An analysis on determinants of farmers' willingness for resource utilization of livestock manure

Electric field as an activator of inoculated Bacillus clausii enhances humification during electric field-assisted aerobic composting

A novel electric field-assisted aerobic composting (EAC) method effectively facilitates compost disposal by applying a low electric field to conventional aerobic composting (CAC). The humification effect of inoculation with Bacillus clausii in the EAC system was better than that in the CAC system, so this study focused on the enhancement effect of microbial inoculation in the EAC system. Compared with EAC, EAC with microbial inoculation (AMI-EAC) increased the degradation of cellulose, hemicellulose, and lignin. Furthermore, AMI-EAC improved the humification index by 42.89 % relative to EAC. AMI-EAC also increased the relative abundance of Bacillus, enriched thermophilic and electroactive microorganisms, and enhanced the activity of associated degradative enzymes, which promoted the decomposition and humification of organic matter. Partial least squares-path model analysis showed that Bacillus inoculation during AMI-EAC enhanced the direct positive effect of microorganisms on enzyme activity and strengthened the positive impacts of substance degradation and enzyme activity on compost maturation. This study provided new insights for inoculating microbial agents to enhance composting efficiency in future engineering applications of EAC.

Interaction mechanism of biochar dissolved organic matter (BDOM) and tetracycline for environmental remediation

The persistent organic pollutant of water by residual antibiotics, particularly tetracycline, posed serious environmental and health risks. Biochar dissolved organic matter (BDOM) sorbed pollutants and mitigated migration and transformation. This study investigates the binding interaction mechanisms between BDOM and tetracycline under varying pyrolysis temperatures biochars and pH, with fluorescence quenching techniques. The influence of biochar pyrolysis temperature on tetracycline adsorption behavior by BDOM-tetracycline was also researched. The key results revealed that higher pyrolysis temperatures and lower solution pH enhanced the binding affinity of BDOM for tetracycline, which was mainly attributed to increased aromaticity and reduced oxygen-containing functional groups. The hydrophobic forces of biochar dominated the interaction, with positive enthalpy (ΔH) and entropy (ΔS) values confirming an endothermic, entropy-driven process. The BDOM modified the mobility and bioavailability of tetracycline in the process of environmental pollution remediation, which not only enhances plant growth, but also mitigates ecological risks.

Heavy metals concentrations in commercial organic fertilizers and the potential risk of fertilization into soils

Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect heavy metals in 74 typical and representative commercial organic fertilizers (COFs) collected in major COF production areas in China. The potential risk of fertilization into soils was evaluated. The concentrations of heavy metals (mg kg- 1) in these COFs were 1.55-36.95 (As), 0.04-2.32 (Hg), 1.43-78.05 (Pb), 0.15-7.49 (Cd), 11.03-212.90 (Cr), 7.74-555.11 (Cu), 21.46-2705.68 (Zn), and 5.62-244.47 (Ni), respectively. Based on China's Organic Fertilizer Standard (2021), COFs with excessive heavy metals accounted for 45.95% (As), 1.35% (Hg), 2.70% (Pb), 8.11% (Cd), and 6.76% (Cr). According to the European Union standard (2019), the rate of COFs with excessive heavy metals was 32.43% for Cu, 75.68% for Zn, and 85.14% for Ni. Estimated by applying 3854 kg hectare- 1 (dry bass) of fertilizer per hectare per year, to guarantee the safe use of organic fertilizer, the risk monitoring of Cd in soil should be emphasized. China should formulate appropriate standards for the limits of Cu, Zn, and Ni in organic fertilizer as soon as possible and should pay great attention to heavy metal pollution of soils.

