Compost Incorporation Research Articles

Compost incorporation and wildflowers introduction for stormwater infiltration and erosion-control vegetation cover establishment in post-construction landscapes

Urban and suburban development frequently disturbs and compacts soils, reducing infiltration rates and fertility, posing challenges for post-development vegetation establishment, and contributing to soil erosion. This study investigated the effectiveness of compost incorporation in enhancing stormwater infiltration and vegetation establishment in urban landscapes. Experimental treatments comprised a split-split plot design of vegetation mix (grass, wildflowers, and grass-wildflowers) as main plot, ground cover (hydro-mulch and excelsior) as subplot, and compost (30% Compost and No-Compost) as sub-subplot factors. Wildflower inclusion was motivated by their recognized ecological benefits, including aesthetics, pollinator habitat, and deep root systems. Vegetation cover was assessed using RGB (Red-Green-Blue) imagery and ArcGIS-based supervised image classification. Over a 24-month period, bulk density, infiltration rate, soil penetration resistance, vegetation cover, and root mass density were assessed. Results highlighted that Compost treatments consistently reduced bulk density by 19–24%, lowered soil penetration resistance to under 2 MPa at both field-capacity and water-stressed conditions, and increased infiltration rate by 2–3 times compared to No-Compost treatments. Vegetation cover assessment revealed rapid establishment with 30% compost and 60:40 grass-wildflower mix, persisting for an initial 12 months. Subsequently, all treatments exhibited similar vegetation coverage from 13 to 24 months, reaching 95–100% cover. Compost treatments had significantly higher root mass density within the top 15 cm than No-Compost, but compost addition did not alter the root profile beyond the 15 cm depth incorporation depth. The findings suggest that incorporating 30% compost and including a wildflower or grass-wildflower mix appears to be effective in enhancing stormwater infiltration and provides rapid erosion control vegetation cover establishment in post-construction landscapes.

Bio-control efficacy of selected indigenous nematophagous fungi against Meloidogyne enterolobii in vitro and on dry bean (Phaseolus vulgaris L.).

Dry bean (Phaseolus vulgaris L.) is an important commercialized field crop in South Africa for aiding in food security as a cheap protein source. However, it is highly susceptible to root-knot nematodes (RKN), Meloidogyne species. Use of indigenous nematophagous fungi as bio-control agents (BCA) of Meloidogyne nematodes is a promising research focus area. This is because indigenous fungal species are naturally part of the ecosystem and therefore compatible with other biological processes unlike most synthetic chemicals. The objective of the study was to identify indigenous nematophagous fungal BCA and establish their potential efficacy in reducing M. enterolobii population densities on dry bean with and without incorporation of compost. Screened indigenous fungal species included Aspergillus terreus, Talaromyces minioluteus, T. sayulitensis, Trichoderma ghanense, and T. viride. There were observed significant parasitism differences (P ≤ 0.05) among the BCA, with T. ghanense showing the highest egg parasitism (86%), followed by T. minioluteus (72%) and T. sayulitensis (70%). On the other hand, the highest J2 parasitism was observed on T. minioluteus (95%), followed by A. terreus and T. viride (63%). A similar trend was observed under in vivo conditions, with higher efficacy with compost incorporation. This provides a highly encouraging alternative and ecologically complementary Meloidogyne management in dry bean production.

Incorporation of compost and biochar enhances yield and medicinal compounds in seeds of water-stressed Trigonella foenum-graecum L. plants cultivated in saline calcareous soils

