Upcoming Tour for Greenhouse Soil Health

 Extra! Extra! Learn All About It!

Judson Reid and Talia Plaskett will be making the rounds in Nova Scotia July 3-July 5 for farmer-guided discussions on soil health in tunnel spaces! These sessions will be primarily focused around nitrogen management, and the crucial considerations to make when selecting nutrient inputs to make sure that we are supporting a healthy and resilient soil system, as well as maximizing the productivity on our target crops. This conversation is easily catered to production that is organic, conventional and everything in-between.  Feel free to bring your most recent soil test and tissue test results for some feedback and general discussion surrounding what those results are telling you.

Where soil health is a complex, multi-dimensional topic, the tour team will also be talking about the use of cover cropping in protected spaces. Where cover crops are hardly a new practice, the inclusion of this concept into tunnel spaces is not as commonly practiced. Cover crops offer a handful of benefits to protected producers, where erosion may not be the primary concern, but they can help facilitate drainage, fix nitrogen directly into the soil, maintain healthy microbial communities, and help to build organic matter in these highly productive, highly utilized spaces. 

The intention of these sessions is to provide a space for current and prospective tunnel producers to talk about soil health, and how protected production can lend to some unique challenges not typically seen in outdoor settings. So grab a friend, and register today for your closest tailgate meeting, for what should make for a very interesting session! 

More information can be found here

Posted by: Talia Plaskett

Managing Nitrogen in Soil-Based, Protected Crops

The first session of our mini-series set the stage on some of the issues we are seeing regarding soil health and long-term resiliency in protected spaces. For those of you who missed the first session, or are interested in revisiting the teachings before building on it in part 2, you can find the full recording here (Managing Nitrogen in Protected, Soil-Based Systems). A summary of some of the information presented is listed below:

One of the re-occurring themes in protected soil production is an accumulation of nutrients, specifically things like Mg, Ca, and K, as a result of large deposits of compost before a cropping season. While these are necessary nutrients for healthy crop production and good quality fruit, too much of a good thing is not always a good thing. Typical supplementation focuses so heavily on achieving a target N value, that a lot of the micronutrients that come along with that N slip by unnoticed.

Not only are we concerned with high levels of certain micronutrients, but also have to be aware of the soil structure itself. One of the soil health indicators we talk a lot about is percent organic matter. While we like to see higher percentages of organic matter, it can come at a cost to other macro- and micro- nutrient availability to the plant when not executed properly. Paying attention to the cation exchange capacity value, or CEC, on a soil test, is important for those who regularly apply compost. While not mentioned in this webinar with Judson, the higher the CEC value, the tighter bond exists between the soil particles and the nutrients, which make it harder to make adjustments to the nutrient composition/balance without significant intervention.

Combine these two factors with the lack of overhead precipitation in tunnels, we see astronomical values of these micronutrients, which are going to contribute to a rising pH, and a significant hinderance on the plant's ability to take up all of the nutrients in the required quantities/balances that the crop needs. Here is an example of the soil test presented in the webinar highlighting this exact trend. The top image highlights a soil that has been supplemented but not to any excessive extent, and the second image highlights how that soil has evolved with continual additions of a compost:

When it comes to the use of compost in protected settings, conducting a compost analysis before application is strongly encouraged, as is yearly soil testing so that we see what is happening in these soils that do not have the same opportunities for drainage as an exposed soil would. Understanding exactly what you are putting into the soil, and how often, is crucial to avoiding buildup to the levels displayed here. Generally when it comes to supplying nutrients to the crop, scenarios that require supplementation are much easier to navigate compared to a heavily loaded and complex soil as what is projected above. The use of fertilizer blends can also contribute to the accumulation of certain nutrients. Consider this - the go-to fertilizer you use in your system is 20-20-20. While that is a great source of nitrogen, your P and K are already very high, and is going to add to the already-existing nutrient load. In soils such as these, single nutrient sources are going to be a much better choice as we attempt to remediate these soils into something that are resilient and will support crop production well into the future.

