SFF Project Summary
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Latest update
Updated:
03 March 2009
Northland Kikuyu Action Group Newsletter, July 2008 [PDF 324KB]
Project description
Northland Kikuyu Action (KAG) group is a farmer driven group that started in 1999 to identify methods for maximising pasture production of kikuyu dominant pasture. Interest by farmers in the work of the group continues to be high.
The issue/opportunity
Kikuyu is among the four most important pasture species in Northland. It continues to spread both within in Northland and in other areas of New Zealand, including the Waikato, Bay of Plenty, Taranaki - indeed farmers as far south as Nelson are now finding Kikuyu growing. This situation that will only be exacerbated by current climatic trends. Loss of production from poorly managed kikuyu pasture on sheep and beef farms is becoming more significant each year. Increasingly farmers are ‘trying' management options on steep kikuyu pasture – but in the absence of properly designed and monitored trials, these remain anecdotal at best. They may in fact lead to pasture production decreases and environmental damage.
At present Northland farmers don't have any trialled information on options for maximising production from a kikuyu dominant pasture that don't rely on the use of a tractor.
The context/background
As demonstrated by previous Kikuyu Action Group trials poor autumn kikuyu management impacts significantly on subsequent winter and spring production. Effective management of kikuyu dominant pasture relies on control of kikuyu during the autumn period to enable ryegrass and other species to compete and continue producing during the winter/spring period. But achieving this control by grazing alone can be challenging at best, and impossible to achieve is some seasons. For many Northland farmers current control options are not practical or cost effective on some or all of their property. These farmers are desperate for practical solutions which would allow them to control kikuyu in the autumn, leading to better productivity and profitability from the farms during the spring.
Given that the majority of Northlands sheep and beef production occurs during the late winter and early spring period, and this also coincides with premium payments for stock, any method of producing more pasture through the winter and spring period will produce additional income for farmers.
Provision of practical options for effective management of kikuyu pasture in the autumn on non-tractorable country will therefore lead to direct economic benefits.
Methods
There are 4 components to this project:
(a)Strategic use of nitrogen in late autumn/early winter as a tool to change pasture composition and increase pasture growth in the spring
(b) Enhanced grass establishment and animal performance through the spring using strategic application of nitrogen to overcome the potential immobilisation of nitrogen by rotting kikuyu residue.
(c) Re-evaluate the role of the breeding cow in managing kikuyu relative to other classes of stock. This trial will look at both the animal and pasture impact of using breeding cows as a tool.
(d) Initial analysis of the data collected over the past year on pasture growth and quality at Jaggers, followed by a further years collection of data and final analysis. It will provide valuable information comparing seasonal performance of kikuyu and ryegrass pasture. This information will help demonstrate to farmers the importance of correctly managing kikuyu on sheep and beef farms
All these trials will be run on commercial sheep and beef farms throughout Northland.
Latest update
Using nitrogen to establish oversown grass - Taipa
Once again, this trial is being run on the 10 lane techno-system at Dennis & Rachelle O'Callaghan's farm at Taipa. The intention of using the techno-grazing system was to complement pasture production data with animal production data. More information about the trial design is available in the trial protocol.
This season the strong kikuyu growth during autumn, combined with a very wet winter had a significant impact on the trial. The technosystem had been closed up from February to build pasture cover and manage parasite burden prior to the bulls being stocked. When the bulls started grazing the system in early May, the grass was too long for the seed to be sown ahead of the cattle and was applied following grazing. Grass seed and nitrogen was applied in late April and May (later than planned) on the first cells of the system (where the cages were sited). The back sections of the system did not have seed or nitrogen applied at all, due to the very wet weather.
The late application of nitrogen and seed on the systems, combined with severe pugging events on some cells during the winter has made it difficult to identify any consistent trends in the pasture data. The animal production data is expected to have less relevance because some areas of the system did not receive nitrogen or grass seed.
The final pasture data has been collected and will be available for analysis shortly.