Microplastic pollution in organic farming development cannot be ignored in China: Perspective of commercial organic fertilizer

Commercial organic fertilizer, an essential fertilizer for developing organic farming in China, has been identified as a potentially important source of microplastics (MPs) on farmland. However, little is known about the occurrence of MPs in commercial organic fertilizers and their potential ecological risks nationwide. Here, stereoscopy and laser-infrared imaging spectrometry were used to comprehensively investigate the abundance, size, type and morphology of MPs in commercial organic fertilizers collected from mainland China, assess the ecological risks, and predict MP contamination. Commercial organic fertilizers contained many MPs (8.88 ×103 to 2.88 ×105 items/kg), especially rich in small-size MPs (<100 µm), accounting for 76.53%. The highest MP pollution load value was observed in fertilizers collected from East China. Chlorinated polyethylene, polyurethane, polyethylene and polypropylene were the dominant MPs with the shape of film and fragment, concentrated in small sizes (<100 µm). The risk index (H-index) of the MPs was used to quantify the ecological risk of the MPs in the different samples, and most of the fertilizers were at level Ⅲ with high risk. Predictably, 2.32 × 1013 - 2.81 × 1016 MPs will accumulate in orchard soils after five years of fertilization, especially in South, Southwest and East China. This study provides primary scientific data on MP pollution in commercial fertilizer and the health development of organic farming.

Insights into carbon loss reduction during aerobic composting of organic solid waste: A meta-analysis and comprehensive literature review

Carbon neutrality is now receiving global concerns for the sustainable development of human societies, of which how to reduce greenhouse gases (GHGs) emissions and enhance carbon conservation and sequestration becomes increasingly critical. Therefore, this study conducted a meta-analysis and literature review to assess carbon loss and to explore the main factors that impact carbon loss during organic solid waste (OSW) composting. The results indicated that over 40 % of carbon was lost through composting, mainly as CO2-C and merely as CH4-C. Experimental scale, feedstock varieties, composting systems, etc., all impacted the carbon loss, and there was generally higher carbon loss under optimal conditions (i.e., C/N ratio (15-25), pH (6.5-7.5), moisture content (65-75 %)). Most mitigation strategies in conventional composting (CC) systems (e.g., additive supplementary, feedstock adjustment, and optimized aeration, etc.) barely mediated the TC and CO2-C loss but dramatically reduced the emission of CH4-C through composting. Among them, feedstock adjustment by elevating the feedstock C/N ratio effectively reduced the TC loss, and chemical additives facilitated the conservation of both carbon and nitrogen. By comparison, there was generally higher carbon loss in the novel composting systems (e.g. hyperthermophilic and electric field enhanced composting, etc.). However, the impacts of different mitigation strategies and novel composting systems on carbon loss reduction through composting were probably underestimated for the inappropriate evaluation methods (composting period-dependent instead of maturity originated). Therefore, further studies are needed to explore carbon transformation through composting, to establish methods and standards for carbon loss evaluation, and to develop novel techniques and systems for enhanced carbon conservation through composting. Overall, the results of this study could provide a reference for carbon-friendly composting for future OSW management under the background of global carbon neutrality.

The effect of perceived value on farmers' livestock manure resource utilization behavior: Evidence from Shandong, China

Introduction

The rapid development of animal husbandry has brought many problems such as ecological environmental pollution and public health damage. The resource utilization of livestock manure is the key way to deal with the above crisis and turn waste into treasure.

Methods

Based on the theory of perceived value, this paper uses multi-group structural equation model to explore the driving mechanism of perceived value on the resource utilization behavior of livestock manure.

Results and discussion

The results showed that: (1) The resource utilization behavior of livestock manure followed the logic of "cognitive level → cognitive trade-off → perceived value → behavioral intention → behavioral performance." Perceived benefit and perceived risk have positive and reverse driving effects on perceived value, respectively. Perceived value has a positive driving effect on behavioral intention. The behavioral intention has a positive driving effect on utilization behavior. (2) Among the observed variables of perceived benefits, ecological benefits have the greatest impact; Among the observed variables of perceived risk, economic risk has the greatest impact. Among the observed variables of perceived value, Significance cognition has the greatest influence. Among the observed variables of behavioral intention, utilization intention has the greatest influence. (3) The perceived value has a differential effect on the utilization behavior of livestock manure resources of different part-time farmers, and the driving effect is more obvious for full-time farmers.

