I have noticed that fruit trees and deciduous trees develop a good soil around themselves probably from the falling leaves dragging up nutrients from below the ground and dumping it on the surface.
Gum trees lose leaves but they don’t seem to develop or encourage soil.
Whats going on?
Skunkworks said:
I have noticed that fruit trees and deciduous trees develop a good soil around themselves probably from the falling leaves dragging up nutrients from below the ground and dumping it on the surface.Gum trees lose leaves but they don’t seem to develop or encourage soil.
Whats going on?
I read somewhere that eucalypt leaves do not collect around the base of the tree, and instead blow away due to the lack of moisture. This in turn has meant the trees don’t waste nutrients in their discarded leaves.
Carmen_Sandiego said:
Skunkworks said:
I have noticed that fruit trees and deciduous trees develop a good soil around themselves probably from the falling leaves dragging up nutrients from below the ground and dumping it on the surface.Gum trees lose leaves but they don’t seem to develop or encourage soil.
Whats going on?
I read somewhere that eucalypt leaves do not collect around the base of the tree, and instead blow away due to the lack of moisture. This in turn has meant the trees don’t waste nutrients in their discarded leaves.
They probably dont waste them, deciduous trees leaf fall is old leafs and the plant recovers essential ummm stuff from them before they fall. But I can see a gum leaf being so dry it blows away.
Still not convinced though, they seem to do fuck all for the soil. Deciduous trees have light blow away leaves as well, it may be that falling all at once is what makes the difference.
All I know is that soil around young deciducous trees is way better than soil around much older gum trees.
Better is probably a bad word. It appears better cos it is dark, organic and has worms in it. This may not be better from the perspective of the plant but it appears better to me.
It is more that the opposite is true.
It may appear that the soil is depleted under Eucalypts because the leaves contain chemicals that kill weeds.
Skunkworks said:
Better is probably a bad word. It appears better cos it is dark, organic and has worms in it. This may not be better from the perspective of the plant but it appears better to me.
The worms are there because of the shade and the water. You do water fruit trees but in general practice you don’t water Eucalypts. They find their own water and this robs other plants around them of water.
roughbarked said:
Skunkworks said:
Better is probably a bad word. It appears better cos it is dark, organic and has worms in it. This may not be better from the perspective of the plant but it appears better to me.
The worms are there because of the shade and the water. You do water fruit trees but in general practice you don’t water Eucalypts. They find their own water and this robs other plants around them of water.
roughbarked said:
It is more that the opposite is true.It may appear that the soil is depleted under Eucalypts because the leaves contain chemicals that kill weeds.
I get that, but at the base it still appears to be clay, all off those leaves contribute nothing the soil I hydrophobic and not a worm to be seen. Tree looks happy though. My thought is that over the years it would have dropped tons of leaves but the ground around still looks impoverished.
WA Peppermint seems to have leaf fall that kills all around it. Don’t know if it helps the Peppermint itself, but not much else can grow.
Stealth said:
WA Peppermint seems to have leaf fall that kills all around it. Don’t know if it helps the Peppermint itself, but not much else can grow.
Carmen_Sandiego said:
Skunkworks said:
I have noticed that fruit trees and deciduous trees develop a good soil around themselves probably from the falling leaves dragging up nutrients from below the ground and dumping it on the surface.Gum trees lose leaves but they don’t seem to develop or encourage soil.
Whats going on?
I read somewhere that eucalypt leaves do not collect around the base of the tree, and instead blow away due to the lack of moisture. This in turn has meant the trees don’t waste nutrients in their discarded leaves.
Trees that are in open forest situations may have more leaves blow away but denser forests and plantations are affected little by wind blowing leaves away and in fact can increase the organic matter in the soil significantly.
Stealth said:
WA Peppermint seems to have leaf fall that kills all around it. Don’t know if it helps the Peppermint itself, but not much else can grow.
I get that leaf fall can kill other plants, what I don’t get is that leaf fall doesn’t really make a rich soil. A big tree here that has been here forever has a plain clay base and the leaves cannot blow that far away. Soil around three year olkd fruit trees planted in the same soil are developing rich lush grasses around them.
