I had planned a different article for this week, but a more pressing topic came up that I felt like I wanted to talk about.
I’ve lived on the Canadian Prairies for my whole life, outside of a couple of years in Europe, and there are several things that can be counted on. First, traffic flow is always slower during construction season (a.k.a. summer) and potholes are like infrastructural wormholes that pop up seemingly at random. Second, winter days are long and dark, and summer days stretch on forever. Third, we’ll always have at least a few really uncomfortably cold or uncomfortably hot days each year, no matter what the average ends up being.
Last, but not least, the day-to-day weather can fluctuate wildly. At the same time, the short to medium-range season climatic conditions (what I’ll call strings of weather schmushed together) can also swing back and forth. I have paid better attention to the weather since I moved to Alberta in the early 2000s, largely because it mattered to the people I worked with/for (horticultural producers) and I needed that sort of awareness to better do my job. In the 20+ years I’ve been here, I’ve seen several stretches of dry conditions, and several significant shifts away from dry conditions. This year, the spring has been weird. We’ve had an extended spring, with temperatures yoyo-ing up and down, but mostly staying cooler, for the most part. Most of Alberta was pretty dry coming out of winter, but then we’ve seen a sudden and extreme reversal of that, with most parts of the province being very, very wet. There have been some significant rainfall events in most areas, which have made things quite uncomfortable and difficult for some people.
There are a few things that I’ve been thinking about, with regards to horticulture crop production, which I wanted to address. The good news is that we’ve been here before, and it will pass, as it always does. There will be (hopefully) short-term pain and adjustments required, but with those adjustments, it is possible to recover and be successful. I want to put forward a few thoughts on the implications of the high moisture levels and share a few suggestions for possible adjustments or actions that might be necessary.
Patience
Before I dive into the specifics, one thing I want to stress is patience. You will want to respond and get out there and fix things. I get it. I really do. Let me be clear. I. HATE. WAITING. It sucks. I especially hate it when I can see things that might be done, and I am forced to wait. But, in this situation, “haste makes waste”, as the saying goes.
Other than dealing with immediate threats to life, safety, and doing obvious things to remove the overarching issue (i.e. excess standing water), just wait. Assess baseline levels of damage and issues. Even though the stress and pressure to deal with flooding may press in on you, if you get a chance, note where the low spots are in fields, or where high water flow pathways are, as you might be able to adjust your operation to take advantage of that knowledge, either in planning future layouts, or in adjusting infrastructural elements to support you. Gather information that might support your management when things aren’t what they are now.
Once things have calmed down, reassess after about 3-7 days. Note any developing or emerging issues, like plant decline, changes in colour, or slowed growth. Then start making some decisions about what might be done now, or what might need to be done in future, due to what happened now. Recovery is a walk, not a sprint, with multiple milestones.
In-season Implications and Actions
Heavy rains, with associated localised or widespread flooding, can cause physical damage to infrastructure, fields, soil, and plants (annual and perennial), whether in terms of damaging plants, causing increased erosion and soil loss, or affecting productivity.
With all incidences of excess water accumulation, it is important to try and move the bulk of the excess water to a more appropriate location, as quickly as possible. You don’t want plants to be submerged or sitting in saturated soils for too long, but you can only do what you can, as quickly and safely as you can.
Avoid working or moving across saturated or wet soils as much as you can. Wet soils are sensitive to compaction and structural damage, and those are hard to undo later on. You might have to wait a bit for things to dry a bit, but eventually, you’ll be able to get back on them.
Flooding or saturated soils can cause young plants to suffocate and die, and seeds can rot. It really depends on how old a plant is. A young plant or newly seed field will likely see greater immediate impact than something that is further along in development, or that is well-established. They will probably have developmental delays, depending on the weather that follows. Young crops may need to be abandoned, if they are beyond salvage. You’ll have to assess things over the course of a couple of weeks, as hard as that might seem. Don’t rush a decision.
Annual plants that were a bit bigger or more substantial when they were impacted may respond in a few different ways. They might just stall for a week or two, but may recover. They may also have an increase in disease, or may decline gradually. They will need careful monitoring and assessment
Perennial crops will need a different kind of care. A woody perennial crop that is mature or that has been established for 3-5 years is probably pretty resilient and can weather a short period of poor conditions. If things stretch out, you might see them stumble a bit. In general, established crops don’t necessarily show the problems right away, so the monitoring might need to be longer. Younger plants might suffer a bit more, especially if they are on the smaller side, with a smaller root system. Younger, smaller plants are more sensitive to stress, and this sort of climatic event definitely counts as stress. Herbaceous perennials will probably react more like younger plants. They will be more prone to root and crown rots, or dieback. Plants that are struggling will signal their unhappiness through changes in colour, premature leaf drop, reduced fruit production, or more obvious decay or dieback.
Fungi and bacteria really like moisture and moist conditions, so as you can expect some more leaf wetness and elevated humidity for a while, expect the associated diseases. If you are seeing increased foliar disease development, or if you anticipate them, you may need to take protective or preventative action using foliar fungicides (based on label recommendations, of course). You don’t necessarily need to go out and immediately spray, but add that consideration to your assessments and planning.
One of the issues that comes with high moisture is loss of nutrients. Soluble nutrients will likely be moved out of the root zone, becoming less available to plants, if not lost entirely. For some crops, such as annual crops that will respond to fertilizer application (and that have a finite lifespan), you could do some light, targeted applications of nutrients. You don’t want to go crazy and hit them hard, as that would stress them out, and probably push them over the edge, but you want to support their recovery and growth. You also don’t want to push them into lush, vegetative growth. For future adjustments, soil test and then fertilize accordingly.
For perennial crops, specifically woody plants, you probably don’t want to get too carried away with fertilizing at this point in time. We’re approaching mid-season, which means that most of the active growing has already occurred, and we don’t want to push plants to grow into the fall, beyond what they would do normally. Just think about bumping future fertilizer applications to bring up what might have been depleted or lost. For example, for an orchard crop, don’t try and replace lost nutrients from spring applications, but rather go with a somewhat higher application next spring.
For crops like day neutral strawberries in plastic mulch, fertilization is still important, but may not change too much. You would have been applying fertilizer regularly under the mulch, so you will continue that plan. You might go a bit higher if you think that there was a fair bit of loss from the soil fertility piggy bank.
For June-bearing strawberries, you will just do normal applications after harvest during renovation, and then replenish things next spring (maybe going a bit higher than you would have). You could soil test to get more and better data to support that decision.
Future Adjustments
Based on the observations and notes that you made during your initial (and subsequent) assessment(s), there may be some things that you can do to future-proof your farm, soils, or plantings the next time this sort of thing happens.
Perpetual low spots might perhaps be converted to some sort of water storage area, if that is a viable option. For low spots in the field, rather than leaving a bunch of half alive woody perennials or having sickly or dead plants most of the time, both of which can elevate your disease risk, maybe remove the plants or switch things to either a water-tolerant plant.
Consider how much bare soil you have at a given time. If erosion and runoff is a concern, perhaps you could put in some short-term cover crops prior to wet periods. These will hold the soil better, and perhaps use some of the excess up. There is a trade off in this strategy, as you might run into issues with competition or you might need to find a way to remove them when things dry out again.
Conclusions
Bad weather is always challenging to deal with, but some of the negatives will eventually be positives (like replenishment of water reserves from heavier rains), hopefully. And challenges can help you identify weak spots you can fix.