BackgroundThe combination of compost and biochar (CB) plays an important role in soil restoration and mitigation strategies against drought stress in plants. In the current study, the impact of CB was determined on the characteristics of saline calcareous soil and the productivity of fenugreek (Trigonella foenum-graecum L.) plants. The field trials examined CB rates (CB0, CB10 and CB20 corresponding to 0, 10, and 20 t ha‒1, respectively) under deficit irrigation [DI0%, DI20%, and DI40% receiving 100, 80, and 60% crop evapotranspiration (ETc), respectively] conditions on growth, seed yield (SY), quality, and water productivity (WP) of fenugreek grown in saline calcareous soils.ResultsIn general, DI negatively affected the morpho-physio-biochemical responses in plants cultivated in saline calcareous soils. However, amendments of CB10 or CB20 improved soil structure under DI conditions. This was evidenced by the decreased pH, electrical conductivity of soil extract (ECe), and bulk density but increased organic matter, macronutrient (N, P, and K) availability, water retention, and total porosity; thus, maintaining better water and nutritional status. These soil modifications improved chlorophyll, tissue water contents, cell membrane stability, photosystem II photochemical efficiency, photosynthetic performance, and nutritional homeostasis of drought-stressed plants. This was also supported by increased osmolytes, non-enzymatic, and enzymatic activities under DI conditions. Regardless of DI regimes, SY was significantly (P ≤ 0.05) improved by 40.0 and 102.5% when plants were treated with CB10 and CB20, respectively, as similarly observed for seed alkaloids (87.0, and 39.1%), trigonelline content (43.8, and 16.7%) and WP (40.9, and 104.5%) over unamended control plants.ConclusionsOverall, the application of organic amendments of CB can be a promising sustainable solution for improving saline calcareous soil properties, mitigating the negative effects of DI stress, and enhancing crop productivity in arid and semi-arid agro-climates.

Electromagnetic Water Treatment and Soil Compost Incorporation to Alleviate the Impact of Soil Salinization

This study explores the effects of alternating current-induced electromagnetic field (EMF) on mitigating brackish water irrigation and soil salinization impacts. Greenhouse experiments were conducted to evaluate the effect of EMF on plant growth, soil properties, and leaching of ions under different conditions, including using brackish water and desalinated water for irrigation and soil compost incorporation. The experiment was performed with four types of irrigation water using soil columns representing field soil layers. EMF-treated brackish water maintained a sodium adsorption ratio of 2.7 by leaching Na+ from the soil. EMF-treated irrigation columns showed an increase in soil organic carbon by 7% over no EMF-treated columns. Compost treatment reduced the leaching of NO3− from the soil by more than 15% using EMF-treated irrigation water. EMF-treated brackish water and compost treatment enhanced plant growth by increasing wet weight by 63.6%, dry weight by 71.4%, plant height by 22.8%, and root length by 115.8% over no EMF and compost columns. EMF-treated agricultural water without compost also showed growth improvements. The findings suggest that EMF treatment, especially combined with compost, offers an effective, low-cost, and eco-friendly solution to mitigate soil salinization, promoting plant growth by improving nutrient availability and soil organic carbon.

Synergistic Benefits of Combined Application of Manures and Chemical Fertilizers: Enhancing Growth and Yield of Rice and Wheat

The incorporation of compost and manure with chemical fertilizer has become a key concern to sustain soil fertility. Because the nutrients are continuously depleting from the soil and consequently creating a risk to preserving soil health. Aims: This study assesses the response of different doses of cowdung (CD), municipal solid waste compost (MSWC), oil cake (OC), and poultry manure (PM), incorporated with fertilizers on the growth, yield and protein content of BRRI dhan49 rice and BARI Gom-24. Study Design: RCBD with 8 treatments and 3 replications. Place and Duration of Study: Field experiment and nutrient analysis were carried out at Bangladesh Agricultural University (BAU), Mymensingh. Wheat was grown during the rabi season from October 2018 to March 2019. Again, rice was cultivated during kharif II season from August 2019 to December 2019 on the same field. Then the laboratory analysis was performed till June 2020. Methodology: Eight treatments i.e., T0 Control (no fertilizer), T1 Recommended Fertilizer Dose, T2 (CD + NPK), T3 (MSWC + NPK), T4 (OC + NPK), T5 (PM + N), T6 (MSWC + N), T7: (CD + OC) were accommodated. Data on the growth parameters including grain and straw yields were documented after the harvest of the fully matured crop simultaneously determining the nitrogen (N) and protein content. Results: Adoption of various combinations of compost and manures with fertilizer accorded an increase in yield contributing characters as well as the N and protein content. Integrating MSWC @ 10 t ha-1+N projected the highest grain yield (7.11 t ha-1 in rice; 4.84 t ha-1 in wheat) and straw yield (8.8 t ha-1 in rice; 5.55 t ha-1 in wheat). It also promisingly secured the highest protein content compared to all other treatments. Conclusion: The appliance of MSWC @ 10 t ha-1 with the recommended dose of N may be endorsed for rice and wheat cultivation in the AEZ-9 region and retaining the physicochemical properties of Old Brahmaputra Floodplain soils.

