Matching crop inputs to season outlooks makes dollars and sense
Author: Sharon Watt | Date: 19 Jan 2016
Grain growers could be missing out on millions of dollars of potential income because they are failing to see the whole picture between planting and harvest.
That’s according to Dr Kate Burke of Think Agri who says growers need to generate production scenarios and monitor them throughout the season to ensure they base operational decisions on the most likely range of outcomes.
Speaking at Grains Research and Development Corporation (GRDC) grains research Updates in the southern region, Dr Burke said if growers continually reviewed a range of production scenarios based on the broadest range of information they would make smarter long-term decisions.
“Different thinking and learning styles help users analyse different scenarios and regardless of the specific tools used, the broad strategy described is applicable to all soil types and climate zones – and can be particularly profitable if applied habitually,” said Dr Burke.
“The reliability and availability of resources to help manage seasonal risk and uncertainty have improved markedly in the past five years.
“However, human factors often get in the way of making decisions that would lead to the best financial outcomes.
“So what’s really at stake? Under or over-estimating yield potential results in an enterprise not realising income in high yield potential years, or overspending in low-yield potential years.”
Dr Burke claimed that in a favourable yield potential situation, an extra $5 million of wheat income could be generated just in the South-East of South Australia by simply improving wheat yield by 0.5 tonne/hectare across the region (assuming an average wheat price of $250/t).
She said the time and energy spent by growers and advisers on understanding a season’s true potential could have a massive impact on the financial outcome.
“The potential of the season is governed by what has happened up to now, and what may happen in the future,” Dr Burke said.
“Monitoring what has happened up to now and combining that with what may happen in the coming months provides a framework to judge season potential and aid decision making.”
She said the key to providing a viable foundation for any production program was reviewing grain protein achievement as part of the annual planning process.
“This is a broad indicator of yield performance relative to potential and a history of low protein wheat production indicates yield is nitrogen (N) limited.
“Paddocks or zones producing wheat with protein less than 11 per cent are highly likely to be N responsive.
“Consistently high protein production (>13 per cent) and high screenings can indicate that N is not yield-limiting, but that some other factors could be at play in limiting yield.”
She said the big four yield determinates of reaching water-limited yield potential in dryland cropping (if pests, weeds and disease aren’t limiting) are usually out-of-season weed control, time of sowing, N, and varietal choice.
Dr Burke’s key factors for production scenario analysis are:
- Estimate or measure starting soil water and use growing season rainfall to date.
- Look at low, medium, and high rainfall options going forward.
- Calculate yields based on water use efficiency (WUE).
- Look at your crops and use common sense to check the scenarios.
- Consider the effects of temperature on yield and grain quality.
- Consider the effect of waterlogging.
- Repeat after significant rainfall events or on a fortnightly basis.
“There are tools such as CliMate or the Bureau of Meteorology (BOM) rainfall range; you can use rainfall deciles for the months going forward (Rainman® streamflow or BOM data or measure soil water at the start of the season and modelling on Yield Prophet®,” she added.
“Approaches to estimating yield potential (what might happen) include French Schultz style WUE calculations or fit-for-purpose decision support tools such as Yield Prophet®, PYCal, iYield on iPaddock, ProductionWise®, yield and N calculators.
“Consensus within the majority of models is a strong indicator. If there is no consensus, then the outcome is less certain.”
Dr Burke said making yield scenario analysis a habit tightened decision-making and reduced risk.
“It will not be exactly right, but it is better than getting caught up in populist optimism when it rains and populist pessimism when it’s been dry for a while.”
Kate Burke, Think Agri
Sharon Watt, Porter Novelli
Caption: Dr Kate Burke of Think Agri says growers need to generate production scenarios and monitor them throughout the season to ensure they base operational decisions on the most likely range of outcomes. Photo: K Burke