The Impact of Farmer Differentiation Trends on the Environmental Effects of Agricultural Products: A Life Cycle Assessment Approach

Abstract

Farmer differentiation has led to significant differences in input behaviors, presenting new challenges for agricultural environmental governance. However, previous studies evaluating agricultural production systems often overlook the impact of farmer heterogeneity, and the relationship between farmer differentiation and environmental impacts remains unclear. This study takes the apple production system as a case and employs life cycle assessment (LCA) using the IMPACT 2002+ model to establish environmental impact evaluation indicators for agricultural products. The environmental impacts of different types of farmers are analyzed. The findings are as follows: Overall, orchard systems under Type II part-time farmer (PTF(II)) management show the highest environmental impacts, whereas Type I part-time farmer (PTF(I)) systems exhibit the lowest, with pure farmer (PF) systems falling in between. Endpoint assessments reveal that human health is the most affected, with resource impacts being the least significant. Further analysis reveals that fertilizers are the primary environmental hotspot in the apple production system. For PFs and PTFs(I), the second-largest source of pollution in the orchard system is the purchase of storage services, whereas for PTFs(II), it is irrigation. Therefore, the government should strengthen the management of fertilizers and irrigation, and promote measures such as eco-friendly fertilizers and water-saving technologies, thereby reducing the environmental burden of production.

1. Introduction

In the context of global climate change and the Sustainable Development Goals (SDGs), exploring the environmental impacts of agricultural production systems is of significant importance for agricultural sustainability, ecological environmental protection, and improving farmers’ livelihoods. Farmer differentiation provides a new opportunity to achieve a balance between economic growth and environmental sustainability. Farmer differentiation refers to the process by which homogeneous agricultural households within a given region evolve into heterogeneous households engaged in agriculture, industry, commerce, and other sectors. Specifically, it involves the gradual transformation of purely agricultural households into part-time households engaged in both farming and non-farming activities, as well as non-agricultural households. This results in the dynamic coexistence and continuous evolution of pure farmers, part-time farmers, and non-agricultural households [1]. Existing studies suggest that the differentiation of farmers in terms of their occupational structure—shifting from purely agricultural households to those engaged in both agricultural and non-agricultural activities—can indirectly influence their agricultural practices, including crop selection, adoption of irrigation technologies, pesticide and fertilizer use, agricultural machinery demand, access to credit, and land transfer practices [2,3]. However, the comprehensive environmental impact of this differentiation trend remains unclear. With the advancement of urbanization and the relaxation of population mobility policies, traditional farmers are gradually evolving into pure farmers, Type I part-time farmers, and Type II part-time farmers [4,5]. Specifically, households with non-agricultural income accounting for less than 10% of total household income are classified as PFs; households with non-agricultural income accounting for 10% to 50% are classified as first-class part-time farmers, who primarily focus on agriculture with supplementary non-agricultural activities; households with non-agricultural income accounting for 50% to 90% are classified as second-class part-time farmers, who focus primarily on non-agricultural activities but still maintain some involvement in agriculture [4,5]. Some studies suggest that the increase in non-agricultural income can alleviate financial constraints on agricultural investments, thereby intensifying agricultural inputs and exacerbating environmental pollution [6]. Other research argues that exposure to non-agricultural sectors enables farmers to better access market information and technological advancements, thus driving the innovation and adoption of green agricultural technologies [3]. Non-agricultural employment encourages farmers to lease out more land by changing the allocation of production factors [7]. The level of farm household diversification suppresses the transfer of farmland into cultivation and promotes the transfer of farmland out of cultivation [8]. Furthermore, farmer differentiation has also promoted the development of socialized professional service organizations, which provide a range of services from production to sales. As a result, farmers may allocate more time and resources to non-agricultural activities, and standardized production models may help reduce environmental impacts [9].

The mechanisms through which farmer differentiation impacts the environment are multidimensional and interrelated. Existing studies have identified four potential pathways by which farmer differentiation affects the rural ecological environment: land use change, agricultural management practices, patterns of natural resource consumption, and shifts in energy structure.

(1)

Land Use Change. With the intensification of farmer differentiation, land transfer has become increasingly frequent, leading to the concentration of farmland in the hands of a few large-scale operators or agribusinesses. This trend drives agricultural production toward greater intensification and scale, potentially resulting in issues such as the abandonment of marginal lands and the expansion of high-intensity cultivation areas, which in turn may cause soil erosion and ecological degradation [8].

(2)

Changes in Agricultural Management Practices. The diversification of farmer types leads to differences in agricultural management strategies. For instance, in pursuit of higher returns per unit of labor, some part-time or non-agricultural households may favor crop production models with high economic returns that rely heavily on external inputs. This may increase the use of agrochemicals such as pesticides and chemical fertilizers, posing risks to soil health, water quality, and overall ecosystem stability [10].

(3)

Patterns of Natural Resource Utilization. The diversification of livelihood strategies alters the degree of farmers’ dependence on natural resources such as land and water. An increase in non-agricultural income may alleviate economic reliance on farmland, particularly in mountainous or remote areas, helping to reduce deforestation, reclamation of sloped land, and other unsustainable land use practices. This shift is conducive to ecosystem restoration and improvements in land cover [11].

