scholarly journals Compost Quality Recommendations for Remediating Urban Soils

Author(s):  
Hannah Heyman ◽  
Nina Bassuk ◽  
Jean Bonhotal ◽  
Todd Walter

Poor soil health is a critical problem in many urban landscapes. Degraded soil restricts plant growth and microorganism activity, limiting the ability of urban landscapes to perform much needed ecosystem services. Incorporation of approximately 33% compost by volume into degraded soil has been proven to improve soil health and structure over time while avoiding the financial and environmental costs of importing soil mixes from elsewhere. However, additions of high volumes of compost could potentially increase the risk of nutrient loss through leaching and runoff. The objective of our study was to consider the effects of different compost amendments on soil health, plant health and susceptibility to nutrient leaching in order to identify ranges of acceptable compost characteristics that could be used for soil remediation in the urban landscape. A bioassay was conducted with Phaseolus vulgaris (Bush Bean) to measure the effect of nine composts from different feedstocks on various plant health parameters. Leachate was collected prior to planting to measure nutrient loss from each treatment. All compost amendments were found to improve soil health. Nutrient-rich, manure-based composts produced the greatest plant growth, but also leached high concentrations of nitrate and phosphorus. Some treatments provided sufficient nutrients for plant growth without excess nutrient loss. When incorporating as much as 33% compost by volume into a landscape bed, the optimal compost will generally have a C:N ratio of 10–20, P-content <1.0% and a soluble salt content between 1.0 and 3.5 mmhos/cm. These recommendations should ensure optimal plant and soil health and minimize nutrient leaching.

Author(s):  
Hannah Heyman ◽  
Nina Bassuk ◽  
Jean Bonhotal ◽  
Todd Walter

Poor soil health is a critical problem in many urban landscapes. Degraded soil restricts plant growth and microorganism activity, limiting the ability of urban landscapes to perform much needed ecosystem services. Incorporation of approximately 33% compost by volume into degraded soil has been proven to improve soil health and structure over time while avoiding the financial and environmental costs of importing soil mixes from elsewhere. However, additions of high volumes of compost could potentially increase the risk of nutrient loss through leaching and runoff. The objective of our study was to consider the effects of different compost amendments on soil health, plant health and susceptibility to nutrient leaching in order to identify ranges of acceptable compost characteristics that could be used for soil remediation in the urban landscape. We conducted a bioassay with Phaseolus vulgaris (Bush Bean) to measure the effect of nine composts from different feedstocks on various plant health parameters. We collected leachate prior to planting to measure nutrient loss from each treatment. We found that all compost amendments improved soil health. Nutrient-rich, manure-based composts produced the greatest plant growth, but also leached high concentrations of nitrate and phosphorus. Some treatments provided sufficient nutrients for plant growth without excess nutrient loss. We concluded, when incorporating as much as 33% compost by volume into a landscape bed, the optimal compost will generally have a C:N ratio of 10-20, P-content &lt;1.0% and a soluble salt content between 1.0 and 3.5 mmhos/cm. These recommendations should ensure optimal plant and soil health and minimize nutrient leaching.


1999 ◽  
Vol 50 (2) ◽  
pp. 217 ◽  
Author(s):  
D. O. Huett ◽  
S. C. Morris

Nutrient leaching loss, plant growth, and nutrient uptake of 4-week (transplanting to sale) ground-cover species were investigated under a range of leaching conditions and with different sources of a controlled- release fertiliser (CRF), Osmocote NPK (3–4 month) (Osm). Osm was applied pre-planting at a rate equivalent to 800 g N/m3 to pots containing sand, and composted pinebark and hardwood sawdust medium that had received nutrient amendment during formulation. Two experiments were conducted in a glasshouse over summer–autumn where irrigation treatments produced defined leachate volumes. In Expt 1, leachate volumes of <5, 50, and 200 mL every 2 days each received an additional single heavy leaching event of 400 mL after 1, 2, or 3 weeks. In Expt 2, the 3 leachate volumes were each fertilised with new Osm (a newly purchased Osm) or old Osm (a 2-year-old source), where both of these sources contained 0.5–1.5% visibly damaged prills; and damaged Osm, where damaged prills were used exclusively. In both experiments, increasing leachate volume increased (P < 0.001) leaching of N (nitrate + ammonium), P, K, Ca, and Mg. In Expt 1, leaching was highest (P < 0.01) when the heavy leaching event occurred after 2 or 3 weeks for N and after 2 weeks for P. When damaged Osm was used, N, P, and K loss was 3–15 times higher (P < 0.001) than from new and old Osm (98.5–99.5% undamaged). The highest leaching loss of N, P, K, Ca, and Mg occurred in the first week after potting up, with damaged prills at highest leaching volume. Increasing leachate volume (in the presence of a heavy leaching event) reduced (P < 0.001) electrical conductivity (EC) of potting medium after 4 weeks from 1.02 to 0.54 dS/m. Damaged prills reduced (P < 0.001) EC at the high leachate volume in relation to new Osm (2.38 v. 0.29 dS/m). Treatments that increased (P < 0.05) nutrient leaching generally reduced (P < 0.05) nutrient concentrations in shoots and depressed the growth of some plant species. Shoot growth of 2 of 5 species was reduced (P < 0.001) at the highest leachate volume with an additional heavy leaching event in Week 1 or 2, and root growth of all but the slowest growing species declined with increasing leachate volume. Damaged prills reduced (P < 0.001) shoot growth of 2 of the 5 ground-cover species. This study demonstrated that excessive leaching and the use of damaged prills for containerised nursery plants fertilised with CRF results in high nutrient loss, low residual nutrient content, reduced nutrient uptake in shoots, and reduced shoot growth of some species.


