#agriculture meaning

[lonelysocksclub]

Oh boy I need patience this weekend. My cousin is visiting and he just explained to me, a biologist who has worked with maize genetics, how to make a kind of supermaize by using electromagnetic fields to manipulate DNA expression. The goal is to trick the maize to express the genes it had millions of years ago, a time when maize as we know it definitely existed and agricultural yield was famously high. And it's only Friday.

[theology101]

If Helio turns out to be Cassandra and Ankarna’s son and Sol forcefully adopted him through ‘As Above, So Below’ then it PROVES TO ME that he Chose Kristen well

[sedlex]

[kulapti]

Oct 2023, pen & inks. Grass is not all the same.

Many people don't know that grasslands have fall colors. This is partly because over 75% of the prairie habitat on the North American continent has been destroyed by agriculture, systematic destruction, and more recently by urban sprawl. We have less than 1% of historic tallgrass prairie remaining. Please learn about these beautiful and rare spaces to help them, and if you get the chance, go see a prairie in national grassland or in a state or national park.

Aside from the sparkly ink, this illustration has a narrower color range than the Red Hills mixedgrass prairie it represents.

Species: Little bluestem (S. scoparium), big bluestem (A. gerardii), maidenhair (Sporobolus sp.), sideoats grama (B. curtipendula), blooming prairie blazing star (Liatris sp.), and the late season remnants of basketflower (Centaurea americana) and dwarf four-nerve daisy (Tetraneuris linearifolius).

[rocketbirdie]

i would love to enjoy everything that stardew valley has to offer but unfortunately i approach this game the same way i approach real life: avoid all social interaction and tend to my garden in belligerent silence

[just-call-mefr1es]

rlly torn on if i should keep griff in district 4 or move him to 11

like,, i like olympic swimmer griff™️ but also almost dying of starvation griff sounds more his character or something idk how to word

[bookie-the-reading-junkie]

me reading an article from 1963 about how fruit farming was introduced in the Okayama prefecture by coping and pasting page by page into google translate: hmm yes, very interesting and definitely will be very useful for writing my latest fic chapter

[iwouldliketoeatrandy]

Fun fact: did you know the US government has been awarding Automattic Inc. millions of dollars since 2021 which will run until December of 2024? Specifically, the presidential office has been funding tumblr.

Automattic Inc. bought tumblr in 2019.

Do you know who else funded Automattic Inc. in 2019 some $70,000? The US Department of Defense.

[batmanshole]

never forget when me and my dad were discussing uni + college options for me and he was like

"oh you might like guelph. you like plants. Oh, and back when i was in university, they used to call it 'Dyke U' because all the hot farmer lesbians went there. you'd like it."

[purble-gaymer]

spring term shaping up to be the first term i spend entirely in the science center haha…..

[cookie-nom-nom]

The Impacts of Agricultural Practices on Arbuscular Mycorrhizal Fungi

By popular demand (one single person) I present a semster's worth of research into the scientific uncertainty surrounding Arbuscular mycorrhizal fungi as pertaining to agriculture because oh boy. is there some uncertainty. Which is a boring way of saying the world is ripe with potential and the mycology is a blossoming field of research! Yippee!

Arbuscular mycorrhizal fungi (AMF) have potential to increase the efficiency of modern agricultural practices due to its beneficial impacts on crops. AMF are a broad category of fungi species that live in the soil and connect to the roots of plants, forming symbiotic relationships between them and other plants connected through the mycelium network. Due to their fine mycelium and ability to extract nutrients from inorganic compounds, AMF can access nitrogen and phosphorus from the soil and exchange it with for carbon compounds generated in photosynthesis by their plant hosts (Hodge and Storer 2014). This can provide crucial, often limiting nutrients to crops which otherwise deplete the nutrients in the soil with each harvest. AMF have also been found to increase plant resistance to pathogens, drought, or salinity (Cheng et al. 2023; Buysens, de Boulois, and Declerck 2014). However, the benefits of AMF to crops vary wildly, and in the wrong conditions AMF can become parasitic to their hosts (Hodge and Storer 2014). The complexity of AMF networks makes it difficult to ascertain their impacts, with variables such as available nutrients, soil conditions, or species involved in the symbiosis changing the results of studies. One component of addressing its potential use comes from examining how current farming practices impact the effectiveness of AMF for agriculture and the uncertainty obfuscating it.

