Adding humates to urea (essentially carbon coating of urea granules) has given increases of 50 – 80% in dry matter production over urea alone, and the more humates added, the greater the increase. This occurs on unfertilised sites as well as developed pasture, and shows that responses to biological fertilisers are not the result of “mining” of previous applications of P.

These results most likely reflect the stimulation of the action of soil microbes by humates plus a reduction in the volatilisation of urea. They are highly significant and go against conventional wisdom, but are consistent with results obtained in trials in two other parts of the country. They challenge some widely held views that humates are a “waste of time” and are likely to change the way soils are fertilised to increase pasture production.

The site for the Hieracium test is an intermediate terrace between the low and the high hills where Hieracium has invaded aggressively. Trials are examining the use of combinations of boron plus biological stimulants as a means of Hieracium control. Hieracium is more sensitive to boron than other typical pasture plants and so can be suppressed or killed without damaging pasture or adversely affecting its establishment.

“Soils on the hills