Category Archives: Water

Help Wanted

We’re not quite sure what to call the job: science manager, extensionist, project manager, consultant? We know it offers diverse activities and needs excellent communication skills and practical knowledge of horticulture and technology.

We are looking for someone to help identify and lead research projects and extension activities across a variety of issues and regions. For the right person, this is a role with considerable potential to grow.

This will be a Page Bloomer Associates appointment. They provide our science, management and support services while having addditional private consultancy activities.  Working closely together, we know they share our passion for sustainable land and water management.

Since the dawn of the new millennium we’ve been providing progressive, pragmatic and independent services through projects and consultancy. A key feature of our work is close collaboration with end users, researchers and developers. We talk about “linking thinking from the farm out”.

The role includes engaging with growers, industry and researchers to identify opportunities to review practices and integrate new technologies to create sustainable cropping systems. The appointee will develop and manage projects and support services that support economically and environmentally sustainable primary production.

If you know someone with passion for smarter farming who wants a key role in a small dedicated organisation, Page Bloomer Associates would like to chat with them!

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Fertiliser Calibration Assessments

One of the four key areas within the Future Proofing Vegetable Production project aims to improve the accuracy of fertiliser applied. This work is part of the MPI Sustainable Farming Fund “Future Proofing Vegetable Production” project, co-funded by Horizons Regional Council, Potatoes NZ, Gisborne District Council, Ballance AgriNutrients and LandWISE.

Growers were invited to participate in having their equipment assessed. Equipment was tested with growers in both Horowhenua and Gisborne. Ten fertiliser applicators have been assessed through working with eight growers. Multiple settings or products were tested for some equipment.

In-Field Fertiliser Applicator Calibration Test

Performance assessment of fertiliser application equipment provides information on actual rates applied and the evenness of application. Ensuring that fertiliser is applied evenly minimises the risk of leaching if over application occurs, or the risk of yield penalties if under application occurs where nutrient availability is limiting plant growth. Growers were confident their equipment was spreading evenly, however the assessment results show there is room for improvement.

Fertiliser application equipment measured can be split into two main categories:

  1. Broadcast fertiliser spreaders (spinning disc, oscillating spout)
  2. Direct placement machines (banders, side dressers and planters)
Figure 1: Examples of fertiliser application methods commonly used in vegetable growing systems: broadcast (left), potato planter (centre), and modified into 2 row bander (right)

Methodologies

Different methodologies are appropriate for broadcast versus direct placement equipment.

  • Broadcast fertiliser spreaders were tested according to the FertSpread Protocol: see www.fertspread.nz
  • Power take off driven placement equipment (banders or adapted oscillating spouts) were assessed by placing buckets under the outlets and collecting fertiliser for a measured time (~30 – 60 Seconds). By determining travel speed the application rate can be calculated.
  • Ground driven equipment (most side dressers and planters) were assessed by collecting fertiliser from outlets over a set distance in-field or from 20-wheel rotations in static testing.

Tests were repeated twice, however where results between tests appeared quite different, the test was repeated up to six times. For some machines multiple settings or fertiliser products were tested.

Direct placement machines were assessed using a calibration calculator that has been developed over the period of testing this equipment as there is currently no industry accepted assessment calculator available.

The draft fertiliser calibration calculator for the assessment of direct application machines is included in the supporting documentation. This spreadsheet calculates and reports a wide range of statistics to assess performance.

Three key performance indicators are suggested:

  1. Target application rate vs. actual rate applied
  2. Variation between outlets/spouts
  3. Variation between test runs

Results

The application variability of the direct placement equipment tested varied quite markedly; from 0.4% CV to 26.4% CV.  A summary of the test results for direct application equipment is provided in Table 1.

Table 1

All but one of the machines tested are within the SpreadMark accepted performance for broadcast spreaders applying nitrogen-based fertilisers.

The actual rates of fertiliser applied varied from the target rates. In one case the actual average rate applied was 48% of the target rate, the greatest over application was 152% of the target rate.  

Fewer broadcast spreaders were assessed as direct placement machines are more commonly used in intensive vegetable production systems. Table 2 provides a summary of the two broadcast spreaders assessed.

Table 2

Figure 2 gives a snapshot of part of the report produced through the FertSpread website. In this example, if the grower reduced their bout width from 22.5m to 19m, the machine performance would be within the acceptable level for nitrogen and non-nitrogen fertilisers.