Organic Amendment for Disinfecting Soil Alters the Metabolites in Spinacia oleracea

Solar radiation and the incorporation of compost into soil is a practice for disinfecting soil that could have some other effects on spinach cultivation. The quality of spinach leaves after two types of soil disinfection, non-amended soil (NAS) and compost-amended soil (CAS), was compared in order to find biomarkers of both types of disinfection. These practices did not show significant differences in nutrient composition (N-P-K) compared to the control soil (CS). However, the amount of harmful nutrients such as NO2− was significantly lower in CAS (65.74 mg kg−1 FW) and NAS (49.99 mg kg−1 FW) than in CS (114.39 mg kg−1 FW). In addition, NO3− levels did not exceed the EU-recommended limit (<3500 mg kg−1 FW). Both types of disinfected soils produced higher concentrations of total phenols and more individual flavonoids in spinach leaves than the control. Combined chemometric analysis of the HRAMS data showed different clustering depending on the type of disinfection (NAS and CAS). Fifteen metabolite compounds could be identified, seven of which are beneficial for health and were more abundant in spinach grown in CAS compared to that grown in NAS or CS. Such beneficial metabolites measured with non-target analysis as markers of CAS-grown spinach. However, more studies are necessary in order to determine the differences between the metabolites of spinach grown in NAS or CAS.

Short-term effects of subsoil management by strip-wise loosening and incorporation of organic material

Agricultural production in Central Europe increasingly suffers from extreme drought events. Improving root access to nutrient and water resources in the subsoil below the plow layer is a potential option to maintain productivity during dry summers. Here, we tested a strip-wise subsoil amelioration method that combines subsoil loosening with organic matter incorporation into the subsoil (biowaste or green waste compost) and compared it with a treatment of only subsoil loosening and a non-ameliorated control. A field experiment with randomized block design was conducted on a Luvisol with an argic horizon (Bt), with a rotation of spring barley and winter wheat. In the first two years after amelioration, we monitored soil physico-chemical parameters, microbial biomass, and shoot and root growth at anthesis as well as harvested grain yield and quality. Subsoil loosening with organic matter incorporation significantly decreased soil bulk density at the depth of compost incorporation when biowaste compost was used, but not when green waste compost had been incorporated. Nutrient stocks, nutrient availability and microbial biomass were not consistently affected by the subsoil amelioration. Nevertheless, the incorporation of organic material, especially biowaste compost, significantly increased root growth into the subsoil and subsequently significantly enhanced crop nutrient uptake, biomass and grain yield production. Green waste compost incorporation had less pronounced effects, with an increase in grain yield only in the second year after amelioration. Differences in crop development could not be explained by any single soil parameter, suggesting that it was rather a combined effect of loosened subsoil and better supply of subsoil resources that resulted in an increase in subsoil root length density and subsequently led to better crop performance.

Mean nutrient uptake depths of cereal crops change with compost incorporation into subsoil – evidence from 87Sr/86Sr ratios

