Climatic analysis as the basis for productivity benchmarking

John and Robyn Ive
Dicks Creek NSW

Long before the ‘Rainman’ software package made climate prediction easier for farmers, John Ive was painstakingly writing his own software to predict climate and measure productivity increases on his property just outside the ACT.

For 20 years John and Robyn have spent their weekends farming ‘Talaheni’, a 250 hectare property in the southern tablelands of NSW. They run Angus beef cattle and a self-replacing merino flock producing superfine wool. During the week John works as a principal research scientist for CSIRO, developing computer software for land use and management planning.

Using Southern Oscillation Index values, historic rainfall records from weather stations in Yass and Canberra and 20 years of his own weather records, John tries to predict rainfall for critical periods ahead, particularly for Autumn when seasonal breaks are very unreliable.

‘Given the prominence of the SOI as an indicator of rainfall prospects for eastern Australia, I have been exploring the value of the SOI as a predictor of rainfall at Talaheni’ said John.

‘I’m working on building a relationship between the SOI in January or February and the rainfall from March to May.

‘Unfortunately, the predictions so far have not been tremendously successful, but that doesn’t deter me from keeping on trying!’

More interesting and useful results have come from John’s development of software which relates production values to rainfall in the preceding 12 months to develop productivity benchmarks.

‘Rainfall is the limiting factor here and while we cannot influence the amount of rainfall, we obviously want to get maximum productivity from the rainfall we do get’ said John.

‘Every year we do an analysis of how we’ve performed relative to the climatic conditions.

‘With the cattle I’ve found that our individual weaning weights have increased by about 2kg for each additional 10mm of rain received in the 12 months prior to weaning.

‘On top of that, over the 18 years there has been a mean gain in individual weaning weight of around 2.5kg per year or nearly 45kg per head increase over the 18 years after allowing for rainfall variation.

‘This figure reflects our productivity gain, separated from any gains relating to annual rainfall conditions. It means that overall we’re making quite significant gains in terms of the amount of beef produced per unit of rainfall over the 18 year period.’

John uses similar methods to examine productivity in superfine wool production.

‘Gross wool production increases by 1kg for each additional millimetre of rainfall in the 12 months prior to shearing’ said John.

‘If the results for individual seasons are below what they should be, then rainfall wasn’t efficiently utilised for wool production. I go back and look at the reason. In the early years it was factors like low stocking rate, age structure of the flock, and severe El Nino drought in 1983.

‘We look at the figure of clean fleece weight over mean fibre diameter cubed. This is a recognised measure that takes out seasonal variability and establishes long-term productivity gains and we’re making good progress with that too.’

Staple strength is of primary importance for superfine wools of the type produced at ‘Talaheni’. One factor known to influence staple strength is seasonal conditions. John keeps track of the staple fibre diameter profiles and modifies flock management to minimise the variation coming from climatic indicators.

‘We shear here in August, which can be pretty miserable weather and the last thing we want to do is lose sheep or subject them to undue discomfort’ said John.

‘We had a series of anemometers over the place to measure wind from June to September for a couple of years and that assisted in the location of ‘mia-mias’ to shelter the freshly shorn sheep. We chose places that had the least wind.’

John was chairman of the Yass River Valley Revegetation Project for a number of years and the Ive family has been enthusiastically involved in revegetation to improve the property.

Some 20,000 trees have been planted on recharge areas to help combat rising water tables. A series of piezometers was installed on the property and readings have been taken weekly for the past ten years. John looks at climatic conditions when analysing the piezometer readings and assessing environmental improvements.

‘As expected, the fluctuations in piezometer readings track closely with the seasonal rainfall pattern’ said John.

‘However the readings also indicate that water tables are declining, with the decline being greatest close to the major recharge plantings. This is in spite of increasing rainfall over the measurement period. We’re finding that base groundwater levels have dropped over two metres near the planted trees since we started recording and the influence has been recorded over 500 metres from the planting.

John attributes his productivity improvements to several factors: improved genetics, detailed monitoring and objective assessment of each individual animal, improved condition of the property and better understanding of local weather and climate conditions over time – all combined with a willingness and keenness to do better.

‘Farming is very much at the vagaries of the climate and weather’ said John. ‘You can either cop it on the chin or be proactive.

‘Even with the approach of using climate information I’ve made bad decisions, but I like to think I’ve made more good decisions than I would have otherwise.’

You may also like...