(4)

Shifts in Energy Consumption Structure. As rural livelihoods transition from agricultural to non-agricultural activities, the structure of household and production energy use also changes. Dependence on traditional biomass energy sources (such as firewood and crop residues) declines, while the share of commercial energy (including electricity, natural gas, and solar energy) increases. This transition helps to reduce pressure on forest resources, enhance rural energy efficiency, and improve ecological environmental quality to a certain extent [12,13].

As the demand for and export of Chinese apples continue to grow, it has become particularly important to identify the environmental impacts and key environmental hotspots associated with different types of farmers in the apple production process. As the world’s largest producer of apples, China accounts for over 50% of the global apple planting area and total production. However, research on the environmental impacts of apple production systems in the context of China remains relatively scarce [14,15,16]. Existing studies abroad typically treat farmers as a homogeneous group, thus overlooking the environmental assessment of agricultural production systems influenced by farmer differentiation [17,18,19,20]. Unlike standardized orchards abroad, orchards in China typically have smaller production scales, lower levels of standardization, and greater heterogeneity in orchard size, standardization level, and production practices, which increases the complexity of agricultural environmental governance. The high profitability has led farmers to adopt high-input production methods, such as excessive fertilization, pesticide use, and improper use of agricultural plastic films and paper bags. These practices exacerbate agricultural environmental pollution issues [21]. Environmental problems related to fruit tree production include water eutrophication, greenhouse gas emissions, human toxicity, and energy consumption [14,15,22].

With the continuous development of socio-economic conditions, farmer differentiation has become a prominent reality. As a result, conclusions and management recommendations based on the assumption of homogeneous farmers are increasingly losing their relevance and adaptability. Given the full-process nature of agricultural production, the complementarity of input factors, and the diversity characteristics of environmental impacts, there is an urgent need to construct a comprehensive framework that includes overall resource and environmental indicators to evaluate the environmental impacts of farmer differentiation trends. This framework will help address critical concerns related to human health, ecosystem quality, and climate change. Therefore, this study aims to bridge this gap by using data from 172 typical mountainous apple production systems in Yuncheng County, Shanxi Province, and applying the IMPACT 2002+ model to construct environmental impact evaluation indicators for agricultural products. By analyzing the environmental impact results of different types of farmers, this study provides scientific support for agricultural environmental governance and offers insights into how differentiated farming practices can influence sustainability. It also contributes to policies aimed at addressing environmental degradation, ecosystem protection, and climate change mitigation.

2. Materials and Methods

2.1. Case Study Area

As shown in Figure 1, the data for this study comes from information about farmers in five major apple-producing regions of Yuncheng City, including Wanrong County, Linyi County, Pinglu County, Ruicheng County, and Yanhu District. To ensure the reliability and accuracy of the data, the research team employed a random sampling method and conducted face-to-face interviews with key decision-makers in orchard management. A total of 202 valid questionnaires were collected, with an effective response rate of 87.8%. The distribution of the questionnaires is as follows: Wanrong County—60, Linyi County—48, Pinglu County—40, Ruicheng County—54, and Yanhu District—54.

2.2. Research Methodology

Life cycle assessment (LCA) is a systematic analysis method that quantifies the potential environmental impacts of a product, process, or activity throughout its entire life cycle, including raw material extraction, product manufacturing, transportation, use, waste disposal, resource consumption, and pollutant emissions [23]. In life cycle impact assessment, two main characterization approaches are commonly used: the midpoint approach and the endpoint approach. The midpoint approach characterizes environmental impacts at an intermediate point along the cause-effect chain, whereas the endpoint approach aggregates these impacts to assess their consequences on areas of protection such as human health, ecosystem quality, and resource availability. IMPACT 2002+ is an environmental impact assessment method proposed by the Swiss Federal Institute of Technology Lausanne (EPFL). This method links inventory data to environmental damage categories through characterization factors at the midpoint level, using the quantified results of environmental damage indicators to represent the impact on resource environments. For example, it can show how much a product’s life cycle contributes to pollution or resource depletion. It is an intuitive and easily quantifiable environmental impact assessment method. The IMPACT 2002+ model integrates the midpoint type from CML2001 and the damage type from Eco-indicator99 as the base indicators, connecting the inventory data through the midpoint type to the environmental damage types [24]. This method allows users to choose between using midpoint or damage-type indicators based on their needs, providing flexibility and ease of use. It also facilitates a comparative analysis of impact results from both midpoint and damage-type perspectives, providing an intuitive understanding of the relationship between different stages of the orchard system and its resource and environmental impacts.

In recent years, LCA has been increasingly applied in agricultural research [25,26,27]. Existing studies have included the assessment of various agricultural products’ life cycles, such as fruit production and crops like corn and soybeans [28,29]. By integrating life cycle theory and methods into orchard systems, a comprehensive quantitative evaluation of the resource and environmental impacts can be conducted, offering critical decision-making support for the sustainable development of orchard systems as illustrated in Figure 2. For more detailed calculation procedures, please refer to the Supplementary Materials.

2.3. System Boundaries and Functional Units

The system boundary for this study is defined as cradle to storage gate, covering four subsystems: the agricultural input production system, the orchard management system (which includes agricultural insurance services and network services), the apple storage system, and the transportation system. Farmers in the surveyed area typically do not participate in the retail, consumption, and waste management stages. Figure 3 illustrates the boundaries of the apple production system.

