Infact , no chemical fertilizer is detrimental to any microbe of soil , we just creaet a wrong hype. Why dont we look at the effect of fungicides/herbicides/pesticides having so many reaction products , so immune to biological/microbial degradation for years , but we never debate these issues. Just imagine , if this is the case, our soils would have lost their carrying capacity to zero after getting exposed to so many years of fertlization . Yes , i agree , if there is imbalance in fertilization and over-fertlization , soil ecology will be adversely affected. We developed a micrbail consortium with five component micorbes , each having resistanc eto chemical fertilizers upto 900-1200 ppm of ureaor SSP and 600 ppm of ferrous or zinc sulphate. Where is the notion that continuous use of chemical fertilizers has deteriorated the soil fertlity and productivity to an irreparairable limit......i dont agree ,,dear friends

Hi.

I hope the following information is useful.

Chapter 7 - Impact of agrochemicals on soil health Author links open overlay panelAsitMandal1Madhab CManna1 https://doi.org/10.1016/B978-0-08-103017-2.00007-6

Elbana T., Gaber H.M., Kishk F.M. (2019) Soil Chemical Pollution and Sustainable Agriculture. In: El-Ramady H., Alshaal T., Bakr N., Elbana T., Mohamed E., Belal AA. (eds) The Soils of Egypt. World Soils Book Series. Springer, Cham. https://doi.org/10.1007/978-3-319-95516-2_11

Effect of engineered nanoparticles on soil biota: Do they improve the soil quality and crop production or jeopardize them? https://doi.org/10.1002/ldr.3595

The synthetic chemicals in the chemical fertilizers adversely affect the health of naturally found soil micro-organisms by affecting the soil pH. ... The use of chemical fertilizers also jeopardizes the health of bacteria that fix the nitrogen balance in the soil. https://www.hunker.com/13427782/the-effects-of-chemical-fertilizers-on-soil

Organic treatment increased both fungi and bacteria slightly. Synthetic fertilizer did not kill bacteria in soil and it increased the number of fungi. ... Fertilizer, when used properly, does not kill microbes. https://www.gardenmyths.com/does-fertilizer-kill-soil-bacteria/

Sustainable agriculture is an important global issue. The use of organic fertilizers can enhance crop yield and soil properties while restraining pests and diseases. The objective of this study was to assess the effects of long-term use of chemical and organic fertilizers on tea and rhizosphere soil properties in tea orchards. Inductively coupled plasma mass spectrometry (ICP-MS) and high-throughput sequencing technology analyses were used to investigate heavy metals content and bacterial composition in rhizosphere soils. Our results indicated that organic fertilizer treatment significantly decreased Cu, Pb and Cd contents in rhizosphere soil sample. The results also showed that treatment with organic fertilizer significantly decreased the contents of Cd, Pb and As in tea leaves. Furthermore, organic fertilizer significantly increased the amino acids content of tea and the pH of the soil. The use of organic fertilizer significantly increased in the relative abundance of Burkholderiales, Myxococcales, Streptomycetales, Nitrospirales, Ktedonobacterales, Acidobacteriales, Gemmatimonadales, and Solibacterales, and decreased the abundance of Pseudonocardiales, Frankiales, Rhizobiales, and Xanthomonadales. In conclusion, organic fertilizer can help to shape the microbial composition and recruit beneficial bacteria into the rhizosphere of tea, leading to improved tea quality and reduced heavy metals content in rhizosphere soil and tea leaves.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6538140/

Microbes need both nutrients(nitrogen) and available carbon and an environment holding water, temperature etc. Take away one and/or change to a more adverse environment and microbes decrease. Just adding inorganic fertilizers and you deplete the available carbon and likely reduce the quality of the environment they need to live.

But to answer your question; I'm thinking nitrates are the most damaging to microbes. This especially if the pH of the soil is low. Nitrates are aggressive against root hairs and microbes. Also; ammonia in soil with a high pH can be damaging to plants and microbes. The unionized ammonia (NH3) is volatile and toxic.