Background and AimsRoot restricting layers often hinder crops from accessing the large reservoir of bioavailable mineral nutrients situated in subsoil. This study aims to explore changes in the mean nutrient uptake depth of cereal crops when removing root restricting layers through subsoil management.MethodsSubsoil management was performed by deep loosening, cultivation of lucerne as deep-rooting pre-crop, and their combination with compost incorporation. Management effects were evaluated by means of shoot biomass and element concentrations in shoots and soil compartments. The mean nutrient uptake depth was fingerprinted by graphically matching the 87Sr/86Sr ratios in shoots with the 87Sr/86Sr ratios in the exchangeable fraction in soil. Nutrient uplift from depth to topsoil was inferred from element concentrations in the exchangeable fraction in soil.ResultsShoot biomass remained constant in management and control plots. The mean nutrient uptake depth changed with subsoil management in the order: deep loosening < control < deep loosening with compost incorporation. The latter coincided with a reallocation of compost-derived Na and hence resulted in increased levels of bioavailable Na below the depth of compost incorporation, which may have led to an improved water use efficiency of the crops. Thus, Na relocation triggered the deepening of the mean uptake depth of water and nutrients. Moreover, nutrient uplift from depth to topsoil was evident 21 months after subsoiling.ConclusionSubsoil management by deep loosening with compost incorporation provides a sustainable use of soil resources because otherwise unused deep geogenic-derived nutrient reservoirs were additionally involved in crop nutrition.

Assessing the Feasibility of Sustainable Materials to Boost the Sorption of Pharmaceutical Active Compounds When Included in Reactive Barriers in Soil Aquifer Treatment for Water Reuse

We evaluated the feasibility of five sustainable materials (clay, zeolite, biochar, compost, and woodchips) to be included in a reactive barrier intended to improve the removal of pharmaceutical active compounds (PhACs) during soil aquifer treatment (SAT). The potential of the five materials to sorb PhACs was assessed and compared to sand capacity through batch experiments. Materials with high organic carbon content (biochar, compost, and woodchips) exhibited a greater capacity to sorb PhACs than materials with a low organic carbon content (clay and zeolite). The ion speciation of the molecules is a major parameter controlling the fate and transport of PhACs during SAT operations. Anionic species are the ones with the highest risk of reaching the aquifer since they are generally less sorbed compared to cationic and neutral species. Experimental parameters such as contact time, solid:water ratio, and grain size had no a significant effect on the sorption of PhACs in the studied materials. The incorporation of biochar, compost, and/or woodchips into reactive barriers will promote the sorption of PhACs and will boost the ability of the SAT system to improve the quality of the recharged water.

Wood Fiber-Based Growing Media for Strawberry Cultivation: Effects of Incorporation of Peat and Compost

Cultivation of strawberries in greenhouses and polytunnels is increasing, and new sustainable growing media are needed to replace peat and coconut coir. This study investigated the effect of wood fiber and compost as growing media on hydroponically cultivated strawberries. Two experiments were conducted, where the everbearing cultivar ‘Murano’ was grown in mixtures of wood fiber and compost (Experiment 1) and the seasonal flowering cultivar ‘Malling Centenary’ was grown in mixtures of wood fiber and peat (Experiment 2). Additionally, in Experiment 2, the effect of adding start fertilizer was assessed. The yield potential of ‘Murano’ plants was maintained in all substrates compared to the coconut coir control. However, a mixture of 75% wood fiber and 25% compost produced the highest yield, suggesting that mixtures of nutritious materials with wood fiber may improve plant performance. The chemical composition of the berries was not affected by the substrate composition; however, berries from plants grown in the best performing blend had a lower firmness than those grown in coconut coir. ‘Malling Centenary’ plants produced higher yields in substrates enriched with start fertilizer. Generally, the productivity of ‘Malling Centenary’ plants was maintained in blends containing up to 75% of wood fiber mixture even without start fertilizer.

KOMPOSISI CAMPURAN TANAH-KOMPOS DAUN LAMTORO SEBAGAI AMANDEMEN PADA MEDIA TUMBUH POLIBAG UNTUK PERTUMBUHAN BIBIT KELAPA SAWIT PADA TAHAP PEMBIBITAN UTAMA

SOIL-Leucaena leucocephala LEAF COMPOST MIXTURE AS AMENDMENT IN POLYBAG-GROWING MEDIA FOR IMPROVEMENT OIL PALM SEEDLINGS AT MAIN NURSERY STAGE]. Production of oil palm seedling in the nursery mainly utilises top soil as polybag medium. These soils have low fertility especially N and organic matter content. The aim of this study was to determine the effects of top soil and leaf compost incorporation as amendment in polybag medium for oil palm seedlings growth at the nursery stage. This research was carried out at the Paranet House Experimental Garden and Laboratory of the Faculty of Animal Husbandry, Muhammadiyah University, West Sumatra from March to July 2022 using a standard period for oil palm seedling production in main nursery stage with five soil-leaf compost mixture (control, 1: 1, 1: 2, 1: 3, and 1: 4 v/v) as treatments. The treatments were arranged in a Completely Randomized Design (CRD) with three replications and each replication consisted of four polybags. The results showed that soil-leaf compost mixture (1: 4) was the best ratio for the growth of oil palm seedlings.