Skunkworks said:
Stealth said:
WA Peppermint seems to have leaf fall that kills all around it. Don’t know if it helps the Peppermint itself, but not much else can grow.
I get that leaf fall can kill other plants, what I don’t get is that leaf fall doesn’t really make a rich soil. A big tree here that has been here forever has a plain clay base and the leaves cannot blow that far away. Soil around three year olkd fruit trees planted in the same soil are developing rich lush grasses around them.
If you walk across open areas where there are scattered Eucalypts, It can be noted that each tree is an island of greener vegetation. Around the drip line of the canopy will grow many plants weeds and natives.
http://www.jsd-africa.com/Jsda/Vol14No1-Spring2012A/PDF/Impacts%20of%20Pine%20and%20Eucalyptus%20Forest%20Plantations.Saico%20Sibusiso%20Singwane.pdf
The studies indicate that the toxic substances to the soil through the leaf litter remain for a long time in low rainfall areas and will have inhibitory effect on seed germination of crop plants. The inhibitory effect will be minimised once the toxins are leached out by the rains. It may be said that no crop can be grown successfully near Eucalyptus trees in low rainfall areas, where there is every chance of toxic substances remaining in the soil for a long time.
Not only is Eucalyptus toxic to the germination of other plants, it is also toxic to soil organisms responsible for building soil fertility and improving soil structure. Earthworms are significant among the soil fauna for improving the fertility of the soil through deposition of their faecal material and for increasing the permeability of the soil to air and water. Their activity may increase soil porosity by as much as 27 per cent.
In 1881 Charles Darwin, published his last work, the result of a lifetime’s study of earthworms, in which he wrote: ‘It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures.’
These strategies for maintaining the nutrient cycle are not associated with Eucalyptus plantations in India. In semi-arid zones Eucalyptus excludes other plant associates through its high water nutrient demands and its allelopathic effects. The large nutrient deficits created by Eucalyptus as an exotic, therefore, cannot be compensated by the nutrient returns from other species. The scanty leaf litter of Eucalyptus is itself not easily biodegradable because Eucalyptus pollutes the soil for decomposing organisms. Thus, there is no quick release of the nutrients locked in the leaf litter. As a result, continuous cultivation of Eucalyptus will leave the soil drained of nutrients.
from: http://fcbs.org/articles/Eucalyptus_versus_Biodiversity.htm
Many plants are able to grow right up to the base of the trunks of Eucalypts ie: various Chenopods are masters of the art.
Abstract
Soil microbiological properties during decomposition of leaf litter of poplar (Populus deltoides) and eucalyptus (Eucalyptus tereticornis) were studied under laboratory conditions. Microbial biomass C and ninhydrin-N were measured at different intervals up to 90 days following incorporation of poplar and eucalyptus leaves separately 20 and 100t ha-1. In general, the net increase in total biomass C or ninhydrin N following amendment was larger in the soils which received poplar leaves than in the soils that received eucalyptus leaves. The amounts of biomass C, at day 90, in the soils which received eucalyptus leaves 20 and 100 t ha-1 was about half and one-third, respectively, that of the soils that received poplar leaves at the same rates. Similarly, the field soils naturally receiving eucalyptus leaf litter contained about half the amounts of biomass C or ninhydrin N of the soils that received poplar leaf litter. In contrast, the amounts of organic C and total N were more in soils which received eucalyptus leaves both in the laboratory experiment and under field conditions than in the soils that received poplar leaves, indicating that the decomposition of eucalyptus leaves in soils was slower than that of poplar leaves. The ratio of biomass C/soil organic C in soils receiving eucalyptus leaves was about 2–4 times lower than those in soils with no admendment or soils receiving poplar leaves. These results, therefore, suggest that the allelochemicals released into soil during decomposition of eucalyptus leaves had a toxic effect on soil microorganisms and may thus affect the nutrient cycling and hence soil fertility.
http://link.springer.com/article/10.1007%2FBF00336107
Eucalypts may cause soil depletion in many shorter term instances but they also provide a longer term nutrient cycle which leads to soil enrichment.
roughbarked said:
Eucalypts may cause soil depletion in many shorter term instances but they also provide a longer term nutrient cycle which leads to soil enrichment.