Discussion

Assessments have been completed on a range of fertiliser application equipment in both Levin and Gisborne. Most of the equipment tested has been direct application (banders, planters and side dressers), rather than broadcast spreaders. Fertiliser applications for vegetable production are predominantly applied as banded strips along the bed or scarified during planting or as a side dressing. There is currently no accepted protocol for the assessment of this type of equipment.

Direct fertiliser application (banders, side dressers)

To enable the assessments to be completed within the project, a draft protocol and fertiliser calibration calculator for direct applicators has been developed and is being refined. This is currently in an Excel spreadsheet which has been developed as we have been testing equipment. The number of tests required and the statistical analysis to report the suggested three key indicators is still to be discussed and agreed upon. This concept and draft calculator will be taken to the annual Fertiliser and Lime Research Centre conference in February 2019 for advice from leading experts. The acceptable level of equipment performance and report outputs provided to growers will be discussed.

It is currently accepted for broadcast fertiliser spreaders that the coefficient of variation, CV, should not exceed 15% for nitrogen fertilisers and 25% for non-nitrogen fertilisers. The method of calibrating fertiliser rates applied ‘through the spout’ to achieve target rates are accepted, however a different statistical analysis is required for an assessment to be completed and best practice or acceptable levels of variation need to be defined. It is suggested that a CV of 15% for nitrogen or even non-nitrogen fertilisers is well below the capability of these direct placement applicators. Machinery in good working order should achieve a CV of much lower than this, but an acceptable CV is not currently defined.

This has opened discussion around how the acceptable CV is determined and if this is applicable in vegetable production systems. Our understanding is that accepted variance is based largely on pasture value and response curves, we query what values are appropriate for high value vegetable crops. Excess fertiliser increases leaching risk, insufficient fertiliser can make a crop unsaleable through quality loss. This is another area that it is felt important and worth further investigation.

The results of the tests carried out on direct placement equipment highlighted several key areas to address:

  • The target rate is not often achieved, the results showed machines are both over and underapplying, which have implications for leaching risk and potential marketable yield penalties or decrease nutrient use efficiency.
  • In some cases, the outlets are not applying fertiliser at equal rates. The cause of this is different for each machine. However, the growers were keen to investigate why one outlet was applying a lower rate. In one case the grower was able to fix the equipment and significantly reduce the variation between outlets.
  • One machine resulted in different rates being applied in each test. This is a greater concern for older equipment that is worn and manually operated hoppers.  
  • The amount of the fertiliser in the hopper appeared to affect the rate of fertiliser applied. This suggests that as the hopper empties that rate applied to the beds decreases. This also appeared to change significantly with the bulk density of the fertiliser product. More testing is required to investigate this further. There may be a minimum amount of fertiliser (product/bulk density dependent) required to be in the hopper to achieve an even application.

The interest and engagement of growers through testing their equipment has built awareness. Once a protocol is developed, the spreadsheet will then be developed into a tool for growers. Prior to next season, workshops demonstrating how to calibrate equipment, use the tool and interpret the report will be run in Gisborne and Levin, with the possibility of visiting additional regions. Conversations with growers during visits have shown there is good support for an event.

Broadcast fertiliser spreaders

Broadcast spreaders are less commonly used, and only two-disc spreaders were assessed. The results showed that at the current bout width used neither machine was achieving an acceptable CV for nitrogen fertilisers. One of the two was on the limit of acceptable for non-nitrogen fertiliser products. This suggests that the growers need to change either settings and/or bout width to achieve an acceptable CV.

Reports are generated for all equipment we tested and distributed to growers. Some growers have requested that we re-test their equipment after they have made adjustments or prior to next season.

Vegetable Irrigator Assessments

Introduction

Irrigation assessments are important for ensuring the correct amount of water is applied to avoid yield lose due to moisture stress. However, excessive irrigation is a cause of nitrate leaching. A key aspect of our Future Proofing Vegetable Production project addresses keeping nutrient in the root zone. Through assessing irrigation uniformity and depth applied, machine and irrigation management can be improved.

This work is part of the MPI Sustainable Farming Fund “Future Proofing Vegetable Production” project, co-funded by Horizons Regional Council, Potatoes NZ, Gisborne District Council, Ballance AgriNutrients and LandWISE.

Methodologies

The irrigator assessments followed the ‘bucket test’ protocols as described in the Traveling Irrigator Performance Quick Test. In brief, buckets were place at 1m intervals across the path of the irrigator (see Figure 3). The speed of the irrigator was measured as it travelled over the buckets. Once the irrigator had passed over the buckets, the volume of water collected in each bucket was then measured. The data was entered into IRRIG8Lite software and reports generated.

