Mixed Manure Research Articles

Decomposition characteristics of woody peat and its mixtures with liable organic materials in a newly reclaimed saline-alkali soil: A one-year incubation experiment

The combined application of woody peat with labile organic materials has been shown to be an effective strategy for rapidly improving soil organic matter (SOM) and soil fertility in newly reclaimed lands. However, their decomposition dynamics, which can be greatly influenced by the residue-mixing effect, are not well understood. Therefore, this study investigated the decomposition characteristics and residue-mixing effect of woody peat, corn straw, organic manure and their binary mixtures in a newly reclaimed saline-sodic soil through a 360-day incubation experiment. The results revealed that both straw and organic manure contained large amount of O-alkyl C, leading to rapid degradation in mass and organic C (OC). In contrast, woody peat is rich in alkyl C and aromatic C, exhibiting the highest alkyl C/O-alkyl C (A/O-A) ratio and aromaticity. As a result, woody peat only lost less than 6.4% OC and showed minimal changes in mass and nitrogen content within a year, indicating strong degradation resistance in the saline-sodic soil. The combination of woody peat with straw or organic manure induced significant non-additive synergistic effects on mass and OC loss, aromatic C, carbonyl C, A/O-A ratio and aromaticity. This suggests that the addition of woody peat significantly slowed down the degradation of the mixtures and prolonged the retention of OC in soil. On the contrary, the mixing of straw and organic manure led to significant non-additive antagonistic effects on mass and OC loss, indicating that their combination accelerated the decomposition of the mixture. Consequently, this study suggests that, in contrast to the applicated of various labile organic materials, the combined application of recalcitrant woody peat with labile organic materials can extend the presence of organic matter in the soil, thereby promoting a sustained increase in active and passive SOM content and soil fertility.

Cofactor F420 tail length distribution in different environmental samples

Cofactor F420 is an electron carrier playing a crucial role in a variety of microorganisms during redox reactions of the primary and secondary metabolism due to its low redox potential and thus arouses increasing interest. In this study, cofactor F420 glutamyl tail length spectra in various habitats like manure, compost, soil, and digester sludge samples and their respective microbial communities were investigated using high performance liquid chromatography and an amplicon sequencing approach A previous in-silico study was used to identify F420 producing microorganisms. The highest concentration of cofactor F420 could be achieved in the horse manure, digester sludge, and mixed manure samples, which was approximately 100-fold higher than in all the other samples. The high content of the cofactor in the samples with high O2 availability pointed to the important role of the cofactor not only in redox reactions of anaerobic but also for aerobic microorganisms and indicated its ubiquitous character. The most abundant derivate was F420-3 comprising the largest part of the cofactor derivates in seven out of ten samples. The high abundance of F420-3 in samples with distinct properties (e.g. O2 and H2O availability) showed its important role in redox reactions of the primary and secondary metabolism among prokaryotes.

РЕЗУЛЬТАТЫ ЭКСПЕРИМЕНТАЛЬНЫХ ИССЛЕДОВАНИЙ НАСОСА-ПОНТОНА ДЛЯ ЛАГУН-НАВОЗОХРАНИЛИЩ

The main methods of preparing organic fertilizers from manure runoff coming from pigbreeding complexes are analyzed. In particular, one of the effective technologies is the technology of homogenization of runoff in lagoons-manure storages. The purpose of the article is to substantiate the design and parameters of the pontoon pump for homogenization and pumping of liquid organic fertilizers (LOF) from lagoons-manure storages. The analysis of studies on the problem of homogenization and pumping of LFO from lagoons-manure storages made it possible to formulate scientific prerequisites for improving the working process of mixing manure runoff in manure storages and pumping them to the place of application to the soil. Their essence lies in the substantiation of the design parameters of the transporting screw - length, diameter and frequency of its rotation. A new design of the pontoon pump is described and a diagram of its location when changing the depth of the lagoon-manure storage is presented. A diagram of the working process for the pontoon pump, consisting of three stages, is developed. The pump flow rate, the total specific energy of the pumped liquid at the pump outlet, and the pressure created by the conveying screw are determined. The analysis of the forces applied to a point in the conveying part of the pontoon pump is performed, which made it possible to determine the trigonometric functions of the angular parameter. Research is conducted using the multifactorial experiment technique. An analytical dependence of the change in the pump pressure on the diameter of the conveying screw casing and the length of the conveying screw at a constant screw rotation frequency is obtained. A graphical dependence of the response surface is constructed. The obtained design parameters ensure the efficient flow of the working process of pumping ZOU from the manure storage lagoon with the specified parameters of pressure and flow rate.