Infact , no chemical fertilizer is detrimental to any microbe of soil , we just creaet a wrong hype. Why dont we look at the effect of fungicides/herbicides/pesticides having so many reaction products , so immune to biological/microbial degradation for years , but we never debate these issues. Just imagine , if this is the case, our soils would have lost their carrying capacity to zero after getting exposed to so many years of fertlization . Yes , i agree , if there is imbalance in fertilization and over-fertlization , soil ecology will be adversely affected. We developed a micrbail consortium with five component micorbes , each having resistanc eto chemical fertilizers upto 900-1200 ppm of ureaor SSP and 600 ppm of ferrous or zinc sulphate. Where is the notion that continuous use of chemical fertilizers has deteriorated the soil fertlity and productivity to an irreparairable limit......i dont agree ,,dear friends

You may like to go through my attached paper. It is all about the effect of fertilizers on soil health - including the effect on soil microbial life.

En mi libro "SALINIDAD, un nuevo concepto" se señala que los fertilizantes incrementan la salinidad sobre todo en la zona de la rizosfera lo que ocasiona perdida de la microbiota en esta área, en la medida en que persista el fertilizante, claro que se recuperara ,pero el efecto es notable disminución de los microorganismos que intervienen en los ciclos del CARBONO y del Nitrógeno

I fully agree with Dr. Anoop k. Srivastava. Chemical fertilizer do not adversely affect the microbial population. When used as per recommended dose they provide a balanced supply of crop desired nutrients and result in high microbial activities. Soil is a complex system and no of undesired activities in soil environment may affect the microbial load.

The synthetic chemicals in the chemical fertilizers adversely affect the health of naturally found soil micro-organisms by affecting the soil pH. These altered levels of acidity in the soil eliminate the micro-organisms beneficial to plant and soil health as they help to increase the plants' natural defenses against pests and diseases. These helpful micro-organisms consist of antibiotic-producing bacteria and mycorrhizal and other fungi which are found in healthy soil. The use of chemical fertilizers also jeopardizes the health of bacteria that fix the nitrogen balance in the soil. These nitrogen-fixing bacteria are responsible for converting the atmospheric oxygen into a form of nitrogen that can be used readily by plants

Most fertilizers supply nutrients in the soluble form and are extremely beneficial when present in proper amount or integrated application with organic. However, higher quantity causes temporarily inhibit microbial growth.

Chinaza Godswill Awuchi

Frank Shields

Anoop Kumar Srivastava

Bijay Singh

Shaon Kumar Das

Sunita Gaind

Melekote Nagabhushan Arun

Mahipal Choudhary

@ Bijay Singh Sir, thanks for attaching the highly informative article. Regards.

The prolonged use of some fertilizers, particularly Urea and Ammonium Phosphates have been known to lower soil reaction. The low soil pH that results is detrimental to the normal functioning of soil microbes. It is partly for the same reason that best practices are based on integrated soil fertility management that incorporates organic sources of plant nutrients . My thoughts!

No fertilizer is toxic to any microorganisms. addition of nitrogenous fertilizer for long time without addition of any organic matter in the soil is the detrimental to the soil health. easily available nitrogen to the microbes specially bacteria is the feast for them. their population increased rapidly specially allochthonous bacteria (bacillus) and eat soil organic carbon rapidly. their population outgrowth to the autochthonous microbial populations. diversity of microbial population get reduced in a long run. the soil may have more bacterial populations in numbers (so apparently we may concluded that the soil is healthy) but the number of diverse microorganisms get drastically reduced.

So. the term balanced fertilization is really needs to apply in practical to conserve soil health for long term

This topic is such that many times answer by starting phrase as ''in my view...'' or ''I feel...''. To my mind, we as scientists should always say something with the evidence available in the literature. The discussion will then become more useful for all of us.

Fertilizations influence both the aboveground biomass and the belowground microbe biomass. Soil microbial communities play critical roles in ecosystem function and regulate key processes such as carbon and nitrogen cycles During the long-term evolution process, the soil, plants and microbes have co-evolved, forming relatively stable relationships under certain ecosystems. In this relationship, genetic variation in plant phenotypes can change soil processes and biotic communities, whereas soil gradients and microbial communities can influence the expression and evolution of plant phenotypes. When exterior N and P are input into the local ecosystem, the given balance between soils, plants,, and microbes will be destroyed, and a new balance will be formed. For example, in a 50-year-old fertilization experiment, the composition of soil nitrate-reducing, denitrifying and total bacterial communities co-varied with primary production and both were strongly linked to soil properties

Fertilizers, when applied as per the need of the crop (and not more), are generally not harmful to soil microorganisms. If there is any effect, that will be very temporary. However, those fertilizers which create acidity in the soil, may show adverse effect on soil microorganisms. As I have already suggested, you may have a detailed analysis of this issue in my attached paper.

I conquer with your thoughts Bijay Singh.....