How do I know my soil is bad?

This questionaire is not fool-proof. So many types of soil situations can exist such as whether you live on a flat plain or on a steep hillslope; whether you have clay soil or sandy soil; whether you live in a new estate or an old cattle property. This questionaire is a guide which can be used by most residents in this tropical region to determine the likelihood of your soil being healthy or being a potential threat to your local frogs and even yourself. But many of the factors influencing soil ph will exist anywhere so please go through the questionaire even if you live in Canada or Columbia, Turkey or Trinidad, New Zealand or New York!

Grab your pen and paper and write down the number of points which apply to your answers to each question in the two tables below. Add up your points at the end to find out whether you need to take any steps to restore your soil to good health. If a factor/situation listed does not apply to your property, then you get zero points for that item.

For those living on sandy soil outside flood areas and fast draining soils such as rocky hillslopes, human diseases might not be such a problem but drought tolerant fungi can be affecting your frogs. See the special section for sandy soils in the recommendations page.

Soil health can be affected by many things but is largely a matter of two main processes:

• if you are outside flood prone areas - what is draining the good stuff out and what is happening to put the good stuff back in (the more that is removed, the more that must be put back); and
• if you live in flood zones, what is being washed out of soils upstream and deposited into your soil when flood waters drop.

Look at the list below and give yourself the points listed for each of those factors that apply to your property:

Now for factors which are actually helpful to your soil - if these items apply to your property, you can actually subtract the number of points indicated from your total so far:

Add up your total score and check below.

If you have less than 13 points, your soil should be in good condtion. If your veggie and herb garden is doing well, your other garden plants look well and you don't have a lot of weeds, then no special attention is needed. Keep up nutrient levels with an organic fertilizer, especially at the end of the rainy season and about a month before the rainy season starts. Well done!

If you have between 14 and 28 points, your soil could be better and you could enjoy your yard more if the plants were looking better, there were less weeds and you could get some nutritious veggies and fruit. Go to the recommendations page and consider some of these actions to make your yard better. A little help will go a long way!

If you have 29 points or more, your soil is screaming out for help and it would be very wise for your family, your backyard wildlife and your garden plants if you can follow as many of the recommendations as you can for correcting your soil's ph/condition. It's not that difficult and, in most situations, not expensive and it can actually save you a lot of money in the long run!

You can also get some ph testing done on several spots on your property if you want to have some numerical feedback that your soil is too acid. There are testing services for this (in your yellow pages) or your garden nursery can sell you a simple kit to do this yourself at home. If you use the home kit, pick out several spots on the property to check as soil ph under a tree might not be the same as the middle of the lawn which might not be the same as the top or the bottom of a slope. Use a variety of places in the yard to test.

As you went through the list of bad factors and good factors, some situations would have jumped out at you as common causes of soil becoming acid/sour and disease-promoting. For example:

• "garbage in - garbage out": If nearly all the time you spend tinkering in the garden is to spray herbicide on your weeds, you probably have a lackluster garden with struggling plants, sparse lawn and even your tomatoes will shrivel up and die unless grown in pots with purchased potting mix. Alternatively, hand pulling weeds by the roots, composting and using organic fertilizers leads to a more luxurious appearance to your garden beds and you might reap a steady supply of fresh herbs/veggies to enhance your cooking; what you may not have realised before is the more herbicide you use on the garden, the more you are actually promoting the growth of weeds!
• long term rental properties: very few tenants will spend time looking after or expanding gardens in a rental property because the property belongs to "somebody else" so the gardens in long term rentals can be rather plain, weed infested and the soil can be depleted. You may not own it but while you live there, the property is there for you to enjoy on the inside and the outside. It costs very little to correct the soil ph and the results will make the property so much more enjoyable (and safe) for you and your family and the local wildlife that comes to visit your yard.
• clay soils and flood prone areas: red clay is actually a very nutritious soil type and is desired for agriculture but yellow and grey clay is horrible stuff and is an excellent medium for growing soil diseases as well as suffocating plant roots. Poor drainage and/or regular flooding provides all the water diseases love.
• new housing estates and ex-cane land: housing estates are often heavily bulldozed soils that are highly manipulated into being the foundations for a series of neatly aligned housing structures and driveways; filler top soil can be brought in from anywhere and who knows what kind of soil is it or where it came from or if it has any resemblance to the soil that is already there! Likewise, many sugar cane properties are being taken over by housing estates. Years of tillage, fertilizers, fungicides and herbicides have been saturated into the soils and then covered with a thin layer of top soil, a house, a driveway and some minor landscaping.
• severe drought: this causes great stress on soil condition due to the die-off of a whole group of microbials (the moisture dependent ones) and dominance of another, stronger group (the drought-tolerant ones); soils become looser during extended drought and even big trees died and fell down local Cairns hillslopes during 2000-03, causing scars in the sides of hills which will then be eroded further during rainy weather; droughts are likely to become worse under the climate change senario so widespread remedial treatment will be necessary after each drought.
• heavy demands on nutrients: growing your own food is wonderful but just as food feeds you, you need to feed your food; a backyard sporting several fruit trees and especially citrus and mango needs to be fertilised more often or else the soil will be depleted quickly and become acid/sour; this also applies to some extent to a yard landscaped in a rainforest style with several large native trees with extensive root systems - when choosing any fertilizer, go for organics and avoid dynamic lifter or other highly processed products.

Please procede to our Recommendations page for suggestions how to improve your soil health, especially if you scored 29 points or more in the questionaire!

Last updated: August 1st, 2009

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