Molecular Soil Biology 2025, Vol.16, No.4, 214-229 http://bioscipublisher.com/index.php/msb 220 7 Economic and Environmental Evaluation 7.1 Input cost vs. yield/output Soil improvement generally requires the input of some materials, such as organic fertilizer, straw, microbial agents, lime, and some covering materials such as mulch or straw mulch. Studies have found that although organic inputs such as organic fertilizer and straw return to the field are relatively expensive, they can significantly improve the soil, increase organic matter, enrich microorganisms, and increase crop yields (Arb et al., 2020; Tahat et al., 2020; Mwaura et al., 2021; Li et al., 2023; Xing et al., 2025). Long-term use of organic fertilizer or animal manure can increase soil organic carbon by 14.6% to 39.8% and increase yield by 25% to 40%. However, the cost of labor and materials will also increase (Mwaura et al., 2021; Xu et al., 2021; Li et al., 2023). If fertilization is done by machine, 10% to 27% of agricultural costs can be saved (Xu et al., 2021). As for lime, the cost is relatively low. It can adjust soil pH and increase crop yields in a short period of time. For example, rice can increase yield by 8.95% and rapeseed can increase yield by 82.6%. However, it is best to use it together with fertilizers for the best economic benefits (Hijbeek et al., 2021; Xu et al., 2025). Covering materials such as mulch or straw can also help retain soil moisture, improve the root environment, and ultimately increase yield and income (Thidar et al., 2020). 7.2 Return on investment (ROI) analyses for different methods From the perspective of ROI, returning livestock and poultry manure to the field, or combining organic and inorganic fertilizers, has better economic benefits. In some areas, one hectare of land can generate a net return of $440 to $456 per year, which is much higher than the return of using only inorganic fertilizers (Mwaura et al., 2021; Hörner and Wollni, 2022). Although the organic system requires a lot of investment, it is very effective in increasing yields and improving soil. However, this system also requires a lot of labor and management, so its returns should be viewed from a long-term perspective (Arb et al., 2020; Li et al., 2023). Lime is also effective in improving acidic soils, and it takes about 2 years to pay back, but it must be combined with fertilizers to be cost-effective (Hijbeek et al., 2021). Methods such as returning straw to the field and biochar can increase soil carbon storage and health, but due to the cost of materials and labor, the short-term benefits may not be so obvious. However, in the long run, these methods can increase yields and even make money from carbon trading (Gujre et al., 2020; Xu et al., 2021). Mechanization and input cost control can also make ROI more reasonable and farmers more accepting (Klauser and Negra, 2020; Xu et al., 2021). 7.3 Sustainability implications Many soil improvement measures have long-term benefits for carbon sinks and soil health. Methods such as returning straw to the field, organic fertilizers, cover crops, and biochar can store more organic carbon in the soil, which means that more carbon can be "locked" and greenhouse gas emissions can be reduced. Some methods can even neutralize 36.6% to 97.8% of greenhouse gases (Sykes et al., 2019; Lessmann et al., 2021; Xu et al., 2021; T.M. et al., 2023; Liao et al., 2025). The use of organic and inorganic fertilizers together can also increase microbial diversity, promote nutrient cycling, improve soil structure, and enhance water retention capacity, which is beneficial to maintaining soil health in the long run (Arb et al., 2020; Tahat et al., 2020; Li et al., 2023; Xing et al., 2025). The effect of carbon sequestration is also affected by soil texture, original organic carbon level and management methods. Generally speaking, coarse-textured soils have a higher carbon storage capacity (Zhao et al., 2018; Rosinger et al., 2023). It is worth noting that although some measures can increase yields, such as liming, attention should also be paid to the greenhouse gas emissions or other environmental problems they may cause (Hijbeek et al., 2021; Li et al., 2021). 8 Case Study: Application in Yancheng 8.1 Background of the region: soil profile, climate, and history of cultivation Yancheng City, Jiangsu Province is located in the northeast of the middle and lower reaches of the Yangtze River Plain. It has a subtropical humid monsoon climate with an average annual temperature of about 15.1 ℃ and a frost-free period of more than 230 days. The temperature is low in winter and spring, and the humidity is also high. The local soil is mostly tidal soil and clay loam, which is relatively heavy. There is little organic matter, and it often becomes acidic and compacted. Although it can retain water, it is not very breathable (Wei et al., 2021). Motherwort has some planting history in this area, but it used to be mainly sown in spring. Off-season planting is
RkJQdWJsaXNoZXIy MjQ4ODYzNA==