Cropping Trial at Waimate West Farm

April 2013

A trial looking at the benefit of setting aside grazing land for crops on a dairy farm

The Waimate West Demonstration Farm was established in 1917 by a group of local farmers, and since the 1960’s it has had a science as well as a demonstration focus. The land is owned by the South Taranaki District Council and the stock and plant owned by a trust. It is run as a commercial unit and is self funding except for the inputs and monitoring by scientists and technicians.

It is just 36ha (which was probably a good sized economic unit in 1917), flat and divided into 40 equal sized paddocks. The herd consists of 142 Jerseys.

A five-year trial showed that putting about 12% of the farm into crops increased profitability. In the first two years the farmlet with crops was less profitable than the control all-pasture farmlet, because land was taken out of pasture production for crops with no net benefit to the farmlet. Subsequently the operating profit of the cropping farmlet overtook the control probably because of increased dry matter production over the summer. The farm is now expanding the cropped area to 25% of the total farm area to see whether this increases profitability further.

The trial was funded by DairyNZ, the Sustainable Farming Fund and FAR. The farm has a management team from those three organisations plus sponsors from Ballance Agri-Nutrients, PGG Wrightson Seeds, Pioneer and Nufarm. Each year the team plans what is going to happen in terms of trials, and locals within the team get together once a month to review what is going on. Local farmers are also involved.

The aim of the project was to find out how best to introduce crops into a dairy platform in Taranaki as a means of increasing dry matter production, milk production and profit. Crop species and cultivars, drilling and cultivation practices and management practices to establish the crops and integrate them into the farming system were also examined. Soil carbon, nutrient losses and mineral were monitored.

The team decided to establish a 30 paddock farmlet that included 3-4 paddocks of crop. The other 10 paddocks formed an all-pasture control. There were 108 cows in the cropping farmlet and 34 in the control. Over the five years a lot was learnt about crops and their value, and there were some surprises according to Joe Clough, a consultant with PGG Wrightson Consulting.

“We started off wanting to maximise the dry matter produced from crops and initially we discounted some like chicory and turnips because they didn’t have the yield potential. However, we very quickly realised that while crops like maize produced lots of bulk dry matter, they created issues at times of the year by having paddocks out of production,” says Joe.

“We learned that crops like chicory and turnips were very important ingredients in the system and that we could use other crops such as ryegrasses and particularly oats in between maize crops to provide winter feed.”

In the first year they established three paddocks of maize but that reduced dry matter available from early October into May and it made it difficult to get keep stock properly fed through the summer and autumn.

“That’s when we decided we needed chicory, which we had previously discounted because we didn’t think it would yield enough. What we have found is that if we manage it properly it produces pretty well in the first year and if we look after it over the winter it does even better in the second year. We had a second-year crop that produced about 17 tonnes and in this environment that is not too far away from the maize yield,” says Joe.

“So the cropping farmlet was the less profitable in the first two years because it takes time to work the crop into the system and we weren’t able to get the feeding right at the right times. However, we learnt from that experience and we feel that that was a very big part of being successful in the subsequent years.”

“I guess as we understood the cropping system better, the advantages seemed to get greater and in the end we were growing about two extra tonnes of dry matter over and above what we would got from a pasture-only system. That was with about 12% of the farm in crop.”

On a conventional farm, spring is the time when pasture grows for conserving as silage or hay. Having crops growing at that time reduced the area available for conservation and so to get through the subsequent winter it was necessary to establish winter forage crops. They tried a number of crops including forage rape and triticale, but the most successful was a combination of oats and annual ryegrass.

“The oats provided some bulk in late May through to July and that replaced the hay and silage in the diet, and as long as we grazed it carefully and back-fenced it, the annual ryegrass came through and provided feed in the early spring. Then those paddocks went back into crop again – maize or turnips or chicory,” says Joe.

“Growing crops involves a bit more work than just running a grass farm and one of the criticisms of a system like this is that it is too complex, but really we have got the complexities out of the system and learnt from our mistakes so that the structure is relatively simple. You still have to do things right, the timing has to be right for spraying and so on, but when you do then you can reap the rewards.”

Plant and Food Research did extensive soil testing and the crops actually required a lot less fertiliser than might be generally recommended, especially nitrogen. “We did a few side trials with nitrogen on maize because the standard advice is to apply 300 kg per hectare of urea. After a fortnight the plants in the urea plot were visibly much better than the ones they weren’t, but when it came to the end of the cycle there was no difference in yield,” he says.

“That supported work done by FAR in the Waikato on maize crops on land straight out of pasture. If you crop the same paddock for several years you mine the nitrogen and may need more urea. The point is to know that and just put on only what you need.”

In the first two years the profit from the cropping farmlet was about 10% below that of the all-grass farmlet, reflecting the difficulty in providing enough feed to replace the output from the area put into crop. However, in the subsequent three years, it averaged 20% abov. In the final year it was actually 50% higher.

“The message for Taranaki farmers is if you are already efficient in your all grass farming and you have reached a plateau, or if you have been buying in feed and you don’t wish to be at the mercy of the market, there is the potential to grow additional feed on your farm. As long as you manage it correctly you have the potential to produce more milk solids and make more profit.”

“The options that we have come up with include mainly maize for silage, which gives a standard yield in South Taranaki of 18 to 20 tonnes, and a summer crop of turnips and chicory followed by winter crops of oats and annual ryegrass.”

This is the first year of a new trial to see whether it is profitable to increase the area in crop to 25%. The trial will involve the whole farm and there will be no control farmlet i.e. 30 paddocks in grass and 10 in crop.

“This time we have reduced the stocking rate over the winter with the aim of getting a higher per cow production, but once we get the 10 paddocks into crop we will be back up to 5 cows per hectare for the rest of the season. We have to generate enough feed from the cropping system to support that stocking rate through the rest of the year. So in some ways it is a significantly different demonstration to what we had last time.”

“We established a feed pad during the first trial, and for the new trial we would have had to invest in it anyway because if you are feeding significant amounts of supplementary feed is important to reduce pugging and nutrient loss”