Organic Farming And Soil Fertility

[drtreelove]

I first learned about organic gardening in the late 1960's and early 70's. Then the emphasis was on building soil fertility. Even the early organic farm certification programs had a requirement for 5% organic matter content. In fact that's where the term organic comes from. It was recognized that with good soil fertility, 5 to 10% organic matter content, the food produced tastes better and there is better yield. I tried it and it's true. And so are many other benefits.

Now the emphasis in organic gardening and farming is on not using chemical fertilizers and pesticides. This is good, but not enough without good soil fertility in my opinion and experience. Current certification standards don't even require a minimum soil organic matter content. Has something been lost?

Soil fertility comes from comprehensive soil management with composting and mulching for small scale operations; for larger scale farming, the use of cover crops/green manures/incorporation into the soil of crop residues is key.

One of my favorite quotes, from the excellent book Permaculture Home Garden by Linda Woodrow (Viking Penguin Books, Australia):

“ The cure for heavy clay soil is to add organic matter to breakup the clay and improve drainage. The cure for sandy, dry soil is to add organic matter to retain water. The cure for acid soil is to add organic matter, particularly bird manure, to bring the pH up and make more nutrients available. The cure for alkaline soil is to add organic matter to buffer it. The cure for hardpan is to add organic matter to feed earthworms.”

“Compost, mulch, animal manure and worm castings are the great cure-alls. You can build a garden on a concrete car park if you add enough of them. It is usually easier and safer just to add enough of them to correct any deficiency you might have. Just as it is better to feed a person a good, balanced, varied diet than to eat junk food and then worry about which vitamin pills to take, it is better to feed plants plenty of humus than to grow them in skeletal soil and worry about which supplements they need.”

[Smithson]

Good info,

As mulch I'm using coco inner husks (not the hard out part), in some rural areas you can get these for free as they're often burnt. On top of this I throw cow manure, grass clippings and leaves. We now have a nice layer of 2 - 4 inches and I'd like to add composting worms. However I understand these worms can't live in soil, so I'm wondering how well this will work and if there's anything else to add.

Also, I know it's common practice not to have mulch during the wet season. Considering that the mulch is thick, I was wondering about planting straight into it. This would be above the soil level and provide good aeration. Seems a better idea than planting into heavy soil. Any thoughts?

[drtreelove]

Good info,

As mulch I'm using coco inner husks (not the hard out part), in some rural areas you can get these for free as they're often burnt. On top of this I throw cow manure, grass clippings and leaves. We now have a nice layer of 2 - 4 inches and I'd like to add composting worms. However I understand these worms can't live in soil, so I'm wondering how well this will work and if there's anything else to add.

Also, I know it's common practice not to have mulch during the wet season. Considering that the mulch is thick, I was wondering about planting straight into it. This would be above the soil level and provide good aeration. Seems a better idea than planting into heavy soil. Any thoughts?

Composting worms are specialized and thrive in a temperature and moisture controlled, organic waste container. (A Mae Jo University project near my home, big agricultural school in Chiang Mai, uses concrete water tank rings with a drain hole at the bottom.) They produce great material ("worm castings") for incorporation into growing soil. They are a different species with different requirements than common earthworms.

With the great muclh layer that you have created, if kept moist, earthworms will thrive and propogate and do their thing. Unless the soil base is somehow deficient or chemically compromised, they will appear without adding to the existing population. If you build the right conditions, they will come. Irrigate that mulch until the rains take over. Mid rainy season go out and dig anywhere and you should have a handful of earthworms.

The mulch only needs to be removed for the rainy season if you need to facilite the planting of a crop. Otherwise continue to allow it to decompose and become soil.

You can't plant just anything directly into a mulch layer, you will lose a large percent to birds and rodents or just to drying out, you need to get most seeds or starter plants into the soil. Depending on what you are planting, you could just clear away enough mulch to put your seed or plant into the ground by hand. Tractor work will probably require rototilling in the mulch first.

[Smithson]

Composting worms are specialized and thrive in a temperature and moisture controlled, organic waste container. (A Mae Jo University project near my home, big agricultural school in Chiang Mai, uses concrete water tank rings with a drain hole at the bottom.) They produce great material ("worm castings") for incorporation into growing soil. They are a different species with different requirements than common earthworms.

The guy I got my worms of was from Kasetsat uni in Bangkok, but he mentioned the project at Mae Jo. He also talked of a method where composting worms were added to a thick mulch layer and fed from there, which is what I'm keen to do.

The worms I got were 'Indian Blues'. At our office we have a plastic chest of draws full of them, I collect the scraps from the fruit seller for food. I also have several bins at home in Bkk, which are now pretty full. I bought a nice thick book on worms, but it's all in Thai. My wife loves gardening, but not reading!

Besides the blue worms, I've also noticed some larger ones of a different variety.

With the great muclh layer that you have created, if kept moist, earthworms will thrive and propogate and do their thing....

The only worms we seem to have are the large ones that like hard clay soil. I will keep an eye out to see if any other types appear.

Edited January 22, 2009 by Smithson

[IsaanAussie]

The only worms we seem to have are the large ones that like hard clay soil. I will keep an eye out to see if any other types appear.

Forget any others, any large ones that like hard soils will do me just fine. How much?

[Smithson]

Forget any others, any large ones that like hard soils will do me just fine. How much?

Actually they're free, I meant these are the only ones we have in the soil. Seems to be heaps of them though, as I chop many in half when digging.

[farmerapache]

hi all,

there is a good product on the market in thailand which reactivates clay soil.

for info:www.pd-im-export-thailand.com