Suss on that statement, central Victoria and gum trees have been here forever, But the trees are still sitting on a plain clay surface. Leaves have been dropping for thousands of years but still no rich organic soil.
Skunkworks said:
roughbarked said:
Eucalypts may cause soil depletion in many shorter term instances but they also provide a longer term nutrient cycle which leads to soil enrichment.
Suss on that statement, central Victoria and gum trees have been here forever, But the trees are still sitting on a plain clay surface. Leaves have been dropping for thousands of years but still no rich organic soil.
That’s why the farmers have been unable to farm the soils they stripped the Eucalypts from?
A big part of the problem you are describing is due to soil compaction and in your case a dense soil profile of finer clay particles which are more easily compacted. Try not watering your fruit trees for a while. Wait and see what happens to them and the soil around them when they are watered at the same rate as the Eucalypt.
Alternatively, you can apply a load of composted organic material to the soil surface under the Eucalypt and see the soil microbe and worm populations increase.
roughbarked said:
What would that do? They are young plants and would die without watering for a summer. I have no objection at all that fruit trees require more water than natives
I have inherited legacy fruit trees so some mature trees can withstand a 10 year drought.
Skunkworks said:
What would that do? They are young plants and would die without watering for a summer. I have no objection at all that fruit trees require more water than natives
I have inherited legacy fruit trees so some mature trees can withstand a 10 year drought.
It isn’t about the fact that you need to water the fruit trees but more about what that water does to the decomposition of organic matter and to the soil microbial activity.
The fact that you are not watering the Eucalypt or providing nutrients and mulches, is a big part of why there are no worms there and the soil is compressed and brick like.
soil tests leaf litter show that Eucalyptus leaves are continually poor performers compared with that of other plants. http://www.banglajol.info/index.php/JBAU/article/download/7929/5883
However, Eucalypts do tend to drop bark more than leaves. In most instances also there is the effect of the fauna which in healthy forests, digests the leaves long before they drop to the ground. It is more what eats Eucalypts that increases the fertility of the soil beneath.
Anecdote alert.
In our backyard in Penhurst are about 10 mature eucalyptus. I think some of them are redgums (E. camaldulensis) or a hybrid of that. Two are bluegums. All except one of them appear to have been planted – they are in rows. I think they are probably 70 to 80 years old. The biggest tree out there is a grand old thing, possibly a couple of hundred years old. They all drop prodigious numbers of leaves, particularly in the summer if there is no rain. Under the big tree I have some plantings, and have let a mulch of bark and leaves develop. Stuff does grow (including running grass weed) and there is friable soil there. But it is very dry. The English bluebells are now making a nice carpet, not yet in flower, but they are only green for a few months and then die down.
I planted, in my innocence, a white daphne pretty much against the trunk of one of the other trees and it is thriving. Geraniums and pelargoniums and bulbs seem to do OK under the gums. The backyard here is an exotic/local mixed garden.
In the front yard near our gate is a peppermint gum. I have correas growing fairly well under there, some white belladonna and some Autumn crocus bulbs. I also planted a Queensland bleeding heart ‘tree’, which at 10 years is still shorter than I am. Difficult to say if that is because of soil depletion/chemicals from the gum, or because I may have planted it on a rock. There is quite a good accumulation of leaves and bark under this tree too, and the soil is not too bad. In Penshurst there are lots of rocks from the volcano. When you start digging you sometimes have to abandon the hole because the rock you decide to dig out assumes the proportions of a monolith. One of our fences is a little off line because you simply could not dig a post hole where you wanted to.
Out in our bush, where the basic soil is sandy (sand-dunes when the dinosaurs wandered) there is a few centimetres of leaf litter. Brown stringybark out there. The leaf litter is good, underneath is the sand. The bracken seems happy. And if you try to dig, you encounter a very entangled web of roots.
