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Article

Evaluating the Impact of Green Manure Incorporation on Cotton Yield, Soil Fertility, and Net Eco–Economic Benefits

1
Shandong Agricultural Technology Extension Center, Jinan 250014, China
2
State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang 455000, China
3
Shandong Zhongli Cotton Industry Technology Co., Ltd., Jinan 250014, China
*
Authors to whom correspondence should be addressed.
These authors contributed equally to this work.
Agronomy 2025, 15(3), 559; https://doi.org/10.3390/agronomy15030559
Submission received: 13 January 2025 / Revised: 18 February 2025 / Accepted: 20 February 2025 / Published: 25 February 2025
(This article belongs to the Special Issue Advances in Tillage Methods to Improve the Yield and Quality of Crops)

Abstract

:
Incorporating green manure is a vital strategy for optimizing cropping systems and improving soil quality. However, it is unclear whether the effects of different types of green manure on subsequent cotton yield and soil fertility improvement are uniform. This study evaluated the effects of three green manure incorporation treatments over a two-year cropping cycle (Chinese violet-cotton-Chinese violet-cotton (T1), rapeseed-cotton-rapeseed-cotton (T2), and ryegrass-cotton-hairy vetch-cotton (T3)) on cotton yield and yield components. These treatments were also compared with the winter fallow-cotton (T0) to analyze differences in soil nutrients and net ecological–economic benefits. No significant differences in cotton yield or yield components were observed among the green manure incorporation treatments. However, averaged across two years, T1 produced a seed cotton yield 8.1% higher than T2 and 3.9% higher than T3. T2 and T3 significantly enhanced soil alkali-hydrolyzed nitrogen, organic matter, and total humus content compared to T0. Notably, T3 increased these parameters by 18.7, 23.9, and 26.8%, respectively. Additionally, T3 achieved the highest net ecological–economic benefit, exceeding T0 by $405/ha. This study highlights the potential of green manure to enhance soil fertility and ecological–economic sustainability in cotton fields. Further research is required to evaluate its long-term benefits and broader implications for sustainable agriculture.

1. Introduction

The Yellow River Basin is one of the main cotton-producing regions in China, predominantly characterized by monoculture cotton cultivation [1]. However, following cotton harvests, a six-month fallow period not only results in the waste of natural resources like solar and heat resources, but also leads to a series of ecological problems, including soil erosion, soil degradation, and nitrate leaching [2,3]. Furthermore, monoculture cotton farming, particularly in saline–alkali soils, often relies on plastic mulch to enhance seedling emergence and growth [4]. Prolonged use of plastic mulch has caused the accumulation of residual mulch, which negatively impacts soil quality and poses a significant threat to the sustainability of agroecosystems [1]. These challenges severely limit the efficient development of cotton agriculture and hinder the rational use of land resources, thus impeding sustainable agricultural practices.
To address these challenges, the practice of planting winter green manure has emerged as a promising ecological agricultural strategy. Green manure, a valuable organic fertilizer, refers to crops specifically grown to cover bare ground and improve soil fertility when incorporated into the soil at a certain growth stage [5]. As the plant residues decompose, they release essential nutrients such as nitrogen, phosphorus, and potassium [6]. This process also stimulates soil microbial activity by providing a continuous food source, which enhances microbial diversity and nutrient cycling [7,8]. Additionally, green manure improves soil structure by promoting aggregation and increasing porosity, which in turn enhances water retention and nutrient availability [9]. During the winter, green manure cover reduces wind erosion, prevents soil loss, and maximizes the utilization of solar and heat resources [10]. In agricultural systems, green manure planting is regarded as an effective method for improving the yield and quality of subsequent crops, serving as a sustainable approach to optimizing soil resource use [11,12]. Furthermore, the incorporation of green manure before planting short-season cotton can eliminate the need for plastic mulch, promoting mulch-free cultivation and mitigating residual mulch pollution.
Green manure species exhibit a wide range of ecological functions and agricultural benefits, which vary considerably depending on the species used [13]. Leguminous green manures, through nitrogen fixation by rhizobia, can significantly increase soil organic matter and fertility [14]. In contrast, non-leguminous green manures, with a higher carbon-to-nitrogen ratio, contribute to long-term organic matter accumulation and stabilize the carbon pool [13]. Moreover, metabolites such as organic acids and glucosinolates in cruciferous green manures not only enhance nutrient availability but also help suppress soil-borne diseases [15]. By intercropping leguminous and non-leguminous green manures, spatial and temporal differences in growth and decomposition can be leveraged, optimizing nutrient availability at various stages of crop growth and achieving higher agroecological efficiency [16,17].
In recent years, the role of green manure in improving soil fertility and boosting crop productivity has been extensively researched. Studies have shown that intercropping Chinese violet cress in cotton fields improves agronomic traits, enhances nitrogen accumulation, and increases cotton yield [18]. Incorporating green manure crops such as rapeseed and annual ryegrass has demonstrated significant improvements in soil enzyme activities, organic matter content, and the availability of phosphorus, potassium, and nitrogen [19]. Moreover, green manure incorporation has proven effective in improving carbon and nitrogen levels in saline–alkali soils, leading to increased cotton yields [20]. However, the practical benefits of green manure are influenced by climatic conditions, soil types, species selection, and management practices. Despite growing interest, comprehensive evaluations of the ecological and economic benefits of green manure remain limited in current studies.
In summary, while previous research has highlighted the potential of green manure in improving soil nutrients and enhancing crop yields, studies focused on cotton systems in the Yellow River Basin are still lacking. In particular, there is insufficient understanding of how different green manure species impact short-season cotton growth and yield, as well as their specific roles in soil nutrient dynamics. Therefore, this study aims to conduct field experiments with various green manure species to: (1) compare the effects of different green manure species on the growth and yield of subsequent short-season cotton; (2) evaluate the effectiveness of green manure incorporation in improving soil fertility; and (3) assess the comprehensive ecological and economic benefits of green manure incorporation relative to traditional winter fallow practices. This study seeks to provide scientific evidence and practical guidance for the promotion and application of green manure in the Yellow River Basin and for optimizing agricultural resource management.