Given all of this information, what can we do to better balance out our nutrient supplementation to prevent this from happening? One of the best strategies is going to be split nutrient, application throughout the season. This is a much more targeted approach, where we know:

    1) nutritional targets for the crop in question

    2) recent soil tests outlining nutrient composition

    3) BONUS when we consider the long-term nutrient output of supplements such as                      compost or manure

From here, we are able to formulate a plan that sees regularly scheduled nutrient introduction via fertigation into the tunnels, specifically targeted for when the plant needs those nutrients the most. In doing so, we can reduce the loss of nitrogen to the environment, prevent unnecessary buildup that impede production success, maximize the impact that each $$ of fertilizer has on crop performance, and generally contributes to resilient and long-lasting productivity of those greenhouse soils.

Interested in learning how to set yourself up for split applications during the season? Join Judson Reid and Talia Plaskett at noon (AST) on April 13th for a ‘Lunch and Learn’ session on how to set yourself up for split applications of nitrogen throughout the season! This is a great opportunity to help establish the fertigation plan for 2023 and fine-tune your calculator skills to make sure that you are getting the maximum impact for every drop of fertilizer injected into the soil. For more information, or to register for the session, please check out our learning portal.
 

Posted by: Talia Plaskett

 

 

Protected culture fertility survey!

Growing crops under cover is a separate skillset compared to growing under the open sky.  Fertility management, integrated pest management, environmental management are all very different.  Last year a survey went out to find out more about the protected culture industry in Nova Scotia.  To drill deeper on the learnings from that survey, Rosalie Gillis-Madden, Perennia's Vegetable Specialist, Talia Plaskett, Perennia's Protected Crop Specialist, and Caitlin McCavour, Perennia's new Soil Specialist would like to identify where there are knowledge gaps and pain points in protected crop production, specifically targeting fertility management.  Our goal is to determine where outreach and support might help the industry move forward and how we might serve you better.  This applies to growers who grow in soil or in substrate, who use conventional fertility or organic nutrient sources (composts, manures, organic fertilizer, etc.)  Please take the time to complete this survey to help us determine how we might best support growers, it should take you about 10 minutes to complete.

The mission of Perennia is to help farmers, fishers, and food processors be prosperous and profitable.

Soil Salinity in High Tunnels

Drought stress on tomato leaves. Soil salinity can cause
increased susceptibility to drought stress in plants. 
Photo: Long Island Horticultural Research & Extension Center

Soil salinity can occur in high tunnel production due to some of the characteristics unique to this type of growing system. High tunnels are often used as a season extension tool, meaning that they are in production for a longer period of time and managed more intensively than a typical field. This management can include fertilizer applications, irrigation, and heavy traffic leading to compaction and poor drainage, all of which contribute to salt buildup in the soil.

The other major difference between tunnel and field production with an impact on soil salinity is that the ground under tunnels is protected from the elements, most notably precipitation. In a field situation salts would have more opportunity to be flushed through the system by rainfall, while tunnels aren’t able to take advantage of this type of natural cleansing. 

Soil salinity is a concern for a number of reasons including that plants in saline soils are more susceptible to water stress, which is particularly prevalent in a year with so little excess water around anyway. Saline soils can also lead to salt injury in plants and adverse affects on soil structure. It is important to monitor the salt levels of your soil and take preventative measures to avoid excess buildup. Some strategies for preventing or managing saline soils include utilizing mulch to reduce evaporation from the soil, deep tillage, and exposing the soil to rain by removing the plastic from the tunnel. As you start to think about coming to the end of the production cycle, it might be a good time to employ some of these strategies or plan preventative measures for next season.

For more information, check out Perennia’s factsheet: Soil Salinity in Nova Scotia High Tunnels.

Getting Into the Weeds - November 19th, 2019

This winter, Perennia Horticulture Specialists Rosalie Gillis-Madden and Jennifer Haverstock, are planning a workshop series called "Getting Into the Weeds."  This series will offer an in-depth look into certain aspects of horticulture production.

In collaboration with NSDA Regional Offices, the inaugural session is taking place on Tuesday, November 19th, from 10:00 - 11:30 at locations across the province.  Topics for discussion include: High Tunnels – site selection and preparation, and long term nutrient management, as well as soil-less substrate and different potting technologies. Using remote technology, we are excited to welcome guest speakers from across North America.