Conclusions

Therefore, it is necessary to improve the resource utilization system of livestock manure, increase the channel for realizing the output of manure resources, strengthen technical assistance and policy subsidies, and implement policies according to local conditions to improve the overall perceived value of farmers.

"Forced Transformation" or "Regulation Capture"-Research on the Interactive Mechanism between Environmental Regulation and Green Transformation of Dairy Farming Subject Production

Under the situation of an increasing resource and environment shortage, the green transformation of dairy farming subject production driven by environmental regulation is the concentrated embodiment of a "promising government" to solve the problem of breeding environmental pollution. Due to the shortcomings of environmental regulation itself and the undefined connotation of the green transformation of dairy farming subject production, the interactive relationship between the two remains unclear at present. Based on defining the concept of green transformation of dairy farming subject production, this paper aims to analyze the interactive mechanism between the environmental regulation and green transformation of dairy farming main production, build a dynamic game model between the environmental regulators and dairy farming subject, and introduce the constraints and benefits of a reputation mechanism on the behavior in the model to explore whether environmental regulation can drive the green transformation of dairy farming subject production. The results showed that the green transformation of dairy farming subject production followed the "subject substitution view" and emphasized "source reduction, process control and terminal treatment". Strictly designed environmental regulations could effectively drive the green transformation of dairy farming subject production, but it was inevitable that the environmental regulators were vulnerable to the rent-seeking behavior of dairy farming subjects, which was "regulation capture". The introduction of the reputation mechanism has greatly improved the rent-seeking behavior of dairy farming subjects and the probability that environmental regulators have "regulation capture", indirectly forcing dairy farming subjects to participate in the green transformation of production. The greater the punishment for dairy farming subjects who do not participate in the green transformation of production was, the more they can be forced to participate in the green transformation of production. At the same time, it also reduces the risk of damage to the credibility of the government. Based on the studies above, this paper also further discussed the shortcomings of environmental regulation itself, including the "re exit and light implementation" of the environmental regulation policy, "decentralization and light inspection" of the environmental regulation subject, "result and light process" of the environmental regulation mode, and "formal regulation and light informal regulation" of the environmental regulation form, which provides a scientific reference for the formulation of the environmental regulation policy of livestock and poultry breeding in the future. Compared with previous studies, this paper is innovative in two aspects: first, it defines the conceptual connotation of a green transformation of dairy farming subject production, and second, it systematically discusses the interaction mechanism between the environmental regulation and green transformation of dairy farming subject production. This paper provides a scientific reference for the development of future environmental regulation policies for livestock and poultry farming.

Recognition on characteristics and applicability of typical modes for manure & sewage management in pig farming: A case study in Hebei, China

Scale-up intensive pig farming can increase profitability by economies of large scale, but it also exacerbates environmental pollution caused by the disordered discharge of manure and sewage. Manure & sewage management (MSM) is critical to mitigate environmental pressure and reuse livestock waste. However, the corresponding MSM measures adopted by pig farmers are multitudinous in reality, due to the diversity of MSM methods and heterogeneity of farmers' characteristics and behaviors. Thus, this study empirically categorized five typical MSM modes (i.e., traditional simple mode (TSM), mixed processing mode (MPM), semi-biogas mode (SBM), professional processing with simple utilization mode (PPSUM) and professional processing with full utilization mode (PPFUM)) by clustering analysis, based on the field data from 406 pig farms, and further discriminated farmers' heterogeneous characteristics on corresponding mode adoption. Results revealed that each mode was distinctive. The applicability of the corresponding mode was reflected in the synthesis deliberation, involving farming structure, land, farmers' characteristic and their subjective awareness. Farmers' education level and pro-environmental perception are significantly promoted to adopt technology-intensive MSM modes. Scale upgrading has a positive effect on mechanization adoption and diversified strategies application. Land as an unalterable objective factor restricted the extension of MSM modes based on field returning. Conclusions clarified typical MSM modes and provided references to individual pig farms on appropriate mode selection, further enhancing the efficiency of MSM and contributing to the sustainability of green development of pig farming in China.