In the background systems, the scope encompasses the production of seedlings, fertilizers (including nitrogen, phosphorus, and potassium), pesticides (such as insecticides, fungicides, and herbicides), paper bags, plastic films, diesel, and organic fertilizers. Notably, the production of agricultural materials is modeled using background databases, with further details provided in the relevant literature [30,31,32] and Supplementary Table S3.

The orchard management system encompasses various activities, including fertilization, pesticide application, irrigation, bagging, plastic film covering, and weeding. Additionally, it incorporates the procurement of social services, such as agricultural insurance and Internet services. The application of chemical fertilizers is instrumental in enhancing apple yields. Typically, during the initial stages of apple growth, nitrogen fertilizers are predominantly utilized, while phosphorus and potassium fertilizers become more significant in later stages. A variety of fertilizers are employed, including ammonium nitrate (typically containing 35% nitrogen), ammonium sulfate (typically containing 21% nitrogen), compound (typically containing 15% nitrogen, 15% phosphorus, and 15% potassium), phosphate fertilizers (typically containing 46% P₂O₅), potassium sulfate (commonly 50% K₂O), and potassium chloride (commonly 60% K₂O). The primary active ingredients in these fertilizers include nitrogen (N), phosphorus (P₂O₅), and potassium (K₂O).

Organic fertilizers play a crucial role in enhancing soil quality, ensuring sustained crop yields, and promoting ecological balance, thereby contributing to sustainable agricultural development. In orchard management, organic fertilizers are typically applied post-harvest, and in the research area, the fertilizers are mainly in the form of feces (especially pig manure). The nutrients in organic fertilizers are released gradually, providing a prolonged nutrient supply to plants and extending fertilizer efficacy.

Pesticide applications primarily consist of insecticides, fungicides, and herbicides, with active ingredients, including thiabendazole, glufosinate ammonium, and imidacloprid. Among these, herbicides are utilized the least to uphold the quality and safety of apples. Insecticides and fungicides are applied approximately 5 to 8 times per year.

Irrigation water usage is significantly influenced by natural precipitation patterns. In years with adequate rainfall, apple trees typically receive irrigation 2–3 times annually. Pruning and weeding activities utilize semi-mechanized equipment, while bagging and plastic film covering are labor-intensive processes that necessitate hiring additional labor during specific periods. The pruning of apple trees is carried out once a year in spring, autumn, and winter, mainly to adjust the growth of branches. The paper bags used for bagging are generally made from kraft paper, with standard dimensions of 15 cm × 18 cm. Wrapping the fruit in these specially designed bags during the early growth stage protects it from adverse external factors, thereby enhancing fruit quality, reducing pest and disease prevalence, mitigating the effects of natural disasters, and lowering pesticide residues. For plastic film, black polyethylene film is commonly employed. This agricultural technique helps to raise soil temperature, retain soil moisture, and suppress weed growth. However, improper application of plastic film can lead to issues such as soil structure deterioration and residual plastic pollution. Given that both bagging and plastic film covering largely depend on hired labor, this study focuses on assessing the environmental impacts associated with farmers’ management of plastic film and paper bags.

Existing studies suggest that life cycle assessments of apple production primarily use process-based analysis methods, which often omit peripheral but increasingly relevant inputs, such as agricultural insurance and Internet services [14]. While their individual environmental impacts are relatively minor compared to inputs like fertilizers or pesticides, their inclusion helps ensure completeness of the system boundary in line with modern production realities. This study examines the social service activities that farmers engage in during the production stage, focusing on agricultural insurance services and Internet services. Agricultural insurance plays a crucial role in helping farmers mitigate risks associated with natural disasters (such as floods, droughts, pests, and diseases) and market volatility, thereby reducing potential economic losses. In contrast, Internet services offer farmers timely access to critical information, including agricultural techniques, market trends, and weather forecasts, enabling them to make informed production decisions. Additionally, these platforms facilitate direct sales to consumers or remote markets, expanding sales channels and enhancing product value. Overall, both agricultural insurance and Internet services significantly contribute to the stability and efficiency of agricultural production, empowering various types of farmers to better navigate production and market challenges, thus improving the overall competitiveness and sustainability of the agricultural sector. Figure 1 shows the average consumption amounts for agricultural insurance and Internet services among different categories of farmers.

Regarding the apple storage system, farmers transport harvested apples to nearby cold storage facilities until they are sold. The choice of apple storage services varies with the duration of storage, and farmers pay corresponding fees based on their needs. To prevent damage from long-distance transport, fruit farmers often opt for local storage solutions. Notably, there are substantial discrepancies in the utilization of apple storage services across different farmer types. The duration for PFs to purchase these services is 1.4 times that of PTFs(I). Furthermore, the separation of apple grades for storage is often unnecessary, as both apples intended for direct consumption and those earmarked for processing are typically sent to storage before reaching their final destinations. In other words, all apples are sent to cold storage without any differences in the process.

The transportation system encompasses two primary components: the transportation of agricultural materials from distribution centers to orchards and the transportation of apples from orchards to cold storage facilities. For most agricultural materials, except for compost, the transportation distance is standardized at 30 km, representing the distance from the farmer’s village to the city. In contrast, composting production is based on a shorter distance of 10 km, as pig farms located within townships provide free manure. Cold storage facilities are typically situated in towns that are conveniently accessible to fruit farmers, leading to the assumption that the transportation distance from the orchard to cold storage is also 10 km. Light trucks, which can carry weights ranging from 1.8 to 6 tons, are primarily used for these transportation activities, with an estimated fuel consumption of 5–6 L per 100 km.