Soil properties and nutrient uptake of maize (Zea mays) as influenced by mixed manure and blended inorganic fertilizer in Haramaya district, eastern Ethiopia

The deteriorating state of soil fertility and low agricultural productivity in Ethiopia can be traced to the lack of equivalent consideration given to the soil's biological, chemical, and physical properties. A pot experiment was conducted to investigate the effect of mixed manure and blended nitrogen, phosphorus, sulfur and boron (NPSB) fertilizer on phosphorus adsorption, and other properties of Vertisols, nutrient uptake, and growth performance of maize. The study findings indicate that the combined application of mixed manure and blended NPSB significantly reduced soil pH from 7.87 to 7.68, phosphorus adsorption efficiency from 93 to 88.5 %, and Freundlich adsorption capacity from 194 to 100.75 mg kg−1 , intensity from 1.96 to 1.27 compared to control. However, combined application of these two treatments significantly increased the organic carbon from 0.81 to 1.64 %, total nitrogen from 0.04 to 0.13 %, and available phosphorus from 6.96 to 73.82 g kg−1. The study further revealed that mixed manure and blended NPSB resulted in significantly (p ≤ 0.05) higher contents of nitrogen and phosphorus in the maize leaves as well as their uptake compared to their sole application and control. The highest values of these parameters were observed in plots treated with a combined application of 15 t ha−1 mixed manure with each rate of 100 and 150 kg ha−1 blended NPSB. Additionally, the maize plant height (p ≤ 0.05) and above-ground biomass (p ≤ 0.01) also exhibited significant increase. Compared to the control and full dose of NPSB, all the treatments that received a combined application of 15 t ha−1 mixed manure with blended NPSB ranging from 50 to 150 kg ha−1 resulted in significantly higher above-ground biomass of maize. The results suggest that the combined use of mixed manure and blended NPSB could be a practical and effective approach to improve soil properties and maize above-ground biomass yield.

Effects of swine manure and straw biochars on fluorine adsorption-desorption in soils.

With increasing global awareness of soil health, attention must be paid to fluorine exposure in soils, which poses a threat to human health. Therefore, this study aimed to study the fluorine adsorption characteristics of swine manure and straw biochars and their impact on fluorine adsorption-desorption in soil with batch experiments. The biochar samples originated from high-temperature anaerobic cracking of swine manure (350°C, 500°C, and 650°C) and straw (500°C). Results indicated that the adsorption of soil fluorine reached adsorption equilibrium at around 4 h after the mixing of swine manure and straw biochar. Fluorine adsorption kinetics using these biochars conformed to the quasi-two-stage kinetic model. The fluorine adsorption kinetics for biochar-treated soils conformed to the double-constant equation and the Elovich equation, and the soil treated with straw biochar showed the fastest fluorine adsorption rate. The adsorption isotherms of fluorine for biochars and biochar-treated soils could be fitted by the isothermal adsorption model of Langmuir and Freundlich. The maximal equilibrium quantity of fluorine was 73.66 mg/g for swine manure biochar. The soil, adding with 2% of swine manure biochar achieved with showed at 650°C had the smallest adsorption. This study also shows that the adsorption of fluorine by biochar gradually decreased with the increase of pH. Comparing with other factors, the mixture pH with biochars added had a significant effect on fluorine adsorption. The decreased fluorine adsorption capacities for soils treated with swine manure and straw biochars were closely related to the increased pH in soils after adding biochars. Considering the fluorine threat in soil, this study provides a theoretical basis for the application of biochars on soil fluorine adsorption.