Bucket test layout under a traveling boom irrigator assessed as prt of Future Proofing Vegetable Production project.

Results

All three irrigators tested were traveling booms. The performance assessment was carried out twice on one of the traveling booms. An example of the distribution graph is provided in Figure 4. Of the four tests completed, the distribution uniformity assessment for two were ‘adequate’ and two were ‘poor’. The distribution uniformity for the four tests were 0.72 and 0.75 for the ‘adequate’ performing machines and 0.6 and 0.45 for the ‘poor’ performing machines.

Example distribution graph from a traveling boom irrigator assessed as part of the project

Discussion

The results so far show that there is room for improvement in the performance of the irrigators tested so far. Higher than average rainfall has meant irrigation events have not been required as often so far this season. However, some growers briefly ran their irrigators to allow tests to be completed. We will continue to assess irrigators as we are able to access them over the coming months.

Dan Bloomer

Dan Bloomer is the Manager of LandWISE having been instrumental in our formation and evolution since 1999. He and partner Phillipa established the Centre for Land and Water in Hastings and host the LandWISE MicroFarm.

The 2018 conference sees the wrapping up of three years of Onions NZ research in partnership with Plant & Food, much of the activity being undertaken at the MicroFarm. LandWISE has captured numerous paddock scale images of the onions crops using satellites, UAVs, sensors and smartphones. This has given insights into which tools have strengths for what purposes at what crop growth stages.

Using algorithms proposed by Plant & Food, LandWISE developed the on-line tool SmartFarm which allows smartphone captured crop development data to identify different management action zones and give guidance to the degree of variability.

Dan is particularly interested in soil and water issues, how we can continue to benefit from farming while maintaining or enhancing profitability and environmental health.

Dan has developed many resources for irrigators to check their systems. He spent many years on the Board of Irrigation New Zealand, developed Codes of Practice for Performance Assessment and has run many training programmes.

In recent years his attention has been drawn to precision drainage technologies, and he uses OptiSurface to understand and quantify ponding and erosion risk in paddocks and to design solutions for surface drainage. 

Dan actively scouts people,  technologies and problems, identifying opportunities to bring them together to effect change on farm. As such, he has initiated LandWISE’s research and extension programmes including some new initiatives to be launched at LandWISE 2018.

Dan represents LandWISE on the Precision Agriculture Association of New Zealand Executive Committee and is a frequent presenter at conferences and seminars.

When not working for LandWISE, Dan is an independent consultant at Page Bloomer Associates.

 

Dan Drost

Professor Daniel Drost is a vegetable researcher and extension specialist from Utah State University.

Dan Drost grew up on a small diversified animal and crop farm in Michigan (USA). He graduated from Michigan State University with a BS and MS degree in Horticulture. In 1983, he moved to New Zealand to teach Horticulture at Massey University. He returned to the US in 1987 to study at Cornell University where he was awarded a PhD in 1991 in Vegetable Crops and Plant Physiology. 

Dan’s research and outreach efforts focus on small intensive production systems, sustainable and organic agriculture, and how land-use management impacts field and farm scale productivity. In his 25 years at Utah State, he has authored more than 150 extension and scientific articles on vegetable production and management practices, shared his understanding of farming systems with producers, scientists and industry leaders around the world, and focused his attention on sustainable vegetable cropping systems that are farm appropriate, socially acceptable, and economically viable.

One of our invited international keynote speakers, Dan was bought to New Zealand in conjunction with Onions NZ and Plant & Food Research to discuss sustainable production systems. His presentation to LandWISE 2018 was titled “Sustainable Crop Production: Field and Farmscape Management for Sustainability”.

Dan says,

Insects, diseases, nutrient management, and weeds pose yearly threats to vegetable productivity and sustainability. This presentation will address how to best manage the farmscape (whole farm) to protect and mitigate these risks in field and farm settings. Using examples from a variety of vegetable crops (annuals, perennials, intensively managed) grown in a range of settings, I will outline how modern farms adapt to and deal with yearly uncertainty.

Dan and colleagues have completed a lot of work on high tunnels for crop production. See a video here.

You can hear and discuss sustainable production with Dan at LandWISE 2018 in Havelock North on 23-24 May.

 

 

Dan’s attendance at LandWISE 2018 was supported by AGMARDT

Aldrin Rivas

Aldrin Rivas is a Catchment Hydrologist at Lincoln Agritech. He has over ten years of professional experience in the fields of water and environmental science, engineering, and management; and has worked for private and government entities.

