Cyclone

People

If you or someone you know is struggling, reach out for help today. There’s a huge amount of support on hand. The health and wellbeing of you and your team is top priority to enable you to take care of the animals and the damage.

Assess damage of all on-farm housing. Do not enter properties alone or if they look unsafe. Develop a plan/strategy, set priorities and assign responsibilities as a team. Prioritise tasks, who is responsible for what, who is helping. Support your farm team and keep them updated as your plans change.

Feed

Provide clean water and feed to your animals as soon as possible. If the water is not safe for you to drink, it is not safe for your animals. If possible, do not let animals drink floodwater.

Pasture and feed can be contaminated with sewage, bacteria, chemicals, and other toxins. Moulds can develop easily on water damaged crops, hay, and silage. Minimise access to contaminated feed and avoid using feeds that are showing signs of mould growth as these can be toxic to animals and people.

Prioritise feeding to high-priority animals e.g. cows close to calving and young stock. If you are using feed you haven’t fed before (e.g. fodder beet, kiwifruit, etc.), be sure to understand the risks and follow good management practices.

If you need assistance sourcing water and supplementary feed for your animals, contact Federated Farmers on 0800 327 646.

1. If you desperately need feed contact: Federated Farmers National Feed Coordination Service. Farmers are responsible for paying for the feed, arranging delivery and checking the quality of the feed.
2. Protect your existing pastures and paddocks - Stand-off cows if another adverse event comes through. Protect paddocks by managing pugging damage.
3. Complete a feed budget and understand where your feed pinches could occur, to help you decide on a plan of action for pastures and crops. Contact your local extension or regional partner for help completing a feed budget.
4. Assess each paddock for:
   • time underwater
   • the density of live pasture remaining after 10 days
   • silt type (sandy, clay/silt loam)
   • depth of sediment (<5 cm, 5-10, 10-25, >25 cm).
5. Contact your local rural supply store representative or agronomist to help you decide on an individualised plan for your farm.
6. Be prepared to use some alternative crops and pasture species (e.g. Oats and short rotation ryegrass) over the next couple of seasons to meet feed demand.
7. Download and use the below flood damaged farm decision tree:

Regrassing and recovering pasture

Understanding the feed requirement for the upcoming winter and following spring and summer is important. Therefore, needing a plan for pasture recovery will help you recover.

There is little point to putting the entire flooded farm into temporary pastures to find that an identical feed pinch exists in the following spring when the pastures must be renewed again.

Using the information gained by assessing each paddock and rough feed requirements in the future, plan the recovery using the appropriate mix of short-term and permanent pastures. Then develop a timeline for regrassing. Some paddocks will need immediate action while others will need to dry before cultivation. Back-up plans are needed if the contractor is delayed or will only visit once e.g., is there some way to get pasture established using own machinery or that available from other farmers?

The regrassing response will differ depending on the depth of silt. Where no signs of grass growth have been visible after a week, consider the pasture dead. Paddocks recently grazed before the flooding will be worse affected. Shallow silt (<5 cm) can be ignored, up to 10-15 cm silt can be cultivated and greater than 20 cm will either need to be oversown or partially cultivated.

Flood sediment characteristically lacks structure and organic matter and comes in varying textures ranging from heavy to light i.e. from clay to silty loams to sand.

Clay based sediment

The clay loams are normally flat and feel smooth and silky and are usually found in ponding areas some distance from the river. The clay loams retain water for some time and if deep can’t be cultivated for considerable time because machinery will bog.

Sandy silt sediment

Silt to silty sands are often ruffled in surface texture and slightly gritty to touch. The surface of this medium flood sediment dries quickly but the subsurface remains moist. Sand flood sediment is often rolling, gritty to touch and drains very rapidly and is usually adjacent to the river and may contain a lot of gravel and flood debris.

Shingle

Revegetating shingle will be difficult. If grazing is required within 2 years then the sand/shingle needs to removed and stacked in a big stockpile. It can then be used for races or sold. Alternatively, the area can be retired and revegetated using such things as blue lupins. However, be careful not to build up seed stores of undesirable species if you are intending to regrass at a later date.

Flood sediment 5-10cm

If silt has completely covered the pasture than it will not survive and will need to be regrassed.

Normal cultivation methods will apply at these depths. Cultivation is recommended because silt is relatively infertile, will contain no organic matter or N, and have poor structure making it prone to pugging. A barrier to water drainage may also occur on the interface between the old pasture and flood silt. It is better in the long run to cultivate these depths of silt, so silt and underlying topsoil are combined. The resowing should have a high chance of success as it is normal farm practice in moist areas of lower North Island to resow pastures in early autumn March-early April.

When sowing the whole paddock, it is best to decide whether to sow short-term species, or perennials, as it is not always wise to mix them. Short-term Italian and hybrid ryegrasses will be preferred where feed production this winter is crucial, or where weeds/ fertility are expected to make it difficult to establish a good perennial pasture mix this year. Apply potassium and phosphate fertilisers with regular dressings of nitrogen as there will be little or no nitrogen cycling in the silt.