Magnesium stable isotopes as a potential geochemical tool in agronomy – Constraints and opportunities

A sustainable use of soil resources is urgently required to cope with the increasing demand for agricultural products during climate change. To inspire farmers on new soil cultivation methods like subsoil management requires not only yield measurements but also nutrient use efficiency measurements for which analytical tools are still missing. Stable isotopes of the macronutrient magnesium (Mg) are a potential novel subsoil management evaluation tool in agronomy and soil/plant sciences because its isotope ratios shift considerably during Mg uptake by crops. The feasibility of Mg stable isotopes was first demonstrated conceptually by simulating subsoil management on soils with low, middle, and high inventories of bioavailable Mg and crop plants typically cultivated in Germany. This simulation showed that the magnitude of Mg isotope shifts among crops and the exchangeable fraction of Mg in soil is resolvable from the long-term external precision of Mg isotope analyses only if three conditions are met. First, the crop uptake-related Mg isotope fractionation factor should be at the upper end of hitherto published fractionation factors. Second, a high Mg uptake flux of crop plants (e.g., sugar beets) is matched by a low Mg supply from the exchangeable fraction in soil (e.g., sandy soils). Third, subsoil management causes a considerable deepening of the rooting system (e.g., flipping the topsoil root cluster below 30 cm depth). If these conditions are met, Mg stable isotopes can be used in a qualitative manner to identify the main Mg uptake depth, and in a quantitative manner by calculating the Mg use efficiency, defined here as the ratio of Mg uptake versus Mg supply, solely from Mg isotope ratios. This concept was tested for Alfisols on field trials by conducting deep loosening with and without the incorporation of compost. Magnesium isotope shifts in crops and the exchangeable fraction of Mg in soil were mostly unresolvable from the long-term external precision of Mg isotope analyses, which positively tested the Mg isotope concept for well nurtured soils. However, systematic Mg isotope shifts among bulk crops cultivated on and beside a melioration strip were found and attributed to the uplift of isotopically distinct compost-derived Mg on the melioration strip and root restricting layers beside the melioration strip. Given that the Mg isotope composition of the exchangeable fraction barely varies with depth, field-based crop uptake-related ‘apparent’ Mg isotope fractionation factors of winter wheat and spring barley could be determined, which differed from one another (Δ26Mgwheat-rem. exch. = 0.63 ± 0.05‰, Δ26Mgbarley-rem. exch. = 0.37 ± 0.12‰). Nonetheless, the quantitative approach of Mg isotopes was violated when calcareous fertilizer was applied to the field as differences in the isotope-derived Mg use efficiency could be attributed to the uneven distribution of lime-derived Mg with depth. Using Mg stable isotopes as a new geochemical routine for agronomy and soil/plant sciences requires future work focussing on isotope fractionation factors related to crop uptake and intra-plant translocation of Mg – which may depend on species, environmental conditions, and nutrient status – to allow minimally invasive sampling of the soil-plant system and to reduce sample sets.

Field Validation on Incorporation of Rice Husk Biochar and Paddy Straw Compost on Crop Attributes and Soil Properties in Rice Ecosystem

