How much nitrogen to add to fresh hugelkultur bed?

Hello.

I have cleared my mountainside lot in order to build a house. There were a lot of huge poplar trees. So, I have put the leftover trunks, logs and branches on the bottom of the lot. I am talking trees 3'-4' in diameter. The logs cover the area approximately 16' x 50'. There is some topsoil that I will put on top of the logs and I am planning to bring enough soil to cover the logs, maybe a foot deep. It is not a mound like, more like a little field. I still have a plenty of surplus log to create a large mound in the middle, but it will be much harder to cover with soil.

My question is - would it make any sense to add nitrogen fertilizer right now and how much? Since the rotting process will be using the nitrogen from the soil, that sounds to me like a good idea. I have a plenty of free nitrogen from the local water processing plant!

Thank you.
Two+Suns

I also have several huge brush piles on my lot - some 15' high. Would it be a good candidate for a large hugelbeet?
Please, help me to calculate the necessary amount of nitrogen fertilizer to add?

Thank you.

Before I would add nitrogen, I would fill in some of the space between the wood with leaves, grass clippings and other compostable materials including meat scraps. The logs can be left as in your photo or better yet, stacked somewhat so they don't use so much ground space and will also give more areas for compostable material addition prior to covering with any soil. The purpose of the wood is to retain water for future release to root systems, so the fewer large air pockets you have at the start, the better it will perform.

I like to lay the logs in layers, so I can make compostable additions as layers between the wood. I also like to water each layer as I build, this gets a growing mound started off faster. Additionally, if you have some partially rotted wood, especially any that has fungi growing on it, those are wonderful additions to a mound, since they will spread inside the mound and help rot the wood as well as attach to the new roots growing down and so help the crops grow.

For nitrogen additions, you can use coffee grounds, manures, green cuttings. I would not use commercial products myself since this is all about helping nature do what nature does and those products are not "natural". If you can estimate the weight of the wood, then divide by 1000, you would have a fair idea of how much N to add to the mound. Normal builds tend to take a year or two to mature and this is normal, if you make additions of manures, green clippings and coffee grounds as you lay up the mound, you most likely will not need to worry about the nitrogen, it will be there in enough quantity naturally.

The mound will settle as it matures so you will keep adding compostable material and manures to fill in the holes and raise the level of the mound back to what size you want it to be, if you want to try and keep it a certain height.

I have a few mounds that are getting leaves this winter as well as some additional wood since they have settled and are showing large holes where the soils have sunk around the logs in them. I consider this normal maintenance.

The second photo, of a brush pile, shows some filling in of spaces by leaves and soil, just as I have described above, all that is needed is to continue till you are ready to lay on the blanket of soil as a finish.

Unless you want all kinds of animals digging through your mound I would avoid meat scraps in your mound. Watering each layer as you build your mound is a very good idea as the bed tends to be pretty hydrophobic in the beginning.

Slava On wrote: It is not a mound like, more like a little field.

What is recommended to plant on a hugel field? I haven't done any hugelbeds, but I've been curious and reading about them, and one thing I read was you shouldn't plant trees or woody perennials on a hugelbed, since it will settle.

Rebecca Norman wrote:

Slava On wrote: It is not a mound like, more like a little field.

What is recommended to plant on a hugel field? I haven't done any hugelbeds, but I've been curious and reading about them, and one thing I read was you shouldn't plant trees or woody perennials on a hugelbed, since it will settle.

Every mound will settle, that's just the nature of them. I would plant trees close to the base of a mound rather than actually on the mound, I do get some high winds and prefer my trees to remain upright. As for mound planting, you can plant most anything on them. I have not had much success with beets in a mound so far but we have special beds for those. Any of the squashes, kale, spinach, corn, all grains, peas, peppers, potatoes, and most other vegies will grow very well on a mound. If you have started the mound with added water during the build, you should not have to worry much about watering since that is the purpose of putting the rotting wood into them.

If you put any meat scraps in (mostly bones, any meat that is left on is what I couldn't keep with the muscle, true meats like left over from stock making either get fed to the dogs or go into the worm bins) put that in with the very bottom layer so those are deep in the mound. I build my mounds usually to a 4 foot or five foot height and have not had any problems with animals digging for the deeply buried scraps.

When I first finish building any mound, I throw on an initial cover crop of scarlet clover, rye cereal, winter field peas or kale. I build new mounds during our fall, so even if I plant during the end of November to the middle of December, the plants will get a foot hold. As and example, we planted new kale at the end of November and it is up and doing just fine now. In the spring, we will start planting squashes, spinach, peppers, radishes, melons, corn and everything else. We use row covers at the beginning then take those off by march 15 since that's when the weather starts to really warm up. By using stakes (2-3 ft. out of the ground) to hold the material off the plants, we can even use plastic as a cover and so have mini green houses over the mounds. I don't bring plastic all the way to the ground usually, just staple it to the bottom stakes a foot from the ground, this lets just enough air exchange happen to keep everything under it happy.