Are You About to Use a Weedicide?

Important points to consider when choosing to use a chemical hopefully as a last resort. Last week I was speaking with a farmer who was farming without chemicals but said that regrettably he had to use glyphosate recently.

So what could he have done to lessen the damage?
Many growers have been faced with making a similar decision. However while they still choose to use the weedicide they also add nutrient to the chemical; it is called buffering. Many farmers have been buffering total weedicides for years. Buffering with commercial fulvic acid is common. Other nutrients such as fish fertiliser, humic acids and worm cast teas have also been used with success.

What happens when you buffer a weedicide?
Buffering has 3 major effects.
Firstly less chemical is used which saves money!
Secondly, and more importantly, the chemical does less damage to the soil life, in particular to the mycorrhizal sphere, nature’s connector, the bridge between the plant and the locked up minerals in the soil. These fungi are very easy to annihilate and when you apply a weedicide they are set back severely as they can also only survive in the presence of a live host. That is why many farmers now add VAM (vesicular arbuscular Mycorrhizal fungi) into the soil when sowing to ensure a better strike rate.
Thirdly nutrients required by the soil microbes are added to the soil when the weedicides plus buffer is applied. Oddly enough the buffering often makes the weedicide even more effective and the remaining soil is healthier.

What is the importance of mycorrhizal fungi?
The mycorrhizal fungi provide all the mineral nutrients (notably phosphorus) to the plant and draw energy compounds from the host. “Many plants are very dependent on mycorrhizal symbiosis and make little growth without it unless heavily fertilised. Such plants are said to be mycotrophic. Perennial grasses are often strongly mycotrophic. …There are 2 types of Mycorrhizal fungi but the far most dominant type (and of more importance to the grower) is the group known as the arbuscular mycorrhizal (AM) or vesicular arbuscular mycorrhizal (VAM) fungi. This last group is so dominant in the plant kingdom…. Only about 150 species of these fungi are known, yet they are capable of forming mycorrhizal associations with 70% of Angiosperms as well as many ferns and conifers. In agricultural field soils up to 50 metres of AM hyphae per gram of soil have been observed and hyphae can extend more than 9 cm beyond the roots (Nasim, 2005).” *

The importance of buffering
By buffering you somewhat alleviate the damage done to the soil life and it is far less costly. We have heard of only 20% of glyphosate being used in trials with the same results being achieved as using the recommended rate on the label. Note: The label reads that the recommended rates must be used so do your own trials to find out for yourself.
Caution: Trial any product first especially if you are using a selective weedicides as buffering can make the weedicides less selective and set back non targeted plants.

 

* Ref. Rod Rush Agricultural Consultant