Archive for the ‘Sustainable farming’ Category

Water quality – its Basic!

Saturday, December 24th, 2016

Its December and in South Gippsland our creeks have slowed to little more than a trickle. Like many rural properties we have to rely on water stored in dams to get us through to Autumn. Our garden and nursery stock put extra demands on our supplies, and of course the cows are always thirsty!

Around the farm we use rainwater tanks for the house and dam water for the cows. We also need water to wash down the dairy. For that we keep back and recycle rinse water but use dam water as well. In the dairy we need better quality water for washing down milking machines and for feeding to calves. For this we use rain water supplemented with treated dam water.

Through Summer as water levels fall, dam water comes under many stresses. This shows up as changes in pH, oxygenation, build up of nutrients and salts, turbidity and organic matter levels.

Farm dam at low water level in Summer

One of our dams at low level during Summer of 2015. As water level drops basic water quality can change and is shown by factors like clearness, oxygenation, pH, salts and nutrients.

Where does water come from for your farm or rural property? Are you getting the right quality for the right use?

A water test can be a good first step to get your water supply right. It can tell which supplies can be used in different parts of the farm. A test can also pick up changes in water quality or even hazards in the water.

There are many options to treat water so that it can be used in more critical applications. At Apps Laboratories we provide the testing that gives a start in improving your water quality.

Our Basic water quality test is designed to test for around 9 critical water quality factors. We do the tests in our own lab – on our farm.

No you won’t be left with a report that makes no sense because we highlight all the key issues and talk about the possibilities for your water in a way that ‘normal folks’ understand because we know that’s what you expect.

Our Basic water quality test is good for tank water, dams, springs and bores.

To get your water tested is easy. Just go to our appslabs.com.au How to order page for instructions on collecting and posting samples.

Farm soil testing – acidity and phosphorus

Thursday, April 24th, 2014

In a previous blog entry, March 11 2014 I described some of the physical factors in a pasture soil in Gembrook that I had tested. The soil was very acidic with a very low proportion of fresh organic matter.

Exchangeable acidity results from prolonged leaching of good nutrients from soils. The pool is considerable larger than that represented by pH but is in balance with pH. A high exchangeable acidity usually means low pH. In this soil exchangeable acidity is very high and is creating a low pH. A low level of exchangeable acidity is normal and is always present in soils but a high level indicates a problem. The exchangeable acidity has to be at least partly overcome to raise the pH. Therefore exchangeable acidity is a good measurement on which to base calculation of lime requirement.

Exchangeable acidity (calculated by our partner lab as Lime requirement) is 4.8 meq% which is high. The exchangeable acidity determined on the same soil by Apps Labs was 0.32 meq% which by comparison to other figures is relatively low. Around 0.5 to 1 meq% is normal and acceptable (the lower the better). It looks like our lab is including aluminium in the exchangeable acidity whereas our method specifically measures the H ions.

Gembrook pasture and soil. The photo was taken in Summer and shows exposed soil and weeds.

Gembrook pasture and soil. The photo was taken in Summer and shows exposed soil and weeds.

The M3-PSR is the Mehlich Phosphorus Saturation Ratio, an environmental and soil quality test designed to show if phosphorus is likely to be leached from the soil. Conversely it will show the tendency of the soil to fix phosphorus and to make it less available to plants. A M3-PSR < 0.062 in below the agronomic minimum and shows that P uptake by plants will be poor. The result for this soil is 0.003 which indicates a strong tendency of the soil to hold phosphorus in an unavailable form.

The red Kraznozem soils around Gembrook are highly oxidized soils and the red colour comes mainly from the oxidized iron. These are similar to many of the soils found in equatorial regions including those in Africa, Asia and south America. I already expected a problem with phosphorus lockup in this soil as phosphorus binds strongly with iron and aluminium minerals at low pH. The M3-PSR mostly confirmed this.

Soil phosphorus was extracted using Mehlich 3 extractant. Mehlich 3 extractable P has been found to correlate well with a number of other indicators for more readily ‘plant available’ or potentially available phosphorus (see my previous blog entry on phosphorus in dairy farm soil for more detail). The result for phosphorus was 6.2 ppm. The ideal range is 30 – 70 ppm.  Therefore not only will this soil tend to bind up phosphorus, the overall level of plant available phosphorus is very low.

If inorganic phosphorus fertilizers are added to this soil much could be potentially lost before being used by plants. To get around this some farmers add up to twice the calculated plant phosphorus requirement. The result is that some soils have high phosphorus levels (see my previous blog entry on phosphorus in dairy farm soil). Other solutions are to use a slowly soluble form of phosphorus like rock phosphate or to create a fertilizer made up of granules of inorganic phosphorus compounds coated in compost or organic matter.

Sustainable farming – what is it?

Wednesday, March 19th, 2014

Yesterday as a guest of Trevor and Anne-Marie Mills and the Western Port Catchment Landcare Network I attended a field day on the Mills’ dairy farm at Drouin South.

Amongst the principles of sustainable agriculture are that farming should:

– provide an amenable lifestyle for the farmer & family

– protect and enhance the productive capacity of the farm

– protect and nurture the natural environment and reduce environmental impacts

Judging by these criteria, the Mills have gone a long way to creating a sustainable farm. Much of this has been achieved by thinking ‘outside the square’ and often going against conventional thinking. For example T & A-M have fenced off and replanted many of the drainage areas and watercourses on the farm. Water is now piped to stock high up in each paddock. The result; less contamination of water, less nutrient runoff and cleaner water for the cows to drink.

The South Gippsland area was originally heavily forested and early accounts have detailed the diversity of wildlife that once existed. Now with areas on the farm returning to natural vegetation, some of the native animals are also returning. Happily these areas are often those that would be less productive and difficult to manage. The photos below taken from the same spot approx 5 years apart show the dramatic change around a natural waterway.

Before and after watercourse revegetation on the Mills Farm at Drouin South. By excluding stock from wet gullies significant improvements have been made to the quality of water flowing from the farm and as drinking water for stock. Approx 5 years between photos. Courtesy of T & A-M Mills and WPCLN.

Before and after watercourse revegetation on the Mills Farm at Drouin South. By excluding stock from wet gullies significant improvements have been made to the quality of water flowing from the farm and as drinking water for stock. Approx 5 years between photos. Courtesy of T & A-M Mills and WPCLN.

The WPCLN as part of their involvment in the property have been monitoring water quality and this has provided valuable feedback for farm planning.

On the farm management side T & A-M have adopted a rotational grazing system that takes advantage of the natural productivity of the soil and facilitates nutrient cycling whilst protecting against overgrazing and damage to pasture. The result, an increase in productivity which has meant that the herd size can be reduced whilst maintaining production.

I was especially interested to hear how Trevor had cut back on use of urea as a nitrogen fertilizer. This came about because he saw that the urea was favouring grass growth and supressing clovers. Now clovers are thriving and producing nitrogen naturally!

I think that soil testing still has a role to play on this farm. Particularly if it is done in a way that provides a better understanding of management effects on soil processes and the dynamics of nutrient movement around the property as well as off the property as natural losses and in farm products.

Judging by the attendance at the field day there is a lot of interest in sustainable farming and land management. The Mills farm is an excellent example for all to see that shows how productive farming can go hand in hand with protecting and enhancing environmental quality.