The Impact of Risk Perception Difference of Members of a Scientific Research Project Team on Information Adoption: The Moderating Effect of Knowledge Inertia

A scientific research project is always full of uncertainties and risks. In this condition, full exchange and complementarity of information resources among project team members are necessary and important to meet the information needs for project risk management and even affect the success of the project. The differentiated risk perception of members with various professional backgrounds can contribute to the communication and complementary of the necessary information within the team. However, too much difference in perceptions of project risks may cause members’ information conflicts, which may hinder the adoption of various information and do harm to the risk management. Considering the limited research on this “contradictory” relationship, especially for the scientific research project team, a special group, this study explores the impact of the risk perception differences of the scientific research project team members on information adoption behavior through the large sample empirical statistical method. The results show the hat risk perception difference of members positively affects the learning willingness and information adoption behavior but does not show a negative effect, and there is no inverted U-shaped relationship. Further, learning willingness plays a mediating role between both, while learning inertia and experience inertia positively and negatively moderate the positive effects of risk perception differences on learning willingness, respectively. From the cognitive perspective, this study further reveals the internal influence mechanism of risk perception difference of scientific research project team members on information behavior and provides a theoretical reference for improving the efficiency of information communication and optimizing collaborative team management.

Labor Endowment, Cultivated Land Fragmentation, and Ecological Farming Adoption Strategies among Farmers in Jiangxi Province, China

A deeper understanding of the factors that influence the ecological farming adoption strategies of farmers can help in developing effective adaptation measures to mitigate the degradation of cultivated land quality and ecological degradation. This study used a stratified random sampling technique to select 1488 households in Jiangxi Province, while the double-hurdle model was used to analyze the influence of labor endowments (LEs) and cultivated land fragmentation (CLF) on ecological farming decision-making. The results indicate that LEs and CLF play important roles in farmers’ decision-making with regard to ecological farming. To be more specific, the total household population and CLF have negative effects on adoption willingness, while the number of laborers has a positive effect. For the degree of adoption, the total household population has a negative effect, while the number of laborers and part-time employment have positive effects. In addition, farmers’ ecological farming behavior is also influenced by factors such as education, agricultural income, cooperatives, and agricultural subsidies. Overall, farmers have a high willingness to adopt ecological farming, but the degree of actual adoption is low. This is not conducive to the promotion of ecological farming techniques and the sustainable development of agriculture in China. The study proposes that the government should further improve financial investment and provide relevant technical services. In addition, a temporary work platform should be set up for farmers to encourage them to find other work during the agricultural low season.

The Impact of Training on Beef Cattle Farmers’ Installation of Biogas Digesters

Anaerobic digestion is one of the leading ways to manage livestock manure for energy production and move towards the target of carbon neutrality in the agricultural sector. Based on field survey data from China, a binary probit model and the propensity score matching method are employed to empirically examine the impact of agricultural training on livestock farmers’ installation of biogas digesters to manage livestock manure. The survey results show that beef cattle farmers in our study area are reluctant to install biogas digesters and the actual installation ratio of farmers is much lower than that that is willing to install. On the contrary, the beef cattle farmers are enthusiastic to participate in training (e.g., policy-oriented, technology-oriented, and field-based) related to sustainable farming practices. Regression results suggest that training can effectively promote the installation of biogas digesters, and with the increase of training intensity, the probability to install biogas digesters increases. We further find three other factors that affect farmers’ installation of biogas digesters: the education level of a farmer, which is one of the most important factors positively affecting the installation of biogas digesters; longer farming experience of a farmer, which can significantly promote biogas digester installation; and the farther away a farm is from town/urban centers, which means the more likely it is that the farmer will install biogas digesters. Policy implications are discussed.