2. Materials and Methods

2.1. Experimental Materials

This study included four green manure crops: Chinese violet (Orychophragmus violaceus L.), rapeseed (Brassica napus L.), ryegrass (Lolium perenne L.), and hairy vetch (Vicia villosa Roth). These green manure crops were incorporated into the soil before planting short-season cotton. Two cotton varieties were selected for the study: a full-season cotton variety, Lumian 696, and a short-season variety, Lumian 532.

2.2. Experimental Design

The field experiment was conducted from 2020 to 2022 at the Yangliuxue Experimental Station of the National Crop Variety Regional Experiment Station in Binzhou, Shandong Province, China (117°57′14″ E, 37°25′34″ N). The experimental site was previously used for spring cotton monoculture cultivation. Before the trial began, a baseline soil fertility survey was conducted to assess initial soil nutrient information. The soil type is loamy fluvisol. In the 0–20 cm soil layer, the levels of alkali-hydrolyzed nitrogen, available phosphorus, available potassium, and organic matter were 61.01 mg/kg, 4.3 mg/kg, 171 mg/kg, and 14.39 g/kg, respectively. In the 20–40 cm soil layer, the corresponding values were 28.6 mg/kg, 1.2 mg/kg, 109 mg/kg, and 10.3 g/kg.
The experiment was conducted using a randomized block design with three replicates. The control treatment was conventional full-season cotton monoculture cropping with winter fallow (T0). Four treatments were implemented over a two-year cropping cycle: winter fallow-cotton-winter fallow-cotton (T0), Chinese violet-cotton-Chinese violet-cotton (T1), rapeseed-cotton-rapeseed-cotton (T2), and ryegrass-cotton-hairy vetch-cotton (T3). Full-season cotton was sown in mid-April (15 April and 16 April in 2021 and 2022, respectively) using a plastic mulch planting method. The row spacing alternated between 100 cm (wide rows) and 50 cm (narrow rows), resulting in an average row spacing of 75 cm. Short-season cotton was sown in mid-May without plastic mulch, using an equal row spacing of 75 cm. This study included a total of 12 plots, each with an area of 60 m2 and consisting of 10 rows, each row measuring 8 m in length. Green manure crops were sown immediately after the short-season cotton harvest, in mid-October (15 October, both 2020 and 2021). These crops were incorporated into the soil by April or early May of the following year. Green manure crops were grown without additional fertilizer applications. At cotton sowing, 25 kg of compound fertilizer (20-20-5) per hectare was applied, followed by an additional 10 kg of urea per hectare top-dressed at the squaring stage. Other agronomic practices, including irrigation, weeding, and pest and disease control, followed the standard field management protocols for the region.

2.3. Sampling and Measurements

2.3.1. Crop Productivity Measurements

During the boll opening stage, 10 m representative rows were selected from each plot. Open cotton bolls were manually harvested three times (28 September, 25 October, and 10 November), while unopened bolls were excluded from yield calculations. Seed cotton was air-dried to a moisture content of ≤12% before weighing. In each harvest, 50 randomly selected bolls were dried, weighed, and ginned to calculate boll weight and lint percentage. Prior to green manure incorporation in mid-April, fresh weight yields were measured in a 6.67 m2 area per plot.

2.3.2. Crop Nutrient Content Measurement

Representative samples of three cotton plants and ten green manure plants with uniform growth per plot were collected at harvest, including both roots and aboveground biomass. For cotton plants, the samples were further divided into reproductive organs (bolls) and vegetative organs (roots, stems, and leaves). The samples were cleaned, dried at 105 °C for 30 min, and then dried to constant weight at 65 °C. Biomass was recorded, and the contents of nitrogen, phosphorus, and potassium were analyzed. Total nitrogen in plant organs was determined using the Kjeldahl method [21]. Total phosphorus was measured using the molybdenum-antimony colorimetric method [21], and total potassium was determined by flame spectrophotometer [21].

2.3.3. Soil Nutrient Analysis

Soil samples were collected from 0–20 cm and from 20–40 cm layers at key stages: before green manure sowing, before incorporation (prior to cotton sowing), and after cotton harvest. For each treatment, three replicates were collected, with two random sub-samples per replicate, which were combined into one composite sample per soil layer. The soil samples were sieved (0.01 mm), air-dried, and then analyzed for the following soil parameters [21]: alkali-hydrolyzed nitrogen was determined by the alkali diffusion method; available phosphorus was measured using the molybdenum–antimony colorimetric method; available potassium was determined using flame photometry; and humus content was measured by extraction with sodium pyrophosphate–sodium hydroxide and potassium dichromate and the sulfuric acid method [22].

2.3.4. Net Ecological and Economic Benefits

Net ecological–economic benefits ( V t o t a l ) were calculated based on the evaluation of two primary ecosystem services [18]: agricultural production value (VP) and soil nutrient cycling value (VS):
V t o t a l = V P + V S
V P = I n c o m e y i e l d C o s t i n p u t
where I n c o m e y i e l d represents revenue from crop yield, and C o s t i n p u t accounts for agricultural input costs, which include both material and labor costs. The material costs encompass seeds, plastic film, fertilizers, pesticides and growth regulators, while the labor costs include labor for sowing, management, and harvesting. VS was estimated using the replacement cost method based on local fertilizer market prices, accounting for soil organic matter (SOM), alkali-hydrolyzed nitrogen, available phosphorus, and available potassium in the 0–20 cm soil layer:
V S = i ( W × S N i × S P i )
W = A r e a × ρ × d
where W is the weight of the 0–20 cm soil layer, S N i is the content of specific nutrients (g/kg), and S P i is the market price of specific nutrients. Area, ρ and d represent area (m2), bulk density (g/cm3), and soil depth (cm), respectively.

