Thursday, 27 October 2016

Introducing: ANGUS KNOX

Continuing on with our series introducing the contributors to the H2Grow blog - today we'd like to let you get to know Angus Knox, Precision Ag Technician (Field Services) with Agri Optics New Zealand.

While Angus may not have grown up wearing Red Bands and riding shotgun in the farm ute his fresh perspective, smarts and injection of enthusiasm are what our industry needs to continue to thrive and grow into the future.


Six months ago I had perhaps slightly more knowledge of agriculture in general than your average city boy. But I had no idea of what Precision Agriculture was, or how it was being used to change the landscape of Agriculture in New Zealand.

Originally from Dunedin, I moved to Christchurch in 2012 with the intention of studying engineering (after a year of studying law and commerce at Otago University). I eventually found my niche and completed a BSc majoring in Geology and Geography with an endorsement in Environmental Science in 2015.

After a few months working as a GIS Analyst in Wellington, I began to get cabin fever and moved back to Canterbury to find something that would provide a balance between field and office work. Enter Agri Optics. Prior to starting at Agri Optics I had been exposed to some of the technology and sensors we use during my studies but the application to agriculture was entirely new to me.

I admit, I was pretty apprehensive about the steep learning curve I faced to educate myself about how these solutions could actually be used to benefit farmers in the real world. The thing that has struck me the most since coming on board, has been everybody’s willingness to share their knowledge. From the whole team here at Agri Optics to client farmers, I’ve had no shortage of expertise to draw on.

As a newcomer to the industry, it is clear to see that there is no future of agriculture in New Zealand without Precision Ag becoming widely adopted across all kinds of farming operations. The combination of Variable Rate Irrigation (VRI),  soil moisture probes and EM soil surveys have the potential to drastically reduce water wastage and potential nutrient leaching by making sure the right amount of water goes where it’s needed and doesn’t get put where it’s not.

Precision nutrient management and variable rate nutrient application is another tool that has impressed me. Anything that can help maximise yields while simultaneously reducing unnecessary use of additives and chemicals has to be a good thing.

As essentially an agricultural layman, it seems that the sooner we all get on board with adopting this technology, the sooner it will pay for itself. I have thoroughly enjoyed the last five months learning about our country’s largest and most challenging industry. I can only imagine where Precision Ag will take us in the years to come!

Angus Knox - Precision Ag Technician (Field Services), Agri Optics NZ

Wednesday, 5 October 2016

Improving Irrigation Efficiency for Only $50 cont.

Here is the much anticipated second installment from the Improving Irrigation Efficiency field day run by The Waihao Wainono Group and Morven Glenavy Irrigation. Dr Anthony Davoren, renowned Irrigation Consultant with Hydroservices, shares how drainage through the soil profile can be measured. With this key piece of information we can improve our irrigation management, and know when to turn the irrigator on (or off) to ensure all irrigation that is being applied is going to benefit the grass or crops we are growing.

Thank you to Dr Anthony Davoren, Waihao Wainono Group and Morven Glenavy Irrigation.

Thursday, 29 September 2016

Improving Irrigation Efficiency for Only $50

Dr Anthony Davoren is renowned as one of New Zealand’s leading irrigation consultants, establishing Hydroservices in 1983. If you have a question about irrigation management, soil and soil water assessment or surface and groundwater water resources then Tony will have the answer. What sets Tony apart is his practical, hands-on approach and the way he communicates information in a way that farmers can easily understand and relate to… I mean how many other speakers will you find presenting from a hole in the ground!

The Waihao Wainono Group and Morven Glenavy Irrigation recently hosted a field day focusing on improving irrigation efficiency. H2Grow is lucky enough to be able to share with you some short videos from this day. In the first in this series Tony explains how the root depth of the pasture or crop you are growing should be considered when deciding on the most appropriate soil moisture measuring equipment for your property.

Considering Root Depth when Measuring your Soil Moisture Levels

Keep a look out for the next video in this series where Tony explains how to measure drainage so that you can better manage your irrigation and prevent irrigation water, and nutrients, draining through the soil... and his top tips of how to greatly improve your systems irrigation efficiency for as little as $50!

Thank you to Dr Anthony Davoren, Waihao Wainono Group and Morven Glenavy Irrigation.

Wednesday, 21 September 2016

Soil Properties Critical when Applying Effluent

Dairy effluent is a great source of nutrients for growing pasture. But if not managed properly effluent can also be a significant source of contaminants which harm our waterways. Understanding how soil properties affect nutrient loss is a key to maximising the benefits of effluent on farm and minimising its impacts on waterways.

Soil texture and structure determine the amount of water that can enter and be retained within a particular soil, and the rate of transmission of excess water through that soil. So effluent irrigation systems should be matched to soil properties to minimise runoff and leaching. The rate at which effluent can be applied to the land for maximum production benefit is determined by the soil’s properties including structure, porosity and infiltration rate.

