Use and understanding of organic amendments in Australian agriculture: a review

Soil Research ◽  
2011 ◽  
Vol 49 (1) ◽  
pp. 1 ◽  
Author(s):  
J. R. Quilty ◽  
S. R. Cattle

A wide range of organic amendments (OA) is currently available to Australian farmers. These products have numerous agronomic applications, including the supply of plant nutrients, control of pests and diseases, and in management of soil health. Several of these products are also used in contaminated and degraded land remediation. The most commonly identifiable groups of OA in Australia are composts, compost teas, vermicasts, humic substances, meat, blood and bone meal, fish hydrolysates, seaweed extracts, bio-inoculants, biodynamic products, and biochars. Many of these OA contain nutrients within organic molecular structures; these nutrients are usually not immediately available to plants and must first be mineralised. Mineralisation often occurs as OA are consumed by microbes, thereby stimulating soil microbial activity. The application of OA such as bio-inoculants, humic substances, and seaweed extracts can potentially stimulate crop growth and development through the actions of plant growth-promoting hormones, including cytokinins, auxins, and gibberellins. Yet despite these apparent benefits, the widespread adoption of OA in Australia has been limited, due in part to the high application rates required to produce agronomic benefits, a lack of consistency in the composition of some products, a poor public perception of their utility, and a lack of unbiased scientific research into the agricultural potential of these products.

2019 ◽  
Vol 9 (22) ◽  
pp. 4757 ◽  
Author(s):  
Mikel Anza ◽  
Oihane Salazar ◽  
Lur Epelde ◽  
José María Becerril ◽  
Itziar Alkorta ◽  
...  

Here, we aimed to bioremediate organically contaminated soil with Brassica napus and a bacterial consortium. The bioaugmentation consortium consisted of four endophyte strains that showed plant growth-promoting traits (three Pseudomonas and one Microbacterium) plus three strains with the capacity to degrade organic compounds (Burkholderia xenovorans LB400, Paenibacillus sp. and Lysinibacillus sp.). The organically contaminated soil was supplemented with rhamnolipid biosurfactant and sodium dodecyl benzenesulfonate to increase the degradability of the sorbed contaminants. Soils were treated with organic amendments (composted horse manure vs. dried cow slurry) to promote plant growth and stimulate soil microbial activity. Apart from quantification of the expected decrease in contaminant concentrations (total petroleum hydrocarbons, polycyclic aromatic hydrocarbons), the effectiveness of our approach was assessed in terms of the recovery of soil health, as reflected by the values of different microbial indicators of soil health. Although the applied treatments did not achieve a significant decrease in contaminant concentrations, a significant improvement of soil health was observed in our amended soils (especially in soils amended with dried cow slurry), pointing out a not-so-uncommon situation in which remediation efforts fail from the point of view of the reduction in contaminant concentrations while succeeding to recover soil health.


2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.


Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 32
Author(s):  
Haddish Melakeberhan ◽  
Gregory Bonito ◽  
Alexandra N. Kravchenko

Soil health connotes the balance of biological, physicochemical, nutritional, structural, and water-holding components necessary to sustain plant productivity. Despite a substantial knowledge base, achieving sustainable soil health remains a goal because it is difficult to simultaneously: (i) improve soil structure, physicochemistry, water-holding capacity, and nutrient cycling; (ii) suppress pests and diseases while increasing beneficial organisms; and (iii) improve biological functioning leading to improved biomass/crop yield. The objectives of this review are (a) to identify agricultural practices (APs) driving soil health degradations and barriers to developing sustainable soil health, and (b) to describe how the nematode community analyses-based soil food web (SFW) and fertilizer use efficiency (FUE) data visualization models can be used towards developing sustainable soil health. The SFW model considers changes in beneficial nematode population dynamics relative to food and reproduction (enrichment index, EI; y-axis) and resistance to disturbance (structure index, SI; x-axis) in order to identify best-to-worst case scenarios for nutrient cycling and agroecosystem suitability of AP-driven outcomes. The FUE model visualizes associations between beneficial and plant-parasitic nematodes (x-axis) and ecosystem services (e.g., yield or nutrients, y-axis). The x-y relationship identifies best-to-worst case scenarios of the outcomes for sustainability. Both models can serve as platforms towards developing integrated and sustainable soil health management strategies on a location-specific or a one-size-fits-all basis. Future improvements for increased implementation of these models are discussed.


2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Federica Zanetti ◽  
Barbara Alberghini ◽  
Ana Marjanović Jeromela ◽  
Nada Grahovac ◽  
Dragana Rajković ◽  
...  

