All posts by LandWISE Admin

Agronomy, Irrigation, MicroFarm, Soil, Water

Irrigation: Do peas benefit? Do farmers?

February 9, 2014 LandWISE Admin Leave a comment

At the MicroFarm, we just harvested our second lot of peas. We tracked their water use since planting to build on learning from our first crop (see the December 2013 issue of “Grower”, reproduced here>).

Once again, HydroServices’ Melanie Smith established three neutron probe access tubes in each of two crops. These were read weekly and analysed to tell us paddock soil moisture content down to 80 cm.

Both pea crops were planted on the same day with the same drill. Paddock 1 is dryland and Paddock 2 has drip irrigation installed 200mm deep.

Figures Paddock 1 and Paddock 2 show soil water content for each crop.

We see the crops tracked about the same at the start. In mid-December, Paddock 2 received two 9mm irrigations from our buried dripline.

Melanie estimated that the irrigation was 80% efficient, so only added about 7.5mm to the budget each time. Paddock 1 is not irrigated, and continued to drop towards stress point.

Paddock 1 reached Refill Point on Boxing Day two days before rain fortunately lifted it back out of stress. Paddock 1 again hit stress point on about 6^th January. With no more significant rain, it stayed stressed. With irrigation applied as required, Paddock 2 remained stress-free throughout.

Overall, the two crops used similar amounts of water through until early January. After that the 0 – 30 cm soil reached stress point, and water use from the unirrigated Paddock 1 began to taper off. The steeper lines in the bottom part of the graphs show it began to get more water from deeper in the profile.

By harvest, Paddock 1 was using only about half as much water as the drip irrigated Paddock 2 and drawing it from much deeper in the profile.

The difference in what a crop did use and what it could have used if the water was available is described by Potential Soil Moisture Deficit.

We estimate that by harvest, Paddock 1 suffered about 100mm of PSMD. I am not sure what the pea response is to stress. I am told it is a “very elastic” crop. For many crops this would indicate a growth reduction of about 20%.

So did irrigation pay?

We sampled each crop pre-harvest and found Paddock 2 had about 30% more fresh weight canopy than Paddock 1. The difference was easily seen, being significantly taller and generally more “lush”. The peas in Paddock 1 reached harvest maturity at least three or four days before the irrigated peas in Paddock 2.

We get paid for peas not canopy. We also sampled yields and quality as measured by TR (pea tenderness) and found differences.

There was a lower tonnage in Paddock 2, but the quality (and pay-out value) was much higher.

At harvest the Paddock 1 tonnages were reasonable at 6.85 t/ha paid yield. But TR was 137; a bit high and the lowest pay-out grade.

We delayed harvesting Paddock 2 for two days. The paid yield was similar at 6.55 t/ha but the TR was 102, a 30% higher pay-out grade.

Paddock 1 returned $2,059/ha and Paddock 2 returned $2,625/ha gross, so a benefit of $566/ha from irrigation.

We applied 81 mm so our return from irrigation was $6.99/ha/mm applied. Many people quote an irrigation cost of about $2/ha/mm so let’s claim a benefit of $5/ha/mm applied.

Looking at it another way. If we had a 20ha paddock, irrigation would have made us about $8,000 better off. If we also sold pea hay, the benefit would be even greater.

Answer: Irrigation pays!

Thanks to: Centre for Land and Water, ThinkWater, Netafim, HydroServices, McCain Foods, Ballance AgriNutrients, BASF Crop Protection, FruitFed Supplies, Agronica NZ, Nicolle Contracting, Drumpeel Farms, Greville Ground Spraying, True Earth Organics, Tasman Harvesting, Plant & Food Research, Peracto NZ

MicroFarm

MicroFarm Open Day

December 12, 2013 LandWISE Admin Leave a comment

The first MicroFarm Open Day was held on Thursday 5th December. The event received significant media coverage, including a two page spread in Rural News.

We are grateful for the excellent presentations made by our speakers, and for the quality of discussion that followed. Attendees travelled from South Canterbury, Manawatu and Gisborne to join local growers, contractors and their support industry colleagues.

You can see Sarah Pethybridge’s presentation on Plant Growth Regulators on the MicroFarm website.