2.4. Data Analysis

Data were processed in Microsoft Excel for mean calculation and normalization. One-way analysis of variance (ANOVA) was conducted using SPSS 20.0 (SPSS Inc. Chicago, IL, USA) to determine significant differences among treatments (p < 0.05), and Tukey’s multiple comparison test was used for post hoc analysis. To evaluate cotton yield and nutrient uptake, we examined the effects of various green manure treatments on cotton yield, excluding a control group due to differences in cotton cultivars. However, when comparing the impacts on soil nutrients, all treatments were included. Data visualization, including bar and line plots, was performed using GraphPad Prism 8.0.2 (GraphPad Software, San Diego, CA, USA).

3. Results

3.1. Effects of Green Manure Incorporation on Cotton Yield and Plant Nutrients

No significant differences were observed in seed cotton yield or yield components (boll number, boll weight, and lint percentage) among the green manure incorporation treatments in 2021 and 2022 (Table 1, Figure 1). Nevertheless, T2 consistently achieved the highest seed cotton yield in both years. Averaged across the two years, seed cotton yield under T2 and T3 was slightly lower than T1, with reductions of 8.1% and 3.9%, respectively. In terms of boll number, T1 demonstrated the best performance, recording 67.1 bolls/m2 in 2021 and 58.0 bolls/m2 in 2022. Conversely, T3 had the fewest bolls among all treatments, with 63.0 bolls/m2 in 2021 and 53.1 bolls/plant in 2022. Lint percentage showed minimal variation across all treatments.
No significant differences were observed in the nutrient content of cotton’s vegetative and reproductive organs across the three green manure incorporation treatments in 2021 (Figure 2). However, in 2022, significant differences were observed in the total nitrogen (N) and total potassium (K) content of the reproductive organs, as well as the total phosphorus (P) content in the vegetative organs among the treatments (Figure 2). The T1 treatment showed the highest total N content (21.8 g/kg) but the lowest total K content (22.0 g/kg) in the reproductive organs compared to the other treatments. In contrast, for the vegetative organs, the only significant difference was observed in the total P content, with T3 exhibiting the highest P content (2.1 g/kg), while T1 had the lowest (1.5 g/kg). Overall, green manure incorporation did not significantly affect cotton yield in either year, but certain treatments showed potential for improving nutrient content.

3.2. Comparison of Biomass and Nutrient Content Among Different Green Manure Crops

The results showed no significant difference in fresh weight between T1 and T2 over two years, with mean values of 43.05 t/ha and 54.11 t/ha, respectively (Figure 3). Both treatments produced significantly higher fresh weight than T3. Regarding nutrient content, no significant differences in total N were observed among the green manure incorporation treatments in 2021. However, total P in T1 was significantly lower than in T2 and T3, while T1 had significantly higher total K compared to T2 and T3. In 2022, significant differences in nutrient contents were observed. T2 and T3 exhibited similar total N and P contents, both significantly higher than T1. For total K content, T3 outperformed both T1 and T2, with no significant difference between T1 and T2. These results suggest that biomass and nutrient content vary significantly among different green manure crops, with T3 showing the most consistent nutrient levels.

3.3. Green Manure Incorporation Effects on Soil Nutrients

Dynamic changes in soil nutrients were analyzed over five sampling periods spanning two years (Figure 4 and Figure 5). Soil nutrient content consistently decreased with depth, and significant differences were observed across sampling periods. Before cotton planting (P2 and P4), effective nitrogen levels in both the 0–20 cm and 20–40 cm soil layers were higher under green manure incorporation treatments compared to the winter fallow control. Among the treatments, T2 and T3 demonstrated superior performance across most indicators, including effective nitrogen, available potassium, organic matter, and total humus, with T3 generally outperforming T2 in the majority of cases. These findings suggest that T3 is the most effective green manure treatment for improving soil nutrient availability and promoting long-term soil fertility, though T2 also showed strong potential.
After the two-year cropping cycle, soil nutrient results indicated that green manure incorporation significantly influenced alkali-hydrolyzed nitrogen, available potassium, organic matter, and total humus in the 0–20 cm soil layer (Figure 6), while no significant effect was observed on available phosphorus. Notably, the T2 and T3 treatments exhibited the most pronounced effects. The T3 and T2 treatments resulted in the highest alkali-hydrolyzed nitrogen contents (80.27 mg/kg and 79.8 mg/kg, respectively), significantly surpassing those of T0 (67.67 mg/kg) and T1 (60.67 mg/kg). Available potassium content was highest in the T2 treatment (139.67 mg/kg), significantly exceeding T3 (123.5 mg/kg), T0 (111.67 mg/kg), and T1 (113.67 mg/kg). Soil organic matter was highest in the T3 treatment (16.14 g/kg), significantly higher than T0 (13.02 g/kg), but not significantly different from T2 (14.25 g/kg) or T1 (13.55 g/kg). In terms of total humus, T3 (9.51 g/kg) and T2 (9.48 g/kg) were significantly higher than T1 (8.24 g/kg) and T0 (7.5 g/kg). Overall, green manure incorporation significantly improved soil nutrient levels, with T3 and T2 demonstrating the most positive effects on soil fertility, while the winter fallow control (T0) showed the lowest values.

3.4. Changes in Net Eco-Economic Benefits Under Green Manure Incorporation

Compared to the winter fallow control, the three green manure treatments had different effects on soil nutrients and ecological–economic benefits (Table 2). The T1 treatment increased potassium value by $40/ha, but cotton revenue dropped by $2557/ha, and green manure costs were $535/ha, resulting in a net loss of $3359/ha compared to T0. The T2 treatment improved nitrogen ($22/ha), potassium ($58/ha), and organic matter ($914/ha), but cotton revenue decreased by $3114/ha, and green manure costs were $440/ha, leading to a net loss of $2174/ha. The T3 treatment showed the greatest improvement in soil nutrients, with increases in nitrogen ($21/ha), potassium ($24/ha), and organic matter ($3356/ha). Although cotton revenue dropped by $2810/ha and green manure costs were $574/ha, the nutrient gains led to a small net gain of $405/ha compared to T0. Despite the initial costs, the T3 treatment demonstrated the most beneficial ecological–economic outcomes, with a net gain observed due to improvements in soil nutrients.

