Bioscience Methods 2025, Vol.16, No.4, 193-203 http://bioscipublisher.com/index.php/bm 195 2.3 Nutrient composition and soil health Organic fertilizers contribute to the nutrient composition of the soil, thereby improving soil health and plant growth. The use of organic manures has been shown to enhance soil organic matter, microbial biomass carbon, and nutrient availability (Su et al., 2021). For instance, the application of dairy manure and vermicompost significantly improved soil physical properties, such as soil organic carbon content and nutrient availability, leading to better plant growth and fruit quality. Additionally, organic amendments have been found to increase the diversity and abundance of beneficial microorganisms in the rhizosphere, which in turn promotes plant growth and reduces the prevalence of plant pathogenic fungi. The integration of organic fertilizers with inorganic fertilizers has also been shown to improve soil fertility, as evidenced by increased soil organic carbon and available nitrogen content (Zhao et al., 2017). The use of organic fertilizers not only enhances the nutrient composition of the soil but also supports a healthy soil ecosystem, which is essential for sustainable kiwifruit production. 3 Impact of Organic Fertilization on Kiwifruit Productivity 3.1 Yield performance under organic fertilization Organic fertilization has been shown to significantly enhance the yield performance of kiwifruit. Long-term application of organic amendments, such as pig and sheep dung compost, has been found to improve the yield and quality of kiwifruit by increasing rhizosphere microbial diversity and the relative abundance of plant growth-promoting bacteria (Liu et al., 2020). Additionally, the use of organic fertilizers produced through quick artificial decomposition of biological wastes has been reported to increase kiwifruit yields by 15.2% compared to mineral fertilizer treatments (Ma et al., 2021). Another study demonstrated that the combined application of organic manure and chemical fertilizers (NPKM) resulted in the highest average yield of 44.6 t/ha, outperforming other fertilization treatments. 3.2 Long-term effects on soil fertility and crop sustainability The long-term application of organic fertilizers not only boosts kiwifruit yield but also enhances soil fertility and sustainability. Organic amendments have been shown to increase soil organic carbon content and improve soil nutrient availability, which are crucial for sustainable crop production (Rahman et al., 2011). The use of organic manures, such as dairy manure and vermicompost, has been found to improve soil physical properties, nutrient absorption, and overall soil health, leading to better crop performance (Sharma et al., 2022). Moreover, organic fertilization practices have been associated with higher soil microbial biomass and enzyme activity, which contribute to improved nutrient cycling and retention in the soil (Lago et al., 2019). 3.3 Comparison with conventional fertilization When compared to conventional fertilization, organic fertilization offers several advantages in terms of yield, soil health, and environmental sustainability. Studies have shown that organic fertilization can lead to higher fruit quality, including increased vitamin C, soluble solids, and firmness, compared to conventional methods (Zhao et al., 2017; Lago et al., 2019). Additionally, organic fertilization practices have been found to reduce the relative abundance of plant pathogenic fungi and enhance the presence of beneficial microorganisms in the rhizosphere, which can further improve crop health and productivity (Ku et al., 2018). In contrast, conventional fertilization often results in higher nitrate accumulation in the soil, which can lead to environmental issues such as nutrient runoff and water pollution (Lu et al., 2018). Therefore, organic fertilization presents a more sustainable and environmentally friendly alternative to conventional fertilization practices. 4 Quality Parameters of Kiwifruit Affected by Organic Fertilization 4.1 Influence on fruit size and weight Organic fertilization has been shown to significantly impact the size and weight of kiwifruit (Figure 2). Studies indicate that the application of organic amendments, such as pig and sheep dung compost, can enhance the yield and quality of kiwifruit by improving soil nutrients and microbial diversity (Liu et al., 2020). Additionally, the use of organic manures like dairy manure and vermicompost has been found to improve fruit production and leaf area, which are directly related to the size and weight of the fruit (Sharma et al., 2022). The combined application of
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