Nutrients

Modern agriculture depends on ample fertilizer use to maintain yield output, which has heavy environmental costs, from excess nutrients causing eutrophication, to being carcinogenic and potentially radioactive, to the damage from mining and processing phosphate (Lubkowski 2016). One of the main advantages of AMF symbiosis is increased access to nutrients for the crop hosts, thus positioning it as a potential alternate source of nutrients. Understanding both the impact of fertilizers on AMF networks and how they compare in enriching crops is crucial when considering the potential of AMF in agriculture.

Over time, conventional fertilizers' usage greatly decreased the diversity of AMF species and their impact on crops (Oehl et al. 2004; Wang et al. 2018; Peng et al. 2023). Organic fertilizers resulted in nearly double the amount of AMF species compared to the plots using artificial fertilizers (Oehl et al. 2004). The composition of the fungal species was also different, with the species prevalent under organic farming more closely resembling those of a natural ecosystem. Furthermore, the dominant AMF species under long term, high intensity artificial fertilizer were less beneficial to crops (Peng et al. 2023). Potentially less efficient AMF species were selected for by high input farming as the crop would trade for phosphorous less readily due to the abundance from the fertilizer (Oehl et al. 2004). Less diversity in AMF resulted in decreased benefits to crops, suggesting that farming techniques that increase the diversity of AMF will be more beneficial to farmers (Oehl et al. 2004; Wang et al. 2018). However, Peng et al. found that the lower AMF diversity in fertilized fields did not cause lower crop yield, but did find increased soil stability and nutrient cycling (2023). As it was the diversity of the AMF being measured, the diverse and partially conflicting results are logical because of the different AMF species and dynamics present in each study. AMF diversity appeared to relate to multiple but inconsistent positive effects for agriculture and was clearly harmed by the use of conventional fertilizers.

Fertilizer negatively impacted the root colonization of AMF (Oehl et al. 2004; Sheng et al. 2012; Peng et al. 2023). Cultures taken from organic farming plots had a higher chance of inoculation and faster root colonization compared to traditional fertilizer use (Oehl et al. 2004). AMF species that quickly and more fully colonize roots would be highly valuable in modern agriculture, which prioritizes annual plants and thus would need to quickly renew relationships with AMF networks in order to benefit from the symbiosis. Potentially the particular species predominate under organic farming was well suited to swift colonization of the crops used. Alternatively, the diversity of the AMF species may have been the cause due to an increased chance of having a fungal species suited to the crop species. More testing is necessary to ascertain which variable has the greatest impact on root colonization.

Other indicators of fertilizer impact on AMF growth were not so clear-cut, as hyphal and spore density had conflicting responses to long-term fertilizer use. Sheng et al. posited that the limited benefits of AMF in fertilized fields could be attributed to added phosphorus causing limited hyphal growth in the top layers of soil, reducing the amount of root connections with crops (2012). However, Peng et al. found that hyphal length density increased with the addition of nitrogen and phosphorus in tandem but having neutral impact separately (2023). Potentially the negative impact Sheng et al. noted was influenced by a lack of nitrogen, but that would not fully explain the anathema results. Additionally, in two experiments fertilizer increased the spore density, potentially due to the fungi being in unfavorable conditions and consequently switching from an emphasis on hyphal growth to spores to increase their long-term survival (Sheng et al. 2012; Peng et al. 2023). In contrast, Oehl et al. found a decreased abundance of spores in fertilized fields (2004). The reason for the stark contrast in results is unclear, and could be contributed to different crop species, duration of studies, soil characteristics, or any other plethora of variables that without further study will not be elucidated.