2019 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Salah Eddin Khabbaz ◽  
D. Ladhalakshmi ◽  
Merin Babu ◽  
A. Kandan ◽  
V. Ramamoorthy ◽  
...  

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 682
Author(s):  
Bruno Henrique Silva Dias ◽  
Sung-Hee Jung ◽  
Juliana Velasco de Castro Oliveira ◽  
Choong-Min Ryu

Plant growth-promoting rhizobacteria (PGPR) associated with plant roots can trigger plant growth promotion and induced systemic resistance. Several bacterial determinants including cell-wall components and secreted compounds have been identified to date. Here, we review a group of low-molecular-weight volatile compounds released by PGPR, which improve plant health, mostly by protecting plants against pathogen attack under greenhouse and field conditions. We particularly focus on C4 bacterial volatile compounds (BVCs), such as 2,3-butanediol and acetoin, which have been shown to activate the plant immune response and to promote plant growth at the molecular level as well as in large-scale field applications. We also disc/ uss the potential applications, metabolic engineering, and large-scale fermentation of C4 BVCs. The C4 bacterial volatiles act as airborne signals and therefore represent a new type of biocontrol agent. Further advances in the encapsulation procedure, together with the development of standards and guidelines, will promote the application of C4 volatiles in the field.


Author(s):  
Hashmath Inayath Hussain ◽  
Naga Kasinadhuni ◽  
Tony Arioli

AbstractThis study investigated the effects of seaweed extract (SWE) made from the brown algae Durvillaea potatorum and Ascophyllum nodosum on plants and soil. The application of SWE to soil growing tomato plants showed dual effects. SWE comprehensively improved tomato plant growth (flower clusters, flower number, fruit number, root length, root and shoot dry weight, SPAD) and increased plant productivity (yield and quality). Similarly, SWE application effected soil biology at the soil root zone by increasing total bacterial count and available soil nitrogen and impacting bacterial community diversity with an increase in certain bacterial families linked to soil health. A broader understanding of the effects of SWE on the plant-soil ecosystem may offer breakthrough approaches for sustainable food production.


Stresses ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 200-222
Author(s):  
Aniruddha Sarker ◽  
Most. Waheda Rahman Ansary ◽  
Mohammad Nabil Hossain ◽  
Tofazzal Islam

Climate change imposes biotic and abiotic stresses on soil and plant health all across the planet. Beneficial rhizobacterial genera, such as Bacillus, Pseudomonas, Paraburkholderia, Rhizobium, Serratia, and others, are gaining popularity due to their ability to provide simultaneous nutrition and protection of plants in adverse climatic conditions. Plant growth-promoting rhizobacteria are known to boost soil and plant health through a variety of direct and indirect mechanisms. However, various issues limit the wider commercialization of bacterial biostimulants, such as variable performance in different environmental conditions, poor shelf-life, application challenges, and our poor understanding on complex mechanisms of their interactions with plants and environment. This study focused on detecting the most recent findings on the improvement of plant and soil health under a stressful environment by the application of beneficial rhizobacteria. For a critical and systematic review story, we conducted a non-exhaustive but rigorous literature survey to assemble the most relevant literature (sorting of a total of 236 out of 300 articles produced from the search). In addition, a critical discussion deciphering the major challenges for the commercialization of these bioagents as biofertilizer, biostimulants, and biopesticides was undertaken to unlock the prospective research avenues and wider application of these natural resources. The advancement of biotechnological tools may help to enhance the sustainable use of bacterial biostimulants in agriculture. The perspective of biostimulants is also systematically evaluated for a better understanding of the molecular crosstalk between plants and beneficial bacteria in the changing climate towards sustainable soil and plant health.


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