Programme

Short “theory” presentations in the Green Shed

Why a MicroFarm; what we expect to learn – Dan Bloomer, LandWISE (and others)
Soil nutrient picture; what we found, what we’ve done – Mark Redshaw, Ballance AgriNutrients
Inoculants for legumes; our first trial and hopes – Weston Hazelwood, BASF Crop Protection
Plant Growth Regulators; compressing pea flowering – Sarah Pethybridge, Plant & Food Research
What the MicroFarm still needs – Dan Bloomer, LandWISE

Outside practical demos and discussions

Buried drip for vegetables – Anthony Waites, ThinkWater
Soil moisture monitoring; water use messages – Melanie Smith, HydroServices
Soil compaction; penetrometers, VSA and a plan – James Powrie, Hawke’s Bay Regional Council
Herbicide selection – Vaughan Redshaw, Fruitfed Supplies
Plant Growth Regulator treatments; a first scoping study – Tim Robinson, Peracto

Download a printable pdf Open Day Programme here

The MicroFarm is a genuine community activity, as shown by the sponsors and supporters listed below. We are unsure of all the outcomes, but we know there will be much learning along the way.

Agronomy, Irrigation, MicroFarm, Soil, Water

Irrigation demand: alike as two peas?

December 9, 2013 LandWISE Admin Leave a comment

The MicroFarm has two crops of peas almost ready for harvest. We have been tracking their water use since planting. We want to learn as much as we can about our soil and irrigation.

HydroServices’ Melanie Smith is our specialist support for soil moisture monitoring. She established three neutron probe access tubes in each of our first two crops. These are read weekly and analysed to give a Paddock soil moisture content down to 80 cm.

Both pea crops were planted on the same day with the same drill. One had some nitrogen starter-fertiliser because our discussion group wondered if it would make a difference, but that is another story. For now, we are talking irrigation management.

We are seeing significantly different patterns from our two crops. Significant in that considering the usual 30 cm root depth, one crop needed irrigating a week before the other. Significant in that one would get through to harvest at the start of December without needing to be irrigated. The other would need irrigation. What’s going on?

Let’s look at two graphs: Paddock 3a and Paddock 4a which are the two crops in question.

The top parts of these graphs show soil water content in the top 30 cm. We see that in each case the Full Point (116 mm) and Refill Point (82 mm) is the same. So we have 34 mm of readily available water our plants can access from the first 30 cm depth of soil.

The graphs show Paddock 4 reached Refill Point a whole week before Paddock 3. In fact, Paddock 4 hit Refill Point almost three weeks before Paddock 3, and but for a chance 12 mm rainfall would have gone into critical deficit in early November.

Let’s compare these graphs a bit more closely.

We see they tracked about the same to start with, then at the beginning of November Paddock 4 suddenly used significantly more water from the 0 ‑ 30 cm root zone than did Paddock 3. This is around the time the canopies reached full ground cover.

Our observations of the crops suggest Paddock 3 had more canopy so we thought it would be using more water than Paddock 4. Looking at the lower parts of Graphs 3a and 4a, we see that Paddock 3 used more water from deeper in the profile at 40 – 50 cm.

We did some Visual Soil Assessments and found more evidence of soil compaction in Paddock 4. Being the main gate access into the area it has seen more tractors, trucks and paddock forklift activity. So we expected to see compaction limiting root development.

Now lets look at the water content in the whole soil profile, right down to 80 cm, presumably well past any pea roots (Figures Paddock 3b and Paddock 4b).

The first thing to notice is much higher water storage, because 80 cm of soil has more readily available water than 30 cm of soil. So now Full Point is 314 mm and Refill Point is 232 mm giving 82 mm of readily available water for our crop to grow before we would need to irrigate.

When we compare these two graphs we get a different picture. Now we see the two crops using similar amounts of water through until 14 November. After that, Paddock 3 (the fuller canopy and better soil condition) used slightly more water than Paddock 4, and actually hit Refill Point a day or so earlier.

Overall, it seems our Paddock 3 crop is getting more water from deeper in the profile, accessing water from 50 ‑ 80 cm deep.