Aldrin has experience in denitrification in natural and engineered systems and will tell delegates at LandWISE 2018 about a Lincoln Agritech, ESR and Aqualinc project investigating woodchip bioreactors to remove nitrate from drainage water. Some say this is closing the stable door after the horse has bolted. Others say it’s catching the horse and putting it somewhere safe!

With a mixed background in engineering and science, Aldrin is involved in a variety of Lincoln Agritech projects including the Ground Water Mitigations project and the Transfer Pathways Programme.

His interests include:
• Groundwater
• Denitrification in the vadose and saturated zones
• Vulnerability assessment of freshwater resources
• Integrated catchment development and management
• Water supply systems and management
• Environmental and hydrological modelling

You can hear and discuss this with Aldrin at LandWISE 2018 in Havelock North on 23-24 May.

Soil to sprinkler, automating irrigation management

Anthony (Tony) Davoren is a Director of Aqualinc with responsibility for the HydroServices business unit that provides irrigation and environmental management services; soil moisture, and water level and water meter monitoring. 

Tony’s expertise in and knowledge of soils and hydraulic properties, irrigation systems and design, and crop water demand has been applied and enhanced over the last 35 years working in these fields.

We asked Tony to talk about automating irrigation – from the soil to the sprinkler and round again. He’s doing just that at LandWISE 2017: Are we ready for automation?

Tony says several questions need to be asked and honest answers or solutions given:

  • Are we and you ready?
  • What do we need?
  • Is automating irrigation management wise or the right solution?

Are we or you ready?

When considering automating irrigation management, both the provider and the user must be an “innovators”; i.e. they must be in the top 2.5% of the industry.  It may be that some “early adopters”, the next 13.5% of the industry, might be ready for the technology and its application to automate irrigation management.

What do we need?

Because it will be the innovators who adopt and field prove any technologies, these technologies must be robust and proven with a sound scientific backing.  Innovators will identify the financial benefits of the automation, which needs:

  • Well-designed irrigation systems
  • High uniformity irrigation systems
  • Well maintained irrigation systems
  • Precise soil moisture and/or crop monitoring systems
  • Interface “model” to irrigation controller

Are these all in place?

Is automation wise or the right solution?

Tony established HydroServices providing on-farm irrigation management services based on in situ soil moisture measurements in Canterbury, Pukekohe, Waikato, Gisborne, Hawkes Bay, Manawatu, Wairarapa and Central Otago. During this he provided specialist soil moisture monitoring for Foundation for Arable Research, LandWISE, Crown Research Institutes, Regional Councils, Clandeboye Dairy Factory and others.

Tony completed his PhD in Engineering Science at Washington State University, Pullman, USA.

Benchmarking Onion Variability 2016-17

Now in year two of our OnionsNZ SFF project, we have trials at the MicroFarm and monitoring sites at three commercial farms in Hawke’s Bay and three more in Pukekohe.

2015-16

A summary of Year 1 is on our website. A key aspect was testing a range of sensors and camera systems for assessing crop size and variability. Because onions are like needles poking from the ground, all sensors struggled especially when plants were small. This is when we want to know about the developing crop, as it is the time we make decisions and apply management.

By November our sensing was more satisfactory. At this stage we captured satellite, UAV, smartphone and GreenSeeker data and created a series of maps. 

We used the satellite image  to create canopy maps and identify zones. We sampled within the zones at harvest, and used the raltioship between November canopy and February yield to create yield maps and profit maps.

Yield assessments show considerable variation, limits imposed by population, growth of individual plants, or both

We also developed relationships between photographs of ground cover, laboratory measurements of fresh weight and leaf area and the final crop yield.

In reviewing the season’s worth of MicroFarm plot measurements and noticed there were areas where yield reached its potential, areas where yield was limited by population (establishment), some where yield was limited by canopy growth (development) and some by both population and development.

This observation helped us form a concept of Management Action Zones, based on population and canopy development assessments.

Management Action Zones – If population is low work for better establishment next season. If plants are small see if there is something that can be done this season

2016-17

Our aims for Year 2 are on the website. We set out to confirm the relationships we found in Year 1.

This required developing population expectations and determining estimates of canopy development as the season progressed, against which field measurement could be compared.

We had to select our “zones” before the crop got established as we did a lot of base line testing of the soil. So our zones were chosen based on paddock history and a fair bit of guess work. Really, we need to be able to identify zones within an establishing or developing crop, then determine what is going on so we can try to fix it as quickly as possible.

