Is there a place for inorganic fertilisers?

I’m going to put my foot in it again and offend the puritan. green, organic gardening/farming brigades by challenging the notion that there is no place for inorganic fertilisers if you’re growing crops to organic principles.

The ideal—that you should be able to grow strong, healthy crops with high yields with only organic inputs—is a good mid to long-term approach, but it’s not necessarily practical or realistic in the short-term.

Looking at our example on the croft, we moved in during early spring and had to grow enough vegetables to store for our first winter.

As I’ve mentioned before, our starting soil was very poor, low in nitrogen, potash and magnesium, and was very fast draining. 

We had access to some well-rotted manure on the croft (left by previous owners) and a lady nearby gave us a couple of Land Rover loads of manure (some fresh, some rotted down).

The bulk of the manure was immediately dug into what would become potato beds for the first year (the tatties have since moved out to the field), but we were then left with very poor soil for everything else.

Our answer was to spread the remaining manure thinly around the other beds, then use inorganic sources of nitrogen, potash and magnesium to fertilise the beds, plus copious amounts of seaweed extract and bonemeal.

We needed short-term results from poor soil in order to feed the four of us through our first winter and inorganic fertilisers were the pragmatic solution to getting our crops up and running.

Organic theorists and idealists are often shocked by this, without appreciating that they have the luxury of gardening as a hobby and not relying on their crops to feed their families.

Organic farmers have the luxury of a business plan that allows several years for the transition, plus markets for the transitional crops.

We had seven months to relieve the pressures on our limited income and start feeding ourselves.

As a result of our experience, I have no problem with people using inorganic fertilisers when starting from scratch and needing reasonable vegetable crops from poor soil within the first year or two.

Inorganic fertilisers should not be over-used, should not be relied upon, and should not be used as an excuse to delay starting the long-term soil improvement as this all leads to the problems suffering by commercial, non-organic farming—over-dependency on outside fertility, declining yields and soil quality, environmental problems, and vulnerability to price fluctuations.

As for the long-term, I prefer deep beds, particularly in poor soil.

Deep beds can be raised (as is the fashion at the moment) or dug deep into the soil (an older technique).

The beds are marked out and then one of two techniques can be used.

The first is to skim off all the grass and weeds, then cover the soil with a thick layer of well-rotted manure or compost.

Then dig out a trench two spits deep, put the soil and manure from that trench to one side, then dig a new trench out next to the first one.

Turn the soil and manure from the second trench into the first; then repeat along the length of the bed. The set-aside soil and muck from the first trench goes in the last one.

The second technique is similar, but instead of spreading the muck on top and digging it in, the bottom of each trench is forked over, a thick layer of muck spread in the bottom, and the soil from the successive trenches placed over the muck.

With both techniques, I find it best in the first year or two to stick the weeds and grass in the middle of a very hot compost heap. After that, they’re dropped in the bottom of the trenches.

We used the second technique to establish the beds on the croft as we needed the muck intact and deep to slow the drainage of water.

I’ve previously used the first deep bed technique locations where drainage was acceptable or slow, so a more even mix of soil and muck from the start made more sense.

Depending on how poor the soil is, the deep bed technique requires four to eight years of hard work to get a good mixture of humus and soil.

After that, though, it should only be necessary to fork in some well-rotted manure each year as the soil structure and nutrient levels should be excellent.

While well-rotted muck should provide all the nutrients needed in the long term, well-rotted compost may be lower in potash than needed (depending on what goes into it).

Adding layers of wood ash to the compost heap helps overcome this.

Finally, it should be born in mind that I’m writing this with poor soil and a short time frame in mind.

If the ground is in good heart with a balanced mix of nutrients, then inorganic fertilisers won’t be needed even at the beginning.

They’re also unnecessary if you have a year or two’s grace before you need a good crop, or if you’re not depending on your vegetables as your main source of food.

But if good crops are needed from the start and the soil is not yet good enough to deliver them, don’t be afraid to use inorganic fertilisers.

I’m sure the idealists and puritans will get the heebie-jeebies in reading this, but if a lot of vegetables are needed to feed a family from the off then be pragmatic in the short-term while building up to be sustainable, responsible and even idealistic in the long-term.

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This post was partly prompted by a question from Captain Caveman on Self-sufficientish. Photo from summer, 2006.