Soil Organic Matter (OM) also influenced the relationship between AMF, fertilizer, and harvest due to influencing the amount of nutrients available to plants. The benefit of fertilizer on inoculated raspberries was significantly less pronounced in high OM environments, where the weight of berries had a negative relation to the amount of fertilizer (Chen et al. 2022). In low nutrient conditions with low OM and fertilizer usage, inoculated raspberries had small berries, potentially due to the host and fungi competing for limited nutrients. A similar trend was found with the fruit set, or percentage of flowers that produced berries. In an inoculated field with low OM, fertilizer increased the fruit set but in high OM it decreased (Chen et al. 2022). Furthermore, the highest fruit set belonged to an inoculated field with high OM and no fertilizer. Therefore, there is likely a limited range of available nutrients (whether from OM or fertilizers) wherein AMF are beneficial to crops, suggesting that future experiments concerning AMF and fertilizer must take pre-existing soil nutrients into consideration. Further testing is required to determine the optimal combination of OM and fertilizers to achieve the benefits of AMF, because as of yet the impact of nutrients on AMF networks is still not fully understood.

Crops

The AMF represent only one half of the symbiotic relationship, and so the hosts available to them greatly determine the impact of AMF. The harmful effects of annual monocultures are well established, resulting in decreased biodiversity and nutrient loss that could negatively impact AMF networks (Crews, Carton, and Olsson 2018). The prevalence of monocultures in modern agriculture raises the question of how the limited selection of hosts impacts AMF networks.

Crop diversity is clearly linked to AMF diversity. Oehl et al. suggested that the seven- year crop rotation method used in their experiment contributed to the high diversity of species, as they had more similar numbers of species in wild grasslands than is found in cropland that utilizes the same monoculture every year (2004). Intercropping systems were likewise found to sustain richer and more diverse AMF communities than monocultures (Lu 2018; Cheng et al. 2023). It is likely that the variety of the hosts provides a variety of symbiosis opportunities for differently adapted AMF species to bond with, thus increasing the AMF diversity and richness.

But as previously discussed, AMF diversity is not a clear indicator of benefit. Crop diversity may benefit AMF networks, but farmers are more interested in how that impacts crops. Intercropping results in a significant increase in yield compared to monocultures, known as over yielding. Cheng et al. found a positive correlation between intercrop yield and AMF diversity, though Wang et al. clarified that not all inoculated crop species in an intercrop system experienced an increased yield, further cementing how varied AMF-crop interactions are (2023; 2018). Lu hypothesized that the AMF nutrient transfers explained over yielding in intercropping system but due to confounding variables it was difficult to ascertain (2018). Notably, the yield benefits of intercropping were diminished in fields with high amounts of phosphorus from added fertilizer (Wang et al. 2018). Combined with the theory that less beneficial AMF were selected for in fertilized fields, the success of intercropping beneath conditions favorable to AMF suggests AMF could be a contributing factor to the over yielding phenomena found in intercropping and thus practice that support AMF are vital to intercrop systems (Oehl et al. 2004; Peng et al. 2023).

Annual crops dominate modern agriculture and thus their relationships with AMF are valuable to examine. The disruption of the soil from the tillage necessary for annual crops results in severe soil and nutrient erosion in a way that is unsustainable (Crews, Carton, and Olsson 2018). Tillage has a harmful impact on AMF due to severing the mycelium networks, so the practices associated with annual crops are already known to harm AMF communities due to severing mycelial networks and causing changes in nutrients (Peng et al. 2023; Sheng et al. 2012). Periods of bare soil between yearly annuals and destruction of weeds result in stretches of time when AMF have reduced host possibilities. Overall, the associated farming techniques used for annuals are not beneficial to AMF.

Annual crops also face the added complication of new plants having to re-establish their symbiosis with AMF. Due to the lag in benefit from AMF, short-lived plants may be less likely to invest in a symbiotic relationship with them. Perennial legumes with AMF networks had more growth than annual species, with increased nitrogen and phosphorous given to the crops (Primieri et al. 2021). It was possible the AMF reinvested in perennials over and over because they have proven to be good symbionts, whereas there was a time lag in reinvesting in a new year of annuals. Therefor agriculturalists using perennials may have even more investment in using practices that compliment AMF as they have an increased impact. However, the study’s results should be treated with caution as the perennial crop was an undomesticated crop species due to farming crops being mostly annuals and comparisons show that domesticated species can be less able to support AMF (Primieri et al. 2021). Because species react differently to AMF symbiosis, studies between annual and perennials were difficult to construct. However, combined with the associated practices of tilling and periods with decreased access to hosts, it is likely that AMF is more helpful to farmers in perennial systems. Though there is some uncertainty, the consensus of research is that perennial and diverse crops have more beneficial symbiotic relationships with AMF.