Applying coal char to cattle pens for sustainable agriculture in the semiarid US High Plains

AbstractApplying high carbon (C) additive to cattle pens and land application of the resultant manure mix offers a potential strategy for optimizing manure and soil management while mitigating environmental concerns. An experiment was conducted in western Nebraska from 2019 to 2022 to evaluate the effect of adding coal char (∼290 g C kg−1 by wt.) on feedlot manure's properties and stability and the interacting effect of manure‐char on crop yields in a corn (Zea mays L.)–dry bean (Phaseolus vulgaris L.)–corn rotation. Treatments in the crop field included manure from pens with or without char (each at 34 and 68 Mg ha−1; low and high rate), urea at 100% recommended nitrogen (N) rate with or without 45 Mg char ha−1, and a control. Applying char to pens kept them drier following snowfall events. The high surface area and cation exchange capacity of char improved soil and manure nutrient retention. The 100% urea‐N plus char treatment had a greater corn yield than the low‐rate char–manure mix or high‐rate manure in 2020. In 2021, there was a trend for higher bean yields with the high char–manure rate treatment than the control. In 2022, all the fertilized treatments had greater grain yields than the control. A one‐time high‐rate char–manure mix or manure application could replace 314 kg N ha−1 and 90 kg P2O5 ha−1 over 2 years without any yield penalty. This study underscores the synergy between char and manure or chemical fertilizers to improve nutrient balance and supply, ultimately enhancing crop production.

Impact of Biochar on Pathogenic Bacteria and Bermuda Grass (Cynodon dactylon) Growth in Soil Treated with Chicken Manure

Chicken manure plays an important role in soil amendment by improving soil properties for plant growth. However, the high levels of pathogens can have an adverse effect on humans when used for sports turf. This study was conducted to 1) determine the pathogenic bacteria in chicken manure-amended soil, 2) identify the appropriate decomposition stage of manure associated with reduced number of pathogenic bacteria, 3) assess the effect of different rates of biochar on pathogenic bacteria in the amended soil and 4) determine the effect of biochar on the growth of Bermuda grass. The design used for the laboratory experiment was 3˟3 factorial in Completely Randomised Design (CRD) and it was replicated three times. The factors involved were: decomposition stages of chicken manure (3 levels) and the different rates of biochar (3 levels). The best combination of biochar and chicken manure at the percentages of 0, 5, 10, and 15 were then used together with soil and sand mix at a ratio of 100:00 and 70:30 to plant Bermuda grass. This experiment showed that E. coli was present in chicken manure and that increasing the decomposition period had a significant effect on the E. coli by reducing its load. Also, the addition of biochar to the chicken manure resulted in a significant reduction of E. coli count (p<0.01). The soil amended with the biochar and manure also supported very well the growth of Bermuda grass with the 10% and 15% biochar manure mix in 70 to 30 ratio of topsoil and sand giving the best grass growth in terms of spread, thickness, height, and color. A regression analysis given by the equation Y(coverage)=176.857-23.0402(sprouting) (R2=0.99), indicated that sprouting significantly affected grass coverage such that 99% variation in the grass coverage was attributed to the sprouting. At the end of the study, it was concluded that well-composted chicken manure should be used together with biochar on sports fields to help remediate the problem of E. coli infestation and also improve the growth of grass on fields. Furthermore, biochar with chicken manure-amended soil could be ideal for vegetable garden to help reduce foodborne diseases caused by E. coli infestation.

Evaluation of Claw Lesions in Beef Cattle Slaughtered in Northern Portugal: A Preliminary Study

Claw diseases have a profound impact on cattle welfare, affecting behaviors such as grazing, rumination, rest, decubitus, and water consumption. This study aimed to assess the prevalence of claw lesions and classify them according to the ICAR Claw Health Atlas (International Committee of Animal Recording) in two slaughterhouses. The influence of claw lesions on carcass weight, classification, and fat deposition was also examined. Involving 343 crossbreed cattle from 103 different extensive or semi-intensive farms, this study found an animal prevalence of claw disorders at 65.8%, with a higher incidence in females (n = 207, 60.35%) compared to males (n = 136, 39.65%). Despite the observed prevalence, claw lesions were not influenced by age or sex (p > 0.05). The main claw lesions identified, including heel horn erosion, double sole, and asymmetric claw, were consistent with the cattle management practices in the study area. These cattle were raised in small, rustic premises with uneven floors, utilizing a mix of manure and plant material as bedding and lacking access to pasture. Also, no negative economic impact was detected concerning carcass weight, classification, or fat deposition. Consequently, it was concluded that the presence of claw lesions in beef cattle raised under the characteristic management of this geographical area does not adversely affect animal health or farm economics.

