Back in July I decided to do a little demonstration / experiment of the effects of lime and fertiliser on my pasture land. Now, just three weeks later, I’m starting to see some result.
Three of the test plots are showing a deeper green and more growth than the others. And they’re NOT the ones I expected. After discussions with my neighbours who reckoned the pH was as low as 4.5 and the farmer who rents some fields, I was firmly convinced that lime would have the most beneficial effect, above that of the fertiliser.
But it’s the fertiliser plots that are showing a positive result. Now this is very early days for a horticultural test but it goes to show I don’t know it all (despite what my wife says!). It’s very possible that the limed plots will just take longer to show some benefit. Lime does take longer to work into the soil than fertiliser.
It’s also possible that the fertiliser will give a flush of growth and then peter out whilst the lime has a longer benefit. Whatever the cause or final result, it’s interesting to see how this develops. The farmer, with his years of experience honed by the need to make a living, is certain that liming is more important than fertilising in the first instance.
My broad beans have perked up a bit after being given some nitrogen in the form of chicken manure pellets and a liquid feed of urea. That’s not to say they’re looking good. Something isn’t right for them by any means.
It’s pretty obvious to me that I need to know what the exact pH and nutrient levels of my soil are. Everyone agrees it is acid, but I want know exactly how acid so I can calculate how much lime I need to add to get it right. The three main nutrients, NPK, are probably very low as well. So even making them available by reducing the acidity of the soil won’t help a lot if they’re not there to start with.
A general fertiliser like fish, blood and bone or Growmore will help increase nutrient levels as will manure. Adding manure and compost will also increase the humus in the soil which acts like a sponge, absorbing and holding water and retaining nutrients that would otherwise wash out.
Now a farmer wouldn’t just bung on fertiliser willy nilly. It’s wasteful and expensive. He’d find out what was needed, that is to say the base level in the soil and top it up to meet the nutritional requirements of his crop.
I don’t see why home growers shouldn’t take a tip from the professionals so I’m getting a soil test kit. After all, it’s pointless adding phosphorus if I really need potash. I’m not attempting the precision of an East Anglian arable farmer but I’d like a good idea of what I’m up against.
So I’ll take a number of samples from the veg plot area and average them out to get a fair impression and some guidance as to the best course of action. Now the basic nutritional elements, NPK, are not all that there is to it. Plants need a range of micro-nutrients in the same way we need vitamins to thrive. We can live for a while on protein and carbohydrates but lack of vitamin C will give us scurvy and eventually kill us.
But eating vitamin C pills is pointless if we’ve not got the basic foods to fuel us. Luckily micro-nutrients are rarely a problem for plant growth if we add manures and composts. Adding artificial fertilisers alone is likely to result in a lack of them though.
That’s why I view fertiliser as corrective aid rather than the long-term, continual solution. Good growing needs a good soil and that takes time, effort and some knowledge.