For a lower price crop like peas, reducing costs makes a big difference. Can avoiding compaction save the need to irrigate?

How deep are your crops’ roots?

Many thanks to HydroServices for the soil moisture monitoring at the MicroFarm

Agronomy, Controlled Traffic Systems, MicroFarm, Soil, Tillage

In search of best practice

November 1, 2013 LandWISE Admin Leave a comment

The LandWISE MicroFarm in Hastings is an attempt to discover and apply best practice for cropping. Our aim to maximise production while minimising the environmental footprint.

We believe the soil has amazing abilities to grow and restore itself if we avoid compaction and over-working. So we want to minimise the area we drive on and do whatever operations are needed at the best time with least structural impact.

We have seen time and time again that controlled traffic systems provide good “roads” to drive on and good gardens to grow in. But are they realistic in a typical process crop regime?

We can start by avoiding unnecessary traffic. Trucks can be particularly damaging

At the MicroFarm, this season started with six paddocks of vining peas for McCain Foods; early peas in early September, late peas in late October. They were followed by four paddocks of green beans and two of sweetcorn.

In September the soil was at field capacity, and it was raining. The forecast promised showers or rain every day for a week. Thankfully, we got the pasture sprayed out while it was a bit drier, though even then the tractor and spray trailer left visible tracks.

Our paddocks are part of the overall “grand plan”. The planners at the factory worked out their through-flow needs on a daily basis. The field staff worked out how many hectares to plant each day. We need to plant when the schedule dictates. The alternative may be less attractive.

Think about risks. The basic idea behind risk assessment is to combine assessments of hazards with assessments of probability that the event will occur. A serious hazard with a high probability of occurring is assigned the highest priority for risk management.

At planting time the average grower is facing many risks, and constantly ranking them in their mind, even if informally. “Not getting a crop planted” might rate higher than “avoiding a bit of compaction”. So we are going to plant. And there is a high risk of soil compaction.

What can we do to reduce the impact of the hazard, to reduce the likelihood of it happening, or to reduce its severity if it does?

Conventional tractor set up can have a lot of ground:tyre contact and a lot more from drills and other equipment

The key is planning ahead, and taking sensible steps well in advance of the problem arising. We can plan for this when we have a less stressful period, install drainage in a quieter time, and plan a reduced wheeling strategy well before the season even starts.

We can plan drainage to keep excess water off the paddocks and remove excess water in a timely way. That should reduce the likelihood and severity of damage.

We can ensure our soil is in the best condition possible. That will increase infiltration and drainage rates removing water faster and make it structurally stronger to carry traffic. We can put only essential wheels on only the minimum area of paddock. That will reduce the damage area.

We could remediate. We could aerate after planting to remove compaction, get air back into the rootzone and give the roots a chance to penetrate. That won’t reduce the compaction, but at some financial cost it will help remove it. And the soil is too wet anyway.

Last season we visited minimum tillage sites after operations in sub-optimal conditions. We were very pleasantly impressed at how little damage these paddocks suffered.

We’ll still have to tidy up if we make a mess, but we’ll have to do it less often and more easily.

This posting first appeared as an article in “The Grower” magazine

Agronomy, MicroFarm, Projects, Soil

LandWISE MicroFarm Activated

October 11, 2013 LandWISE Admin Leave a comment

With the generous support of many companies and individuals, the LandWISE MicroFarm is established and active. The first of two vining pea plantings has germinated and the rest is sprayed out in preparation for another planting in late-October.

We are holding the first MicroFarm Open Day on Thursday 5th December 2014. More in our newsletters.

We have set up a separate website for the MicroFarm at www.microfarm.landwise.org.nz There you’ll find an increasing amount of information as we post details of activities, progress and outcomes.

It is the first season of many over the next five years and like others we’ve struggled at times with weather and wet soil. Weather records from the on-site weather station are available on the MicroFarm website at http://microfarm.landwise.org.nz/farm/weather/ thanks to HortPlus.

With marking the paddocks out, setting AB lines and checking we can fit in the number of rows we want, spraying and planting we’ve driven on our soil a lot. A lot more than we would like. We want to minimise traffic impacts but with many different vehicles involved we’ve not done so well.