Effect of Mixed Manure and Inorganic Fertilizer on Phosphorus Adsorption and Desorption Characteristics of Vertisols in Haramaya District, Eastern Ethiopia.

Applying inorganic phosphorus fertilizer is less effective in increasing crop yields in tropical soils due to precipitation and adsorption reactions. However, research suggests that partial substitution of organic and inorganic fertilizers has shown to improve the efficiency of applied phosphorus fertilizer by reducing its adsorption and enhancing desorption due to their synergistic effects. This study aimed to investigate the impact of treating the soil with mixed manure (MM) rates and blended nitrogen, phosphorus, sulfur, and boron (NPSB) fertilizer on the soil's phosphorus adsorption and desorption characteristics. Results showed increased adsorbed phosphorus in all treatments, with increased added phosphorus (P) concentration from 100 to 500 mg kg-1. However, the efficiency of adsorbed P decreased significantly as added P concentration rates increased from 100 to 400 mg·kg-1 in all treatments and then decreased as the added P concentration advanced to 500 mg·kg-1. Moreover, in all treatments that received combined applications of MM and blended NPSB, both quantity and percentage of desorbed P showed a significant increase. The Freundlich adsorption coefficient and constant were also significantly reduced because of the combined application of MM and blended NPSB, compared to the control and their sole applications. Overall, the soil treated with a combined application of 15 t·ha-1 of MM with 100 kg·ha-1 of blended NPSB showed the highest reduction in the efficiency of adsorbed P, percentage of desorbed P, Freundlich adsorption capacity, and intensity by 8%, 37.5%, 60%, and 58%, respectively, as compared to the control. These findings indicate that the combined application of MM and blended NPSB can improve the P availability and uptake by maize by reducing its adsorption while increasing desorption characteristics. Finally, this experiment recommends further research on the long-term effects of MM and blended NPSB on P adsorption and desorption characteristics of vertisols.

Influence of topsoil manure mix on affects germination in Pea and Onion seeds

Nutrient-rich southern chernozems have lost a significant part of their fertility during their exploitation in agrocenoses. The decrease in the fertility of the surface layer of soils in the steppe landscapes of the Orenburg Cis-Urals contributed to a decrease in the yield of grain crops and an increase in the volume of applied mineral fertilizers. The use of reverse technology of mechanical tillage contributed to the weathering of the surface fertile soil layer and its degradation. Plowing of the Orenburg steppes for agrocenoses led to a decrease in the number of wild ungulates and their adaptation to new living conditions in agrocenoses. Our work was devoted to modeling the process of the influence of the soil-manure mixture of the surface layer of southern chernozem and the manure of large phytophages on the germination of pea and onion seeds in laboratory conditions. Changes in the composition of bacterial communities during the preparation of the soil-manure mixture are one of the factors influencing the germination and morphometric growth parameters of onion and pea seeds. There is no doubt that the nutritional composition of the manure of large phytophages is of decisive importance for stimulating the growth of onions and peas. However, the differences we have shown in the bacterial composition of soil-manure mixtures of two large phytophages raises the problem of increasing or decreasing the nutritional value of the soil-manure mixture depending on the composition of the microbial communities of the manure of large phytophages.