• Elizabeth Buck, Extension Vegetable Specialist, Cornell Cooperative Extension Vegetable Program Avoiding a “Tunn”-el of Trouble: Site Selection and Prep
• Judson Reid, Extension Vegetable Specialist, Cornell Cooperative Extension Vegetable Program High tunnel soils: Long term nutrient management for crop health
• Shawn Mallen, Sales and Hydroponics Manager at A.M.A., Horticulture Inc. Substrate and Potting Choices in Tunnel Production

Admission is free, but space is limited, so we ask that you register in advance.  The deadline to register is Nov 18th at noon.  For details on how to register and to find the location nearest you, please click here!

Fall rippping

Penetrometer

Deep tillage can be a great way to break up subsurface soil compaction and has become a common practice.  It is always worth it to determine if compaction is the problem at hand however.  Each Nova Scotia Department of Agriculture office throughout the province has a soil penetrometer that you can use for free to help you identify compaction.  These handy tools are very easy to use, just contact your local NSDA office or Agriculture Resource Coordinator (ARC) to borrow one.  Compaction layers where resistance exceeds 300 PSI (pounds per square inch) are very difficult for plant roots to penetrate and would indicate that compaction is a limiting factor in your field.

Keep in mind that ripping is only a temporary fix for compaction, and there are best management practices that can help you avoid future compaction.  This can be done by

• Avoiding operations when the field is wet
• Minimizing tillage
• Reducing axle loads
• Controlling and concentrating traffic patterns
• Decreasing contact pressure (using wide flotation tires)
• Traveling less over the field

Forces of heavy loads are transferred deep into the soil, especially when the soil is wet.  Image from Building Soil for Better Crops by F. Magdoff and H. Van Es

Soil salinity in Nova Scotia high tunnels

When evaporation from the soil surface and transpiration from plants exceeds water input, salts can start to accumulate at the soil surface. This is because when water from the soil surface evaporates, it wicks salts that are suspended in the soil solution to  the soil surface.  This is particularly a problem in high-tunnels that are in production year-round.  

Accumulating salts are not just sodium (Na⁺) and chloride (Cl^-) ions, but are also essential plant nutrients... calcium (Ca²⁺), magnesium (Mg²⁺), potassium (K⁺), ammonium (NH₄⁺), hydrogen (H⁺), phosphate (HPO₄^2-), sulfate (SO₄^2-), and nitrate (NO₃^-) are all salts. Nitrate accumulation is particularly frequent in high tunnels as high-value crops are well fertilized, and since there is no rainfall to leach the nutrients, they accumulate year after year.

To learn more about soil salinity, how it happens, and what you can do about it, please read Perennia’s factsheet: http://www.perennia.ca/wp-content/uploads/2015/12/Soil-Salinity-NS-Hi-Tunnels.pdf 

Integrated Weed Management in Cucurbits

Plywood separators used to partition a grain drill seed box.

In the Fall of 2016, Perennia, in conjunction with local growers and Agriculture and Agri-Food Canada, undertook a new on-farm trial that demonstrates the use of mulched cover crops to suppress weeds and promote soil health in cucurbit production.  

Partitions expertly secured with a suitable application of duct tape.

In a previous project (Cover crops and zone tillage for reduced risk weed management in field vegetables in Eastern Canada), Agriculture and Agri-Food Canada scientists evaluated weed control methods in cucurbits using cover crops and generated recommendations for using certain techniques to manage weeds in squash production. The technique that we are trying in Nova Scotia integrates the use of fall-seeded rye and banded fall-seeded oats.  

Two rows of oats seeded for eight rows of rye, September 30, 2016.

Oat and rye establishment on October 19, 2016.

The oats will winter-kill, leaving a clear narrow band into which squash can be planted.  The surviving rye is left to grow until late spring at which point it is rolled down to serve as a weed-controlling mulch. This technique has been shown to reduce weed pressure and the amount of herbicides needed, as well as increase marketable squash yield. Squash that is grown on the rolled down rye mulch should be cleaner at harvest, have less disease symptoms, and require less cleaning prior to heading to market.