James Powrie and Dan Bloomer completed initial Visual Soil Assessments in each of the six Blocks. Worm numbers were lower than expected, contributing to moderate rather than good scores in two Blocks. More details here>

Block 4, with the main access gateway, shows significantly greater evidence of compaction. We’ll monitor that as we go: dealing with residual compaction is a key question as we try to maximise crop production.

Melanie from HydroServices has installed neutron probe soil moisture monitoring sites into Blocks 3 & 4. We are interested to see what the impact of compaction in Block 4 might mean for soil water holding. We’ll post results as testing progresses.

Paul Johnstone, Bruce Searle and Sarah Pethybridge from Plant & Food, together with Fenton Hazelwood and Grant Hagerty from BASF have designed a first look at plant growth regulators to control flowering in vining peas. We hope some control can raise harvestable yield. Vaughan Redshaw and Scott Marillier from Fruitfed Supplies in Hastings have sourced the materials we need. Because of significant rain, Tim Robinson from Peracto and Ben Watson from McCain Foods tested leaf status before first treatments are applied.

The remaining Blocks have been sprayed off for late peas. We are anticipating a slightly later planting date. In part we want to modify Patrick Nicolle’s drill to apply inocculants at planting and the parts have yet to arrive. . .

Agronomy, Uncategorized

Resilience

February 13, 2013 LandWISE Admin Leave a comment

Resilience is the ability tobounce back from adverse events. When we are generally happy and healthy we can handle most things nature (or life) throws at us. If we are run down, tired and sick, the slightest thing seems to knock us for six.

Farms are very much the same. They handle adverse events better if the soil is healthy, water available, and infrastructure (and capital) in place. And the reverse is true too. Beaten up soils, lack of water, inadequate or poorly maintained infrastructure and high gearing leaves a farm (and its people) at higher risk when bad things happen.

Resilient Cropping Workshops

Building resilience into cropping farms is the aim of our “Resilient Cropping” project. A joint venture between LandWISE, Foundation for Arable Research, Horticulture NZ and Tahuri Whenua the Maori Vegetable Growers Collective, it is funded by the Ministry for Primary Industries.

A main focus of Resilient Cropping is preparing for adversity such as extreme weather events, fuel cost spikes and restricted access to irrigation water. In-field workshops across the country involve local growers sharing experience and ideas and proposing local solutions.

Among the topics covered are soil quality, irrigation efficiency, nutrient management and energy use. A common question is, “what can we do to best prepare for uncertainty?” An alternative is, “How should we farm knowing that adverse events will certainly happen sometime, and possibly more often?”

Is resilience an issue?

The first stage of the Resilient Cropping project was a survey of growers about the impact of adverse weather on farming businesses. 101 replies were collected. Some respondents were offended by the survey and made the point that managing the impacts of the weather on their farming businesses was what farming was all about.

Diana Mathers reported that, of 101 respondents, only 9 had not lost money from a climate related event in the last 5 years. Only 7 believed that climate variability would not affect their business in the future.

Severe weather had impacted two thirds of cropping businesses two to four times in the last five years. Weather events affected profitability of more than three quarters of growers. Almost half said the losses were severe.

Farmers in Canterbury, Hawkes Bay and Gisborne said both drought and rain are important regional issues. Those without irrigation ar condisering a change their farming system. Some are looking to reduce cultivation intensity to reduce soil moisture losses, while others are changing the sort of crops that they grow.

What do undesirable events cost?

Estimating crop yields, their value, and the cost of lower production is made easier by a LandWISE tool called YieldEst. It is an output from our Sustainable Farming Fund project, “Assessing the cost of crop loss at paddock scale”.

Growers and agronomists recognise areas of suppression, damage and loss within crops. YieldEst systematically assesses the financial cost of losses and the contribution of adverse events. Quantifying the cost of lost production and the relative impact of different problems also helps target where efforts will have most benefit.

YieldEst starts by assessing the yield in the main part of a paddock, and comparing that to expected or “potential” yield. Because it can consider multiple grades with different prices, a shift to lower grades will be also identified, along with the monetary implications.

