Saturday, October 7, 2017

Interesting info from Rosenberg et al 2009

"Positive effects of bacteria–protozoa interactions on plant growth are well documented (Bonkowski 2004) and recent findings strongly indicated that grazing induced shifts in bacterial diversity and function are responsible for plant growth promoting effects of bacterial grazers (Bonkowski and Brandt, 2002Kreuzer et al., 2006Mao et al., 2007). In fact, shoot and root biomass of A. thaliana increased significantly in presence of amoebae and the early growth response of plants was not linked to increased nutrient availability from consumed bacterial biomass (Krome et al., 2009). Our results confirm that grazing-induced changes in bacterial community composition are strongly interlinked with protozoan effects on plant growth. These findings have important implications for the success of applied studies, such as plant inoculations with growth-promoting bacterial strains.
In conclusion, protozoan grazing rapidly and significantly affected the diversity, activity and function of rhizosphere bacteria. Dominant bacterial groups were reduced, marginal groups gained competitive advantage, leading to greater evenness of grazed communities. However, the treatment-specific banding pattern in DGGE gels indicates that distinct mechanisms based on specific feeding preferences and competitive outcomes structured bacterial community composition in a well-defined way, despite bacterial communities were highly diverse. Our model system has been shown to warrant standardized experimental conditions to further investigate the mechanisms responsible for structuring of bacterial communities and its coupling to plant growth promotion by protozoa. Undoubtedly, protozoa need to be considered an important structuring force in investigations on plant–microbial interactions."

Tuesday, April 4, 2017

Organic food no more nutritious than conventionally grown food

This article at Harvard Health Publications reviews a super study of 250 studies on nutritional value of organic vs conventionally farmed produce.  Shows 30% less pesticides in organic but little or no difference in nutritional value

Monday, April 3, 2017

Soil Fertility and Biodiversity in Organic Farming by Maeder

Great article on organic farming vs traditional farming pluses and minuses

African farmers save the soil

Great article on how African farmers are replenishing their soils without chemical fertilizers

Monday, October 10, 2016

MicroBiometerTM gives results comparable to Carbon Fumigation and it takes only 12 minutes.

I just spent a marvelous week with Professor Paolo Grazziatti and his soil microbiology team at Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM Campus JK - Diamantina/MG correlating the MicroBiometer™ method with the carbon fumigation method.  Initial results with excellent and Prolific Earth Sciences and UFVJM are continuing the collaboration.  

Microbial Biomass reflects the nutrient value and pH of soil, from Anderson and Joergensen

TH Anderson and RG Joergensen 1997 SoilBiolandBiochem

Reviewed their data showing excellent correlation of Microbial Biomass as calculated by Soil Respiration with the Carbon Fumigation method, R2 = 0.89.  Interesting their data shows that Microbial Biomass is just a reflection of the pH and nutrient value of the soil, R2 = 0.89

Review or “Hotspots of microbial activity induced by earthworm burrows, old root channels, and their combination in subsoil. 
Hoang D.T.T. et al. Biol Fertil Soils 26 September 2016, generously shared by the authors on Research Gate. 

Great article -- reports that Microbial Biomass and Soil organic matter is orders of magnitude increased in earth worm burrows as compared to bulk soil.  Interestingly they show that the quality of the organic matter correlates with the microbial biomass.  Also show that levels of critical nutrients like N and Phosphorous are significantly higher in the burrows where they increase the quality of the nutrients.  They compared biopores made by worms with those, made by decaying roots and those made by root biopores with worms.  The increase in microbial biomass is attributed not only to the increase in substrate but to the quality of the organic material that is created by earth worms as they process soil as shown by the superiority of the burrows inhabited by both decaying roots and worms.