Cassava (Manihot esculenta) Yield, Nutrition, and Heavy Metal Bioaccumulation Responses to Circular Economy-Based Innovations in a Mining-Degraded Landscape

Mining operations in Ghana's Forest-Savannah Transition Zone have caused widespread land degradation, jeopardizing ecosystems, food security, and agroecological sustainability. In response, we conducted an experiment to evaluate the effects of biochar and poultry litter amendments on cassava (Manihot esculenta) growth, nutritional quality, and heavy metal accumulation at an illegal mining-degraded site in the Amansie Central District of Ashanti, Ghana. The experiment included five treatments: biochar (10 ton/ha), poultry manure (10 ton/ha), a biochar-poultry manure mix (1:1 ratio, 10 ton/ha each), and two control groups (degraded and forest sites). The combined biochar and poultry manure treatment yielded the highest cassava stover biomass (22.9 ton/ha) during the first year. Nutritional characteristics of cassava such as %carbohydrate, %protein and %total ash tubers were influenced by treatment amendments. Additionally, biochar and poultry manure reduced the accumulation of Arsenic (As) by 168.9% and Lead (Pb) by 149.8% in cassava compared with galamsey soil control. This study showcases a circular economy-based approach that employs locally available resources to restore mining-degraded landscapes and enhance regenerative agricultural practices, reducing waste, bioaccumulation of heavy metals and improving carbon sequestration. Promoting the use of biochar and poultry manure amendments for ecological restoration in mining-degraded areas can contribute to sustainable land use, food security, and livelihoods. Policymakers should consider these strategies to align with global and national development goals while improving food systems and ecosystem services. Future research should explore the long-term impacts of cassava cultivation on amended mining sites and assess the potential of these amendments for agroecological enhancement and heavy metal immobilization.

Rice (Oryza sativa L.) response with the Application of Manure and Liquid Organic Fertilizer

Organic fertilizers are necessary for environmentally friendly agriculture. The study aimed to determine rice response to manure and liquid organic fertilizer application ratio. The study was conducted by experimental method with a Complete Randomized Design with five replications. The treatment consists of 6 treatments, namely organic fertilizer, 25% goat manure + 75% commercial liquid organic fertilizer, 50% goat manure + 50% commercial liquid organic fertilizer, 75% goat manure organic + 25% commercial liquid organic fertilizer, 100% goat manure, and 100% manure goats + 100% commercial liquid organic fertilizer. The results showed that plant height during the middle of the vegetative phase treatment of 25% goat manure + 75% commercial liquid organic fertilizer was higher than the treatment of 50% solid organic fertilizer goat manure + 50% commercial liquid organic fertilizer and 100% treatment of goat manure solid organic fertilizer. The root length and volume of treatment 25% goat manure + 75% commercial liquid organic fertilizer is longer and higher than the combined treatment of manure and other liquid organic fertilizers. The grain weight per clump of mixed manure and liquid organic fertilizer treatment is no different. In the future, treatment of 25% goat manure + 75% commercial liquid organic fertilizer can be applied to increase the rice roots.

Effect of mixed manure on selected chemical properties, and phosphorus adsorption characteristics of Vertisols in Haramaya district, eastern Ethiopia

AbstractThe phosphorus (P) fixing behaviors of Vertisols have been identified as one of the key drivers of crop response to fertilizer application. More than 75% of applied P in tropical soil was found to be inaccessible to crops due to adsorption and precipitation reactions. A pot experiment was carried out to investigate the effect of mixed manure (MM) on P adsorption characteristics and other selected Vertisol properties. The soil was amended with 0, 5, 10, and 15 t ha−1 of MM. Changes in selected soil parameters and P adsorption characteristics were evaluated after a 30‐day incubation period. An analysis of variance was used to analyze the data. The results demonstrated a substantial drop in soil pH and an increase in soil organic carbon, total nitrogen, available P, and cation exchange capacity compared to the control. The overall quantity and efficiency of adsorbed P were drastically reduced as a result of MM rates. Moreover, the interaction effect of MM and added P concentration demonstrated a considerable increase in both the quantity and efficiency of adsorbed P. Both parameters increased with increased rates of added P concentration but decreased with increasing rates of MM. Despite the fact that all treatments fit well to both the Freundlich and Langmuir isotherms, the former was used due to its greater R2 value. When compared with the control, the Freundlich adsorption coefficient and intensity were found substantially lower. As a result, MM treatment boosted P availability by decreasing adsorption and associated Vertisols characteristics.