In previous seasons we experimented with smartphone cameras and image processing to assess canopy size and relate that to final yields. We are very pleased that photographs of sampling plots processed using the “Canopeo” app compare very well with Leaf Area Index again this season.

Through the season we tracked crop development in the plots and using plant counts and canopy cover assessments to try and separate the effects of population (establishment) and soil or other management factors.

We  built a web calculator to do the maths, aiming for a tool any grower or agronomist can use to aid decision making. The web calculator was used to test our theories about yield prediction and management zones.

ASL Software updated the “CoverMap” smartphone application and we obtained consistent results from it. The app calculates canopy ground cover and logs data against GPS position in real time. Because we have confidence that ground cover from image processing is closely related to Leaf Area Index we are working to turn our maps into predictions of final yields.

Maps of canopy cover created from the CoverMap smartphone application show significant variability across the paddock. Canopy increase is seen over time in two maps created a week apart

The current season’s MicroFarm crop is certainly variable. Some is deliberate: we sat the irrigator over some areas after planting to simulate heavy rain events, and we have a poorly irrigated strip. We know some relates to different soil and cover crop histories.

But some differences are unexpected and so far reasons unexplained.

Wide variation within the area new to onions does not follow artificial rain or topographic drainage patterns. This photo is of the area shown far right in the cover maps above.

Together with Plant and Food Research we have been taking additional soil samples to try and uncover the causes of patchiness.

We’ve determined one factor is our artificial rain storm, some crop loss is probably runoff from that and some is historic compaction.  We’ve even identified where a shift in our GPS AB line has left 300mm strips of low production where plants are on last year’s wheel tracks!

But there is a long way to go before this tricky crop gives up its secrets.

This project is in collaboration with Plant and Food Research and is funded by OnionsNZ and the MPI Sustainable Farming Fund.

We also appreciate the support of growers, seed companies and our MicroFarm sponsors Ballance AgriNutrients, BASF Crop Protection and the Centre for Land and Water.


 

Drainage and Erosion Planning

The Arawhata Catchment Integrated Storm Water Management project is drawing to a close, the majority of work is done but farm follow-ups continue. The aim of the project was to reduce crop loss from ponding and minimise erosion of soil to Lake Horowhenua. 

We completed OptiSurface drainage analyses for 26 Levin properties covering 450ha of intensive vegetable cropping. OptiSurface calculates flood patterns and erosion risk and creates cut & fill maps for GPS levelling. An example is shown in our earlier post “Mapping for Drainage”.

Drainage and Erosion Management Plans were developed for each block. The plans identify drainage problem areas and erosion risks and recommend management strategies to respond.

Individual farms have done significant work to prevent erosion and reduce crop damage. Farmer actions to reduce sediment runoff and ponding include realigning bed direction, levelling, grassed headlands and drains and swales and sediment traps.

Stages in headland redevelopment

Original design used narrow headlands subject to pugging in wet weather with high risk of slumping soil into vegetation-free drains

Headland lowered to ensure adequate drainage from furrows. Vegetation being encouraged to protect drain from sediment inflows

Land-shaping created a much wider headland for a greater vegetation buffer between cultivated land and drains

Completed headland with its well-established vegetated buffer filtering sediment from drainage water

Now farms are required to have consent in this catchment, the Drainage and Erosion Management Plans are a useful component of the overall Farm Nutrient Management Plans required.

Onion Crop Development

The crop at the MicroFarm is showing increasing variability.  The cause of some is understood, essentially excessive water pre-germination.  But in some poor performing areas the causes have yet to be determined.

The effect of our artificially applied rain event pre-emergence is clearly evident in late November.

The lasting effect of a heavy (artificial) rain event pre-emergence (right panel) shows low population and poor growth compared to areas without heavy rain (left panel)
The lasting effect of a heavy (artificial) rain event pre-emergence (right panel) shows low population and poor growth compared to areas without heavy rain (left panel)

However, we also see other areas that have poor crop development that are outside the area irrigated to create the artificial rain event.

Wide variation within the area new to onions does not follow artificial rain or topographic drainage patterns.
Wide variation within the area new to onions does not follow artificial rain or topographic drainage patterns.

Sharp differences in crop growth are evident in the new onion ground. Some parts that were heavily irrigated to simulate heavy rain show reasonable development. Areas that were not irrigated also show good development, but in some patches total crop loss.

Investigations of soil physical properties in these different areas are underway.