Maximising Crop Production at FAR

20 by 2020 is an ambitious FAR led programme to achieve the highest feed wheat yields in the world –  of 20 t/ha by 2020, enabling farmers to increase productivity and profitability.

Rob Craigie from FAR says a lot of their work has been on fine-tuning programmes, like getting a fungicide programme bang-on with the idea of maintaining yields with the minimum inputs possible, for example getting the optimum out of nitrogen and no more.

“To make economic gains we need to be doing more than fine-tuning things; we need a leap in yield. We are looking for a step change, and more outlandish ways of doing things. The world record is 15.6tonnes/ha and we are seeing yields in some of our trials towards 17t, so 20t is a stretch. In the UK harvest yields are up to 14t, and usually average about 8t/ha. At this site 13-15t are achievable now. We really want to see how much we can push it,” Rob says.

A recent grower survey showed that wheat is the key crop driving the economics of the arable rotation and the New Zealand environment is ideal for achieving the highest crop yields in the world. The combination of high radiation levels for high rates of photosynthesis and a cool maritime climate to lengthen crop development are New Zealand’s advantage, as are the skills of the growers.

Data from the Canterbury autumn sown wheat Cereal Performance Trials (CPT) show a steady increase in yield of about 200 kg/ha/year (2% / year) that plateaued in 2006. This increase is partly due to genetic improvements but also earlier planting, more irrigated crops and improved agronomy.  However, the four-year average yield from irrigated autumn sown feed wheat cultivar trials through Canterbury is higher at 12.2 t/ha.

The current world record for wheat yield (gained in 2010) stands at 15.63 t/ha and is held by Mike Solari in Southland, New Zealand.

In the 2012 season, the highest yielding treatment in one of the FAR trials in the 20 by 2020 programme topped out at 16.95 t/ha.

Internationally increasing crop yields is a priority because of world population growth and the fear that there will be insufficient food because of land and water limitations.

FAR’s research in the last three to four years has shown bringing sowing dates forward is giving good yield increases.  Rob says “We are exploring the real extreme of this to find the earliest possible sowing date. Usually most feed wheat is sown in April, although some growers are planting in March. We are sowing in February, March and April to compare yields from the different sowing dates.

This throws up a heap of crop management issues: if we are planting earlier, then the cultivars need to be suited to this time. The wheat is in the ground for almost a year depending on how the harvest season (in February) goes.

The longer the wheat is growing, the more issues there are with disease. If planting is earlier, the crop is growing in warmer autumn conditions and more nitrogen is mineralised which makes the crop more growthy.

The right cultivar is key, because it has to be more resistant to pests and diseases, and have a shorter and stiffer straw, so it is more likely to stay standing up.

As well, the cultivar has to mature late. So we are trying to find a cultivar with good disease resistance which stands up well and is later maturing. Planting earlier is potentially growing more biomass and as a result, increasing grain yield.

Nitrogen fertiliser is being looked at closely as part of the trial too: the objective at the end of the season is to have supplied only exactly the amount of fertiliser the crop needs. “We are running it right down so that there isn’t nitrogen sitting around to be leached.”

One way to look at the project is to say the higher the yield the more efficient the growers become – not only in fertiliser use but in water use. 

The programme has a number of strands.

Plant & Food are measuring many aspects of the crop including stem counts, dry matter and how much light the different plots are intercepting. In this strand FAR is collaborating with Plant & Food Research (NZ) and NIAB TAG (Cambridge, UK).

Within the plots there are five plant populations: the earlier you plant, the lower you can drop plant populations. Stem counts are making sure we have enough stems to get enough ears of wheat to achieve a high yield.

Another research area is investigating the use of novel plant growth regulators. For this strand FAR are collaborating with Canterbury University. 

The main research site is located on the 180ha arable farm of Paul and David Birkett at Leeston, Canterbury. This is a very high yield potential site which regularly yields in the range of 13 to 15 t/ha.

David says last year the trial used small plots, and growers wanted to see the research carried out with commercial paddocks. So this year the paddock has been split into three sowings in February, March and April, each of 2ha.

One of the challenges is that no-one has experience of managing February sowings. “Essentially we are feeling our way,” he says.  “Last year was a very good autumn, with the plants establishing well. But as a result there was more disease and excess bulk, leading to crop lodging.  As soon as lodging occurs, yield is compromised, but with nine separate trials within this paddock of Wakanui feed wheat, there will be lots of data collected.”

Yields may not be as high this year as in last year’s plots, especially as during five days over Christmas, which is when the wheat ears fill, drizzly rain fell. But the only day that really matters is the day of harvest.

Last year yields were just shy of 17t/ha, and in the next door paddock David grew a commercial crop of wheat which also reached 17t/ha.

But it’s not the peak tonnage which is most important commercially, rather it is learning how to bring the average crop up as high as possible.

The arable industry is concerned it has been losing ground to dairy, so moves such as this to improve the economics of cropping by increasing yield will help keep land in arable crops.

About 50,000ha of wheat are grown in NZ, and one of the industry goals is to make NZ more self sufficient in wheat production. Milling wheats are imported from Australia. David says “If we can increase yields we can have a bigger chunk of the domestic market. We need to make sure the research is done in a way which is sustainable so we don’t have to spend a lot more money on the crop. There were big yield gains in wheat in the early 2000s, but there is a bit of a barrier between the 15 and 16t/ha level. This research will help us understand what limitations there are to that barrier.”

Wheat is the backbone of the Birkett’s operation, with 55ha grown this year.  Half of their production is sold to a feed mill for chickens, the other half sold on the open market, either going into the dairy industry or chickens.

They have 10-12 crops in their rotation, including white clover for seed, grasses for seed, hybrid radish and hybrid cabbage seed, red beet, peas and beans for Watties, dry peas and beans for seed, barley, and lucerne.