Production of Eudrilus eugenia and Compost From Breeding Manure (Cattle, Cavies, Rabbits, And Poultry) In South Of Côte D’ivoire

Developing countries must, in order to support agriculture, integrate available natural resources and promote management of livestock waste. Therefore, the potential of earthworms to decompose organic waste must be exploit : vermicomposting. Thus earthworm Eudrilus eugeniae was cultured in 4 simples treatments and 6 mixed manure treatments. These treatments are combination or not of manure of cattle, cavies, rabbit and poultry. Each treatment has undergone 3 repetitions. The experiment lasted 12 weeks. pH, numerical productivity of E. eugeniae and biomass of E. eugenia have been determined. The results showed that all treatments containing rabbit manure have a final pH close to 7 (neutral pH) with the exception of MG +MR treatment. Those based on poultry or guinea-pig manure and the control range between 5 and 6.5 and are therefore more acidic. The average density and the earthworm biomass of the MC + MR treatment respectively 2889 ± 333 ind./ m2 and 397.22 ± 234.44 g / m2 are different from other treatments. the manure mixture is a privileged environment for Eudrilus eugeniae. It provides a significant biomass of earthworms that can be used in fish farming or in the diet of monogastric animal feed.
 

Managing nitrogen in maize production for societal gain.

Highly productive agriculture is essential to feed humanity, but agricultural practices often harm human health and the environment. Using a nitrogen (N) mass-balance model to account for N inputs and losses to the environment, along with empirical based models of yield response, we estimate the potential gains to society from improvements in nitrogen management that could reduce health and environmental costs from maize grown in the US Midwest. We find that the monetized health and environmental costs to society of current maize nitrogen management practices are six times larger than the profits earned by farmers. Air emissions of ammonia from application of synthetic fertilizer and manure are the largest source of pollution costs. We show that it is possible to reduce these costs by 85% ($21.6 billion per year, 2020$) while simultaneously increasing farmer profits. These gains come from (i) managing fertilizer ammonia emissions by changing the mix of fertilizer and manure applied, (ii) improving production efficiency by reducing fertilization rates, and (iii) halting maize production on land where health and environmental costs exceed farmer profits, namely on low-productivity land and locations in which emissions are especially harmful. Reducing ammonia emissions from changing fertilizer types-in (i)-reduces health and environmental costs by 46% ($11.7 billion). Reducing fertilization rates-in (ii)-limits nitrous oxide emissions, further reducing health and environmental costs by $9.5 billion, and halting production on 16% of maize-growing land in the Midwest-in (iii)-reduces costs by an additional $0.4 billion.

ECOSCHEMES AS A NEW TOOL TO SUPPORT AGRICULTURE – THE STATE OF IMPLEMENTATION IN POLAND

The article outlines the changes to the EU’s Common Agricultural Policy for 2023-2027 with a particular focus on a new type of direct payment, i.e. ecoschemes. The aim of the article is also to present the interest of farmers in this tool for obtaining funds in the initial period of its operation, i.e. in the first half of 2023. The level and spatial differentiation of interest of Polish farmers in this new type of direct payments was analyzed. It was indicated that the number of applications submitted is influenced by the production specialization of individual provinces. The results of the study further confirm that carbon farming is the most popular of the five types of ecoschemes, with practices such as mixing straw into the soil (61.2%), using winter intercrops/intercrops (35.0%) and mixing manure on arable land within 12 hours of application (23.8%). This state of affairs was influenced by the previous experience of farmers related to the improvement of soil structure.