I’m not entirely convinced the better soil under your fruit trees is really the result of the leaf fall. I don’t think there would be enough leaves yet, on the young ones. I suspect it is more that the leaves and the watering keep that soil wetter for the microbes and worms. Have you been mulching as well with hay over the hot summers? Peastraw makes fabulous soil as it breaks down.
Buffy is correct. It has little to do with the nutrition in the type of leaves falling. Possibly if anything, more to do with the fact that the leaves from the prunus and the malus are soft and malleable. A sprinkle of water and they stay where they are, do not blow away. They lay flat rather than naturally on edge, they mould themselves to the surface and stick. This allows more moisture to be retained under the leaf and more shade for worms.
Eucalypt leaves are generally thick and hard compared to most fruit trees, so that factor alone would slow the rate of decomposition. Another feature would be the oil within the leaf, which is a natural anti-septic; this again would slow decomposition. Being evergreen against mostly deciduous fruit trees is yet another factor.
Eucalypts are usually much larger trees with an extensive root system, which dominates moisture availability and coupled with a permanent overhead (evergreen) canopy, the light that reaches the ground and so will curtail competing species. This situation exists in the bush and is especially evident in mallee environments.
After a bushfire in mallee areas and the trees have been burnt to the ground, they need to either germinate from seed or resprout from the lignotuber, this provides a window of several years when they lose their dominance of the environment. This window provides opportunity for a large range of annual herbs and perennial shrubs to thrive, but once the eucalypts again begin to dominate, these will very largely disappear until the next bushfire.
buffy said:
I’m not entirely convinced the better soil under your fruit trees is really the result of the leaf fall. I don’t think there would be enough leaves yet, on the young ones. I suspect it is more that the leaves and the watering keep that soil wetter for the microbes and worms. Have you been mulching as well with hay over the hot summers? Peastraw makes fabulous soil as it breaks down.
I have noticed it under the old established trees as well, come spring, lush grass growing in and within the dripline. Everything here gets mulched, if nothing else it makes mowing easier. Straw mulch for the trees and pounded pine for the natives as it doesn’t break down as quick. Having said that the natives don’t get much of watering after they have established themselves. Last year I kept an eye on a young tee tree thing, when it looked a little weary that was a sign they needed water. The young fruit trees got watered more, the old established ones get no water at all.
http://en.wikipedia.org/wiki/Eucalyptus
Is this relevant?
South Africa. Numerous Eucalyptus species have been introduced into South Africa, mainly for timber and firewood but also for ornamental purposes. They are popular with beekeepers for the honey they provide. However, in South Africa they are considered invasive, with their water-sucking capabilities threatening water supplies. They also release a chemical into the surrounding soil which kills native competitors.
Eucalyptus seedlings are usually unable to compete with the indigenous grasses, but after a fire when the grass cover has been removed, a seed-bed may be created. The following Eucalyptus species have been able to become naturalised in South Africa: E. camaldulensis, E. cladocalyx, E. diversicolor, E. grandis and E. lehmannii.
> Peastraw makes fabulous soil as it breaks down.
Just be careful using it for selective mulching in places where roos have access to it. They love the peas that are left in it and will spread it out in an effort to get to the peas.
morrie said:
> Peastraw makes fabulous soil as it breaks down.Just be careful using it for selective mulching in places where roos have access to it. They love the peas that are left in it and will spread it out in an effort to get to the peas.
The advantage of living in a well-watered abode.
I have noticed our local roos moving armloads of grass clippings around just to make comfy beds for themselves.
Ian said:
I have noticed our local roos moving armloads of grass clippings around just to make comfy beds for themselves.
After they dig a hole?
One would be surprised if the kangaroo didn’t have a lot to tell us about living in this environment.
>>After they dig a hole?
The only hole is the depression remaining from the removal of the grass clippings.
Ian said:
>>After they dig a hole?The only hole is the depression remaining from the removal of the grass clippings.
I suppose a lot depends on the environment they are in. I see them dig holes to get at the cool earth beneath like your dog does. I also see them digging grass, if it is there.
My example was them making a dry bed in wet weather.
Ian said:
My example was them making a dry bed in wet weather.
OK.
as I said.. different climes..