4. Discussion

4.1. Effects of Green Manure Incorporation on Cotton Yield and Nutrient Uptake

Cotton yield is fundamentally determined by key components such as boll number, boll weight, and lint percentage, all of which are directly influenced by soil conditions and nutrient availability [23]. Incorporating green manure indirectly supports these yield components by enhancing soil nutrient cycling and availability, thereby creating a more favorable environment for cotton growth [24,25]. Previous studies have shown that the effects of green manuring on subsequent crop yields are often inconsistent [13,26,27]. Some studies have reported negative impacts on the crop yield, and most of these studies are based on a short-term field experiment period rather than a long-term field experiment [28]. Studies on green manure incorporation in maize production found that long-term application significantly increased yield, though the effects varied depending on the type of green manure used [13]. This study evaluated the effects of three green manure treatments on cotton yield and its components, and no statistically significant differences were observed among the treatments, although notable trends emerged that provide insight into their agronomic potential (Figure 1). In previous studies, the continuous incorporation of Chinese violet was associated with higher maize yields [13]. In our study, although no significant differences in cotton yield were detected among green manure treatments, the highest cotton yield was also observed under Chinese violet incorporation, a trend consistent with previous findings [13].
Both Chinese violet and rapeseed exhibited the highest fresh weight production over the two-year study period (Figure 3), which was consistent with previous studies that also show that Chinese violet produced greater biomass [29]. Despite these differences in biomass production, no significant variations in cotton N uptake, either in vegetative or reproductive organs, were observed among the different green manure treatments (Figure 2). Previous studies have demonstrated that leguminous cover crops can rapidly release substantial amounts of mineralized nitrogen in the short term, thereby enhancing nitrogen availability for subsequent crops [13]. However, this effect was not observed in our study, which may be attributed to relatively short experimental duration and differences in nutrient uptake and utilization patterns between different crops. Therefore, further long-term studies are necessary to comprehensively evaluate the effects of different green manure incorporation strategies on cotton yield and nutrient uptake dynamics.

4.2. Effects of Green Manure Incorporation on Soil Nutrients

Soil nutrients are crucial for crop growth and productivity, and the incorporation of green manure has long been recognized as an effective strategy to enhance soil fertility [14]. Non-leguminous green manures can absorb part of the soil mineral N and convert it into plant biomass during their growth, thereby reducing nitrogen losses in the ecosystem of cropland [30]. In contrast, leguminous species, such as hairy vetch, can fix atmospheric nitrogen in the atmosphere, contributing to soil nitrogen enrichment after incorporation [18,31]. The present study demonstrated that green manure incorporation, particularly treatments T2 (rapeseed-cotton-rapeseed-cotton) and T3 (ryegrass-cotton-hairy vetch-cotton), significantly improved soil nutrient contents compared to the control. Specifically, these treatments resulted in a marked increase in soil nitrogen, phosphorus, and potassium levels in the topsoil (0–20 cm) (Figure 4 and Figure 6), aligning with previous findings [13]. The significant improvement in soil nutrient content can be attributed to two main factors: (1) the direct nutrient contribution from decomposing green manure residues and (2) the positive impact of increased organic matter on soil structure and nutrient retention. As green manure residues decompose in the soil, they release essential nutrients into the soil while simultaneously enriching soil organic matter. This process not only replenishes the immediate nutrient pool but also improves the soil’s long-term capacity to retain and release nutrients, consistent with previous studies showing that green manure incorporation significantly increases soil organic matter content and accelerates nitrogen mineralization [32,33].
Among the treatments, T3 was particularly effective in increasing soil nutrient levels (Figure 4 and Figure 6). Hairy vetch is known for its ability to fix atmospheric nitrogen through biological nitrogen fixation, significantly increasing soil nitrogen levels [34,35]. Additionally, the decomposition of green manures contributed to increased organic matter, improving soil structure and nutrient retention [36]. This finding is consistent with previous studies, which also reported that among different green manure incorporation treatments in the topsoil layer, Chinese violet cress had the lowest inorganic nitrogen content, whereas hairy vetch and ryegrass had the highest [13]. Furthermore, T3 demonstrated superior soil nutrient contents in deeper soil layers (20–40 cm), with higher available potassium and total humus levels (Figure 5). This might be attributed to the deep-rooting nature of non-leguminous green manures, such as those in T1 and T2, which likely remove more nutrients from deeper soil layers compared to leguminous green manures like those in T3, which tend to have shallower root systems [13,37]. Given these findings, further research is necessary to elucidate the long-term effects of root depth on nitrogen cycling and nutrient availability in different cropping systems. Understanding these dynamics will provide valuable insights into optimizing green manure management strategies for sustainable soil fertility improvement.

