Crop Diary, September

[Transcript of Crop Diary, September]

Hi. Welcome to this month’s Crop Diary report for September.

Last month I talked about the Carbon farming conference held in Albury New South Wales where the federal government direct action policy of carbon segregation into agriculture soils was the main discussion, and where I presented a paper on building soil carbon and the barriers from doing so.

This month I want to talk to you about subtle soil degradation, a term in which I use to describe a decline in soil health over many years, which is generally not noticed by the land holder. No till farming and stubble retention may help to retain existing carbon in soils however as shown by many long term trials in Australia and other countries, it will not help build carbon levels. Although the majority of farmers are very keen to look after their soils many traditional agriculture inputs of some fertilisers and chemicals are having a detrimental effect on carbon levels and therefore soil health. Fungicides and insecticides are very detrimental to soil biology.

Biology which in ideal conditions which can measure up to Tons per hectare, which greatly increases and encourages root systems, all of which become organic carbon in the soil. To give an example it has been said by SARDI researchers the more Urea the farmer uses, the more lime they will need to apply. Another has said, the more Urea you apply the more fungicides will need to be used to control such diseases as strike rust. The reason for this as nitrate nitrogen from Urea is very leachable it takes calcium and other nutrients down the soil profile and with it causing soil structure to decline and therefore effecting biological activity. The concentration of Urea banded in the soil creates a toxic zone to root systems and biology up to 8 weeks, and thus reducing the available mineral nutrients to the plant.

This toxicity of nitrate also greatly reduces the all-important mycorrhizal fungi in the soil. I mentioned Urea because the application of this fertiliser has increased dramatically in recent years and it has always been know that is causes adverse effects to our soil. So, in short we can not hope to build soil and carbon levels unless we adjust the input to more soils friendly inputs.

Next month, we will look at alternatives to some of our exciting inputs with the objective of building soil health. In the meantime, if you have any questions on this presentation, please feel free to call.