Antibiotic degradation dominates the removal of antibiotic resistance genes during composting

To identify the key hosts involved in horizontal gene transfer (HGT) and vertical gene transfer (VGT) of antibiotic resistance genes (ARGs) and to determine the extent to and ways in which environmental properties contribute to ARG removal, the changes in ARG profile and key hosts during biogas residue and pig manure composting were investigated using metagenomic sequencing coupled with network analysis. Composting significantly reduced the abundances of ARGs other than bacA. Seventy and 41 hosts from Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes were associated with HGT and VGT, respectively. The key environmental properties were determined using structural equation modelling. Antibiotics directly affected HGT and determined ARG removal. Temperature indirectly affected HGT, mainly by influencing the degradation of antibiotics. BacA was associated only with hosts involved in VGT, which may lead to its low removal rate. These findings specify the priority and pathway of antibiotics and temperature affecting ARG profile.

Does policy cognition affect livestock farmers' investment in manure recycling facilities? Evidence from China

An increase in living standards and dietary changes have induced a rapid growth in the livestock sector worldwide, which has led to considerable environmental damages due inappropriate disposal of livestock manure. Using primary data from a field survey of cattle farmers in China, this paper empirically examines the impact of policy cognition on livestock farmers' investment in manure recycling facilities. The impact is tested through the multiple mediator model to accommodate two potential mediating mechanisms, which are the agricultural cooperative membership and land leasing. Three conclusions arise. First, policy cognition has a significant positive impact on both the diversification and amounts of farmers' investment in manure recycling facilities. Second, membership in agricultural cooperatives and participation in land leasing are two important mediating mechanisms for policy cognition to affect farmers' investment decisions on manure recycling. Finally, for the two mediating variables, leasing additional agricultural land promotes more investment in manure recycling facilities, but less in investment diversification, while cooperative membership has the opposite impact. This study contributes to three areas of literature on the factors affecting investment decisions, the mediating effects of policy cognition and the investment in non-production related assets. Regarding policy implications, we identify the importance of promoting policy awareness and agricultural cooperatives among livestock farmers, as well as developing land lease markets in agricultural regions in promoting investment in manure recycling facilities.

Co-composting materials can further affect the attenuation of antibiotic resistome in soil application

This study investigated the effects of representative co-substrate (corncob particles) and additive (brick granules) alone on antibiotic resistome of swine manure during composting and subsequent compost application. For relative abundances, four antibiotic resistance gene (ARG) types encoding resistance to aminoglycoside, multidrug, florfenicol-chloramphenicol-amphenicol-fluoroquinolone-quinolone, and sulfonamide increased remarkably during composting, whereas all the ARG types decreased after compost application. Interestingly, much more ARG subtypes (50.1% in total) were reduced in corncob addition treatment. Meanwhile, the addition of corncob particles lowered the relative abundance and diversity of ARGs more significantly. Microbial community exhibited conspicuous changes across the manure, compost, and soil samples where the dominant genera were completely different. Procrustes test proved the co-occurrence and driving effect of microbial community on resistome variation, especially in corncob addition treatment during composting. Network analysis demonstrated that the dissipation of the dominant genera such as Ruminofilibacter, Luteimonas, and Pseudidiomarina in the composts after application contributed greatly to the reduction in ARG relative abundance. Besides, the low abundance of mobile genetic elements (MGEs) in soil also accounted for the attenuation of ARGs to some extent. Our findings clearly proved that co-composting materials can further affect the attenuation of antibiotic resistome in soil application, which can help in understanding the spread and control of ARGs during agricultural process.