 

Another added benefit of this system is the organic matter that the cover crops will add to the soil.  This, along with the season-long soil cover provided by the mulch, will contribute to improvements in soil health.  The mulch will protect the soil from erosion and will also preserve soil moisture should we have a repeat of last year's growing conditions!

We intend to hold a field day this summer to demonstrate this technique, stay tuned for more details!!  

Winter-killed oats alternating with fall rye, January 31, 2017.

Building Agriculture Resiliency from the Ground Up! - March 16, 2017 - Yarmouth, NS

Join Perennia specialist Rosalie Madden for this free workshop on building agriculture resilience from the ground up! Topics discussed will be soil health, cover crops, soil management, maximizing fertility, and the importance of organic matter.

Building Agriculture Resiliency from the Ground Up!

Thursday March 16, 2017

Rudders

96 Water Street, Yarmouth, NS

11:00 a.m. - 3:00 p.m.

Don’t be late, because we plan to cover a lot of ground!

Please contact Terry McKay at 902-638-2396 or Terry.McKay@novascotia. ca, or Gail Walsh 1-877-710-5210 (toll-free) to register by March 13, 2017.

Lunch is not included in the workshop but can be purchased on site.

Compost Tea

Perennia hosted a workshop on Tuesday, May 17^th, 2016 at the Wolfville Farmer’s Market.  In attendance were some of Perennia’s summer students.  Jonathan Bent, Tamara Dondi, and Jessica MacDonald have written up a brief overview of the morning’s discussion.

Dale Overton, President of Overton Environmental Enterprises Inc. (OEE) situated in Manitoba, held a talk in Wolfville, NS outlining the science behind Eco-Tea. Eco Tea is actively aerated compost tea, infused with an organic blend of humic and fulvic acids, Atlantic kelp extract, complex carbohydrates and enzymes.  Humic acid can be found in compost and acts as a chelating agent, which increases the availability of nutrients to plants and prevents nutrients from leaching.

Eco-Tea is made from four different types of compost. To reduce the number of pathogens, the compost goes through a thermophilic stage where it is heated enough to work against the growth of pathogens.  When making the compost it is essential that air (oxygen) is allowed to move through the pile because anaerobic conditions (no oxygen) favour the development of disease. The compost aims to support the growth of a complex microbial community which will outnumber pathogenic organisms.

A broad definition of compost tea is that it is a liquid extract of compost. In general, compost tea contains nearly 20,000 different species of microorganisms. Similar to when making compost, the goal when brewing compost tea is to produce conditions in which beneficial microbes can grow.
Other things can be added to the tea as well, such as grain meals (food for the microbes), minerals, and bio-stimulants.  Bio-stimulants are not added to the compost until the end to allow enough time for the beneficial organisms to build a complex community. 

If a fungicide is being applied, Dale recommends waiting to spray the tea for 5 to 7 days to limit the detrimental effect of the fungicide on the beneficial microbes in the compost tea.  Sprays should go on either before 10:00 am or after 6:00 pm using a field-jet nozzle, with no filters. For transplants, he recommends a 50:50 dilution in water.

For more information about compost tea, please check out this eXtension webinar: http://articles.extension.org/pages/73211/making-and-using-compost-teas

*** Note that compost teas can pose a food safety risk. To minimize the food safety risk, only use compost tea produced under conditions that are not a source of biological (e.g., pathogens), chemical (e.g., heavy metals) or physical (glass) contamination, and with a documented composting procedure.  Compost teas are approved for use under the CanadaGAP Food Safety Program but their use does require that a letter of assurance from the supplier be filed with the CanadaGap records. For additional information refer to Section 4 and Appendix C of your CanadaGap Manual. ***

Compost Tea Workshop!

Perennia is proud to host Dale Overton, founder of Eco-Tea in Manitoba, as he shares his thoughts on soil health and the uses/benefits of aerated compost tea.  Dale will focus on using compost tea on grapes, haskaps, berries, vegetables, and orchards, however much of his work in western Canada is on grain crops and pastures.

The session is at the Wolfville Farmers’ Market at 10AM on Tuesday May 17^th.  Please share the invite to all interested. 

For more information, please contact Av Singh.