Flood sediment 10 to 25cm

In silt of this depth there will deeper and shallower parts in the paddock. By levelling the paddock it may be possible to bring most of the paddock into the 10-20 cm depth category.

Once the silt has dried heavy machinery can be used and deep ploughing (e.g. swamp plough) will help to mix the silt with the topsoil. If this is successful then cultivate and sow as normal. If the resulting soil is predominantly flood sediment rather than topsoil then sow in either short-term ryegrasses or forage oats or other deep rooted short term crops and return to permanent pasture the following spring or autumn.

Flood sediment >25cm

There are two options for deep clay/ silt loam flood sediment:

• oversowing with a helicopter
• cultivating the silt and drilling

In either case be prepared to recultivate in the following spring or autumn due to poor soil structure. If cultivating deep silt wait for the silt to dry sufficiently to support machinery. Use light weight machinery (including small tractors) and lightly break up surface, drill forage oats (annual, good option from farmer experience) or short-term ryegrass and harrow behind. After winter grazing forage oats can be mulched to aid in organic matter or made into silage in spring. On very sandy areas use the same seed mix as you normally use on your accretion area.

Is the silt smelling?

When river silts become smelly this indicates that toxins are present as a result of anaerobic organism activity. It is probable that seed germination after sowing directly on smelly silt will be impeded by these toxins. However recovery of the anaerobic silt following cultivation will be rapid. It is recommended that anaerobic silt be aerated or cultivate.

Fertility

As a river floods, the coarser sand material is deposited in the higher reaches of a river and closer to the river bank and these will be of poorer quality – less fertile and less suitable for pasture growth. Further down a river and further away from the river more clay loams are deposited and in theory, contain higher nutrient levels. But the immediate fertility of the clay and silt loams will be highly variable and should be tested as it will probably have a very low nitrogen content and low in phosphate with very low organic matter. Silt and sand can intermingle in layers making mixing a good option.

Flood sediment will need potassium and phosphate fertilisers and nitrogen. Pure silt should not have large amounts of fertiliser in one dressing as flood sediment has limited capacity to store fertiliser due to its low anion storage capacity. Smaller more regular fertiliser applications will be necessary. Seek expert opinion based on your soil test.

For advice and help on soil fertility and soil testing contact your local fertiliser company representative.

Pasture species

There will be a desire to grow bulk feed quickly by sowing an annual ryegrass, oats or other bulk crop. Not only could these crops provide quick bulk feed but can be mulched into paddocks to increase organic matter.

To ensure you have a spread of feed throughout the seasons, some of the new hybrid and perennial species will establish with similar vigour but will persist for much longer reducing the risk of a large area being renewed at the same time later down the track.

How to manage bolting Kikuyu

To ensure you're not impacting the establishment of perennial pasture and its production in winter and spring make sure that you:

1. Faster rotations to get rid of as much leaf as possible.
2. When soil and weather conditions allow, use mechanical means to get rid of all the stem that accumulates and reset the residual.
3. Refer to the Northland Dairy Development Trust website for further information on kikuyu management:
   
   • Kikuyu Trial - Northland Dairy Development Trust

Flood affected crops

Assess your winter feed crop. Review the extent of the damage on a paddock-by-paddock basis. Look for plant losses (washed away or lodged), areas still underwater or draining and assess areas that may be suitable for grazing.

Winter crop well-being. Monitor crops regularly over the coming weeks to assess plant survival, dry matter yield and the feed budget. If multiple paddocks are involved, a ranking system might be useful. Decide what paddocks need to be grazed earlier and which can left until later in winter.

Flood water contaminants. Mud and silt that cover bulb crops and kale stems may increase the risk of fungal and bacterial plant diseases. Stock is less likely to eat crops covered in silt so expect feed intakes to be lower.

Grazing of flood affected crops. Once crops paddocks are dry enough to access, restoring power and infrastructure is top priority. Cattle must be break fed on all winter feed crops (do not set stock or block graze).

For more information visit dealing with flood damaged feed crops on the Beef + Lamb website.

Podcast: Recovering from an extreme weather event

It’s been an incredibly tough time for farmers affected by Cyclone Gabrielle. For many, the recovery will be long and challenging. We thought it would be helpful to hear from one farmer who’s been through something similar and can talk about what the recovery looked like.

Dean Bailey was sharemilking in Manawatu when, in February 2004, a devastating flooding event left his farm submerged beneath two metres of water. It was six months before they were milking cows again on the farm. Dean will talk about how the recovery unfolded, the importance of good communication, rallying together as a community, and taking it one day at a time.

Michelle Greaves, a Regional Partner in DairyNZ’s Lower North Island Team, also joins us to talk about DairyNZ’s role in the response and recovery, and provide advice on how farmers can prepare for the seasons ahead.