In this study, the functional unit for life cycle assessment is defined as 1 ton (1000 kg) of fresh apples. With regard to the environmental impacts associated with the main processes of production of one ton of apple fruit, because there were no co-products, no allocation was performed in accordance with the ISO standards: 100% of the environmental impacts corresponded to one ton of fruit in the analyzed apple orchard. Commonly, life cycle assessments in apple production utilize functional units of either 1 ton of fresh apples or 1 hectare of orchard [9,15,16]. Given that the majority of small farmers—94.2%—manage orchards smaller than 1 hectare, this study acknowledges that as orchard area increases, the optimal input factors for maximizing farmers’ income exhibit nonlinear changes. Thus, 1 ton of fresh apples serves as the functional unit to facilitate comparisons of apple yields across different production management strategies employed by various types of farmers.

2.4. Analysis of Farmer Differentiation Types and Orchard System Inventory Data

The widely accepted classification method is based on the proportion of non-agricultural income, which divides farmers into PFs, part-time farmers, and non-agricultural farmers [4,5,33]. Specifically, households with non-agricultural income accounting for less than 10% of total household income are classified as PFs; households with non-agricultural income accounting for 10% to 50% are classified as first-class part-time farmers, who primarily focus on agriculture with supplementary non-agricultural activities; households with non-agricultural income accounting for 50% to 90% are classified as second-class part-time farmers, who focus primarily on non-agricultural activities but still maintain some involvement in agriculture. Non-agricultural households are defined as those with non-agricultural income accounting for more than 90% of total household income. Additionally, some studies propose other classification standards, such as thresholds of 5%, 50%, and 95%, or 20%, 50%, and 80% [1]. This study excludes samples where non-agricultural income exceeds 90% and uses 10%, 50%, and 90% as the boundaries to classify farmers into PFs, PTFs(I), and PTFs(II).

According to the classification criteria for farmer differentiation, the sample consists of 31 PFs, 35 PTFs(I), and 106 PTFs(II), with an additional 30 households classified as non-farmers. The disparities in resource endowments among differentiated farmers lead to variations in behavioral cognition and constraints, influencing the decisions and actions of each type of farmer. This differentiation manifests in distinct behaviors and choices across the various farmer classifications. The primary input data for apple production systems corresponding to these different types of farmers is presented in

Table 1. Main inventory data of apple production systems of different types of farming households.

Characteristics	Unit	PF	PTF(I)	PTF(II)
Fertilizer
N fertilizer	kg·t−1·year−1	23.58	29.36	38.82
N mature	kg·t−1·year−1	8.38	4.88	5.49
P2O5 fertilizer	kg·t−1·year−1	8.81	9.15	12.69
P2O5 mature	kg·t−1·year−1	18.39	10.70	12.05
K2O fertilizer	kg·t−1·year−1	6.70	6.78	9.40
K2O mature	kg·t−1·year−1	5.98	3.48	3.92
Pesticide
Imidacloprid	kg·t−1·year−1	0.09	0.08	0.11
Thiabendazole	kg·t−1·year−1	0.39	0.34	0.45
Glufosinate ammonium	kg·t−1·year−1	0.01	0.02	0.03
Bagging	p·t−1·year−1	6002.61	5098.92	5216.83
Mulching film	kg·t−1·year−1	2.20	1.75	2.51
Diesel	kg·t−1·year−1	18.97	11.70	32.77
Irrigation	m3·t−1·year−1	50.17	40.11	60.40
Socialized services
Handling and warehousing	USD·t−1·year−1	206.02	160.30	148.84
Insurance	USD·t−1·year−1	30.48	27.31	32.18
Internet services	USD·t−1·year−1	216.04	202.60	340.76

.

In the context of orchard management systems, the emission factors associated with pollutants arising from the application of various fertilizers, organic amendments, pesticides, storage services for apples, agricultural insurance, and Internet services are primarily derived from extant literature. The emission inventory data pertinent to apple production systems across diverse farmer categories are detailed in Supplementary Tables S4–S7. Key active ingredients commonly found in fertilizers include nitrogen (N), phosphorus (P₂O₅), and potassium (K₂O). Based on their environmental impacts, fertilizers can be categorized into three pollution types: air, soil, and water. Specifically, air pollution from chemical fertilizers encompasses gases detrimental to respiratory health and contributing to greenhouse gas effects, such as ammonia, nitrous oxide, and other nitrogen oxides. This study focuses on ammonia (NH₃) and nitrous oxide (N₂O) emissions. The findings indicate that ammonia volatilization accounts for 8.74% of nitrogen inputs, while direct N₂O emissions represent 3.01%, with the emission factors based on national data [34]. In apple-producing regions, emissions associated with organic fertilizers are estimated at 2.68% for NH₃ volatilization and 0.78% for direct N₂O emissions, with the emission factors being region-specific [9].