Using Nitrogen to Change Pasture Species - Kawakawa
This trial is being run on the Cookson farm in Kawakawa once again. This season the decision was made to move the site to an area with a combination of steep and easy land and assess the relative performance of nitrogen in changing pasture species. The late winter application of nitrogen was dropped from the project.
Last year there appeared to be a species response to applying the nitrogen, but no subsequent pasture growth response in the spring. This season initial results indicated a good nitrogen response on both the flat and steep sites, but little difference in pasture species or growth rate beyond the initial nitrogen response.
Re-evaluating the role of the breeding cow
This trial is being run on Lindsay and Erica Whyte's farm at Taupo Bay. This season the monitoring was expanded to include three paddocks and three treatments per paddock (heifer only grazing, cow and heifer grazing and heifer grazing and mulching). The new sampling technique is expected to highlight differences between treatments in feed quality and pasture growth more effectively.
Early results indicate some differences between treatments in pasture quality, but little difference on pasture growth. This project will be provide some important insights into the non-tangible benefits of running breeding cows in areas where kikuyu grows well through the autumn.
The decision has been made to extend monitoring to help quantify the effect of cow grazing on pasture quality.
Update
KAG Breeding Cow Project: Results from March to October 2007
What were we trying to do?
Identify whether breeding cows cleaning up kikuyu in the autumn gives better winter and spring pasture growth rates, than using normal grazing or mulching.
How did we do it?
Three paddocks were monitored as part of the trial. These paddocks were split in half with a temporary fence (as outlined in the diagram below).
- Both sides of the paddock were grazed with finishing stock
- Only one side was grazed with a mob of breeding cows
- A strip was mulched on the Finishing stock side of the paddock
Cows were grazed on the measured paddocks from April-June (after calves were weaned)
Cages were used to measure pasture growth on all areas, pasture species and feed quality was analysed through the winter and spring.
What did we find?
Pasture Growth Rate
The area which was neither mulched or cow grazed (i.e. just grazed with finishing stock) grew slightly more pasture in the winter, with similar growth rates during the spring. The graph shows the relative performance of each treatment and highlights the good growth during autumn 2007.
Pasture Species
No major differences were recorded between treatments.
Feed Quality
No major difference in feed quality between treatments.
What Does This Mean?
These results conflict with the first year of monitoring and what we would expect to see based on past Kikuyu Action Group research. The trial design will be changed to allow more detailed monitoring of pasture growth and pasture quality through the critical late winter and early spring months.
Breeding cows remain a valuable tool for maintaining pasture quality in the autumn and grooming pasture for the winter and spring. Detailed monitoring in 2008 will help to quantify the benefits of breeding cows in managing kikuyu.
KAG Nitrogen to Change Pasture Species Project: Results from March to October 2007
What were we trying to do?
Identify whether using a late autumn application of nitrogen encouraged earlier growth of temperate grasses and whether this translated into better late winter/early spring pasture growth rates.
How did we do it?
A kikuyu dominant area of the farm was identified and a series of plots allocated to the following treatments:
- No Nitrogen (Control)
- Early Winter Nitrogen (50 KgN/ha applied on 11 May, soil was 16.1oC and 47% moisture)
- Late Winter Nitrogen (50 KgN/ha applied on 15 August, soil was 11.9oC and 66% soil moisture)
- Both Early and Late Winter applications
Grazing was manipulated to simulate lax kikuyu management (50 day grazing rotation). Apart from lax grazing during autumn, each plot was grazed as part of the normal farm rotation, with cages moved around the grids following each cut. Pasture growth rate and species was assessed regularly through pasture cage cuts.
What did we find?
Pasture Growth Rate
Areas receiving nitrogen fertiliser had greater pasture growth for 6 weeks following application. In general the nitrogen response lasted less than 6 weeks, with a nitrogen response averaging 13 KgDM/kgN for both the early and late winter applications.
Pasture growth rates are outlined in the following two graphs.