Transmission and retention of antibiotic resistance genes (ARGs) in chicken and sheep manure composting

Transmission of ARGs during composting with different feedstocks (i.e., sheep manure (SM), chicken manure (CM) and mixed manure (MM, SM:CM = 3:1 ratio) was studied by metagenomic sequencing. 53 subtypes of ARGs for 22 types of antibiotics were identified as commonly present in these compost mixes; among them, CM had higher abundance of ARGs, 1.69 times than that in SM, while the whole elimination rate of CM, MM and SM were 55.2%, 54.7% and 42.9%, respectively. More than 50 subtypes of ARGs (with 8.6%, 11.4% and 20.9% abundance in the initial stage in CM, MM and SM composting) were “diehard” ARGs, and their abundance grew significantly to 56.5%, 63.2% and 69.9% at the mature stage. These “diehard” ARGs were transferred from initial hosts of pathogenic and/or probiotic bacteria to final hosts of thermophilic bacteria, by horizontal gene transfer (HGT) via mobile gene elements (MGEs), and became rooted in composting products.

A longer biodegradation process enhances the cadmium adsorption of the biochar derived from a manure mix

Adsorption of heavy metals by biochar adsorbents can reduce their bioavailability and mobility. However, the effects of the biodegradation processes of raw material before biochar preparation on adsorption remain unclear. This study utilized the degradation products at different stages of the compost to produce biochars and investigated their adsorption property. Compared to the virgin biochar (IBC) prepared from untreated compost, the biochar (EBC and LBC) prepared from the sample collected by the biodegradation process had more robust adsorption properties. Furthermore, the adsorption capacity of biochar (LBC) prepared from the sample collected in the later biodegradation process was approximately 50% higher than that of biochar (EBC) prepared from the sample collected in the early phase. LBC had more oxygen-containing functional groups, more ion exchange sites, and carbonate ions, improving the adsorption capacity by 100% compared with IBC. The BET surface area of LBC was approximately four times higher than that of IBC and 25% more than EBC. Moreover, the dominant adsorption mechanism of LBC is the formation of insoluble Cd-mineral complexes (cadmium carbonate) with the inorganic. The increase in pH also facilitated Cd (II) precipitation. This study highlighted that appropriate biodegradation before biochar preparation from manure mix is an effective and energy-saving method to enhance the ability of biochar to adsorb heavy metals.

Soil profile N2O efflux from a cotton field in arid Northwestern China in response to irrigation and nitrogen management

It remains uncertain how different N inputs as synthetic fertilizer or manure and irrigation types affect nitrous oxide (N2O) production and effluxes in the subsurface. A field trial was carried out in 2016 to evaluate the impacts of conventional urea, animal manure, and a 50/50 mix of urea and manure on N2O production/effluxes from a cotton (Gossypium hirsutum L.) field under flood or drip irrigation in northwestern China. Soil N2O concentrations were monitored at 5, 15, 30, and 60 cm depths to assess the production and diffusion rates of N2O in the soil profile. The results showed that N2O concentrations in 0–60 cm ranged between 221 and 532 nL L−1 and averaged 344 nL L−1, which was generally lower compared to other studies in the same region. Manure and flood irrigation significantly increased N2O production at 0–5 cm and 5–15 cm, respectively. That is, the effects of nitrogen management and irrigation types on the N2O production of the profile were reflected in the surface layers and subsurface layers, respectively. All N2O production occurred in the 0–15 cm layer, with the 0–5 cm depth contributing 87%–100% of the surface emissions. The response discrepancy of N2O production/diffusion to irrigation and nitrogen management in different soil depths should be fully considered in developing agricultural N2O emission reduction measures.

Microbiome - based agents can optimize composting of agricultural wastes by modifying microbial communities

Microorganisms that facilitate the decomposition of agricultural wastes are of importance during composting processes. Here, we assessed if microbial agents, comprising Clonostachys rosea, Bacillus amylolyticus and Rhodospirillum photometricum can facilitate the decomposition of a compost mix of vegetable waste, chicken manure, sawdust, and biochar. The results showed that inoculating the compost mix with the microbial agents elevated the compost temperature, increased the thermophilic period, and enhanced cellulose degradation. Microbial agent inoculation also changed the diversity and richness of decomposing microbial communities. Among the microbial agents, the mixture of C. rosea and B. amylolyticus performed better than other mixtures. Taken together, the results confirmed that the microbial agents comprising C. rosea can enhance the composting process by ameliorating the physiochemical conditions of agricultural wastes and promoting the diversity and proliferation of beneficial bacteria involved in the decomposition of cellulose.