When Less is More
In life and also in the garden there are many times when "less" is actually "more." I've noticed this most recently with watercolor painting. The trick is to stop before I feel like I'm actually done and avoid adding too much. Once I start fiddling and cramming more strokes into the painting, the paper gets overworked, the strokes get crowded, and by then I can't remove the color or hit an "undo" button. The practice of watercolor recently has also helped me practice doing less in my own life and I couldn't help but think about how this is also true in the garden.
The most striking example I can think of where "less is more" is the System of Rice Intensification (SRI) which was developed a priest in Madagascar called Fr. Henri de Laulanie. He basically found he could dramatically increase yields of rice by planting LESS, using LESS fertilizer, managing LESS, using LESS water and was able to get dramatically MORE yield. How is that possible?! For many farmers and people around him, this seemed far-fetched, unrealistic and too good to be true. But the techniques are based on solid science and the more we understand of soil and plant biology, the more it makes sense why this works. Since he pioneered this work in the 1980's, Cornell University has taken a deeper look into it and exactly how the yield increases, Launanie was seeing were possible. Norman Uphoff, a researcher at Cornell, dove into this topic even further and eventually became an expert on crop intensification by studying how these techniques are being implemented with all manner of crops around the world. He also helped clarify the science of how less could actually equal more: more yield, more resilience, more nutrient density, and more pest and disease-resistant crops. For more info, check out Cornell University's "SRI International Network and Resource Center" which you can check out if you want to dive into the latest developments. Although the focus was originally on rice, other crops benefit from the principles that basically boil down to minimizing stress for young seedlings so they can grow the biggest and most robust root systems possible!
The Basic Principles of Crop Intensification for Rice (a summary):
Plant rice seedlings into the ground at less than 15 days old (instead of 30-60 days as is commonly practiced). This allow plants to grow more "root tillers" or overall bigger underground root structure.
Plant a single seedling per spot, instead of 3-5 in clumps (also commonly practice with rice).
Space out seedlings from each other, sometimes cutting traditional densities in half (or sometimes even more!)
Avoid stressors (stressors could include: too much or too little water, extreme temperatures, crowding, shading, soil compaction) especially at early stages of plant development. An example is waiting for the soil to be warm enough to plant crops that like heat. Also, don't flood the rice fields (common practice as a method of weed control) as flooding stresses the plants with less oxygen to their roots.
Yields following these practices were often 2 to 3 times the amount of traditional methods!
Check out this short 12 minute video on SRI technique if you want to see more of this practice in action: https://www.youtube.com/watch?v=ZGeanXxdE1g&t=30s
Research studying "root tillers" or root scaffolding found that plants produce less underground root mass when stressed. Less roots means less nutrients and water from the soil to support the leaves aboveground. Less leaves aboveground in turn means less sugars or "root exudates" going out through the roots to feed beneficial microbes. Less microbes means less complex compounds back to nourish the plants. In the case of plants, stress equals less roots and less yield. Stress for a plant can happen in several ways.
One example of "less is more" in your own backyard is in thinning. When growing radishes, lettuces, greens, carrots and others crops, it's easy to add more seed! The seeds are small and whether you intend to or not, it's easy for the extra seed to fall into the soil. Completely counter to our intuition, more plants does NOT equal a great yield. In fact if you are able to thin out the plants so each has more space, you can dramatically increase your yield.
Stress can happen by overcrowding. When too many seedlings are grown together the plants' roots "sense" each other or use up locally accessible nutrients and grow less root mass. As we have discussed less root mass ultimately equals smaller plants.
The thinned carrot on the left weighs more than all three of the unthinned carrots grown in the same amount of space on the right.
If you ever want to experiment with the effectiveness of thinning concept, try it with fast growing radishes. Radishes and other root crops are especially prone to being "stunted" or "not bulking up" when sown too tightly together. These radishes in the drawing below were sown at the same time, but the ones on the right were thinned just after the seedlings sprouted.
Another way to minimize stress is by ensuring there is enough air in the soil. Compacted soils means the roots have to work harder to get through the soil. Less air or waterlogged soils means conditions for anaerobic bacteria (aka: non-helpful, often pathogenic microbes) to multiply. These are stresses that all result in the root structure, or underground support scaffold, of the plant being less. The more the roots are stressed early on in their development, the more they set up a root structure that is stunted and ultimately will produce a smaller, less productive plant. This makes sense, but the ramifications are somewhat revolutionary. Imagine the way we grow seedlings? We often grow them in small trays, pots, or plugs that limit their growth quite dramatically in the early time of their life. If the stress is great enough, we can actually substantially decrease our production. Shallower roots means plants more susceptible to drought and flooding and disease.
Another way to minimize stress for plants to ensure enough water. Especially for young plants just beginning to develop, having enough water is crucial for the plants to grow robust, new roots, as well as to keep the soil biology alive and thriving. Remember plant roots and soil biology work together to feed each other and to grow big, beautiful, robust and resilient!
Yet another way to minimize stress on the plant is to ensure it has a functioning "immune system" or healthy soil microbiology. Just like we humans have a healthy gut microbiology, a healthy soil acts as a healthy gut for a plant. Adding or ensuring the young seed or seedling has a robust "gut microbiome" and is in contact with healthy soil microbes can make a dramatic impact on the health and resilience of young seedlings. I often add a broad spectrum soil inoculant with both beneficial bacteria and fungi to seedlings. They typically come in powder form and just a little is needed (ex: 1 oz can inoculate 100 lbs of seed!) to sprinkle over the seeds at planting or directly into seed packets. Some inoculants I've used and liked are: BioCoat Gold from Advancing Eco Agriculture (OH) and MycoApply Endo/Ecto or MycoSeed Treat (cheapest option for small scale growers) from Fedco Organic Growers Supply (ME).
As it turns out the biggest barrier to adoption of SRI, crop intensification or even just thinning in the farm or garden is us. It really is SO hard to plant less... some of the farmers who first pioneered this method were ridiculed by neighbors and colleagues in trying to plant less to get more. How could it work? How could less equal more? Imagine how hard it is to trust that less is more when your family depends on the food you grow?
Isn't that so true for us also? Both in our lives and in our gardens? To work less or take breaks during the day is actually quite difficult even though we have the neuroscience that tells us we can actually be more productive with more rest interspersed throughout our day? Perhaps as we minimize stress in our gardens and in our plants' roots, we also can learn from them and use it as a practice to focus on "less is more" in our own lives, too.
You can eat your thinnings! Here I am thinning some arugula. Thinning your seeds just after they sprout has the biggest effect on growth, but with greens, you can thin or harvest out plants multiple times as they grow and get a continued harvest where you thin out bigger and bigger plants. I like to pinch off young seedlings with my fingers though some people prefer harvesting shears or scissors.