Pasture Species
The treatments which received nitrogen showed more ryegrass during the winter than the area which did not receive nitrogen as outlined in the graph below. The ryegrass component also appeared to sustain longer into the summer.
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Pasture Quality
There was no difference in pasture quality between the treatments.
What does this mean?
In the first year of this project Nitrogen did appear to change the pasture species to encourage earlier emergence of ryegrass. However, this did not result in greater late winter/early spring pasture production, apart from that expected as a result of using nitrogen fertiliser. Graph1 shows that once the initial nitrogen effect has worn off, late winter and spring pasture growth was similar to the area which did not receive nitrogen.
This site was high fertility with a good history of grazing management. In 2008 we are shifting the focus to a more varied mixture of sites and increasing monitoring to determine whether the species change translates into more spring pasture. Watch this space.
KAG Nitrogen to Establish Over-sown New Grass: Results from March to October 2007
What were we trying to do?
Identify whether using nitrogen shortly after sowing helped the establishment of new grass and whether better winter and spring pasture growth translated into better pasture production.
How did we do it?
A technosystem was used to highlight differences between treatments on both pasture growth and beef production. Each techno lane was assigned a treatment:
- No nitrogen or grass seed (Control)
- 50 KgN/ha applied in June (Nitrogen Only)
- 15 Kg/ha treated perennial grass seed applied in May (Seed Only)
- 15 Kg/ha treated perennial grass seed applied in May and 50 KgN/ha applied in June (weeks after sowing) (Seed & N)
A cage was placed in each lane to assess pasture growth rates and pasture species, with at least two replicates (lanes) of each treatment. Grass seed was applied shortly after grazing. Bulls were rotationally grazed through each lane from May-November and were weighed at the start and the end of the trial.
What did we find?
Pasture Growth Rate
Cumulative pasture production from each treatment is outlined in the graph below. Lanes receiving nitrogen showed similar pasture production trends regardless of whether seed was applied. In contrast, the lanes where seed was sown without nitrogen had pasture production similar to the control. This indicates differences in pasture production were most likely due to nitrogen.
The table on the next page shows cumulative pasture growth in the 128 days following treatment and the average daily pasture growth rate over this period (KgDM/ha/day).
Table: Cumulative pasture production (KgDM/ha) from treatment
| Cumulative | 18/07/07 | 24/08/07 | 3/10/07 | 23/11/07 |
|---|---|---|---|---|
| Control | 1158 | 1623 | 2160 | 3328 |
| Seed only | 828 | 1500 | 2102 | 2944 |
| Nitrogen only | 1096 | 1942 | 3325 | 4421 |
| Seed + N | 1261 | 1850 | 2951 | 4226 |
Pasture Species
Lanes receiving nitrogen had a greater proportion of ryegrass from than the control lanes. This ryegrass component probably contributed to the better late winter and early spring pasture production, as shown in the graphs below.
Animal Production
Lanes receiving nitrogen showed greater beef production as shown in the table below:
| LW Gain/ha | % Gain | |
|---|---|---|
| Control | 644 | 0 |
| Seed only | 635 | -1 |
| Nitrogen only | 670 | 4 |
| Seed & N | 702 | 9 |
What does this mean?
Nitrogen appeared to change pasture species and result in better pasture and beef production. Further monitoring in 2008 will consider persistence of seed and confirm these early trends indicating nitrogen does help the establishment of grass and investigate whether this is a cost effect option for farmers.
Update
This project is progressing well. Interest in the project continues to be high among farmers, and response to the regular email updates positive. The project is regularly profiled at other Northland Pastoral events such as Meat and Wool monitor farm field days etc, ensuring that as many farmers as possible are aware of the work.
General comments
The three sheep and beef farms involved in the project have experienced excellent growth though the late autumn, promoting the growth of kikuyu and presenting difficulties in managing the kikuyu.