Aim: To study the effect of rice husk biochar and rice straw compost on Rabi season rice cultivation.&#x0D; Study Design: The randomized block design was used. The treatments of different doses of soil amendments like rice husk biochar, rice straw compost and recommended fertilizer doses are applied.&#x0D; Place and Duration of Study: The experimental trial was conducted during the Rabi season (January - April) of 2022 at Tamil Nadu Rice Research Institute, Aduthurai, Tamil Nadu, India.&#x0D; Methodology: The study consisted of 11 sets of RBD design treatments replicated thrice. The rice variety of ADT57 Short duration variety was used for this study. The observation has been recorded during the crop growing period at regular intervals.&#x0D; Results: The study results revealed that application of PSB @ 2kg/ha + RSC @ 5 t/ha + 75% RDF (T10) treatment showed the highest plant growth parameters like plant height (27.88, 74.22 and 108.89 cm), number of tillers m-2 (122, 620 and 642), leaf area index (2.62, 6.53 and 8.47), SPAD reading (47.22, 43.64 and 40.46), root length (18.86, 37.45 and 56.31 cm) and root volume (17.85, 26.01 and 37.77 ml) at 30, 60 and 90 DAT respectively and yield parameters like grain yield (5133 kg/ha), straw yield (7090 kg/ha), panicle length (25.28cm) and number of productive tillers m-2 (571.6) and was significantly on par with application of PSB @ 2kg/ha + Rice Husk Biochar (RHB) @ 5 t/ha + 75% RDF (T6) and superior over the other all treatments. Plant growth parameters of application of PSB @ 2kg/ha + Rice Husk Biochar (RHB) @ 5 t/ha + 75% RDF (T6) recorded the plant height (27.41, 73.76 and 108.29 cm), number of tillers m-2 (118, 613 and 630), leaf area index (2.54, 6.42 and 8.38), SPAD reading (46.26, 43.10 and 40.20), root length (18.35, 37.05 and 55.40 cm) and root volume (17.42, 25.44 and 37.33 ml) at 30, 60 and 90 DAT respectively and yield parameters like grain yield (4953 kg/ha), straw yield (7077 kg/ha), panicle length (25.07 cm) and number of productive tillers m-2 (555). So, the application of PSB @ 2 kg/ha + RSC @ 5 t/ha + 75% RDF has recorded the best results than all other treatments. With respect to soil properties, application of Rice husk Biochar (RHB) @ 5t/ha + 75% RDF (T4) has reduced the soil bulk density (from 1.52 to 1.47) and application of rice straw compost @ 5t/ha has increased the soil pH (from 6.58 to 7.14) as compared to other treatments whereas the nutrient status (nitrogen (from 212 to 266 kg ha-1); phosphorus (from 45.41 to 61.59 kg ha-1) and potassium (from 192 to 218.4 kg ha-1) has increased by application of PSB @ 2kg/ha + RSC @ 5t/ha + 100% RDF (T11) than other treatments.

Co-Application of Biochar Compost and Inorganic Nitrogen Fertilizer Affects the Growth and Nitrogen Uptake by Lowland Rice in Northern Ghana

Inherent low soil fertility status limits productivity of rice in the lowland ecologies in Northern Ghana. Combining organic and inorganic nitrogen fertilizers could help to maintain the fertility of lowland soils for rice production. A screen house pot experiment was carried out to investigate the combined effect of biochar compost and inorganic nitrogen fertilizer on the nitrogen uptake and agronomic performance of rice plants grown on an eutric gleysol lowland soil. Inorganic nitrogen fertilizer alone and its combinations with different types of biochar compost (based on the proportions of biochar and compost) were used as treatment. A control (unamended soil) was also included. The incorporation of biochar compost and inorganic nitrogen fertilizer improved the growth parameters and yield components of rice plants. The combination of biochar compost and inorganic nitrogen fertilizer was also found to improve nitrogen uptake in rice plants. This practice could be the most likely viable option for alleviating lowland soil fertility issues and increasing rice productivity in Northern Ghana.

