Biostimulation - my land needs it

Week 13

They call it biostimulation, which is what I am trying to achieve with my land. There is a subtle difference between biostimulation and fertilisation, but the distinction is nevertheless clear.

Biostimulation is part of what is called bioremediation and is when a site is stimulated to allow the development of micro-organisms by optimising conditions like aeration, addition of nutrients, pH, and temperature control. Biostimulants act only on a plant’s vigour[i] and ignore its nutrient content[ii].

Meanwhile a fertiliser is a substance that contains one or more recognised plant nutrients and is designed for use in promoting plant growth[iii].

With so much Phytophthora less than ten miles away, I wager it will not be long before it comes nearer. So far, all is fine but with surface water running down the hill towards my land, any nasties from above can find their way to me. Consequently, anything I can do to improve a plant’s resistance to infection is for the better. I have decided on a two-pronged attack. First is hydrogen peroxide, second is phosphite [iv]. Both come with excellent reports of success.

So far, I have soaked the soil of my Cupressocyparis leylandii hedge with hydrogen peroxide. For medics, hydrogen peroxide is an excellent way of cleaning a wound. When it encounters certain chemicals in the human body, it bubbles and releases oxygen. Bugs that dislike oxygen, and they are often the most dangerous, are instantly killed. That is the principle of hydrogen peroxide’s role as a biostimulant for plants, as hydrogen peroxide is a good way of taking oxygen to areas that may not see any. Oxygenating my soil is one method of encouraging healthy root growth. Oxygen also discourages pathogens (bugs) that like the deeper reaches of the soil. There is little downside to hydrogen peroxide other than it may not work and can deteriorate rapidly if left exposed to light for too long. I also used a 1 in 3 dilution of 3% hydrogen peroxide, which is extremely dilute. I have 100 Cupressocyparis leylandii trees that make up my hedge, and some are looking unhealthy. I want to make them as strong as I can so they can resist any bugs they encounter.

Ailing Cupressocyparis leylandii in need of biostimulation — My hedge needs a helping hand from biostimulation

Four weeks after the hydrogen peroxide has been applied, I will introduce phosphite. I do not mean phosphate. Phosphite contains one less oxygen atom than phosphate. This simple change leads to many differences in solubility, plant uptake, and effect on plant metabolism and physiology. Phosphite is the salt of phosphorous acid and contains higher concentrations of phosphorus (P), an essential element required by all living organisms, than a traditional phosphate-based fertiliser. Phosphorous acid contains 39% phosphorus, while a phosphate-based fertiliser will contain 32%.

There is also evidence that phosphite is more mobile, is adsorbed by a plant, and attaches to soil minerals less easily than phosphate. This might make it more mobile. Phosphite has been shown to directly inhibit Phytophthora fungi and generally strengthen a plant’s defences against pathogens[v]. It has been used since the 1970s in many different countries, including Australia and New Zealand[vi]. Consequently, if I wish to strengthen the resistance of the plants on my own land to pathogens, including Phytophthora, phosphite seems a sensible choice. For the farming community, it has been shown to improve crop yield and quality, and phosphite products are being increasingly used for their antifungal and nutritional value. My aim is to apply dilute phosphite once the growing season begins. That is now not far away and my phosphite biostimulant, which was not simple to find, is presently under a bench in my kitchen, waiting for its moment. I intend to spray it on the roots of the Cupressocyparis leylandii trees, although some inject the trees using multiple syringes plunged into the trunks, while others spray the needles, so-called foliar spray.

In addition to biostimulation there are also natural fertilisers[vii]. There are plenty - compost, leaf mould, manure, nettle tea and even seaweed[viii]. It is also possible to use grass clippings, kitchen scraps, coffee grounds, eggshells, banana skins, and weeds[ix], should you believe in them. For weeds, this is weed tea made by soaking weeds in water for a fortnight. The dilution is one part weed to three parts water.

The other day I was challenged by a neighbour, as they had noticed I had recently had a bonfire. I had, so he was right. He did not understand why in one breath I was renaturing and avoiding the use of fossil fuels, while in another I was lighting a bonfire. I admit to struggling to give a decent explanation. Burning vegetation is not illegal unless the smoke is causing a statutory nuisance[x] but my neighbour certainly had a point. Bonfires add to pollution and poor air quality[xi] so composting and the collection of garden waste make more sense.