4.3. Effects of Green Manure Incorporation on Ecological and Economic Benefits

Net ecological–economic benefits refer to the combined improvements in soil nutrients, reductions in crop production costs, and increases in revenue, all of which provide a comprehensive assessment of green manure application [38]. Diversified farming systems that incorporate green manure have been shown to offer significant ecological benefits, promoting more sustainable farming practices [39]. Additionally, the use of cover crops and green manure contributes to long-term sustainability by enhancing nutrient cycling, further boosting ecological–economic outcomes [5,40].
This study revealed that while the incorporation of green manure led to a reduction in cotton production income compared to a full-season cotton monoculture, it also brought about substantial reductions in production costs (Table 2). The decreased income was primarily attributed to the adoption of short-season cotton varieties, which have a lower yield than full-season varieties. However, this shift to short-season cotton reduced production costs by eliminating the need for plastic film mulching and reducing labor costs.
Furthermore, green manure incorporation offers significant long-term ecological and economic benefits [38]. It enhances soil fertility and improves nutrient availability, contributing to greater sustainability over time. Among the treatments, T3 demonstrated the highest net ecological–economic benefits, showing an increase of $405 per hectare over the control. This was largely due to the high potassium value ($256/ha) and substantial organic matter improvements ($20,899/ha), both of which contribute to sustainable nutrient availability and soil fertility (Table 2).
While T1 and T2 exhibited lower short-term net benefits, these systems hold significant potential for improving soil fertility in the long term. By integrating additional green manures, such as leguminous species like hairy vetch, nutrient cycling can be enhanced, reducing reliance on synthetic fertilizers. Additionally, optimizing the management of green manure residues through practices such as proper shredding or timely incorporation can improve soil structure and facilitate better nutrient release. These strategies would make T2 and T3 more sustainable and economically viable over time.
In contrast, the winter fallow control showed higher short-term economic stability, with a net income of $9664/ha (Table 2), but lacked the soil improvement benefits associated with green manure treatments. In the long term, however, T3 has the potential to maximize both ecological and economic benefits by improving soil nutrient reserves. Future research should investigate the impacts of green manure incorporation on greenhouse gas emissions, soil microbial communities, and long-term productivity to gain a deeper understanding of its broader ecological contributions.

5. Conclusions

In summary, this study underscores the potential of green manure incorporation, particularly the T3 treatment, to enhance soil fertility, especially in the topsoil (0–20 cm), and to provide significant ecological–economic benefits. Despite a slight reduction in cotton yield compared to the winter fallow control, this practice offers valuable contributions to sustainable agriculture by reducing reliance on synthetic fertilizers. The findings suggest that green manure could play a crucial role in long-term soil health and ecological balance. Future research should focus on assessing the long-term impacts of green manure under diverse climatic and soil conditions and explore the scalability of this practice to maximize its benefits across a wider range of agricultural systems.

Author Contributions

X.W. and D.Q.: conceptualization, methodology, software, writing—original draft preparation; Z.Y.: data curation and validation; G.W.: methodology and formal analysis; L.L.: investigation and visualization; L.F. and Q.X.: funding acquisition, project administration, resources, supervision, and writing—review and editing. All authors have read and agreed to the published version of the manuscript.

Funding

This study was financially supported by Shandong Provincial Comprehensive Experiment of Cotton Industry Technology System, China (SDAIT-03-12) (SDAIT-03-12) and Key R&D Program of Shandong Province, China (2023LZGC007).

Data Availability Statement

The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors.

Conflicts of Interest

Author Lin Li was employed by the company Shandong Zhongli Cotton Industry Technology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