In addition to direct N₂O emissions, both nitrate nitrogen leaching and ammonia volatilization contribute to indirect N₂O emissions, with parameters estimated at 2.5% for nitrate leaching and 1% for ammonia volatilization [35], with the emission factors being based on national data. nitrate (NO₃⁻-N) leaching associated with chemical fertilizers accounts for 17.21% of nitrogen inputs [9,36], while that associated with organic fertilizers accounts for 14.42% of nitrogen inputs [9]. Due to insufficient data regarding phosphorus loss in orchard systems, this study adopts the national average for phosphorus loss, estimated at 0.2% of both inorganic and organic phosphorus inputs [9,37,38].

In this study, greenhouse gas emissions resulting from the application of organic manure were quantified following the methodologies outlined by Ji et al. (2012) and Shen et al. (2015) [34,39], with the emission factors being based on national data. Additionally, certain heavy metals present in fertilizers pose significant risks for soil pollution. The concentrations of heavy metals such as copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) in fertilizers, relevant to soil contamination, are derived from the findings of Ji et al. (2012) [39]. The introduction of organic fertilizers can also contribute heavy metals to the soil, with their concentrations assessed based on research conducted by Huang et al. (2017) [40].

In orchard management systems, pest control predominantly involves the application of pesticides, raising significant concerns regarding the health impacts of pesticide residues on both fresh and processed food products [41]. According to the findings of Zhu et al. (2018) [9], the environmental hazards and health risks associated with the field emissions of pesticide active ingredients are calculated to be 10%, 43%, and 1% of the active ingredient input for pollutants released into the air, soil, and water, with the emission factors being region-specific.

The combustion of diesel fuel in machinery generates various environmental pollutants that are released into the atmosphere. Khoshnevisan et al. (2014) conducted a comparative analysis of combustion emissions using two databases and found that the Ecoinvent 3.6 database encompasses a broader range of emission categories [42]. Consequently, this study employed publications sourced from the Ecoinvent database for its analyses.

The heavy metal content introduced via irrigation water was calculated based on the methodology established by Lei et al. (2020) [43], with the emission factors being region-specific. In other aspects, this study primarily focuses on the environmental implications of farmers’ management practices concerning plastic film and paper bags. Farmers employ varying disposal methods: paper bags are incinerated, whereas plastic film is uniformly recycled and transported to centralized landfills for disposal. The environmental impact data for waste management practices are primarily sourced from the Ecoinvent 3.6 database.

Since the data on apple storage services, agricultural insurance services, and Internet services reflect the actual consumption costs incurred by farmers during the apple production phase, this study draws upon the research conducted by Li et al. (2021) to quantify their environmental impacts [44]. Specifically, the research utilizes Liang et al. (2016) China Environmental Input Output (CEEIO) dataset, which provides environmental data derived from economic transactions across 153 industry sectors and quantifies the environmental impacts associated with various economic activities per dollar spent [45]. This article employs the CEEIO dataset to ascertain the average emissions associated with three economic activities—apple storage services, agricultural insurance services, and Internet services—at a rate of USD 1, measuring the environmental impact by integrating the actual consumption data obtained from the survey.

3. Results Analysis

3.1. Results of Farmer Differentiation

As presented in

Table 2. Basic characteristics of differentiated farmers.

Characteristics	Unit	PF	PTF(I)	PTF(II)
Sample size	n	31.00	35.00	106.00
Scale	hm2	0.56	0.52	0.49
Employment	d·year−1	72.85	77.81	37.43
Yield per unit	kg·hm2	21,255.00	22,740.00	14,977.50
Total household income	USD·year−1	7489.10	8995.23	10,385.11

Note: Employment refers to the amount of time spent working in the orchard. Total household income includes both farming income and income from other sources.

, the data indicate a clear trend of farmer differentiation, especially toward the PTF(II) category. In terms of orchard size, PFs exhibit the largest average orchard size at 0.56 hectares, while PTFs(II) possess the smallest average orchard area. This suggests that PFs are more inclined to enhance their household income through the expansion of orchard size, whereas PTFs(II) tend to favor land transfer.

This study uses employment time to measure employment intensity. The mechanization level of Chinese small farmers’ orchards is usually low, mainly relying on manpower to complete a series of activities such as bagging, pesticide spraying, and picking. The employment intensity of PTFs(I) is the highest, indicating that PTFs(I) can alleviate the constraint of agricultural labor shortage by hiring labor. The employment intensity of PTFs(II) is the lowest, only 48.10% of PTFs(I), which means that PTFs(II) may devote more time and energy to non-agricultural work, thereby neglecting agricultural production. This hypothesis is supported by the unit output data, which reveals that PTFs(II) have the lowest output per unit of apples, recorded at just 14,977.50 kg. Interestingly, while PTFs(II) report the highest total income, this underscores that the core motivation behind farmer differentiation is the optimization of household income. In pursuit of higher non-agricultural earnings, farmers appear to allocate a greater proportion of household labor towards non-agricultural activities.