Variable paddocks are assessed by monitoring yield in “Loss Zones”. Growers are asked to name the “cause” of lower production in each zone and again, multiple grades can be entered.

The project was funded by the MPI Sustainable Farming Fund, LandWISE members and Horticulture New Zealand levy payers through the Vegetables Research and Innovation Board. The YieldEst tool was developed with generous in-kind support from Chris Folkers at ASL Agricultural Software.

Dan Bloomer, LandWISE

Agronomy, Controlled Traffic Systems, Precision Agriculture

Site Specific Management – 2012 Conference Summary

February 13, 2013 LandWISE Admin Leave a comment

“Collaboration is the key,” Alastair Bisley told 160 people at the LandWISE Site Specific Management; growing within limits conference in Havelock North.

The “limits” that gave the LandWISE Conference its focus, are to ensure fresh water quality and quantity are maintained or enhanced. Reporting on the Land and Water Forum, Alastair said collaborative processes identify win-wins and produce more enduring outcomes – with community buy-in.

Collaborative processes place first responsibility on local users, stakeholders and iwi to determine detailed management objectives for catchments. They allow discussion of the benefits and costs of different approaches and determine time frames in which to achieve them.

Precision viticulture was a new event at the Conference. AGMARDT Keynote, Rob Bramley from CSIRO set the scene. A frequent trans-Tasman collaborator, Rob later explained how farmers can (in collaboration with specialists) use smart tools to conduct excellent research on their own farms and fine-tune management for each site.

LandWISE SFF project work with Villa Maria and Mission Estate showed clear benefits of detailed site assessment of soils and canopy vigour. Site specific management raised juice quality and significantly increased winery returns.

Attendees heard how GPS and GIS were used to track and understand the spread of PSA in kiwifruit and leaf roll virus in grapes. The recent fruit fly discovery reminds us just how at risk we are, and how smart we need to be to manage such events.

Tim Neale has collaborated with growers to track harvest vehicles, and to fit yield monitors on to potato, onion and carrot harvesters. The aim: to know where yield and revenue is coming from, and accordingly apply the right inputs at the right rate.

Hydro-Services collaborated with Environment Canterbury and NASA to monitor water use in greater detail using satellite imagery and soil moisture monitoring. FAR collaborated with Plant & Food and growers to develop AquaTRAC for irrigation scheduling with economic considerations.

The final session was a field trip to Hugh Ritchie’s property to view Site Specific Management in action. The site has a variable rate pivot irrigator, a weather station and soil moisture monitoring, and is under-going extensive drainage development.

Without the efficiency gains achievable with variable rate irrigation Hugh could not cover the whole area with the limited water available. The towable pivot has three positions. The VRI avoids overlapping and speeds the machine to reduce return intervals.

One of two drain-laying machines demonstrated uses RTK-GPS, allowing it to optimise fall at multiple grades to maintain depth between pre-set depths. The tile pipe is pulled into the ground, complete with a gravel envelope, as a single operation.

A land levelling scraper, also controlled with RTK-GPS was demonstrated. Topsoil is stockpiled, the sub-soil cut and filled to grade, and topsoil replaced. A key innovation of both GPS drainage systems is that all calculations are completed on-the-go in the tractor cab.

The first LandWISE conference in 2003 attracted 70 people to discuss soil quality, cultivation practice and efficient irrigation. The tenth brought 160 people from across New Zealand and from Australia and the UK to talk about doing the right thing, whatever it is, in the right place at the right time.

Future cropping will see each site having specific management applied to ensure profitable production with environmental stewardship. A focus on soil quality and water care, together with the use of smart tools will be critical. LandWISE looks forward to supporting that progression.

Agronomy, Soil, Uncategorized

Assessing Yield Variability

February 13, 2013 LandWISE Admin Leave a comment

This article first appeared in The GROWER magazine.

Variability in crops shows that some parts are not performing as well as others. So what?

Variability is a major problem in the vegetable sectors. It is responsible for unknown but very significant financial losses all the way through the value chain. Variability comes in varied forms, from a variety of causes, with variable results and various appropriate management responses.

