Why don't you want wood chips on top of soil for an orchard?

Question

Jack Spirko said that you don't want to use wood chips on the surface of soil. Why don't you want to use wood chips? Source

Answer 1

Orchards have wood, so chips could help wood fungus and other wood/root diseases to propagate and then to attack trees.

In general orchards should have no dead wood any kind (e.g. prune and eliminate any dead branches).

Answer 2

I don't have the bandwidth at present to look at your video, but it defies common sense. A summary of his argument should be presented.

Trees evolved in forests and the forest floor is covered in dead organic material including wood.

This paper http://hortsci.ashspublications.org/content/45/4/637.abstract looked at different orchard floor management systems and found

Trees with wood chip mulch performed well and had greater capacity to build N reserves, making wood chips ideal for establishing young organic apple orchards. However, as the orchard matures, it may be beneficial to switch to a groundcover that reduces tree vegetative growth.

Answer 3

I didn't have space to leave this in a comment, but I wanted to address the myth of woodchips spreading plant pathogens. Here is an article called The Myth of Pathogenic Wood Chips by Linda Chalker-Scott, Ph.D., Extension Horticulturist and Associate Professor, Puyallup Research and Extension Center, Washington State University, which explains the issue: https://s3.wp.wsu.edu/uploads/sites/403/2015/03/wood-chip-pathogens.pdf

Main takeaways:

• Fungal species in decomposing wood chips are generally decomposers, not plant pathogens • Healthy soil communities include mycorrhizal species needed for optimum root health • Under healthy (aerobic) soil conditions, beneficial and harmless fungi probably outcompete pathogenic fungi • Healthy plants are not susceptible to opportunistic fungal pathogens• Do not amend soil with wood chips; use them only as a topdressing • Keep mulch away from trunks of trees and shrubs to prevent opportunistic pathogen infection

Making sure to keep the woodchips on top of the soil will reduce the problem stormy mentioned about woodchips tying up nitrogen that should be going to the fruit tree. Plenty of people use woodchips as mulch for fruit trees including: https://gregalder.com/yardposts/using-wood-chips-as-mulch-for-fruit-trees/, . Here is one article about the N issue on almonds: https://orchardrecycling.ucdavis.edu/nitrogen-management They found adding some N fertilizer the first year was beneficial, but in later years could reduce other fertilizers. I didn't read the papers they cite, but I'm pretty sure they mixed the woodchips in with the soil, which would mean more N required.

Anyway, in this study comparing different orchard groundcover management strategies, woodchips did quite well: https://www.researchgate.net/publication/267398286_Comparing_Mulches_Herbicides_and_Cultivation_as_Orchard_Groundcover_Management_Systems Study is Comparing Mulches, Herbicides, and Cultivation as Orchard Groundcover Management Systems by Ian Merwin and others.

Here is another study I only skimmed: https://www.ars.usda.gov/ARSUserFiles/20902500/JeffSmith/Nitrogenfertilityorganicappleorchards.pdf

Orchard floor management effects on nitrogen fertility and soil biological activity in a newly established organic apple orchard by L. Hoagland and others. I think they recommended cultivation as opposed to mulches early on in the trees' lives. If you don't have many trees, you could just pull the weeds though. I am in a sandy area and it doesn't have too much trouble with weeds to begin with.

another supporting article I only skimmed: https://www.theorchardproject.org.uk/blog/mulch-ado-about-nothing/

Answer 4

Wood chips are RAW dead organic matter that HAS TO BE DECOMPOSED. Nothing one can do to stop decomposition once something alive has become dead. Well, there are a few things but within this thin blue line of life on this planet something alive dies and immediately begins the process of decomposition.

The organisms that do this work require 'FUEL' with which to decompose. LOTS of nitrogen. The biggest worry is reducing the amount of nitrogen to the trees and/or adding too much nitrogen to compensate and reducing flowering and fruit production. The chips would keep the grass in check, though.

Grass or any plants within a tree's drip zone competes for chemicals necessary for growth including water. All plants should be removed beneath the canopy of any...plant, really. If a fruit tree is in a lawn one will have a conundrum...to fertilize the lawn or the tree. The lawn requires lots of nitrogen which will severely inhibit reproductive growth for the tree. Another reason for large base circles lightly mulched with decomposed organic matter. Grass with all its 'nitrogen' is alive and growing will do nothing but suck chemicals it needs from the soil. Unless it is decomposed first, that nitrogen is unavailable to any other plants.

Black Thumb, you would do well to take a Master Gardeners's course from your closest University's Cooperative Extension Service. They teach the basics within months and then you pay back your education by working at fairs, conventions to answer people's questions as a Master Gardener... as well as creating a few test gardens with little placards to explain what you are doing. With the knowledge you get on basics you would be able to answer most of your questions. They give you these publications from the University with which to answer basic as well as more advanced questions. You always have to look up the question from these publications, one does not give their opinion for answers when one is acting as a Master Gardener and wears the plastic tag. One learns a lot of respect for information about plants (composting, preserving foods are other classes) already tested, publicized. For you to imagine that you have found a new and better way to grow a plant is crazy. Maybe someday but not with what you know today.