AbstractPromoting crop diversification in European agriculture is a key pillar of the agroecological transition. Diversifying crops generally enhances crop productivity, quality, soil health and fertility, and resilience to pests and diseases and reduces environmental stresses. Moreover, crop diversification provides an alternative means of enhancing farmers’ income. Camelina (Camelina sativa (L.) Crantz) reemerged in the background of European agriculture approximately three decades ago, when the first studies on this ancient native oilseed species were published. Since then, a considerable number of studies on this species has been carried out in Europe. The main interest in camelina is related to its (1) broad environmental adaptability, (2) low-input requirements, (3) resistance to multiple pests and diseases, and (4) multiple uses in food, feed, and biobased applications. The present article is a comprehensive and critical review of research carried out in Europe (compared with the rest of the world) on camelina in the last three decades, including genetics and breeding, agronomy and cropping systems, and end-uses, with the aim of making camelina an attractive new candidate crop for European farming systems. Furthermore, a critical evaluation of what is still missing to scale camelina up from a promising oilseed to a commonly cultivated crop in Europe is also provided (1) to motivate scientists to promote their studies and (2) to show farmers and end-users the real potential of this interesting species.


Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 205
Author(s):  
Ihab M. Farid ◽  
Mohamed A. El-Ghozoli ◽  
Mohamed H. H. Abbas ◽  
Dalia S. El-Atrony ◽  
Hassan H. Abbas ◽  
...  

Organic amendments are important sources of nutrients that release upon organic matter degradation, yet the stability of these organics in arid and semi-arid regions is relatively low. In contrast, humic substances (HS) are resistant to biodegradation and can keep nutrients in the soil available for the plant over a long time. Combinations between humic substances (HS) and mineral-N fertilizers are assumed to retain higher available nutrients in soils than those recorded for the sole application of either mineral or organic applications. We anticipate, however, that humic substances might not be as efficient as the organics from which they were extracted in increasing NP uptake by plants. To test these assumptions, faba bean was planted in a pot experiment under greenhouse conditions following a complete randomized design while considering three factors: two soils (calcareous and non-calcareous, Factor A), two organics (biogas and compost, Factor B) and combinations of the organics and their extracts (HA or FA) together with complementary doses of mineral-N ((NH4)2SO4) to attain a total rate of 50 kg N ha−1 (the recommended dose for faba bean plants) (Factor C). Results indicated that nitrogenase activity increased significantly due to the application of the used organics. In this respect, compost manure caused higher nitrogenase activity than biogas manure did. Humic substances raised NP-availability and the uptake by plants significantly; however, the values of increase were lower than those that occurred due to the compost or biogas manure. Moreover, the sole application of the used organics recorded the highest increases in plant biomass. Significant correlations were also detected between NP-availability, uptake and plant biomass. This means that HS could probably retain nutrients in available forms for long time periods, yet nutrients released continuously but slowly upon decomposition of organics seemed more important for plant nutrition.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 395
Author(s):  
Alex J. Lindsey ◽  
Adam W. Thoms ◽  
Marshall D. McDaniel ◽  
Nick E. Christians

Soil health and sustainable management practices have garnered much interest within the turfgrass industry. Among the many practices that enhance soil health and sustainability are applying soil additives to enhance soil biological activity and reducing nitrogen (N) inputs—complimentary practices. A two-year study was conducted to investigate if reduced N fertilizer rates applied with humic substances could provide comparable turfgrass quality as full N rates, and whether humic fertilizers would increase biological aspects of soil health (i.e., microbial biomass and activity). Treatments included synthetic fertilizer with black gypsum (SFBG), poly-coated humic-coated urea (PCHCU; two rates), urea + humic dispersing granules (HDG; two rates), urea, stabilized nitrogen, HDG, and a nontreated control. Reduced rates of N with humic substances maintained turfgrass quality and cover, and reduced clipping biomass compared to full N rates. There were no differences in soil physical and chemical properties besides soil sulfur (S) concentration. SFBG resulted in the highest soil S concentration. Fertilizer treatments had minimal effect on microbial biomass and other plant-available nutrients. However, PCHCU (full rate) increased potentially mineralizable carbon (PMC) and N (PMN) by 68% and 59%, respectively, compared to the nontreated control. Meanwhile SFBG and stabilized nitrogen also increased PMC and PMN by 77% and 50%, and 65% and 59%, respectively. Overall, applications of reduced N fertilizer rates with the addition of humic substances could be incorporated into a more sustainable and environmentally friendly turfgrass fertilizer program.


2020 ◽  
Vol 112 (6) ◽  
pp. 4723-4740
Author(s):  
Meng Zhou ◽  
Chunyu Wang ◽  
Zhihuang Xie ◽  
Yansheng Li ◽  
Xingyi Zhang ◽  
...  