3.2. Resource and Environmental Impact Results of Farmer Differentiation

Figure 4 shows the cumulative endpoint environmental impact results across multiple impact indicators for PFs, PTFs(I), and PTFs(II), with the unit in mPt (milli-point). These include assessments for human health, ecosystem quality, climate change, and resource consumption. Overall, the orchard system under PTFs(II) exhibits the greatest environmental impact, followed by the orchard system under PFs. The orchard systems of PTFs(I) have the smallest environmental impact. The endpoint environmental impact results for human health, ecosystem quality, climate change, and resource consumption generally confirm this conclusion. It is worth noting that, regarding the climate change and resource consumption indicators, the environmental impacts of PF and PTF(I) orchard systems are lower than those of PTF(II) systems; however, the difference between PFs and PTFs(I) has not been statistically significant. PTFs(II) typically rely on more intensive agricultural practices and higher input methods because they may not have enough time to properly manage their orchards. This can lead to inefficient resource use (such as excessive use of fertilizers and pesticides) and greater environmental impacts. PTFs(I), due to limited resources, are usually more conservative in their practices and use fewer inputs overall. Their agricultural systems tend to be lower-intensity, which may result in lower resource consumption and reduced environmental impact. PFs tend to invest more in technology, equipment, and farming practices aimed at increasing yields and reducing labor. However, since they focus primarily on agriculture, they may use more resources such as water, fertilizers, and energy. Although they may be more efficient than PTFs(II) in some aspects, this can still lead to a higher environmental impact.

As shown in Figure 4, for all types of farmers, the human health indicator scores the highest in the environmental impact of the orchard system, while the resource consumption indicator scores the lowest. This means that the production of 1 ton of apples has the greatest impact on human health, while its impact on resource consumption is relatively small. This result is consistent with the findings of Zamani et al. (2024) and Rasoolizadeh et al. (2022) [46,47]. For the human health indicator, the evaluation includes carcinogenic substances, non-carcinogenic substances, ionizing radiation, ozone layer depletion, and organic and inorganic respiratory system impact substances.

Table 3. The midpoint environmental impact of apple production system producing 1 ton of apples.

Midpoint	Characterization				EF(i)	Damage Indicators	Damage Assessment
	PF	PTF(I)	PTF(II)	Unit	Value		PF	PTF(I)	PTF(II)	Unit
C	77.44 × 100	7.78 × 100	1.01 × 101	kg C2H3Cl eq	2.80 × 10−6	Human Health	2.08 × 10−5	2.18 × 10−5	2.83 × 10−5	DALY
NC	2.45 × 101	2.27 × 101	2.84 × 101	kg C2H3Cl eq	2.80 × 10−6		6.86 × 10−5	6.36 × 10−5	7.95 × 10−5	DALY
RI	1.17 × 100	1.07 × 100	1.32 × 100	kg PM2.5 eq	7.00 × 10−4		8.19 × 10−4	7.49 × 10−4	9.24 × 10−4	DALY
IR	2.95 × 103	2.80 × 103	3.87 × 103	Bq C-14 eq	2.10 × 10−10		6.20 × 10−7	5.88 × 10−7	8.13 × 10−7	DALY
OLD	4.05 × 10−5	3.80 × 10−5	5.95 × 10−5	kg CFC-11 eq	1.05 × 10−3		4.25 × 10−8	3.99 × 10−8	6.25 × 10−8	DALY
RO	2.57 × 10−1	2.36 × 10−1	2.81 × 10−1	kg C2H4 eq	2.13 × 10−6		5.47 × 10−7	5.03 × 10−7	5.99 × 10−7	DALY
AE	2.85 × 105	2.41 × 105	3.05 × 105	kg TEG water	5.02 × 10−5	Ecosystem Quality	1.43 × 101	1.21 × 101	1.53 × 101	PDF
TE	1.24 × 105	1.05 × 105	1.32 × 105	kg TEG soil	7.91 × 10−3		9.81 × 102	8.31 × 102	1.04 × 103	PDF
TA/N	3.29 × 101	3.06 × 101	3.69 × 101	kg SO2 eq	1.04 × 100		3.42 × 101	3.18 × 101	3.84 × 101	PDF
LO	5.42 × 101	4.79 × 101	5.31 × 101	m2org.arable	1.09 × 100		5.91 × 101	5.22 × 101	5.79 × 101	PDF
AA	5.79 × 100	5.50 × 100	6.86 × 100	kg SO2 eq						-
AEU	1.77 × 10−1	1.82 × 10−1	2.35 × 10−1	kg PO4 P-lim						-
GW	1.13 × 103	1.04 × 103	1.33 × 103	kg CO2 eq	1.00 × 100	Climate Change	1.13 × 103	1.04 × 103	1.33 × 103	kg CO2 eq
NRE	7.87 × 103	7.60 × 103	1.10 × 104	MJ primary	1.00 × 100	Resources	7.87 × 103	7.60 × 103	1.10 × 104	MJ primary
ME	3.30 × 101	4.07 × 101	5.11 × 101	MJ surplus	1.00 × 100		3.30 × 101	4.07 × 101	5.11 × 101	MJ primary

Note: C: carcinogens; NC: non-carcinogens; RI: respiratory inorganics; IR: ionizing radiation; OLD: ozone layer depletion; RO: respiratory organics; AE: aquatic ecotoxicity; TE: terrestrial ecotoxicity; TA/N: terrestrial acidification/nutrification; LO: land occupation; AA: aquatic acidification; AEU: aquatic eutrophication; GW: global warming; NRE: non-renewable energy; ME: mineral extraction.

shows that the midpoint impact indicators for inorganic respiratory substances, non-carcinogenic substances, and carcinogenic substances have a large effect on human health, which is in line with the findings of Naderi Mahdei et al. (2023) and Sanchez et al. (2016) [48,49].