Te Mataa Station: N to improve ryegrass establishment
Seed and nitrogen is now all applied as per the trial design. Pre- graze covers were higher than expected, so the decision was made to apply seed following the bulls rather than ahead of the bulls. Pasture was grazed down to 1300 – 1400 kgDM/ha in the first rotation, with the residual pasture being low feed value. Bulls were on a rotation length of 60 days and are about to start their second rotation. No slug bait was applied this year. Any new grass which has established should be identified in pasture cuts from this point on.
Cookson Farm: Autumn and winter N to change pasture species
All autumn nitrogen treatments have been applied, the second harvest was made on Tuesday 26th June. The trial area had deliberately missed a grazing to simulate a scenario where kikuyu had been laxly managed. Initial feedback suggests there is already a large proportion of temperate grasses in the pasture, probably as a result of good grazing control for a number of years. This reinforces a key concept of the kikuyu action group: The better the pasture management, the better the sward. The intensive grazing system associated with 'sticks and strings' gives excellent grazing control.
Whyte Farm: Breeding cows for kikuyu control
We visited the farm as part of a KAG committee day in late May and the group was able to observe the control breeding cows were achieving relative to mulching and finishing stock. Two pasture cuts have been made, differences in pasture growth and species between the breeding cow treatment and the finishing stock will continue to be monitored until the spring.
Jagger Farm: Detailed comparison of kikuyu and ryegrass
The 2007 autumn was a challenging period for the Jagger farm, with little growth recorded in the ryegrass cages from January to March as a result of dry weather. In contrast, kikuyu growth continued through this period at an average of 21 kgDM/ha/day. The final cut is planned for September 2007. When pasture data collection is complete it is proposed to use the data to model the impact of pasture species on a range of different livestock scenarios for both dairy and sheep/beef policies. The data will also highlight opportunities to balance the diet of a kikuyu pasture.
We have had some difficulty accessing technical advice for interpretation. The initial discussion was based around approaching nutritionists from Australia, under the assumption they would have more involvement with the role of kikuyu in a pasture system. We had some difficultly connecting with Australian nutritionists and, on reflection, comments from New Zealand experts suggested that the Australia production system was so different from the New Zealand system (much higher reliance on supplementary feeding) that they may struggle to understand the New Zealand system.
An approach to both AgResearch and Dexcel has been made, Dexcel are yet to submit a quote for the interpretation of the work. Both organizations have indicated they would like to be involved with the project, although both are concerned that there will be no validation of results from the modeling work. AgResearch is proposing to use UDDER for the modeling, while Dexcel is suggesting they would use the whole farm system model to interpret the data. The final decision needs to be made about whether to model the existing data set, and it is proposed to wait until the final measurement is made in September and model the results of the full two years of data.
Dissemination/project profile
- Jim Anderton, Minister of Agriculture, visited Geff Cooksons beef farm on his recent trip to Northland. Here the importance of regionally specific work, such as the trial on kikuyu management underway on the farm was emphasised. The risk of kikuyu dominance spreading as a result of climate change, and the implications for Waikato and the Bay of Plenty were also discussed.
- Dargaville Field Days – work of the Kikuyu Action Group was successfully profiled at the March Northland Agricultural Field Days. Interest from farmers was high, and a considerable number of names and contact details were entered into the database as a result of discussions.
- Pastoral Farming Development Group conference – KAG again supplied speakers to this conference in early May. Although this project was not the direct subject of the presentation, it was mentioned in the discussion.
Meat & Wool Events where we have discussed the KAG project:
- 3 x Far North Monitor Farm community group days
- 2 x Lower North Monitor Farm community group days
- 2 x breeding cow field-day
- 2 x beef council meetings
- 10 + E Diaries (plus a spot on the Meat & Wool New Zealand website)
- Enterprise Northland website
March 2007
Project 1: Detailed Nutritional Comparison of Ryegrass and Kikuyu Pasture (Whangarei Heads) Underway, due to release results late 2007.