Author(s):  
О.Ю. Филатов ◽  
В.А. Назаров

Данная статья обобщает накопившуюся на сегодняшний день информацию о многообразии образраспознающих рецепторов, их роли в регуляции иммунной системы. Распознавание патогена врожденным иммунитетом происходит с помощью рецепторов к широкому спектру антигенов за счет выделения нескольких высоко консервативных структур микроорганизмов. Эти структуры были названы патоген-ассоциированные образы (Patogen-Associated Molecular Patterns - PAMP). Наиболее изученными являются липополисахарид грамм отрицательных бактерий (LPS), липотейхоевые кислоты, пептидогликан (PGN), CpG мотивы ДНК и РНК. Рецепторы, распознающие PAMP, называются PRR. Данная группа рецепторов также распознает молекулы, образующиеся при повреждении собственных тканей. Такие молекулярные структуры называются Damage-Associated Molecular Patterns (DAMP), или образы, ассоциированные с повреждением. В качестве DAMP могут выступать белки теплового шока, хроматин, фрагменты ДНК. В зависимости от локализации, образраспознающие рецепторы принято разделять на: расположенные на мембране Toll-подобные рецепторы (Toll-like receptors, TLR) и рецепторы лектина С-типа (C-type lectin receptors, CLR), а также расположенные в цитоплазме NOD-подобные рецепторы (NOD-like receptors, NLR) и цитоплазматические РНК- и ДНК-сенсоры. Сегодня у человека известно 10 типов TLR, часть из которых расположена на поверхности (TLR1-TLR6, TLR10) большинства клеток, в том числе макрофагов, В-лимфоцитов и дендритных клеток, а часть - в эндосомах (TLR3, TLR7-TLR9). CLR представляет из себя семейство рецепторов, расположенных на мембране и имеющих домены распознавания углеводов (CRD), или структурно сходные лектиноподобные домены типа C (CTLD). В данном семействе рецепторов принято по происхождению и структуре выделять 17 групп. CLR активно участвуют в противогрибковой иммунной защите, а также они играют роль в защите и от других типов микроорганизмов. NOD (нуклеотидсвязывающий и олигомеризационный домен)-подобные рецепторы расположены в цитоплазме. Благодаря этим рецепторам, патоген, который избежал распознавания на поверхности мембраны, сталкивается со вторым уровнем распознавания уже внутри клетки. В данной статье рассматриваются пути активации образраспознающих рецепторов, их эффекты и применение данных эффектов в медицине. This article summarizes currently available information about the variety of image-recognizing receptors and their role in regulation of the immune system. Pathogen recognition by the innate immunity is mediated by receptors to a wide range of antigens via recognition of several highly conservative structures of microorganisms. These structures were named pathogen-associated images or PAMP (pathogen-associated molecular pattern). The best studied types of such structures include lipopolysaccharide (LPS) of gram-negative bacteria, lipoteichoic acids, peptidoglycan (PGN), and CpG DNA and RNA motifs. PAMP-recognizing receptors (PRRS) are a group of receptors, which also recognize molecules released during damage of host tissues. Such molecular structures are called DAMPS (damage-associated molecular patterns) or damage-associated images. Heat shock proteins, chromatin, and DNA fragments may act as DAMPS. Depending on the localization, image-recognizing receptors are generally classified as membrane-located Toll-like receptors (TLR) and C-type lectin receptors (CLR), as well as cytoplasmic NOD-like receptors (NLR) and cytoplasmic RNA and DNA sensors. Today, 10 types of human TLR are known. Some of them are located on the surface (TLR1-TLR6, TLR10) of most cells, including macrophages, B-cells, and dendritic cells, and some are present in endosomes (TLR3, TLR7-TLR9). CLR is a family of membrane receptors that have carbohydrate recognition domains (CRD) or structurally similar lectin-like type C domains (CTLD). Seventeen groups are distinguished within this receptor family based on their origin and structure. CLRs are actively involved in antifungal immune defense and also play a role in protection against other types of microorganisms. NOD (nucleotide-binding and oligomerization domain)-like receptors are present in the cytoplasm. These receptors provide the second level of recognition inside the cell for the pathogens that have escaped recognition on the membrane surface. This article discusses activation pathways of image-recognizing receptors, their effects, and the use of such effects in medicine.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11204
Author(s):  
Maria Viketoft ◽  
Laura G.A. Riggi ◽  
Riccardo Bommarco ◽  
Sara Hallin ◽  
Astrid R. Taylor

Addition of organic amendments is a commonly used practice to offset potential loss of soil organic matter from agricultural soils. The aim of the present study was to examine how long-term addition of organic matter affects the abundance of different soil biota across trophic levels and the role that the quality of the organic amendments plays. Here we used a 17-year-old fertilization experiment to investigate soil biota responses to four different organic fertilizers, compared with two mineral nitrogen fertilizers and no fertilization, where the organic fertilizers had similar carbon content but varied in their carbon to nitrogen ratios. We collected soil samples and measured a wide range of organisms belonging to different functional groups and trophic levels of the soil food web. Long-term addition of organic and mineral fertilizers had beneficial effects on the abundances of most soil organisms compared with unfertilized soil, but the responses differed between soil biota. The organic fertilizers generally enhanced bacteria and earthworms. Fungi and nematodes responded positively to certain mineral and organic fertilizers, indicating that multiple factors influenced by the fertilization may affect these heterogeneous groups. Springtails and mites were less affected by fertilization than the other groups, as they were present at relatively high abundances even in the unfertilized treatment. However, soil pH had a great influence on springtail abundance. In summary, the specific fertilizer was more important in determining the numerical and compositional responses of soil biota than whether it was mineral or organic. Overall, biennial organic amendments emerge as insufficient, by themselves, to promote soil organisms in the long run, and would need to be added annually or combined with other practices affecting soil quality, such as no or reduced tillage and other crop rotations, to have a beneficial effect.


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