It may be a timing thing, a size thing, a quality thing or a quantity thing. It could be caused by weather events, soil differences, seed differences, pest or disease effects or some management factor. It may mean missed yield, lower yield, lower price or higher costs.

Process pea crops are a classic example of relatively minor timing variability causing major losses. If plants flower earlier or later, timing the harvest is problematic and both quantity and quality will be affected. Some plants will not be ready when the harvesters come through. Others will be over mature and downgrade overall quality. Processing, in particular, needs uniform product and reliable supply.

Have you got crop variability? Assume you do, even if it is not at first noticeable. The key is to know if it is significant, what effect is has on your profitability, and whether it is worth fixing. Sometimes the benefits of dealing with it are not worth the cost. But often a cheap fix can avoid an expensive problem.

LandWISE partnered with Horticulture New Zealand to help growers estimate the value of crop yield variation. A spreadsheet calculates the cost of yield variation, based on measurements made in the field.

The three pieces of information needed are the product value, the area affected, and the yields achieved. A small booklet gives guidelines on determining areas and yields and the spreadsheet does the rest. You can download the calculator and guidelines from http://www.landwise.org.nz/projects/crop-variability/.

Why a calculator? While many farmers do observe variability in crops, few spend time quantifying the value (cost). The calculator and guidelines set out a straightforward process that doesn’t take much time, and does the calculations for you. It presents the results as tonnes and dollars in a table, and as graphs showing relative performance.

The Calculator encourages growers to identify the cause of loss in identified parts of the paddock. It then summarises the relative impact each has on yield.

One of the key pieces of information is quantifying the “Yield Gap”. The Yield Gap refers to the difference between the Potential Yield and the Main Area yield. It reflects an overall penalty and often costs more than the obvious losses. But because it affects the whole paddock it is not easily noticed.

If the season has been normal, and there are no obvious seed, equipment or management problems, look to soil condition or irrigation management as possible causes.

The Yield Variability Calculator estimates the value of crop loss. Thinking about how often these losses are suffered, how to avoid them in future what the cost of remediation may be, will help growers determine what, if any, action to take.

Dan Bloomer, LandWISE

Precision Agriculture, Soil, Tillage

My Soil is Different

February 13, 2013 LandWISE Admin Leave a comment

This article first appeared in The Grower in March 2012

“It won’t work here; our soils are different.” A common response to a new idea.

Two excellent events in Australia had me thinking, “Wow, their soils really are different!” But as to “It won’t work here,” that’s like saying you can’t cook carrot cake in a casserole dish. You can, if you are a bit adaptable. It is principles and processes we need to focus on.

The SPAA Precision Agriculture Expo was held in Port Lincoln in South Australia. The PrecisionAgriculture.com.au conference was in Maroochydore, Queensland. Both were characterised by excellent speakers, strong farmer representation, varied topics, and good industry support.

Speakers discussed nutrient tests we don’t use, plants we seldom grow, pests, diseases and weeds that remain thankfully foreign, and yields most New Zealand farmers would consider disastrous. They talked of soil electromagnetic sensors, pH sensors, biomass sensors, protein sensors, animal trackers and robots. Of precision farming in Canada, Scotland, England, New Zealand, Queensland, New South Wales, Victoria and South Australia.

At both events, the farm was the focus, the technologies merely tools to help manage better. Much, much better.

Some of their Australian soils must be among the most inhospitable places on earth for a plant: three inches of sand on a deep, highly saline and toxic sub-soil; heavy compacting clay on compacted clay with horrid pH levels. In our young landscape the soils are quite different indeed.

But for all that, the messages were strikingly familiar. In essence; know and look after your soil, monitor your crop, and apply inputs where they give the best returns.

After decades working their land, farmers know their soils very well. From cultivating and observing patterns in crops they learn about areas that perform differently. Most can draw a pretty good “mud map” if asked. They know where their soil changes physically and use nutrient and pH tests to monitor fertility.

There are new tools to help understand variation, such as the EM38 soil electromagnetic sensor and Thorium sensors. Light sensors can pick up organic matter variation. With GPS the variability can be mapped accurately and we can make more detailed maps. But be cautious.