  1. Feng, L.; Dai, J.L.; Tian, L.W.; Zhang, H.J.; Li, W.J.; Dong, H.Z. Review of the Technology for High-Yielding and Efficient Cotton Cultivation in the Northwest Inland Cotton-Growing Region of China. Field Crops Res. 2017, 208, 18–26. [Google Scholar] [CrossRef]
  2. Zhang, Z.G.; An, J.; Xiong, S.W.; Li, X.F.; Xin, M.H.; Wang, J.; Han, Y.C.; Wang, G.P.; Feng, L.; Lei, Y.P.; et al. Orychophragmus violaceus-Maize Rotation Increases Maize Productivity by Improving Soil Chemical Properties and Plant Nutrient Uptake. Field Crops Res. 2022, 279, 108470. [Google Scholar] [CrossRef]
  3. Guo, Z.; Huang, N.; Dong, Z.; Van Pelt, R.S.; Zobeck, T.M. Wind Erosion-Induced Soil Degradation in Northern China: Status, Measures, and Perspective. Sustainability 2014, 6, 8951. [Google Scholar] [CrossRef]
  4. Dong, H.; Li, W.; Tang, W.; Zhang, D. Furrow Seeding with Plastic Mulching Increases Stand Establishment and Lint Yield of Cotton in a Saline Field. Agron. J. 2008, 100, 1345–1351. [Google Scholar] [CrossRef]
  5. Scavo, A.; Fontanazza, S.; Restuccia, A.; Pesce, G.R.; Abbate, C.; Mauromicale, G. The role of cover crops in improving soil fertility and plant nutritional status in temperate climates. A review. Agron. Sustain. Dev. 2022, 42, 93. [Google Scholar] [CrossRef]
  6. Salahin, N.; Alam, M.K.; Islam, M.M.; Naher, L.; Majid, N.M. Effects of green manure crops and tillage practice on maize and rice yields and soil properties. Aust. J. Crop Sci. 2013, 7, 1901–1911. [Google Scholar]
  7. Prajapati, S.K.; Dayal, P.; Kumar, V.; Gairola, A. Green Manuring: A Sustainable Path to Improve Soil Health and Fertility. Int. J. 2023, 1, 24–33. [Google Scholar]
  8. Asghar, W.; Kataoka, R. Green Manure Incorporation Accelerates Enzyme Activity, Plant Growth, and Changes in the Fungal Community of Soil. Arch. Microbiol. 2022, 204, 7. [Google Scholar] [CrossRef]
  9. Iderawumi, A.M.; Kamal, T.O. Green Manure for Agricultural Sustainability and Improvement of Soil Fertility. Indian J. Agric. For. 2022, 7, 1–10. [Google Scholar] [CrossRef]
  10. Pi, H.; Webb, N.P.; Huggins, D.R. Application of the Single-Event Wind Erosion Evaluation Program (SWEEP) Model in Assessing the Impact of Crop Rotation, Green Manure, Fertilizer, and Tillage on Wind Erosion. Land Degrad. Dev. 2022, 33, 1052–1065. [Google Scholar] [CrossRef]
  11. Fan, F.; van der Werf, W.; Makowski, D.; Lamichhane, J.R.; Huang, W.; Li, C.; Zhang, C.; Cong, W.-F.; Zhang, F. Cover Crops Promote Primary Crop Yield in China: A Meta-Regression of Factors Affecting Yield Gain. Field Crops Res. 2021, 271, 108237. [Google Scholar] [CrossRef]
  12. Jian, J.; Lester, B.J.; Du, X.; Reiter, M.S.; Stewart, R.D. A Calculator to Quantify Cover Crop Effects on Soil Health and Productivity. Soil Tillage Res. 2020, 199, 104575. [Google Scholar] [CrossRef]
  13. Hu, Z.; Zhao, Q.; Zhang, X.; Ning, X.; Liang, H.; Cao, W. Winter Green Manure Decreases Subsoil Nitrate Accumulation and Increases N Use Efficiencies of Maize Production in North China Plain. Plants 2023, 12, 311. [Google Scholar] [CrossRef] [PubMed]
  14. Toungos, M.D.; Bulus, Z.W. Cover Crops Dual Roles: Green Manure and Maintenance of Soil Fertility, a Review. Agric. Rev. 2019, 40, 120–128. [Google Scholar]
  15. Larkin, R.P.; Griffin, T.S. Control of Soilborne Potato Diseases Using Brassica Green Manures. Soil Biol. Biochem. 2007, 39, 2087–2097. [Google Scholar] [CrossRef]
  16. Ghosh, P.K.; Bandyopadhyay, K.K. Legume Effect for Enhancing Productivity and Nutrient Use-Efficiency in Major Cropping Systems: An Indian Perspective. J. Sustain. Agric. 2007, 30, 59–86. [Google Scholar] [CrossRef]
  17. Zhao, N.; Bai, L.; Han, D.; Yao, Z.; Liu, X.; Hao, Y.; Chen, Z. Combined Application of Leguminous Green Manure and Straw Determined Grain Yield and Nutrient Use Efficiency in Wheat–Maize–Sunflower Rotations. Plants 2024, 13, 1358. [Google Scholar] [CrossRef]
  18. Zhang, Z.G.; Wang, J.; Xiong, S.W.; Huang, W.B.; Li, X.; Xin, M.H.; Han, Y.C.; Wang, G.P.; Feng, L.; Lei, Y.P.; et al. Orychophragmus violaceus/Cotton Relay Intercropping with Reduced N Application Maintains or Improves Crop Productivity and Soil Carbon and Nitrogen Fractions. Field Crops Res. 2023, 291, 108807. [Google Scholar] [CrossRef]
  19. Lyu, H.; Li, Y.; Wang, Y.; Wang, P.; Shang, Y. Drive Soil Nitrogen Transformation and Improve Crop Nitrogen Absorption and Utilization: A Review of Green Manure Applications. Front. Plant Sci. 2024, 14, 1305600. [Google Scholar] [CrossRef]
  20. Li, Y.; Zhao, W.; Zhu, H.; Jia, X. Green Manure Mediated Improvement in Saline Soils in China: A Meta-Analysis. Agronomy 2024, 14, 2068. [Google Scholar] [CrossRef]
  21. Bao, S.D. Soil and Agricultural Chemistry Analysis; China Agricultural Press: Beijing, China, 2000. [Google Scholar]
  22. Bierer, A.M.; Leytem, A.B.; Rogers, C.W.; Dungan, R.S. Evaluation of a Microplate Spectrophotometer for Soil Organic Carbon Determination in South-Central Idaho. Soil Sci. Soc. Am. J. 2021, 85, 438–451. [Google Scholar] [CrossRef]
  23. Bednarz, C.W.; Nichols, R.L.; Brown, S.M. Within-Boll Yield Components of High Yielding Cotton Cultivars. Crop Sci. 2007, 47, 2108–2112. [Google Scholar] [CrossRef]
  24. Ma, D.; Yin, L.; Ju, W.; Li, X.; Liu, X.; Deng, X.; Wang, S. Meta-Analysis of Green Manure Effects on Soil Properties and Crop Yield in Northern China. Field Crops Res. 2021, 260, 107980. [Google Scholar] [CrossRef]
  25. Cherr, C.; Scholberg, J.; McSorley, R. Green Manure Approaches to Crop Production: A Synthesis. Agron. J. 2006, 98, 302–319. [Google Scholar] [CrossRef]
  26. Wang, J.; Zhang, S.; Sainju, U.M.; Ghimire, R.; Zhao, F. A Meta-Analysis on Cover Crop Impact on Soil Water Storage, Succeeding Crop Yield, and Water-Use Efficiency. Agric. Water Manag. 2021, 256, 107085. [Google Scholar] [CrossRef]
  27. McNee, M.E.; Rose, T.J.; Minkey, D.M.; Flower, K.C. Effects of Dryland Summer Cover Crops and a Weedy Fallow on Soil Water, Disease Levels, Wheat Growth and Grain Yield in a Mediterranean-Type Environment. Field Crops Res. 2022, 280, 108472. [Google Scholar] [CrossRef]
  28. Fiorini, A.; Remelli, S.; Boselli, R.; Mantovi, P.; Ardenti, F.; Trevisan, M.; Menta, C.; Tabaglio, V. Driving Crop Yield, Soil Organic C Pools, and Soil Biodiversity with Selected Winter Cover Crops Under No-Till. Soil Tillage Res. 2022, 217, 105283. [Google Scholar] [CrossRef]