Project 2: Strategic Use of Nitrogen to Change Pasture Species and Increase Spring Pasture Growth Rates
This trial aims to determine whether nitrogen application can be used as a tool to accelerate the natural change in species composition that occurs during the winter months. It will trial a late autumn or early winter application of nitrogen to encourage the change in pasture species, and provide temperate grasses (eg ryegrass) with a competitive advantage over kikuyu, resulting in increased winter/early spring production and leading to better animal performance.
Trial monitoring due to run from Feb – October with the trial running for 2 years (Kawakawa)
Project 3: Use of nitrogen to enhance grass establishment and animal performance
Temperate grasses being established from seed sown into a kikuyu dominant sward can struggle to compete with kikuyu. One theory is that the very high C:N ratio of rotting kikuyu may immobilise nitrogen in kikuyu residue, effectively robbing the establishing seedlings of nitrogen.
This trial looks at whether nitrogen applied shortly after sowing can improve pasture establishment and lead to more animal production through the spring period. The trial will utilise multiple mobs of animals to monitor actual animal performance gains from a combination of nitrogen and annual grass treatments. In addition to animal performance data, we will be monitoring pasture growth and quality measures.
Trial monitoring due to run from Feb – October with the trial running for 2 years (Taipa)
Project 4: Re-evaluate the role of the breeding cow in managing Kikuyu
Breeding cow numbers are dropping in Northland – is this to the detriment of kikuyu management and overall farm profit? This trial will examine the impact of grazing kikuyu residue on breeding cows performance relative to other classes of stock. Does the ability of the cow to remove kikuyu residue translate into better pasture production and animal performance on the farm in the spring? This trial looks at both the animal and pasture impact of using breeding cows as a tool to manage kikuyu quality.
(Taupo Bay – Running from Feb – Oct for 2 years)
The first year of data has been collected and analysed (report available). Year 1 of the project was run at Maungaturoto as part of the AgResearch Beef Cow Focus Farm. The project showed very similar results between treatments. Although we are still in the early days of the project and the results are not significant, the pasture cleaned up by breeding cows looked to be higher energy in the winter and spring as well as having less kikuyu and more other grasses and legume.
The second and third years of the breeding cow project will be run Lindsay and Erica Whytes property near Taupo Bay in the Far North. We will be adding a mulching treatment to the breeding cow trial to see how those breeding cows really stack up.
We will be regularly updating the results in our email updates, at monitor farms and during Kikuyu Action Group meetings.
For more information on any of these projects please contact Gareth Baynham (09) 430 2410, (027) 442 0556 or email gareth.baynham@meatandwoolnz.com
October 2006
1. Detailed comparison of kikuyu and ryegrass:
Data analysis from the 2005/06 year is underway, there are early indications of trends in pasture growth and ME levels between the kikuyu and ryegrass paddocks.
The next years monthly monitoring will compare dry matter production and a full feed breakdown for kikuyu vs ryegrass.
2. Re-evaluation of the role of the breeding cow in managing kikuyu:
The breeding cow component of the project is underway, the cow grazing versus no cow grazing treatments have been carried out and data from the first cut has been reported by Chris Boom (AgResearch). We hope to identify differences between treatments during the spring and extrapolate these differences into liveweight change for different classes of stock, ultimately arriving at a dollar benefit/loss from the breeding cows.
3. Evaluation of the use of Nitrogen to Change Pasture Species and increase spring growth:
This project will be run on the Cookson property and consists primarily of small plot trials which will be monitored for pasture growth and species. The nitrogen treatments will be applied in May and August to determine whether the applications are capable of accelerating the conversion from dominant kikuyu to dominant ryegrass pastures. There may also be a demonstration area on a larger scale.
The exact site and monitoring contract are still to be arranged, monitoring for this trial is due to start in March 2007
4. Using Nitrogen to Assist in Establishing Annuals:
This project is proposed to be run on the O'Callaghan farm just north of Taipa in Doubtless Bay. The farm has the required techno systems and will also have three years detailed pasture monitoring data (growth, dissection and quality) collected during the monitor farm program. Monitoring for this project is due to start in March 2007.