Flaming garden bonfire — Bonfires can be good and bad

For reference, on the UK’s Bonfire Night (5 November) celebrating the capture of Guy Fawkes, who was about to blow up the Houses of Parliament in 1605, and when more than 20 million people now attend firework parties on that one night, the celebrations contaminate the air with 100 times more soot than usual. Researchers in the North-East of England[xii] found that the levels of PM2.5[xiii] were the highest for the whole year between 6 p.m. and midnight on 5 November. They established a median value of 56mg/m3 against a normal background of 10-20mg/m3. The Department for Environment, Food & Rural Affairs’ (DEFRA) requirements for the annual average value is 20mg/m3. Whether the contamination is because of the fireworks or bonfires is difficult to say, although it is probably a bit of both. Another study from New York showed that PM pollutants were up to eight times higher than normal in the hours after a firework display and up to ten times higher than pollution from vehicle traffic in the same area[xiv]. Bonfires, and fireworks, clearly have their problems.

Yet strangely, fires are also good for you[xv]. Research has shown that an open fire can lower blood pressure, even if it may be suffocating you in the process. Wood ash is good for soil, is a useful addition to a compost heap, is a natural source of potassium and trace elements, and has a liming effect. Liming, because lime is alkaline, can remedy an excessively acidic soil[xvi], just like that in Lakeland. Wood ash can also deter snails and slugs, improve vegetable quality, especially tomatoes, eliminate pond algae, save crops from frost damage, and help birds that are taking a dust bath, as wood ash can kill small insects. Dust baths are how birds keep themselves free of fleas and lice, and wood ash can help them achieve this[xvii]. One simply sprinkles the area around a dust-bathing spot with wood ash and the birds will take it from there. There are plenty of other uses for wood ash, too, such as making soap, polishing silver, cleaning jewellery, freshening up a fridge/freezer, deterring moths, being a dry shampoo, a useful toothpaste, and helping clean wounds[xviii].

So although my neighbour was right, burning vegetation is not all bad.

Love is still in the air on my land if you happen to be a wood pigeon. The other morning I saw a male pigeon sitting on a wooden fence, outside my kitchen window. He appears to have adopted the spot for his personal use. He was looking up, down, left, and right for his lady but she was nowhere to be seen. Normally, she is positioned to his left, the two birds side by side on the same perch. The male pigeon decided to find a better viewing spot and headed for the very tip of a neighbour’s tree. Despite his new and higher vantage point, there was still no lady. I sensed he was about to give up when he froze. He had clearly seen something. Then he was off, having spied his lady love on the far side of my land as she pecked the ground industriously beside an old oak tree. The two had once again been reunited and were clearly happy to be together.

Wild garlic (ramson, Allium ursinum) — Wild garlic

My plants are going haywire at the moment and soon I will have no clue which way to turn. Meanwhile, the air is filled with the aroma of wild garlic[xix] and its flowers should be appearing shortly. They are especially good for pollinators and provide a source of nectar early in the spring. To some, wild garlic (ramson) is a weed. Not to me. Cows love wild garlic and dairy farmers have occasionally had the milk of their herds rejected because of the garlic flavour given to it when the animals graze on the plant[xx]. Wild garlic has many medicinal qualities, too, and is a popular homeopathic ingredient. It is often used for treating cardiovascular, respiratory, and digestive problems, as well as for the sterilisation of wounds[xxi]. It is rich with many minerals, which is why it is sometimes called the Magnesium King of plants, thanks to the high levels of magnesium found in its leaves. Magnesium is the central core of the chlorophyll molecule in plant tissue. Consequently, if magnesium is deficient, there is a shortage of chlorophyll and a plant’s growth is stunted[xxii]. Magnesium as an element is understated but hugely important.

Elements are very important for plants, although poorly understood by most gardeners. Important major elements include nitrogen (N), phosphorous (P), potassium (K), calcium, (Ca), magnesium (Mg), and sulphur (S). Important trace elements are boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn). Plants require both major and trace elements to grow healthily[xxiii]. Different elements do different things. For example, calcium strengthens cell walls, phosphorous strengthens roots, while molybdenum helps plants metabolise nitrogen, and zinc is needed for seed production. A plant is a finely balanced lifeform, which is why it is so sensitive to the environment that surrounds it.

***

Acknowledgement

Take it from me - none of this would be possible without the help of RSG Horticulture. Rufus, who runs it, has far more energy than me and is full of ideas and skills.

Biostimulation - my land needs it

Recent Posts

Commentaires