scholarly journals Agricultural intensification reduces microbial network complexity and the abundance of keystone taxa in roots

2018 ◽  
Author(s):  
Samiran Banerjee ◽  
Florian Walder ◽  
Lucie Büchi ◽  
Marcel Meyer ◽  
Alain Y. Held ◽  
...  

AbstractRoot-associated microbes play a key role in plant performance and productivity, making them important players in agroecosystems. So far, very few studies have assessed the impact of different farming systems on the root microbiota and it is still unclear whether agricultural intensification influences network complexity of microbial communities. We investigated the impact of conventional, no-till and organic farming on wheat root fungal communities usingPacBio SMRT sequencingon samples collected from 60 farmlands in Switzerland. Organic farming harboured a much more complex fungal network than conventional and no-till farming systems. The abundance of keystone taxa was the highest under organic farming where agricultural intensification was the lowest. The occurrence of keystone taxa was best explained by soil phosphorus levels, bulk density, pH and mycorrhizal colonization. The majority of keystone taxa are known to form arbuscular mycorrhizal associations with plants and belong to the ordersGlomerales,Paraglomerales, andDiversisporales. Supporting this, the abundance of mycorrhizal fungi in roots and soils was also significantly higher under organic farming. To our knowledge, this is the first study to report mycorrhizal keystone taxa for agroecosystems, and we demonstrate that agricultural intensification reduces network complexity and the abundance of keystone taxa in the root microbiota.


Author(s):  
В. М. Писаренко ◽  
П. В. Писаренко ◽  
В. В. Писаренко ◽  
О. О. Горб ◽  
Т. О. Чайка

Мета статті – довести необхідність впровадження системних і науково обґрунтованих заходів з адаптації аграрного виробництва до нових кліматичних умов у зв’язку зі збільшенням повторюваності посух. Методика дослідження. Методологічною основою дослідження слугували такі наукові методи: історико-діалектичний, аналізу і синтезу, теоретичний пошук і абстрактно-логічний, математичного та статистичного аналізу на основі результатів досліджень, що проведені на сільськогосподарських угіддях ПП «Агроекологія». Результати дослідження. Досліджено теорії змін клімату, з якими пов’язані посухи: вплив сонячної активності, вплив космічних факторів, антропогенний вплив на природу. Обґрунтовано доцільність розробки адаптаційних заходів у технології сільськогосподарського виробництва, що дозволять зменшити негативний вплив погоди, та технологічні заходи з накопичення, збереження і раціонального використання вологи, особливо в умовах посух.  Показано вплив на збереження вологи, урожайність і рентабельність аграрного виробництва різних систем землеробства: інтенсивної, органічної, no-till, strip-till, точного землеробства, біоензимної технології, біогенного землеробства. Доведено, що в умовах змін клімату  актуальності набувають дослідження вологозберігаючих систем землеробства, однією з яких є органічне землеробство. Елементи наукової новизни. Визначено особливості агротехнічних прийомів, що сприяють накопиченню, збереженню та раціональному використанню ґрунтової вологи, за умов різних систем землеробства. Практична значущість. Проведені дослідження впливу висоти снігового покриву на запаси вологи у метровому шарі ґрунту за системи органічного землеробства, що свідчить про значну роль снігозатримання. Розкрито доцільність регулювання вологозабезпечення культур таких агротехнологічних заходів: створення куліс для затримки снігу, використання лісосмуг, впровадження сівозмін, правильне структурування посівних площ, мінімальний обробіток ґрунту, використання органічних добрив, мульчування поверхні поля. The purpose of the article is to prove the necessity of introducing systemic and scientifically grounded measures for the adaptation of agrarian production to new climatic conditions in connection with the increasing drought recurrences. Methods of research. The following scientific methods were the methodological basis of the research: historical-dialectical, analysis and synthesis, theoretical search and abstract-logical, mathematical and statistical analysis based on the research results conducted on farm lands of the private enterprise "Agro-ecology". The research results. The theories of climate changes, which are connected with droughts –   the influence of solar activity, cosmic factors, anthropogenic impact on nature, have been investigated. The expediency of developing adaptation measures in agricultural production technology, which will enable to reduce the negative influence of weather, and technological measures on accumulation, conservation and rational use of moisture, especially in conditions of drought, has been substantiated. The impact on moisture preservation, productivity and profitability of agrarian production of different farming systems (intensive, organic, no-till, strip-till, precision farming, bio-enzyme technology, biogenic farming) has been shown. It is proved that the research of moisture-conserving farming systems, one of which is organic farming, in the conditions of climate change is topical. The elements of scientific novelty. The peculiarities of agro-technical methods favoring the accumulation, conservation and rational use of soil moisture, under the conditions of different farming systems have been determined. Practical significance. The studies of snow cover height effect on moisture reserves in a meter layer of soil at organic farming system have been conducted and they have shown the significant role of snow retention. The expediency of regulating crop moisture supply with such agro-technological measures as creating gates  for snow retention, using forest bands, introducing crop rotation, correct structuring of sown areas, minimal soil tillage, using organic fertilizers, mulching field surface has been disclosed.





