Organic amendments as ecosystem engineers: Microbial, biochemical and genomic evidence of soil health improvement in a tropical arid zone field site

Abstract The chapter highlights the potential benefits associated with the use of insect-rearing residues as biofertilizers while exploring the mechanisms by which chitin in insect frass might control common crop pathogens. The potential benefits for soil fertility derived from the use of insect frass, comparison of quality of insect-derived biofertilizers and common organic and inorganic fertilizers and insect frass and plant health improvement are discussed. While more research is essential to understand the true value of insect-derived biofertilizers for plant and soil health, preliminary findings suggest there are significant opportunities for beneficial impacts in agriculture and horticulture to be realized.

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Remediation of Organically Contaminated Soil Through the Combination of Assisted Phytoremediation and Bioaugmentation

Applied Sciences ◽

10.3390/app9224757 ◽

2019 ◽

Vol 9 (22) ◽

pp. 4757 ◽

Cited By ~ 2

Author(s):

Mikel Anza ◽

Oihane Salazar ◽

Lur Epelde ◽

José María Becerril ◽

Itziar Alkorta ◽

...

Keyword(s):

Plant Growth ◽

Contaminated Soil ◽

Sodium Dodecyl ◽

Soil Health ◽

Organic Amendments ◽

Bacterial Consortium ◽

Soil Microbial Activity ◽

Total Petroleum Hydrocarbons ◽

Paenibacillus Sp ◽

Cow Slurry

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.

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The 3R Principles for Applying Biochar to Improve Soil Health

Soil Systems ◽

10.3390/soilsystems4010009 ◽

2020 ◽

Vol 4 (1) ◽

pp. 9 ◽

Cited By ~ 2

Author(s):

Mingxin Guo

Keyword(s):

Soil Amendment ◽

Soil Layer ◽

Soil Health ◽

High Water ◽

Crop Productivity ◽

Application Rate ◽

Health Improvement ◽

Erosion Risk ◽

Beneficial Effects ◽

Biochar Amendment

Amending soil with biochar is a promising approach to persistently improve soil health and promote crop growth. The efficacy of soil biochar amendment, however, is soil specific, biochar dependent, and influenced by the biochar application programs. To maximize the benefits of biochar application, this paper proposes the 3R principles for applying biochar to soils: right biochar source, right application rate, and right placement in soil. The quality of biochar as a soil amendment varies significantly with the feedstock and the production conditions. Biochar products capable of everlastingly sustaining soil health are those with high stable organic carbon (OC) content and high water- and nutrient-holding capacities that are manufactured from uncontaminated biomass materials. Acidic, coarse-textured, highly leached soils respond remarkably more to biochar amendment than other types of soils. Soil amendment with particular biochars at as low as 0.1 mass% (equivalent to 2 Mg ha−1) may enhance the seasonal crop productivity. To achieve the evident, long-term soil health improvement effects, wood- and crop residue-derived biochars should be applied to soil at one time or cumulatively 2–5 mass% and manure-derived biochars at 1–3 mass% soil. Optimal amendment rates of particular biochar soil systems should be prescreened to ensure the pH of newly treated soils is less than 7.5 and the electrical conductivity (EC) below 2.7 dS m−1 (in 1:1 soil/water slurry). To maximize the soil health benefits while minimizing the erosion risk, biochar amendment should be implemented through broadcasting granular biochar in moistened conditions or in compost mixtures to cropland under low-wind weather followed by thorough and uniform incorporation into the 0–15 cm soil layer. Biochars are generally low in plant macronutrients and cannot serve as a major nutrient source (especially N) to plants. Combined chemical fertilization is necessary to realize the synergic beneficial effects of biochar amendment.

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Trace Metal Chemistry in Arid-Zone Field Soils Amended with Sewage Sludge: III. Effect of Time on the Extraction of Trace Metals

Soil Science Society of America Journal ◽

10.2136/sssaj1983.03615995004700050011x ◽

1983 ◽

Vol 47 (5) ◽

pp. 898-902 ◽

Cited By ~ 45

Author(s):

Garrison Sposito ◽

C. S. LeVesque ◽

Joseph P. LeClaire ◽

A. C. Chang

Keyword(s):

Trace Metals ◽

Sewage Sludge ◽

Trace Metal ◽

Arid Zone ◽

Metal Chemistry ◽

Field Soils ◽

Zone Field

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

Soil Research ◽

10.1071/sr10059 ◽

2011 ◽

Vol 49 (1) ◽

pp. 1 ◽

Cited By ~ 102

Author(s):

J. R. Quilty ◽

S. R. Cattle

Keyword(s):

Humic Substances ◽

Public Perception ◽

Soil Health ◽

Organic Amendments ◽

Soil Microbial Activity ◽

Molecular Structures ◽

Degraded Land ◽

Pests And Diseases ◽

Seaweed Extracts ◽

Wide Range

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.

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Comparative Effects of Bio-Wastes in Combination with Plant Growth-Promoting Bacteria on Growth and Productivity of Okra

Agronomy ◽

10.3390/agronomy11102065 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2065

Author(s):

Hammad Anwar ◽

Xiukang Wang ◽

Azhar Hussain ◽

Muhammad Rafay ◽

Maqshoof Ahmad ◽

...

Keyword(s):

Plant Growth ◽

Soil Health ◽

Organic Amendments ◽

Plant Growth Promoting Rhizobacteria ◽

Fruit Weight ◽

Growth And Yield ◽

Plant Growth Promoting Bacteria ◽

Randomized Design ◽

Plant Growth Promoting ◽

Growth Promoting

Plant growth-promoting rhizobacteria with multiple growth-promoting traits play a significant role in soil to improve soil health, crop growth and yield. Recent research studies have focused on the integration of organic amendments with plant growth-promoting rhizobacteria (PGPR) to enhance soil fertility and reduce the hazardous effects of chemical fertilizers. This study aims to evaluate the integrated application of biochar, compost, fruit and vegetable waste, and Bacillus subtilis (SMBL 1) to soil in sole application and in combined form. The study comprises eight treatments—four treatments without inoculation and four treatments with SMBL 1 inoculation in a completely randomized design (CRD), under factorial settings with four replications. The results indicate that the integrated treatments significantly improved okra growth and yield compared with sole applications. The integration of SMBL 1 with biochar showed significant improvements in plant height, root length, leaf chlorophyll a and b, leaf relative water content, fruit weight, diameter and length by 29, 29, 50, 53.3, 4.3, 44.7 and 40.4%, respectively, compared with control. Similarly, fruit N, P and K contents were improved by 33, 52.7 and 25.6% and Fe and Zn in shoot were 37.1 and 35.6%, respectively, compared with control. The results of this study reveal that the integration of SMBL 1 with organic amendments is an effective approach to the sustainable production of okra.

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