In terms of climate change indicators, the mean Global Warming Potential (GWP) of orchard production systems across different types of farmers ranges from 1126.29 to 1334.53 kg CO₂eq, slightly higher than the results from Zhu et al. (2018) on conventional orchards in China [9] (913.35 to 956.79 kg CO₂eq), as shown in Table 3.

Regarding ecosystem quality, the most significant impact is on terrestrial ecotoxicity. Similar to the viewpoint of Rafiee et al. (2016) [50], emissions from organic fertilizers and chemical fertilizers play an important role in terrestrial ecotoxicity, with organic fertilizers contributing between 22.3% and 36.1%. Resource consumption has the smallest impact, and it is divided into two components: non-renewable energy and mineral extraction. Non-renewable energy consumption accounts for a higher proportion than mineral extraction. This is consistent with the findings of Canals et al. (2006), who noted the significant role of fertilizers and machinery in resource consumption in orchard systems [22].

3.3. Environmental Hotspot Analysis of Differentiated Farmer Apple Production Systems

According to Figure 5a–c, for all types of farmers, the three factors with the largest environmental impact in the apple production system of this region are fertilizer, storage services, and irrigation. The environmental impacts of fertilizers mainly focus on four categories: inorganic respiratory substances, global warming, terrestrial ecotoxicity, and non-renewable energy consumption. Storage services have the most significant impact on inorganic respiratory substances and global warming, while irrigation has a considerable impact on inorganic respiratory substances, global warming, and non-renewable energy consumption. Fertilizers are the primary source of pollutant emissions in orchard systems. Previous studies have also pointed out that fertilizers are the main pollutants in orchard systems [51,52]. After the farmer differentiation, the fertilization levels of part-time farmers are higher than those of full-time farmers. Since part-time households usually have higher non-agricultural income, they are more likely to allocate more labor to non-agricultural activities, while using more labor-saving production inputs (such as fertilizers), thus exacerbating environmental pollution.

For PFs and PTFs(I), the second-largest source of pollutant emissions in the orchard system is storage services. In contrast, the environmental impacts of insurance and network services are minimal. The storage process requires significant electricity consumption [53], and its environmental impact is similar to that of on-farm electricity use, especially in terms of inorganic respiratory substances and global warming [48]. Compared to PTFs(II), PFs and PTFs(I) have a non-agricultural income ratio of less than 50%, with apples being their primary source of income. Therefore, they need to purchase more apple storage services to obtain better acquisition prices, which may result in longer storage times.

For PTFs(II), irrigation is the second-largest source of pollutant emissions in the orchard system. The irrigation process requires large amounts of electricity and water resources, especially during dry seasons. To meet the crop growth requirements, irrigation frequency and water usage need to be increased. This heightened demand for irrigation leads to higher energy consumption and water resource pressure. As shown in Table 2, compared to full-time farmers and PTFs(I), PTFs(II) have a lower yield per unit area, indicating that for the same output, PTFs(II) require a larger amount of irrigation.

It is worth noting that paper bags have become the fourth largest environmental hotspot for all types of farmers. Consistent with the study by Alaphilippe et al. (2016) [54], in intensive orchards, the production and handling of paper bags (especially the burning of paper bags) have a significant environmental impact across most impact categories. This highlights the urgent need to change the way paper bags are handled in order to mitigate their environmental impact. In this study, the contribution of machinery is relatively low. This is because the orchards in the study area are generally small in scale, with low levels of mechanization, and most of the orchard management relies on manual labor. Zhu et al. (2018) also pointed out that due to China’s very low level of mechanization, energy consumption during the orchard management stage is relatively small [9].

3.4. Endpoint Environmental Impact Results Under the Scenario of Organic Fertilizer Substitution Technology

The above findings reveal that, with the differentiation of farmers, the environmental impacts of orchard systems vary significantly among different farmer types; however, chemical fertilizers consistently remain a key environmental hotspot across all categories. Previous research has indicated that substituting chemical fertilizers with organic alternatives can effectively mitigate the environmental burden associated with orchard systems [55]. However, the findings by Naderi Mahdei et al. (2023) highlight that while manure is generally more eco-friendly than chemical fertilizers, its application may still lead to the emission of certain pollutants within the system boundaries [48]. In 2017, the Planting Department of the Ministry of Agriculture of China launched the “Technology Plan for Replacing Chemical Fertilizer with Organic Fertilizer for Apples”, recommending the use of approximately 25 kg of chemical fertilizer per ton of apple production in the Loess Plateau region. This plan specifies a chemical fertilizer formula comprising 45% (20–15–10 or a similar ratio), alongside the application of fully decomposed farmyard manure—such as cow, sheep, or pig manure—at a rate of 4–8 cubic meters per mu (with an average application of 6 cubic meters). Based on the above policy guidance, a substitution scenario was developed. In this scenario, we used the original input levels of different farmer types (PFs, PTFs(I), and PTFs(II)) as the baseline and simulated the environmental impacts of each farmer type under the organic fertilizer substitution scenario, while keeping all other inputs constant. Following common attributional LCA practices, farmyard manure was treated as a burden-free input at the orchard gate, as it is considered a waste by-product of the upstream livestock system. Accordingly, only the environmental burdens associated with the transportation and field application of manure were included in the model. As illustrated in Figure 6, the endpoint environmental impact results for PFs, PTFs(I), and PTFs(II) in the orchard system under the scenario of substituting organic fertilizers are presented. The analysis shows that replacing chemical fertilizers with organic alternatives has yielded significant environmental benefits in terms of human health damage, climate change, and resource categories, with impacts lower than baseline levels. However, when examining the ecological environment quality category, it becomes evident that as the use of organic fertilizers increases, the associated single score values also rise, exceeding the baseline by 28.79–56.31%. This indicates that while increased organic fertilizer usage can enhance certain environmental aspects, it may also have detrimental effects on overall ecological quality. Longo et al. (2017) assert that excessive application of organic fertilizers can elevate the risk of soil toxicity, potentially surpassing the risks associated with conventional production systems [19], a finding that aligns with the results of this study. In summary, while reducing fertilizer use can diminish many environmental impacts, the overuse of organic fertilizers can also contribute to pollution [50].

