I live and work in the northwestern province of Battambang, Cambodia. My wife and I started a small farm in 2017. We are preparing to plant roughly 85 fruit trees (longan, durian, jackfruit, mango, orange/lime, guava) on very flat ground. The soil, however, is not good, to say the least. First, the top meter of soil is from soil taken out of the ground when digging a pond in 2018; very few weeds even grew in that soil during the 2018 rainy season! Second, even the original soil—the soil that was covered with the pond digging soil—was severely degraded after decades of rice growing using a stew of chemical inputs, being left exposed during the hot season with no vegetation, and continuous deep plowing.
So, I am seeking advice on how to plant fruit trees in such poor soil?
Additionally, whatever I learn from my farm will be passed on to the NGO I work for. We have an organic market garden project, but we have not done work with fruit trees.
I would really appreciate any advice that might be given!
We dug swales and planted the trees into the berms, that helps with water retention. We mulched the trees as much as possible. Chop and drop around them.
Sounds like Bokashi method could be a good fit:
For us, we chose to plant fewer trees, and only plant trees where we could afford to prepare and amend the soil well. That’s meant planting 30-40 trees a year. We still lose 3-5 each dry season. (Our main issue aside from poor soil being extreme dry seasons.) One issue we noticed was that we lost trees that weren’t large enough, with established root systems. We don’t have a good source for trees, so we were raising them ourselves mostly. Following this thread for all your good ideas.
Thanks for your input and for the links to the tree planting videos!
As of today (May 7), we have dug five 1m3 holes (1m deep) to experiment with. We will fill them with organic matter (old cow manure, soil, compost, rice husks). We think that will work, but the problem is the amount of material needed for planting one tree is immense, as well as the cost. We are thinking of getting some water hyacinth from a near-by pond (there are tons of it and the owners want it gone) and using that as our primary organic matter, just not sure if it will work or not.
Thanks again for the discussion!
Hi David wanted to add my comments to this. I used to dig big holes and fill with layers of organic material as described here but became aware of several limitations, such as well obviously it’s a lot of work & requires huge amounts of material (important if your site/work is a demonstration fro training purposes - needs to be as easy/replicate-able as possible); also the pit acted as a sump for water so became waterlogged even in semi-arid conditions, and also that roots weren’t encouraged to “go look” for water and nutrients. So nowadays I opt for a lower-input, smaller pit, very little organic matter in it but thick mulch from the top - so feed from the top, starting with rotted compost covered with semi decomposed biomas, followed by chop & drop of green material. This most imitates a natural forest floor. Once established then just chop & drop. Also I look at the whole site for soil remediation with cover crops/green manures in between the trees. Maybe swales or similar (net & pan) if extreme. I also like the suggestion of bio-fertilizers and bokashi to stimulate fungal/micro-organism activity. If available, sub-soil irrigation with bottles/porous pots is effective. Finally, again looking at the whole system, companion planting of diverse guilds of plants so that your fruit trees are amongst friends. Natural regeneration will of course help with all of this this, so promoting that will benefit the site/system.
Hello David. Thanks so much for sharing your activities with the group here and for your efforts to improve life where you live and work. My advice is less about the planting. It does not seem to be a complicated task to give the individual trees you plant what they need in each particular planting location. The greater task is how to improve the overall environment in which all of those organisms grow and produce. I would direct your attention to the following video from which I gained invaluable information and hope. https://www.youtube.com/watch?v=gSPNRu4ZPvE.
Anyone tested using seeds to plant fruit trees? They develop a much stronger root system that way and the longevity of these trees is much longer, and it cost pennies… It seems that lots of fruits can be successfully grown that way and in particular small fruits. I tested growing small fruits from seeds here in Canada and they take only 3 years to fruit, and the growth is much more vigourous.
What I do and learned as an Intern at ECHO (where we have sandy soils with low nutrients) is similar to what Chris said. I dig a hole about double the pot size (or root ball) and just put the original soil back in the hole when planting the tree and water it well as you add the soil so you don’t have any air pockets. I then mulch it and either add some compost or slow release fertilizer (not always an option) a few months after planting. The thinking is the the roots will grow and develop as it is looking for nutrients, establishing the root system. In my experience keeping the trees well watered (often by planting at the start of the rainy season and occasionally supplementing), mulching (building up the soil over time and retaining water), and weeding when needed was enough to get them going well. Then using a more holistic approach to soil management of the whole orchard or tree planting, whether it is compost, bokashi (I have not done this yet but know others that do), cover crops, mulch (this ends up being what I do the most because I have it), or most likely a combination. As you think of doing larger plantings or encouraging small-scale farmers where labor or compost is hard to come by this might be more feasible. Good luck with the plantings!
I work here at the ECHO Asia office in Thailand. We face similar challenges with our soil, most of it is poor sub soil dug out from our fish ponds. After reading your post, and seeing what we have here, I wouldn’t be surprised if compaction is your real issue. IF that is the case, and you have compacted soils, digging pits may be risky. They will serve you well in the dry season and retain moisture well, but I fear in Cambodia’s rainy season they may act as sumps and not drain at all, leading to root rot problems and anaerobic soil conditions. Drainage will be key. Also planting your seedlings on top of too much organic matter can compound these problems, it is good to mix and incorporate OM above and around the seedling, not directly under it.
Swales and berms may be a good idea, I see that a lot in orchards here. By building up berms you will keep your trees ‘feet out of the water’ in the rainy season and depending on how you construct them, provide some loosened and aerated soil to plant into. You might even consider doing some subsoiling, or chisel plowing, before you get started to break up some of that compaction, or even between rows after being established (if you have access to a tractor and the right implements of course).
Let us know how it goes and what ends up working for you!