The nature of the effluent and cattle treading on soils can affect the infiltration rate. Treading damage, which occurs most when the soils are wet, significantly reduces the infiltration rate. For some soils this can result in accumulation of effluent below slopes and in hollows. It can then enter surface waterways.

Movement of water through soil pores is generally described as hydraulic conductivity. When hydraulic conductivity of the soil is low, irrigation of effluent will result in ponding and run-off once the total water capacity of the soil is exceeded or if application rate exceeds infiltration rate.

Low rates of hydraulic conductivity are found in soils that are poorly drained, and ponding and runoff often occur with high rainfall. Many of these soils are artificially drained to reduce the incidence of ponding and water-logging, and this carries a risk that effluent can bypass the soil and be directed rapidly into waterways

Leaching occurs as excess water moves through the soil. So soils with lower water holding capacity are more susceptible to leaching, while soils with high water holding capacity (deep silt loams) can store significant quantities of effluent.

The soils that have low available water holding capacities, are the shallow to moderately deep soils, as well as sandy or stony soils. Effluent irrigation on these soils is likely to result in leaching unless it is applied at low rates and in small doses. The irrigation system on these soils must be capable of low rates of application to gain the maximum nutrient benefit.

Drainage and the level of biological activity of the soil at the application site are important. Aim to apply effluent at a rate that keeps it in the root zone so that the nutrients can be utilised by pasture.

Permeable soils with a deep water table and no drainage limits are best for putting effluent on. However, on stony soils the risk of effluent draining directly to ground water would be an issue to consider. In such situations, application depths and rates should be adjusted to account for this risk.

Another issue is "bypass flow". When effluent application rates are higher than infiltration rates, water can enter continuous macro-pores that are open at the soil surface, and then move very rapidly via so-called "bypass flow" through a relatively dry soil matrix. This means little opportunity for the water to be retained within the root zone and high leaching of nitrate is likely to occur. Bypass flow of farm dairy effluent can occur in soils that undergo shrinkage and fissuring during drying, especially when these soils have been previously compacted by treading.

Efficient effluent storage provides flexibility when it comes to application and helps maximise nutrient uptake (image: DairyNZ)
A key to avoiding over application can be having adequate effluent storage so that irrigation can be deferred if conditions aren’t right. DairyNZ has released a new smart-phone app to help farmers apply effluent more efficiently. The Dairy Effluent Spreading Calculator app provides dairy farmers and effluent spreading contractors with guidance around nutrient application rates based on the depth and type of effluent they apply.

H2Grow would like to thank Bala Tikkisetty for this blog post. Bala is a sustainable agriculture advisor at the Waikato Regional Council.

If  you are keen for further information about best practice for applying effluent you will find a raft of useful information on the Waikato Regional Council website.

Or alternatively contact Bala directly, email or call (freephone) 0800 800 401.

Wednesday, 14 September 2016

Introducing: NICOLE MESMAN

Today's contributor profile introduces Nicole Mesman. Nicole's energy is inspiring. Her intellect and fortitude to challenge the conventional are just two of many reasons that we hope she does not spread her wings too far astray in the future, as agriculture is sure to benefit from retaining talent of her calibre.


I am a born and bred Cantabrian, from Christchurch, however I am continuing to spread my wings and experience the rural Mid-Canterbury. My childhood was filled with tramping, skiing and hunting holidays and from a young teenager I would say that I wanted to work with and in the environment and outdoors. Aside from rabbit shooting and hunting I never really did a lot on farms growing up. Lincoln drew me in at the end of high school, not for agriculture though but for biogeoscience (which I would realise was a fancy name for soil science). 

Once I got to Lincoln though my perspective and direction started to change. It’s hard not to get roped into agriculture when at Lincoln. Especially when your friends are doing projects like putting nappies on cows, monitoring cows grazing throughout the night and separating different swards of grass from endless piles of clippings. They were always looking for helpers, the fun we had!

It was a third year soils paper that introduced me to precision ag. We were out digging holes at Craige Mackenzie’s to create a soil map and also determine if the properties of the soils we found agreed with his EM map (the relationship was a good one I will add). After this I spent my summer making cakes out of soil, sand and water to review soil moisture sensors and then continued with my honours which analysed the effect of grazing and irrigation on soil physical properties. 

After Lincoln I worked for Lindsay as a summer student looking at their irrigation systems and EM mapping on various farms before going on to work for Ballance Agri-Nutrients. I am constantly learning more about agriculture and farming and I love it. Whenever I can find out about someone’s operation, learn from them and likewise share what I have learnt with them is a very good day.

Nicole fills up most of her weekends with outdoor pursuits; tramping, skiing, hunting and learning the ropes of day-to-day farm jobs

Nicole Mesman