Pesticides, Herbicides, and Fungicides oh my!

Conventional farming heavily relies on utilization of hazardous chemicals to kill organisms that pose threats to crops, be they rivalrous weeds, hungry herbivores, or fungi plagues. While pesticides seek to target specific species or groups, the introduction of toxins in the environment often has unintended side effects that could be influencing mycorrhizal networks. Studies conflict greatly whether pesticides help or hinder AMF, in part thanks to the plethora of confounding variables involved.

The species involved in the system are a large factor in the effect pesticides have on AMF. Different AMF species have various methods of dealing with toxins in their environment, such as compartmentalization, producing protective molecules, and transporting pollutants (Hage-Ahmed, Rosner, and Steinkellner 2018). Therefore, the response an AMF network has to pesticides will depend on the predominant fungal strains. As AMF are in symbiosis with plants, their species are also relevant. The application of herbicides to weeds limits the number of hosts the AMF are able to rely on. However, in some studies the AMF were able to recover after a few weeks, though their ability to do so was dependent on the crop species they were partnered with (Hage-Ahmed, Rosner, and Steinkellner 2018). Other studies even found herbicides had a neutral or positive impact on AMF. Soil bacteria that associate with AMF can also vary in quantity and quality within the same field, especially species that biodegrade pesticides and influence their persistence (Hage-Ahmed, Rosner, and Steinkellner 2018). Due to AMF being symbiotic networks, the species at play, be they fungal, plant, or bacteria, can all highly influence how the system responds to pesticide disturbances.

Fungicides potentially pose a threat to AMF due to being designed to target fungi. At IC50 threshold to control a fungal pest, three fungicides had no impact on AMF except for flutolanil decreasing root colonization (Buysens, de Boulois, and Declerck 2014). Pencycuron had no effect on AMF at threshold concentrations and was contact based compared to the other tested fungicides, which were systemic and infiltrated the body of the plant (Buysens, de Boulois, and Declerck 2014; McGrath 2004). Potentially the integration of flurolanil in the host plant made it more hazardous for AMF. Alternatively, contact fungicides applied through foliar spray could be less likely to contaminate the soil (Hage-Ahmed, Rosner, and Steinkellner 2018). Azoxystrobin, like flurolanil, was a systemic fungicide but had lower systemic activity, which could be why it did not have adverse effects on AMF at the threshold level. Pencycuron and flutolanil were species specific fungicides, so the difference in impact could be attributed to increased effectiveness against a fungus similar to AMF species (Buysens, de Boulois, and Declerck 2014). At levels exceeding the threshold all three fungicides had significant negative impact on spore production, mycelium and root growth, and germination. Therefore, carefully choosing the type and quantity of fungicide is crucial to not harm beneficial fungal species.

When the pesticide is applied also greatly impacts the AMF as certain stages of its life cycle are more vulnerable to interference than others. Certain pesticides impeded germination, but multiple studies found that germination was not completely terminated, and that once the pesticide was removed germination was no longer impeded and AMF were able to establish (Buysens, de Boulois, and Declerck 2014; Hage-Ahmed, Rosner, and Steinkellner 2018). In early stages of its lifecycle, AMF had a limited time to find a host and will die if one is not found. Pesticide interference should be avoided in this stage so the AMF and crops can form symbiosis (Hage-Ahmed, Rosner, and Steinkellner 2018). Once established, AMF will be harmed if most of its plant hosts die, so non-selective herbicides can threaten them. They could depend on spores and colonized root fragments should they lack a host, however.