  29. Zhang, Z.; Li, X.; Xiong, S.; An, J.; Han, Y.; Wang, G.; Li, Y. Orychophragmus violaceus as a Winter Cover Crop is More Conducive to Agricultural Sustainability Than Vicia villosa in Cotton-Fallow Systems. Arch. Agron. Soil Sci. 2022, 68, 1487–1500. [Google Scholar] [CrossRef]
  30. Hao, X.; Najm, M.A.; Steenwerth, K.L.; Nocco, M.A.; Basset, C.; Daccache, A. Are There Universal Soil Responses to Cover Cropping? A Systematic Review. Sci. Total Environ. 2022, 861, 160600. [Google Scholar] [CrossRef]
  31. Langelier, M.; Chantigny, M.H.; Pageau, D.; Vanasse, A. Nitrogen-15 Labelling and Tracing Techniques Reveal Cover Crops Transfer More Fertilizer N to the Soil Reserve Than to the Subsequent Crop. Agric. Ecosyst. Environ. 2021, 313, 107359. [Google Scholar] [CrossRef]
  32. Peoples, M.B.; Herridge, D.F.; Ladha, J.K. Biological nitrogen fixation: An efficient source of nitrogen for sustainable agricultural production? Field Crops Res. 1995, 46, 229–272. [Google Scholar]
  33. Thorup-Kristensen, K.; Magid, J.; Jensen, L.S. Catch crops and green manures as biological tools in nitrogen management in temperate zones. Adv. Agron. 2003, 79, 227–302. [Google Scholar]
  34. Yang, X.; Drury, C.; Reynolds, W.; Reeb, M. Legume Cover Crops Provide Nitrogen to Corn During a Three-Year Transition to Organic Cropping. Agron. J. 2019, 111, 3253–3264. [Google Scholar] [CrossRef]
  35. Lynd, J.Q.; Hanlon, E.A., Jr. Potassium Effects on Improved Growth, Nodulation, and Nitrogen Fixation of Hairy Vetch. Soil Sci. Soc. Am. J. 1981, 45, 200–205. [Google Scholar] [CrossRef]
  36. Simon, L.M.; Obour, A.K.; Holman, J.D.; Roozeboom, K.L. Long-Term Cover Crop Management Effects on Soil Properties in Dryland Cropping Systems. Agric. Ecosyst. Environ. 2022, 328, 107852. [Google Scholar] [CrossRef]
  37. Anugroho, F.; Kitou, M.; Nagumo, F.; Kinjo, K. Potential Growth of Hairy Vetch as a Winter Legume Cover Crop in Subtropical Soil Conditions. Soil Sci. Plant Nutr. 2010, 56, 331–337. [Google Scholar] [CrossRef]
  38. Zhang, L.; Jiang, G.; Xiao, R.; Hou, K.; Liu, X.; Liu, X. An Appropriate Amount of Straw Replaced Chemical Fertilizers Returning Reduced Net Greenhouse Gas Emissions and Improved Net Ecological Economic Benefits. J. Clean. Prod. 2024, 317, 128276. [Google Scholar] [CrossRef]
  39. Rosa-Schleich, J.; Loos, J.; Mußhoff, O.; Tscharntke, T. Ecological-Economic Trade-Offs of Diversified Farming Systems—A Review. Ecol. Econ. 2019, 159, 251–263. [Google Scholar] [CrossRef]
  40. Wang, C.; Wang, Z.; Liu, M.; Batool, M.; El-Badri, A.M. Optimizing Tillage Regimes in Rice-Rapeseed Rotation Systems to Enhance Crop Yield and Environmental Sustainability. Field Crops Res. 2024, 318, 109614. [Google Scholar] [CrossRef]
Figure 1. Effects of different green manure incorporation treatments on seed cotton yield (a), boll number (b), boll weight (c) and lint percentage (d) in studies carried out in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Bars represent mean ± standard error (n = 3). Significant differences among treatments were determined using Tukey’s test at p < 0.05. Different letters above the bars indicate significant differences.
Figure 1. Effects of different green manure incorporation treatments on seed cotton yield (a), boll number (b), boll weight (c) and lint percentage (d) in studies carried out in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Bars represent mean ± standard error (n = 3). Significant differences among treatments were determined using Tukey’s test at p < 0.05. Different letters above the bars indicate significant differences.
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Figure 2. Effects of different green manure incorporation treatments on total N, total P, and total K contents in reproductive organs (ac), and total N, total P, and total K contents in vegetative organs (df) of cotton before harvest. Experiments were conducted in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Data are presented as mean ± standard error (n = 3). Significant differences among treatments were determined using Tukey’s test at p < 0.05. Different letters above the bars indicate significant differences in nutrient contents among treatments.
Figure 2. Effects of different green manure incorporation treatments on total N, total P, and total K contents in reproductive organs (ac), and total N, total P, and total K contents in vegetative organs (df) of cotton before harvest. Experiments were conducted in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Data are presented as mean ± standard error (n = 3). Significant differences among treatments were determined using Tukey’s test at p < 0.05. Different letters above the bars indicate significant differences in nutrient contents among treatments.
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Figure 3. Differences in fresh weight (a), total N (b), total P (c), and total K (d) contents of green manure crops under different incorporation treatments. Experiments were conducted in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Data are presented as mean ± standard error (n = 3). Significant differences among treatments were determined using Tukey’s test at p < 0.05. Different letters above the bars indicate significant differences among treatments for each parameter.
Figure 3. Differences in fresh weight (a), total N (b), total P (c), and total K (d) contents of green manure crops under different incorporation treatments. Experiments were conducted in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Data are presented as mean ± standard error (n = 3). Significant differences among treatments were determined using Tukey’s test at p < 0.05. Different letters above the bars indicate significant differences among treatments for each parameter.
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Figure 4. Differences in (a) alkali-hydrolyzed nitrogen, (b) available phosphorus, (c) available potassium, (d) organic matter, and (e) total humus in the 0–20 cm soil layer under different treatments across five sampling periods. Experiments were conducted in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Data are presented as the mean nutrient contents for each sampling period.
Figure 4. Differences in (a) alkali-hydrolyzed nitrogen, (b) available phosphorus, (c) available potassium, (d) organic matter, and (e) total humus in the 0–20 cm soil layer under different treatments across five sampling periods. Experiments were conducted in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Data are presented as the mean nutrient contents for each sampling period.