Zeolite Oil Palm Compost-Based Organomineral Fertilizer for Shallot Agronomic Performances and N Substitution

Application of organomineral fertilizer (OMF), which is the product of the inclusion of zeolite and palm oil compost in urea needs to be studied to determine its appropriate dose for the growth and yield of shallots and N substitution. This pot experiment was conducted from October to December 2020 at the Teaching and Research Field of Agriculture Faculty and consisted of five treatments arranged in a completely randomized design with five replications. The treatments were (1) 1.0 g urea, (2) 0.5 g urea + 1.15 g OMF, (3) 0.5 g urea + 2.30 g OMF, (4) 0.5 g urea + 3.45 g OMF, and (5) 0.5 g urea + 4.60 g OMF. The results showed that combined application of 0.5 g urea + 4.60 g OMF produced the highest values of plant height (30.60 cm), number of leaves (30.90), fresh weight of tubers per clump (30.90 g), dry tuber weight per clump (24.3 g), and tuber diameter (16.25 mm). The incorporation of zeolite and palm oil compost in urea reduced the application rate of urea up to 50% without reducing the growth and yield of shallot. Thus, N fertilizer use can be enhanced if urea is co-applied with zeolite and palm oil compost.

Managing Fenton-treated sediment with biochar and sheep manure compost: Effects on the evolutionary characteristics of bacterial community

Fenton oxidation is a widely used method for the fast and efficient treatment of contaminated sediment, but few studies have investigated the management of Fenton-treated sediment for resource utilization. In this study, the evolutionary characteristics of bacterial community composition in Fenton-treated riverine sediment were investigated using 16S rRNA gene sequencing after the incorporation of rice straw biochar and sheep manure compost. The Fenton treatment caused a decline in the relative abundance of Bacteroidetes from 39% to 8% on the 7th day, and using biochar and compost rapidly increased the relative abundance of Firmicutes from 13% to 61% and 57%, respectively. Applying 1.25 wt% biochar after the Fenton treatment contributed to high Shannon diversity indices of 4.80, 4.69, and 4.76 on the 7th, 28th, and 56th day, respectively. The reduced differences of Shannon indexes on the 56th day indicated that the bacterial diversity among different treatments tended to be similar over time. The genera Flavisolibacter and Bacillus were representatively detected on the 7th day in the untreated sediment and Fenton/biochar-treated sediment, respectively. The number of feature bacteria decreased significantly from 88 on the 7th day to 29 on the 56th day. The community functions for the carbon, nitrogen, and sulfur cycles were sensitive to the Fenton-treatment and the subsequent treatment with biochar and compost. This study may provide a useful reference for follow-up work on the remediation of contaminated sediment using advanced oxidation processes, and promote the development of resource utilization of amended sediment.

Effects of organic amendment incorporation on maize (Zea mays L.) growth, yield and water-fertilizer productivity under arid conditions

Land degradation is one of the world’s most pressing environmental problems and a constraint to agricultural production. Application of diverse organic amendments provides a management strategy to compensate for soil organic carbon depletion and reduce land degradation. The objective of this study was to investigate the effects of different organic amendments on soil properties, crop growth and water-fertilizer productivity under arid conditions. Soil in a maize field located in the upper reaches of Yellow River was amended with sheep manure compost and maize stover respectively. Five different application rates (2, 4, 6, 8 and 10 t ha-1) were carried out for the compost, and maize stover (6 t ha-1) combined with two different decomposing agents were implemented. Main component of the decomposing agent was Bacillus subtilis and Trichoderma harzianum, respectively. Soil aggregation and physical-chemical properties were generally improved with the incorporation of compost and maize stover. The addition of compost and maize stover reduced the bulk density and increased the field capacity, soil organic matter, aggregate stability and the saturated hydraulic conductivity. The emergence rate and maize growth properties improved in the organic materials amended plots. However, soil properties and crop growth non-monotonically varied with application rate of compost. The addition of different decomposing agents in maize stover amended plots did not show significant impact on most soil properties, but improved soil nutrient status, crop growth and yield with different levels compared with maize stover alone. Comprehensive analysis of yield, crop water productivity and partial factor productivity for nitrogen, incorporation of compost at a rate of 5–6 t ha-1 or 6 t ha-1 maize stover combined with Bacillus subtilis was recommended as a proper strategy in loamy soil under arid conditions.