Author(s):  
С. П. Танчик ◽  
О. П. Мигловець

Приведені результати досліджень зі впливу ґрунтових та страхових гербіцидів на забур’яненість посівів сої під час вирощування її за різних систем  землеробства (промислова та no-till). Встановлено, що найбільша ефективність дії ґрунтових і страхових гербіцидів та найменший рівень забур’яненості відмічений під час застосування бакових сумішей як до появи сходів, так і в період веґетації культури, що впливає на формування врожаю сої. Допосівна бур’янова синузія ефективно знищується гербіцидами суцільної дія за системи no-till. The main results of research on the impact of soil and insurance herbicides on weediness of crops for cultivation of soybean under different farming systems (industrial and no-till) are presented. It was established that the greatest efficiency of soil and insurance herbicides and the lowest level of contamination was marked in the application of tank mixes before sprouting and during the growing season and crops, which influences the crop soybeans. Pre-sowing weed synusia is effectively destroyed by total herbicides continuous action system of no-till.



2009 ◽  
Vol 24 (4) ◽  
pp. 308-318 ◽  
Author(s):  
E.A. Stockdale ◽  
C.A. Watson

AbstractThe health of the soil, recognized by its active role in the linked processes of decomposition and nutrient supply, is considered as the foundation of agriculture by the organic farming movement. Nutrient management in organically managed soils is fundamentally different from that of conventional agricultural systems. Crop rotations are designed with regard to maintenance of fertility with a focus on nutrient recycling. Where nutrients are added to the system, inputs are in organic and/or non-synthetic fertilizer sources that are mostly slow release in nature. Hence a greater reliance is placed on soil chemical and biological processes to release nutrients in plant-available forms. In this respect, nutrient availability in organically farmed soils is more dependent upon soil processes than is the case in conventional agriculture. The development and use of biological indicators of soil quality may therefore be more important in organic (and other low input) farming systems. The aim of this paper is to evaluate current evidence for the impact of organic farming systems on soil biological quality and consider the identification of appropriate biological indicators for use by organic farmers and their advisors. Organic farming systems are generally associated with increased biological activity and increased below-ground biodiversity. The main impacts on biological fertility do not result from the systemsper sebut are related to the amount and quality of the soil organic matter pool and disruptions of soil habitat via tillage. Even within the constraints of organic farming practices it is possible for farmers to make changes to management practices which will tend to improve soil biological quality. It is, however, by no means clear that distinct indicators of soil biological quality are needed for organic farming systems. It is important not only to identify the most appropriate indicators but also to ensure that farmers and land managers can understand and relate to them to support on-farm management decisions.



2016 ◽  
Vol 36 (1) ◽  
Author(s):  
王强 WANG Qiang ◽  
王茜 WANG Qian ◽  
王晓娟 WANG Xiaojuan ◽  
张亮 ZHANG Liang ◽  
张云飞 ZHANG Yunfei ◽  
...  


Author(s):  
Sangeeta Kutty Mullath ◽  
Janusz Błaszkowski ◽  
Byju N. Govindan ◽  
Laila Al Dhaheri ◽  
Sarah Symanczik ◽  
...  

Agricultural practices are known to affect the diversity and efficiency of arbuscular mycorrhizal fungi (AMF) in improving overall plant performance. In the present study we aimed to compare the abundance, richness, and diversity of AMF communities under organic farming of a desert ecosystem in the Arabian Peninsula with those of an adjacent conventional farming system and native vegetation. In total, 12 sites, including six plant species, were sampled from both farming systems and the native site. Spore morphotyping revealed 24 AMF species, with 21 species in the organic farming system, compared to 14 species in the conventional site and none from rhizosphere soil of a native plant (Tetraena qatarensis). The AMF spore abundance, species richness, and Shannon–Weaver diversity index were high under organic farming. In both systems, the AMF community composition and abundance associated with different crops followed similar trends, with pomegranates having the highest values followed by limes, grapes, mangoes, and lemons. Our results show that organic farming in such a desert ecosystem promotes AMF diversity. These data imply that AMF might play an important role in the sustainable production of food in resource-limited desert habitats.



2020 ◽  
Vol 12 (12) ◽  
pp. 4859 ◽  
Author(s):  
Monther M. Tahat ◽  
Kholoud M. Alananbeh ◽  
Yahia A. Othman ◽  
Daniel I. Leskovar

A healthy soil acts as a dynamic living system that delivers multiple ecosystem services, such as sustaining water quality and plant productivity, controlling soil nutrient recycling decomposition, and removing greenhouse gases from the atmosphere. Soil health is closely associated with sustainable agriculture, because soil microorganism diversity and activity are the main components of soil health. Agricultural sustainability is defined as the ability of a crop production system to continuously produce food without environmental degradation. Arbuscular mycorrhizal fungi (AMF), cyanobacteria, and beneficial nematodes enhance water use efficiency and nutrient availability to plants, phytohormones production, soil nutrient cycling, and plant resistance to environmental stresses. Farming practices have shown that organic farming and tillage improve soil health by increasing the abundance, diversity, and activity of microorganisms. Conservation tillage can potentially increase grower’s profitability by reducing inputs and labor costs as compared to conventional tillage while organic farming might add extra management costs due to high labor demands for weeding and pest control, and for fertilizer inputs (particularly N-based), which typically have less consistent uniformity and stability than synthetic fertilizers. This review will discuss the external factors controlling the abundance of rhizosphere microbiota and the impact of crop management practices on soil health and their role in sustainable crop production.



