To mulch or not to mulch, that is the question!

[Big J]

We're nearly finished with a 5.5 hectare spruce clearfell and one of the options is to mulch ahead of restocking. 

 

We've basically got three options, which are low cost, medium cost and high cost.

 

Low cost: Windrow brash

 

Medium cost:  Excavator based mulcher to mulch all brash and grind down some of the old stumps. It can't do anything with the fresh stumps.

 

High cost: Purpose built forestry mulcher, everything ground to a pulp, site left like a tilled field ready for restocking. 

 

Costs are approximately £500/hectare, £1000/hectare and £2200/hectare respectively.

 

Has anyone any contrasting experience with these different approaches from the point of view of future growth rates?

 

My theory is that whilst the complete mulch option is the highest outlay now, the nutrient content ploughed back into the soil will result in a higher growth rate. Even if that's only an extra 2 cube per year per hectare, by the time you're at the first thinning at 15 years, that's 30 cube, which has a minimum roadside of about £1350. Couple that with the complete lack of stumps from the first rotation (and the lower harvesting costs), you're probably beyond the initial cost of £2200/hectare for the mulching. 

 

No massive stumps also means that you're able to use much smaller machines on thinnings that you'd otherwise be using. 

 

I'd be keen to hear about other peoples experiences. We have the luxury of being on a profitable site for the landowner so this is being potentially considered. 

Edited October 17, 2019 by Big J

[Stubby]

Obviously the most expensive option is best for the site , but it surely depends on what the customer is prepared to pay .   I have never been that far up the food chain to have the option of a choice !

[monkeybusiness]

Sounds like you’ve answered your own question!

 

My only concern would be what you may end up disturbing in the historic seed bank if you go for the full mulch option - could your site end up covered in ragwort/thistles/nettles/brambles/birch etc subsequently competing with the new trees?

[Big J]

2 minutes ago, monkeybusiness said:

Sounds like you’ve answered your own question!

 

My only concern would be what you may end up disturbing in the historic seed bank if you go for the full mulch option - could your site end up covered in ragwort/thistles/nettles/brambles/birch etc subsequently competing with the new trees?

That's a fair point. 

 

There is a reasonable amount of sitka regeneration throughout the block, but after 12-18 inches of rain in the 3 weeks we've been on site, the ground isn't looking great at present. Perhaps a mulch will act a bit like a wildfire in Australia, being the catalyst for new growth? It's just a thought. We've 12500 new trees to plant regardless.

[Will C]

Windrows provide a huge resource for the small mammals which in turn help the predators and this continues up the food chain. Sterile closed canopy woodland is best for your bank balance but a bit of diversity can’t be a bad thing can it?

[cl3525]

I assume your not to near any watercourses or a nitrogen sensitive area?

[aspenarb]

Fourth option J and by far the most popular around here. Mulch between the rows leaving all the stumps, replant immediately between the old rows straight through the mulch mat. Allow the regen to go for a few years which will keep the Deer off the new plants. Revisit and run the mulcher through the new rows knocking off any rotten stumps and regen when ready to beat up.

 

Bob

 

By the time you revisit the original mulch will have rotted down and the remaining stumps just explode.

 

 

 

 

 

[Big J]

18 hours ago, cl3525 said:

I assume your not to near any watercourses or a nitrogen sensitive area?

No, nothing.

 

5 hours ago, aspenarb said:

Fourth option J and by far the most popular around here. Mulch between the rows leaving all the stumps, replant immediately between the old rows straight through the mulch mat. Allow the regen to go for a few years which will keep the Deer off the new plants. Revisit and run the mulcher through the new rows knocking off any rotten stumps and regen when ready to beat up.

 

Bob

 

By the time you revisit the original mulch will have rotted down and the remaining stumps just explode.

 

 

 

 

 

Interesting prospect, but would be hard to do with softwood planted without tubes. 

 

We decided to go with an excavator based mulcher on the present site. It's looking very good.

[aspenarb]

2 hours ago, Big J said:

No, nothing.

 

Interesting prospect, but would be hard to do with softwood planted without tubes. 

 

We decided to go with an excavator based mulcher on the present site. It's looking very good.

 

Sounds like you are well underway then J.  I have never really had a problem finding the rows once its edged out providing its planted properly.

 

 

 

 

 

Edited November 8, 2019 by aspenarb