Exploring Impacts of Perceived Value and Government Regulation on Farmers’ Willingness to Adopt Wheat Straw Incorporation in China

In China, wheat straw incorporation (WSI) is the most popular way of utilizing wheat straw. WSI can manage agricultural residues to improve soil quality and avoid open burning in fields. However, farmers have been reluctant to implement WSI, which hinders sustainability. This study collected first-hand data about 1027 wheat growers, and used a Logit model to explore the influence of perceived value, government regulation, and their interaction on farmer willingness to adopt WSI. The results also reveal the differences between farmers with different farm sizes, as well as differences in other characteristics impacting WSI willingness. The study found that implementing government regulations and increasing the positive perceived value by farmers can effectively improve farmer willingness to adopt WSI. For example, government subsidies and farmers’ perceptions about cost-related risks impact farmer willingness. There is an interaction effect between government regulation and perceived value with respect to farmer willingness. Policy outreach could effectively strengthen the positive impacts of farmers’ perception of social benefits on farmer willingness. Government subsidies could effectively weaken the negative impacts of farmers’ perception of cost-related and time-related risks on farmer willingness. Farmers with different sized farms are influenced differently by government regulation and perceived value. The willingness of large-scale farmers to adopt WSI is generally influenced by government regulation and perceived value; in contrast, the willingness of traditional farmers is mainly influenced by policy outreach and perceived economic benefits.

Effects of Value Perception, Environmental Regulation and Their Interaction on the Improvement of Herdsmen's Grassland Ecological Policy Satisfaction

Sustainable utilization of grassland resources was an important topic concerned by worldwide countries and regions, and ecological compensation had gradually become the main policy tool for grassland environmental management and ecological protection. This study adopted face-to-face interviews and questionnaires, and multiordered Logit model was then used to explore herdsmen’s satisfaction with Grassland Ecological Conservation Subsidy and Reward Policy (GECSRP) focusing on identifying the key factors behind it. Results showed that herdsmen were not satisfied with GECSRP on the whole, while value perception, environmental regulation and their interaction played a positive role on improving the satisfaction. Specifically, economic benefits had the strongest promotion impacts, followed by social identity in the two-dimensional variables of value perception. The guiding regulation had stronger promoting impacts, followed by the incentive regulation in the two-dimensional variables of environmental regulation. Interestingly, incentive regulation played an enhanced interaction on the influence of economic benefits and environmental value on herdsmen’s satisfaction, yet the interaction between guiding regulation and environmental value was not significant. These indicated that herdsmen paid more attention to substantial subsidies and rewards in the process of ecological livestock husbandry, and environmental regulation formulated by government had a phenomenon of “relative system failure”. Thus, the grassland ecological environment policy should be further adjusted and improved to promote the economic development of pastoral areas.

Alternative Management Systems of Beef Cattle Manure for Reducing Nitrogen Loadings: A Case-Study Approach

Livestock manure is one of the main sources of agricultural nonpoint source pollution and poses a great threat to the environment and human health. Sustainable management of manure via recycling is an effective means to tackle the problem. Based on field interviews in China, multiple case studies were employed to investigate alternative manure management systems. Four conclusions arose. First, compost-based systems, product-based systems, substrate-based systems, and biogas-based systems were identified as four main types of manure management systems, with each possessing its success factors and risk factors. The adoption of a system was driven by various factors. Second, market-oriented operation was the dominant operation mechanism of all the manure management systems. Third, compared to direct application of manure to croplands, all the four manure management systems could reduce nitrogen loadings from livestock farms and lower their environmental effects. Among the systems, biogas-based systems could reduce nitrogen loadings to the greatest extent, followed by product-based systems and substrate-based systems, and then by compost-based systems. Lastly, integrated management of manure with mixed recycling systems is imperative for reducing its environmental effects, which can benefit from the increasing role of third-party entities in manure recycling. Policy implications were also discussed.