Pesticides vary in effectiveness based on environmental and agricultural conditions, confounding their impact on AMF. The history of the field being tested could greatly affect AMF networks. Practices like tilling and other soil disturbance made AMF colonies more vulnerable to being negatively impacted by pesticides, possibly due to not being as well established as an undisturbed network and thus less resilient. The sheer number of variables involved in studying pesticide’s impact on fungi deeply confound the results of studies.

The amount of exposure to the pesticide impacts to what degree AMF are affected, but it is highly influenced by confounding factors that make it difficult to assess its impact. Practices like tilling and other soil disturbance made AMF colonies more vulnerable to being negatively impacted by pesticides, possibly due to not being as well established as an undisturbed network and thus less resilient (Hage-Ahmed, Rosner, and Steinkellner 2018). The persistence of the pesticide depended greatly on soil condition, including type, pH, moisture, organic matter, and the ability for microflora to degrade substances, all influencing how much exposure the AMF had long-term (Hage-Ahmed, Rosner, and Steinkellner 2018). Furthermore, the type, dose, and application method of pesticide was dependent on the crop being grown, creating even more variation in AMF reaction, and thus confounding studies. In one experiment, going over the recommended dose of a pesticide could either impact the AMF negatively, positively, or not at all, but in another it reduced the effectiveness of symbiosis and the amount of phosphorus transported to the plant (Hage-Ahmed, Rosner, and Steinkellner 2018). Due to the variety of conditions impacting AMF exposure to pesticides, it was difficult to gauge their impact on AMF, and uncertainty in this aspect of studying agricultural AMF held great uncertainty.

Conclusions

The intense networks of factors involved in agriculture systems mean measuring the impact of farming techniques on arbuscular mycorrhizal fungi is difficult. Given the variety of the fungal species involved in AMF networks, it may not be fully possible to have fully accurate generalizations about the impact of farming. With each system of unique combinations of hosts, fungi, and other soil microbiota comes new dynamics to be studied. This is further compounded by soil conditions, nutrient availability, tilling, and potentially many other variables not discussed in this paper. Uncertainty is rampant in this area, particularly as the usefulness of AMF have been discovered only relatively recently. The most evident example is in the realm of pesticides, where the intensity of the variability of results obfuscates broader patterns. However, there is growing evidence that many conventional farming practices such as fertilizers, monocultures, and annuals are damaging to AMF colonies and potentially diminish the benefits they can offer crops. If farming is to become sustainable while still providing enough food for the growing human population, healthier farming practices must be utilized. Though there is uncertainty, there is also great potential once we understand the factors influencing successful AMF symbiosis.

Bibliography

Buysens, Catherine, Hervé Dupré De Boulois, and Stéphane Declerck. 2014. “Do Fungicides Used to Control Rhizoctonia Solani Impact the Non-Target Arbuscular Mycorrhizal Fungus Rhizophagus Irregularis?” https://doi.org/10.1007/s00572-014-0610-7.

Chen, Ke ID, Jeroen Scheper, Thijs P M Fijen, and David Kleijn. 2022. “Potential Tradeoffs between Effects of Arbuscular Mycorrhizal Fungi Inoculation, Soil Organic Matter Content and Fertilizer Application in Raspberry Production.” https://doi.org/10.1371/journal.pone.0269751.

Cheng, Yunlong, Xing Xu, Yang Zhang, Xudong Gu, Haohie Nie, and Lin Zhu. 2023. “Intercropping of Echinochloa frumentacea with Leguminous Forages Improves Hay Yields, Arbuscular Mycorrhizal Fungi Diversity, and Soil Enzyme Activities in Saline–Alkali Soil.” Agronomy 2356: 1-13. https://doi.org/10.3390/agronomy13092356.

Crews, Timothy E., Wim Carton, and Lennart Olsson. “Is the Future of Agriculture Perennial? Imperatives and Opportunities to Reinvent Agriculture by Shifting from Annual Monocultures to Perennial Polycultures.” Global Sustainability 1 (2018): e11. https://doi.org/10.1017/sus.2018.11.

Hage-Ahmed, Karin, Kathrin Rosner, and Siegrid Steinkellner. 2018. “Arbuscular Mycorrhizal Fungi and Their Response to Pesticides.” Pest Management Science 75 (3): 583–90. https://doi.org/10.1002/ps.5220.