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Figure 5. Differences in (a) alkali-hydrolyzed nitrogen, (b) available phosphorus, (c) available potassium, (d) organic matter, and (e) total humus in the 20–40 cm soil layer under different treatments across five sampling periods. Experiments were conducted in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Data are presented as the mean nutrient contents for each sampling period.
Figure 5. Differences in (a) alkali-hydrolyzed nitrogen, (b) available phosphorus, (c) available potassium, (d) organic matter, and (e) total humus in the 20–40 cm soil layer under different treatments across five sampling periods. Experiments were conducted in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Data are presented as the mean nutrient contents for each sampling period.
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Figure 6. Differences in soil available N (a), available K (b), organic matter (c) and total humus (d) among treatments at the end of the two-year rotation cycle in experiments carried out in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Soil nutrients, including alkali-hydrolyzed nitrogen, available phosphorus, available potassium (mg/kg), organic matter, and total humus (g/kg), were measured in the 0–20 cm soil layer after the completion of the rotation cycle. Data are presented as mean ± standard error (n = 3). Significant differences among treatments were determined using Tukey’s test at p < 0.05. Different letters above the bars indicate significant differences among treatments for each soil nutrient parameter.
Figure 6. Differences in soil available N (a), available K (b), organic matter (c) and total humus (d) among treatments at the end of the two-year rotation cycle in experiments carried out in Binzhou, Shandong, during 2021–2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Soil nutrients, including alkali-hydrolyzed nitrogen, available phosphorus, available potassium (mg/kg), organic matter, and total humus (g/kg), were measured in the 0–20 cm soil layer after the completion of the rotation cycle. Data are presented as mean ± standard error (n = 3). Significant differences among treatments were determined using Tukey’s test at p < 0.05. Different letters above the bars indicate significant differences among treatments for each soil nutrient parameter.
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Table 1. Effects of green manure treatments on seed cotton yield and yield components in studies conducted in Binzhou, Shandong from 2021 to 2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Values represent the means of three replicates, and values not sharing a common letter within each column are significantly different at p < 0.05.
Table 1. Effects of green manure treatments on seed cotton yield and yield components in studies conducted in Binzhou, Shandong from 2021 to 2022. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Values represent the means of three replicates, and values not sharing a common letter within each column are significantly different at p < 0.05.
YearTreatmentSeed Cotton (kg/ha)Boll Number (Bolls/m2)Boll Weight (g)Lint Percentage (%)
2021T04175 a85.2 a4.9 a43.2 a
T12895 b67.1 b4.3 b41.1 a
T22745 b63.3 b4.3 b40.4 a
T32880 b63.0 b4.6 ab41.5 a
2022T03886 a68.5 a5.7 a38.7 a
T13075 b58.0 b5.3 a40.4 a
T22739 b53.1 b5.2 a40.0 a
T32856 b53.9 b5.2 a40.2 a
Table 2. Eco--economic benefits of different treatments in experiments conducted in Binzhou, Shandong (2021–2022). Eco–economic benefits represent cumulative results over a two-year rotation cycle. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Nutrient values were calculated based on soil nutrient contents measured after the final cotton harvest. Cotton revenue, production costs, and green manure costs are presented as the two-year totals. Cotton revenue was calculated using seed cotton yield and market prices of $1.31/kg in 2021 and $1.03/kg in 2022. All values were converted from Chinese Yuan¥ to US$ using the exchange rate of ¥6.95 per $1.
Table 2. Eco--economic benefits of different treatments in experiments conducted in Binzhou, Shandong (2021–2022). Eco–economic benefits represent cumulative results over a two-year rotation cycle. The treatments are as follows: T0—conventional full-season cotton monoculture with winter fallow; T1—Chinese violet-cotton-Chinese violet-cotton; T2—rapeseed-cotton-rapeseed-cotton; T3—ryegrass-cotton-hairy vetch-cotton. Nutrient values were calculated based on soil nutrient contents measured after the final cotton harvest. Cotton revenue, production costs, and green manure costs are presented as the two-year totals. Cotton revenue was calculated using seed cotton yield and market prices of $1.31/kg in 2021 and $1.03/kg in 2022. All values were converted from Chinese Yuan¥ to US$ using the exchange rate of ¥6.95 per $1.
TreatmentNutrient Value ($/ha)Cotton Revenue ($/ha)Cotton Production Cost ($/ha)Green Manure Cost ($/ha)Net Eco–Economic Benefit ($/ha)Difference Compared to Control ($/ha)
NPKSOM
T01171923117,54396647135-20,438-
T11051627216,8627107674753517,079−3359
T21391628918,4576550674744018,264−2174
T31381825620,8996853674757420,843405
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Wei, X.; Qin, D.; Yin, Z.; Wang, G.; Li, L.; Feng, L.; Xu, Q. Evaluating the Impact of Green Manure Incorporation on Cotton Yield, Soil Fertility, and Net Eco–Economic Benefits. Agronomy 2025, 15, 559. https://doi.org/10.3390/agronomy15030559

AMA Style

Wei X, Qin D, Yin Z, Wang G, Li L, Feng L, Xu Q. Evaluating the Impact of Green Manure Incorporation on Cotton Yield, Soil Fertility, and Net Eco–Economic Benefits. Agronomy. 2025; 15(3):559. https://doi.org/10.3390/agronomy15030559

Chicago/Turabian Style

Wei, Xuewen, Dulin Qin, Zujun Yin, Guoping Wang, Lin Li, Lu Feng, and Qinqing Xu. 2025. "Evaluating the Impact of Green Manure Incorporation on Cotton Yield, Soil Fertility, and Net Eco–Economic Benefits" Agronomy 15, no. 3: 559. https://doi.org/10.3390/agronomy15030559

APA Style

Wei, X., Qin, D., Yin, Z., Wang, G., Li, L., Feng, L., & Xu, Q. (2025). Evaluating the Impact of Green Manure Incorporation on Cotton Yield, Soil Fertility, and Net Eco–Economic Benefits. Agronomy, 15(3), 559. https://doi.org/10.3390/agronomy15030559

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