Explains all the required topics with plenty of drawings and photos, many of which are new to me. A good refresher and additional knowledge even for those who have been watching related presentations.
Thanks! If you want more information, particularly about agricultural techniques that build soil health, check out this report I wrote: www.iwla.org/soils-agriculture/soilhealthreport
A lot of information presented as general info is actually context specific. For example 5-7 tillage passes to prepare a seed bed. When actually only 1 or 2 are normally used and in rare cases 3. The 5 to 7 tillage passes would be for small scale organic farmers not using regenerative practices and includes cultivating passes in standing crops for weed control. The part on compaction seems to be taken out of a book and not working knowledge as it is a good start but seems to lack a depth of understanding. IMO it seems that more time needs to be spent on multiple working farms to better understand the working context.
Thanks for your comment. There are definitely bacteria and fungi in compost, but they are decomposers rather than plant-growth-promoting bacteria or mycorrhizae. The bacteria and fungi that help plants out in the soil are susceptible to the high temperatures reached in compose. The useful things in compost are nutrients made available through decomposition and organic matter.
@saraviaclimatechangeimpact5272 Decomposing bacteria can also be plant-growth promoting bacteria. They typically attach themselves to the roots of the plant where the majority of the nutrient exchanges happen.
I wonder how many of these beneficial soil microorganisms will survive the greatly increased soil temperatures we will experience as the planet continues to warm. I guess it depends on the particular species since they will all have different max temperature survivability, but surely most of them did not evolve under such extreme conditions? We always worry about the effects of heat stress on the crops themselves, but I don’t see many people talking about the impact on microbes. Maybe it’s not as worrisome as I’m imagining though.
Great question! I read a bit about that and the evidence seems a bit mixed - heat can reduce diversity of the microbial population, and that means fewer species will be doing the same thing. That's not too good because having more 'redundancy' means that there are other species left to do the job if some species drop out. However, bacteria have very short generation times, less than one hour in many cases, so their evolution can be fast. That means that tolerance to increased soil temperature might evolve relatively quickly, perhaps allowing soil bacteria to "keep up" with increasing temps. There is not much info on impacts of soil warming on mycorrhizae, and I don't know how fast they can evolve though it will be slower than bacteria. Bottom line right now is that we don't know as much as we need to about this.
@@saraviaclimatechangeimpact5272Thanks for the detailed response. I suppose mulching will be more important than ever as we try to stave off the higher temperatures.
I'm so lucky to have this lecture, blessing prof.sara ❤❤
Explains all the required topics with plenty of drawings and photos, many of which are new to me. A good refresher and additional knowledge even for those who have been watching related presentations.
Thanks! If you want more information, particularly about agricultural techniques that build soil health, check out this report I wrote: www.iwla.org/soils-agriculture/soilhealthreport
A lot of information presented as general info is actually context specific. For example 5-7 tillage passes to prepare a seed bed. When actually only 1 or 2 are normally used and in rare cases 3. The 5 to 7 tillage passes would be for small scale organic farmers not using regenerative practices and includes cultivating passes in standing crops for weed control. The part on compaction seems to be taken out of a book and not working knowledge as it is a good start but seems to lack a depth of understanding. IMO it seems that more time needs to be spent on multiple working farms to better understand the working context.
Adding compost does add useful microbiology. I'm quite shocked you would say otherwise.
Thanks for your comment. There are definitely bacteria and fungi in compost, but they are decomposers rather than plant-growth-promoting bacteria or mycorrhizae. The bacteria and fungi that help plants out in the soil are susceptible to the high temperatures reached in compose. The useful things in compost are nutrients made available through decomposition and organic matter.
@saraviaclimatechangeimpact5272 Decomposing bacteria can also be plant-growth promoting bacteria. They typically attach themselves to the roots of the plant where the majority of the nutrient exchanges happen.
I wonder how many of these beneficial soil microorganisms will survive the greatly increased soil temperatures we will experience as the planet continues to warm. I guess it depends on the particular species since they will all have different max temperature survivability, but surely most of them did not evolve under such extreme conditions? We always worry about the effects of heat stress on the crops themselves, but I don’t see many people talking about the impact on microbes. Maybe it’s not as worrisome as I’m imagining though.
Great question! I read a bit about that and the evidence seems a bit mixed - heat can reduce diversity of the microbial population, and that means fewer species will be doing the same thing. That's not too good because having more 'redundancy' means that there are other species left to do the job if some species drop out. However, bacteria have very short generation times, less than one hour in many cases, so their evolution can be fast. That means that tolerance to increased soil temperature might evolve relatively quickly, perhaps allowing soil bacteria to "keep up" with increasing temps. There is not much info on impacts of soil warming on mycorrhizae, and I don't know how fast they can evolve though it will be slower than bacteria. Bottom line right now is that we don't know as much as we need to about this.
@@saraviaclimatechangeimpact5272Thanks for the detailed response. I suppose mulching will be more important than ever as we try to stave off the higher temperatures.
Lewis Sharon Clark Karen Anderson Lisa