Hodge, Angela, and Kate Storer. 2014. “Arbuscular Mycorrhiza and Nitrogen: Implications for Individual Plants through to Ecosystems.” Plant and Soil 386 (1-2): 1–19. https://doi.org/10.1007/s11104-014-2162-1.

Lu, Xingli. 2022. “Effect of Intercropping Soybean on the Diversity of the Rhizosphere Soil Arbuscular Mycorrhizal Fungi Communities in Wheat Fields.” Clean – Soil, Air, Water 2100014: 1-14. https://doi.org/10.1002/clen.202100014.

Lubkowski, Krzysztof. 2016. “Environmental Impact of Fertilizer Use and Slow Release of Mineral Nutrients as a Response to This Challenge.” Polish Journal of Chemical Technology 18 (1): 72– 79. https://doi.org/10.1515/pjct-2016-0012.

McGrath. 2004. “What Are Fungicides.” What Are Fungicides. https://www.apsnet.org/edcenter/disimpactmngmnt/topc/Pages/Fungicides.aspx.

Oehl, Fritz, Ewald Sieverding, Paul Mäder, David Dubois, Kurt Ineichen, Thomas Boller, and Andres Wiemken. 2004. “Impact of Long-Term Conventional and Organic Farming on the Diversity of Arbuscular Mycorrhizal Fungi.” Oecologia 138 (4): 574–83. https://www.jstor.org/stable/40005539.

Peng, Zhenling, Nancy Collins Johnson, Jan Jansa, Jiayao Han, Zhou Fang, Yali Zhang, Shengjing Jiang, et al. 2023. “Mycorrhizal Effects on Crop Yield and Soil Ecosystem Functions in a Long- Term Tillage and Fertilization Experiment.” New Phytologist 2023: 1-14. https://doi.org/10.1111/nph.19493.

Primieri, Silmar, Susan M Magnoli, Thomas Koffel, Sidney L Stürmer, St ̈ Stürmer, James D Bever, and W K Kellogg. 2022. “Perennial, but Not Annual Legumes Synergistically Benefit from Infection with Arbuscular Mycorrhizal Fungi and Rhizobia: A Meta-Analysis.” New Phytologist 233: 505–14. https://doi.org/10.1111/nph.17787.

Sheng, Min, Roger Lalande, Chantal Hamel and Noura Ziadi. 2013. “Effect of long-term tillage and mineral phosphorus fertilization on arbuscular mycorrhizal fungi in a humid continental zone of Eastern Canada.” Plant and Soil 369 (1-2): 599-614. http://dx.doi.org.webster.austincollege.edu/10.1007/s11104-013-1585-4.

Wang, Guangzhou, Chengcheng Ye, Junling Zhang, Liz Koziol, James D Bever, and Xiaolin Li. 2018. “Asymmetric Facilitation Induced by Inoculation with Arbuscular Mycorrhizal Fungi Leads to Overyielding in Maize/Faba Bean Intercropping.” Journal of Plant Interactions 14 (1): 10-20. https://doi.org/10.1080/17429145.2018.1550218.

[fullmoonfireball]

whats his problem

[californiaquail]

the apparent existence of pugs in westeros raises some questions

[flashhwing]

I think im only gonna plan my campaign up to level 10 then whatever happens happens. leaving the plot from there up to my players. your turn to weave the narrative bitch

[lunasilvis]

Hesitating if I should apply for a function at a company with close ties to their mother company in Chicago, Illinois... the dilemma I face: I don't want to abnegate + betray my own soul by working commercially, but it could be the right stepping stone to an international career and be able to live abroad for some time in my life (around my mid-late 30s)

Hm i'll ruminate on it

[rotationalsymmetry]

Apparently whether planting milkweed helps the butterflies is More Complicated than it seems, based on variables like where exactly you live and what type of milkweed it is.

On the bright side, I am being pointed in the direction of organizations I very much wanted to know about, like the California Native Plant Society and the Xerces Society (which is about insect/invertebrate conservation.)

Learning things is good, right?