Fertilisers

Fertilisers are a much-discussed item in gardening circles. There are very excellent organic fertilisers out now which somewhat dampens down the furor over using petroleum-based Fertilisers. This is especially true of lawn fertilisation. So what is the argument against using petroleum-based fertiliser?

Petroleum-based Fertilisers

The argument for and against these decidedly most popular fertilisers deals with an amazing number of levels. First, naturally, is the dependence, once again, on oil. We have replaced Nitrogen with this artificial nitrogen which not only costs a lot of money, but which also leaves trace minerals in the soil it affects. Needless to say, oil costs have tripled recently, a fact that we can readily see in our cars. Some of these trace elements remaining from oil based fertilizing are highly contaminating and reside in the soil for thousands of years, virtually indestructible. These elements are things like arsenic, heavy metals, lead and various other, equally-obnoxious substances. The fact is that we have become dependent on these fertilisers which were once considered miraculous and did, indeed, help alleviate poverty to a degree. The problems in the reckoning of which Fertilisers to use in a small scale garden is just this: If we prepare the garden sufficiently, we should not even need any fertilizer.

If, however, we do see a need to boost the growth a bit, there are organic Fertilisers which are far less injurious to the soil over the long run and which act just as well. There are abundant online resources for locating these Fertilisers, all under the name of "organic". I am not trying to sound politically-correct here. I am interested in the long term health of gardens and gardeners. Nor does it hurt to consider options in dealing with fertilizing which do not dictate more oil-based needs. This is everyone's business.

Organic Fertilisers

When used in reference to fertilisers, the word "organic" generally means that the nutrients contained in the product are derived solely from the remains or a by-product of an organism. Cottonseed meal, blood meal, fish emulsion, manure and sewage sludge are examples of organic Fertilisers. Urea is a synthetic organic fertilizer, an organic substance manufactured from inorganic materials.

Some organic fertilisers are high in one of the three major nutrients (nitrogen, phosphorus, or potash,) but low or zero in the other two. Some are low in all three macronutrients. A few organic products can be purchased "fortified" for a higher nutrient analysis. The ingredients used to fortify organic fertilisers are organic materials; for example, rock phosphate to increase phosphorus, or greensand to increase potash.

Organic fertilisers depend on soil organisms to break them down to release nutrients; therefore, most are effective only when soil is moist and warm enough for the microorganisms to be active. Nutrient release by microbial activity, in general, occurs over a fairly long time period. One potential drawback is that the organic fertilizer may not release enough of their principal nutrient when the plant needs it for growth.

Compared to synthetic fertilizer formulations,organic fertilisers contain relatively low concentrations of actual nutrients, but they perform important functions which the synthetic formulations do not. They increase the organic content and consequently the water-holding capacity of the soil. They improve the physical structure of the soil which allows more air to get to plant roots. Where organic sources are used for fertilizer, bacterial and fungal activity increases in the soil. Organically derived plant nutrients are slow to leach from the soil making them less likely to contribute to water pollution than synthetic Fertilisers.