Sensors almost always measure something other than the thing you are interested in. They have been shown to “correlate well” – under certain conditions. But remember, your soils ARE different! The numbers a sensor provides are not necessarily true for you; the sensor needs to be calibrated to your site. And that goes for practically every sensor I know.

Sensors can be very good at identifying differences, and directing our attention to areas worthy of further investigation. EM maps certainly provide evidence of electrical difference. The numbers the sensor generates vary enormously depending on soil moisture, clay content, density and salinity. So the same number in two different parts of a field may be due to different combinations of any of these.

The maps tell us where to investigate further. The most important tool of all is a spade. Decide on a small number of management zones, sample them separately to understand the causes of variability.

Dan Bloomer, LandWISE

Drainage, Soil, Tillage, Water

Coping with Extreme Weather Events

February 13, 2013 LandWISE Admin Leave a comment

This article first appeared in The GROWER in February 2012

Growers suffered significant losses during recent heavy rain. We cannot handle the most extreme events without suffering losses. But we can do a lot to reduce impact and avoid damage from minor events.

Building resilience will help with adverse events and returning to normal operation once the event is over. Focus on soil and its ability to absorb, drain and hold together when large rain events occur. Soil must be protected and enhanced and suitable drainage designed and installed. Managing traffic, reducing cultivation and managing water movement are critical.

Water needs to be absorbed into the soil and allowed to drain through it. The amount absorbed depends on the soil’s infiltration rate and the time that water stays in one place. Well-structured soil has good porosity, which maximises infiltration and drainage.

Compaction means soil damage: soil is deformed forming solid layers with little or no porosity. Water cannot get through these layers fast enough, so builds up in the soil above, drowning plants and weakening soil aggregates.

The common solution is cultivation; ripping soil to break up wheel track compaction. This is expensive and self-defeating as cultivation further weakens the soil and makes future traffic even more damaging.

About 80% of all compaction happens with the first pass, so keep traffic off paddocks in the first place or keep it to defined “roads” as much as possible. Then there is little if any need to cultivate.

While we need to drive on paddocks to plant and harvest crops, we can control essential traffic and keep the rest away. LandWISE farmers have shown clearly that controlled traffic and permanent bed systems reduce equipment needs, save fuel and labour, reduce time to next crop and enhance soil quality. Win, win, win, win and win.

Water runs downhill. Even seemingly flat paddocks have high and low points. If the infiltration rate is too low, water runs to low spots where it ponds. Slowing water down with surface residues or by ground shaping keeps it in place long enough to soak in and avoid ponding and erosion. Lots of micro-dams hold rain where it falls, and slow any rivulets that may form.

HortNZ’s SFF Holding it Together project showed the benefits of furrow dyking that slows water in wheel tracks, giving it time to soak in rather than pond in low areas. This reduces soil erosion and protects crops against flooding and drowning. To sport nuts: “stop, trap, control the ball”!

Once controlled, pass it in a timely fashion. Consider artificial drainage if the soil cannot drain fast enough. Mole and tile drains provide extra flow capacity through the soil. Open drains provide a controlled way to take water to a safe disposal point.

A number of innovative drainage options are available. Old ideas linked to new GPS and computer mapping have revolutionised tile laying, surface drainage planning and ground contouring. Each has its place.

Precision tile-laying maps paddocks with GPS. It automatically surveys elevations while the tractor drives along the next tile line, calculates the depths and grades required, and precisely controls tile laying depth. It is fast and cheap compared to old practices.

Surface drainage planning controls water movement across the surface. It aims to remove excess water safely before it waterlogs the soil, by ensuring a path without ponding areas. New technology allows very detailed surveys and planning, and results in minimal soil movement for optimum drainage.

In extreme cases, surface levelling changes the whole paddock contour, directing water to safe boundaries. Because it typically moves a large volume of soil it is expensive and can have a significant soil impact. But it has other advantages such as avoiding high, dry spots and ensuring even depth to water table.

We often think of water management as irrigation, especially in summer. But we must have our soils and drainage in good order at all times of the year.

Dan Bloomer – LandWISE

So did irrigation pay?

Answer: Irrigation pays!

Resilient Cropping Workshops

Is resilience an issue?

What do undesirable events cost?

Promoting sustainable production