2020 ◽  
Vol 29 (3) ◽  
Author(s):  
Christoph Stephan Schmidt ◽  
Libor Mrnka ◽  
Tomáš Frantík ◽  
Martin Bárnet ◽  
Miroslav Vosátka ◽  
...  

We compared the biostimulant effect of a novel chicken feather hydrolysate (FH) and a reference protein hydrolysate (RH) on barley and wheat in a pot experiment. Their interactions with arbuscular mycorrhizal fungi (AMF) and phosphorus (P) supply were also addressed. All experimental factors influenced barley growth. Shoot height and biomass of barley were increased by FH and reduced by RH. AMF decreased barley biomass at high P-supply. In wheat, the biomass was slightly reduced by AMF while other factors had no significant effect. In the parallel field experiment, RH but not FH increased yield and grain size of barley, while there was no significant effect of either hydrolysate on wheat. Application time had no effect on hydrolysate efficacy. Both hydrolysates promoted severity of net blotch (Pyrenophora teres maculata) on barley in the pot experiment, but reduced it in field. FH promoted wheat root colonisation by AMF under low-P supply. Our results show limited transferability of pot results to field conditions and manifest complex interactions between hydrolysates, soil phosphorus, and plant symbionts and pathogens.



Author(s):  
A.Yu. Egovtseva ◽  
◽  
T.N. Melnichuk ◽  

Microorganisms are the most important bioindicators of the environment and ecological risk assessment. The impact of the no-till farming system in combination with microbial preparations needs to be studied and is an urgent task aimed at preserving fertility. The aim of our study was to determine the effect of pre-sowing inoculation with complex microbial preparations (CMP) and farming systems (no-till and conventional farming system) on the microbocenosis of the rhizosphere of Triticum aestivum L. in the Crimean Steppe. Microbiological analysis of the rhizosphere showed a significant increase in the number of actinobacteria (twice). The number of micromycetes, among which there are many pathogens of various plant diseases, decreased under direct sowing by 23 % as a result of inoculation and amounted to 21.5 thousand CFU/g of soil. The number of cellulose-destroying microorganisms that form soil fertility increased under the influence of microbial preparations by 23 % under conventional farming system (10.0 thousand CFU/g of soil); by 20 % under no-till (15.4 thousand CFU/g of soil). Thus, it was found that the use of microbial preparations under both farming techniques contributed to an increase in the number of microorganisms of most ecological-trophic groups that participate in the transformation of nitrogen in the rhizosphere, enhanced enzymatic processes, reduced the development of pathogenic microbiota and, consequently, contributed to improving the state of soil biocenosis.



2019 ◽  
Vol 48 (4) ◽  
pp. 826-835 ◽  
Author(s):  
Subodh Adhikari ◽  
Laura A Burkle ◽  
Kevin M O’Neill ◽  
David K Weaver ◽  
Casey M Delphia ◽  
...  

AbstractIndustrialized farming practices result in simplified agricultural landscapes, reduced biodiversity, and degraded species-interaction networks. Thus far, most research assessing the combined effects of farming systems and landscape complexity on beneficial insects has been conducted in relatively diversified and mesic systems and may not represent the large-scale, monoculture-based dryland agriculture that dominates many regions worldwide. Specifically, the effects of farming systems on forbs, bees, and their interactions are poorly understood in highly simplified dryland landscapes such as those in the Northern Great Plains, United States, an area globally important for conventional and organic small grain, pulse, forage, and oilseed production. During a 3-yr (2013–2015) study, we assessed 1) the effects of dryland no-till conventional and tilled organic farming on forbs, bees, and bee–flower networks and 2) the relationship between natural habitat and bee abundance. Flower density and richness were greater in tilled organic fields than in no-till conventional fields, and forb community composition differed between farming systems. We observed high bee diversity (109 taxa) in this highly simplified landscape, and bee abundance, richness, and community composition were similar between systems. Compared with tilled organic fields, bee–flower interactions in no-till conventional fields were poorly connected, suggesting these systems maintain relatively impoverished plant-pollinator networks. Natural habitat (11% of the landscape) did not affect small-bodied bee abundance in either farming system but positively affected large-bodied bees within 2,000 m of crop-field centers. In highly simplified agricultural landscapes, dryland organic farming and no-till conventional farming together support relatively high bee diversity, presumably because dryland organic farming enhances floral resources and bee–flower networks, and no-till management in conventional farming provides undisturbed ground-nesting habitats for wild bees (Hymenoptera: Apoidea).



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