4. Conclusions and Discussion

This study examines the environmental impact differences among three categories of apple growers—pure farmers (PFs), part-time farmers Type I (PTFs I), and part-time farmers Type II (PTFs II)—highlighting the complexity of farmer differentiation within orchard systems. Overall, orchard systems under PTF II management show the highest environmental impacts, whereas PTF I systems exhibit the lowest, with PF systems falling in between. The endpoint environmental impact results—including human health, ecosystem quality, climate change, and resource use—support this conclusion. The increasing differentiation of farmers presents new challenges for agricultural environmental governance, as current trends in farmer classification exert negative effects on orchard environmental outcomes [5]. Among all farmer categories, the human health indicator accounts for the highest share of environmental impacts in orchard systems, while the resource use indicator contributes the least. This suggests that producing one ton of apples exerts the most significant impact on human health, followed by climate change and ecosystem quality, with comparatively minimal impact from resource use.

In apple production systems, the primary environmental impact hotspots across all farmer categories originate from chemical fertilizers, storage services, and irrigation. Chemical fertilizers are the main source of pollutant emissions. Substituting chemical fertilizers with organic alternatives can mitigate environmental impacts related to human health, climate change, and resource consumption, but may adversely affect overall ecosystem quality. Longo et al. (2017) assert that excessive application of organic fertilizers can elevate the risk of soil toxicity, potentially surpassing the risks associated with conventional production systems [19], a finding that aligns with the results of this study. In summary, while reducing fertilizer use can lower various environmental impacts, the overapplication of organic fertilizers may also contribute to pollution [50]. Farmers should be encouraged to apply organic fertilizers in moderate, nutrient-balanced amounts, guided by soil testing and site-specific fertilization plans, to avoid ecological risks such as soil toxicity.

We found that handling and warehousing, irrigation, and paper bags also represent significant environmental hotspots within orchard systems. In the context of farmer differentiation, pure farmers (PFs), who are more engaged in full-time agricultural activities, often store apples for longer periods to access better market prices or due to limited sales channels. Extended storage durations can lead to higher energy use and associated environmental impacts, particularly in the human health and climate change categories. In contrast, part-time farmers may rely more on short-term or outsourced storage. To address this issue, the government should support the adoption of energy-efficient cold storage technologies, establish standards for green warehousing in the fruit supply chain, and promote subsidies or incentives for farmers who invest in low-emission storage infrastructure. Additionally, public awareness campaigns should be implemented to encourage consumers to purchase in-season fruit, thereby reducing overall storage duration and its associated environmental burden. The coordinated efforts of stakeholders throughout the apple supply chain are essential for reducing the environmental footprint of apple production. Additionally, Type II part-time farmers (PTFs(II)) tend to be more dependent on mechanized or scheduled irrigation systems due to their time constraints stemming from non-agricultural employment. This greater reliance on irrigation can lead to increased water and energy consumption, and thus higher environmental burdens in resource use and emissions categories. Yu et al. (2011) reported that water-saving irrigation methods offer significant advantages over traditional practices, reducing nitrogen and phosphorus runoff by over 25% and improving nitrogen use efficiency by 3–5% [56]. Adoption of water-saving irrigation techniques, such as drip or micro-sprinkler systems, should be prioritized to minimize nutrient leaching and improve nitrogen use efficiency. Currently, apple growers often burn used paper bags as fuel, resulting in adverse effects on respiratory health, climate change, and terrestrial ecotoxicity. The government should establish paper bag recycling channels to significantly reduce their environmental impacts and promote improvements in human health and ecosystem quality.

The environmental impact management strategies for orchard systems proposed in this study offer valuable insights for the sustainable development of small-scale apple production globally. However, this study has several limitations. One such limitation is the reliance on non-updated background databases, which may introduce measurement errors. Nonetheless, since this study focuses on cross-sectional comparisons among different farmer types, the observed differences are primarily driven by variations in input levels, making the potential errors relatively manageable. Another limitation lies in the classification of farmers solely based on the proportion of non-agricultural income. While this indicator reflects a key structural dimension of rural livelihood transformation, it may overlook other important sources of heterogeneity, such as education level, land tenure, or technology adoption. Incorporating these additional variables in future research could provide a more comprehensive understanding of the behavioral patterns and environmental impacts associated with different farmer types.