Evaluation of Compost and Soil Mix Ratios for Perennial Ryegrass Establishment on Topsoil and Subsoil

Soil degradation during construction often results in soil loss through erosion and reduced vegetation establishment. Composted organic materials are used to restore soil health of compromised urban soils when planting trees and shrubs; however, less is known about compost amendments for turfgrass establishment. The objective of this trial was to determine the effects of differing compost incorporation rates in two soil types on perennial ryegrass [PR (Lolium perenne)] establishment. The hypothesis was that as compost incorporation rates increase, turfgrass germination would increase until the compost rate becomes detrimental to turfgrass germination because of increased nitrate content and electrical conductivity (EC) levels. A salt-sensitive PR cultivar and a salt-tolerant PR cultivar were seeded into a loam topsoil and a clay subsoil at soil:compost volume ratios of 100:0, 80:20, 70:30, 60:40, 50:50, 40:60, and 0:100 using a mixed-source mature compost. Percent green cover (PGC) and leachate pH, EC, and nitrate content were measured during the 5-week establishment period. This trial showed that with a suitable topsoil, compost incorporation may be unnecessary to obtain acceptable PGC, but that compost additions (30% to 40%) to a clay subsoil achieve faster establishment while limiting the potential for reduced establishment because of increased nitrate content or EC associated with greater levels of compost incorporation. The EC or pH of soil:compost leachate was not found to predict turfgrass establishment. This trial suggests that soil type should be considered when making compost use rate recommendations; however, further research is needed to link compost physiochemical properties to compost use rates.

Characterizing Compost Rate Effects on Stormwater Runoff and Vegetation Establishment

Urban development exposes and compacts the subsoil, resulting in reduced infiltration, which often leads to problems with establishing vegetation, increased erosion, and increased runoff volumes. Compost incorporation into these soils can potentially enhance soil physical properties, vegetation establishment, and pollutant removal. The goal of this field study was to determine the efficacy of compost as a soil improvement measure to reduce runoff volume, improve runoff quality, and increase vegetation establishment on a disturbed sandy clay subsoil representing post-development conditions. Two sources of compost were tested: (1) a certified yard waste product at 10%, 30%, and 50% by volume, and (2) an uncertified yard waste product at 30% by volume, both compared to a tilled, no-compost control. Treatment plots were established at Lake Wheeler Road Field Laboratory in Raleigh, NC, and observed for one year. Tilling alone may have been sufficient to reduce runoff quantity as few differences were found between tilled and compost amended plots. Runoff water quality also did not differ according to compost addition. However, the certified compost increased biomass production proportionally to the amount added and compared to the uncertified compost at the same rate. The improved vegetation establishment with compost is important for long-term erosion control and ecosystem services. The results of this study suggest (1) tilling is a viable option to achieve high infiltration rates and reduce runoff volumes, (2) compost incorporation does not reduce nor improve water quality, and (3) compost may yield more robust vegetation establishment.

Effects of soil mitigation on lawn-dwelling invertebrates following residential development

Abstract Residential areas are the most rapidly expanding land use type in the southeastern USA. Residential development impairs soil functions primarily through compaction and the removal or burial of topsoil and natural vegetation, which reduces water infiltration and retention, root penetration, and plant establishment. Plant stress reduces plant-derived ecosystem services and increases vulnerability to pests, often leading to supplemental management inputs in the form of irrigation, fertilizers, pesticides and labor. Soil-dwelling invertebrates, including detritivores and natural enemies of pests, drive valuable ecosystem functions that facilitate plant establishment and reduce maintenance inputs. Although poorly understood, soil disturbance during residential development likely disturbs these communities and reduces the services provided by soil-dwelling invertebrates. Here, we compare the effects of two soil compaction mitigation techniques, tillage with and without compost incorporation, on invertebrate communities and the services they provide over 2 years following residential development. We focus on the relationships between detritivores and detritus decomposition rates, entomopathogenic nematodes and the activity density of a key turfgrass pest and other arthropod herbivores and predators. We found that soil mitigation had no detectable benefit for epigeal arthropods within 1 year after disturbance, but that compost-amended soils supported greater arthropod richness and predator activity density than unmitigated soils in the second year after disturbance. In contrast, we found reduced insect-parasitic nematode activity associated with compost amendment. All taxa increased in abundance with time after development. These results can inform more sustainable residential development and landscape maintenance practices for more biodiverse and functional urban and residential ecosystems.