*2.2.4 On-farm management of under-forest* P. notoginseng

1.Water management. The water management of under-forest *P. notoginseng* is divided into four stages: ① Before seedling: The soil should be given a good soaking timely after sowing, and the humidity of ridge surface should be observed regularly. It should be watered well in time when the soil moisture content is less than 20%. In the case of too much rainfall, pay attention to drainage and waterlogging prevention.② Seedling germination: After seedling emergence, a small

amount of water should be irrigated many times to ensure that the soil moisture content is not less than 20%. The germination period of *P. notoginseng* overlaps with the dry season in Yunnan. The soil under the forest is loose and the water retention capacity is poor. *P. notoginseng* is easy to dehydrate, which leads to pests and root rot. Therefore, attention must be paid to soil moisture management in production to avoid drought. ③ Rainy season: After entering the rainy season, simple rain shelters should be constructed to avoid excessive soil moisture. When the soil moisture content is less than 20%, the rain-avoidance film can be lifted to accept natural rain showers until the soil is soaked. ④ End of the rainy season and dormant period: The soil also needs to be moist during this period. Soil water shortage will aggravate the problems of root pests and root rot, resulting in a decrease in seedling emergence rate in the next year and affecting the yield of under-forest *P. notoginseng*.


We conducted the protocol for diseases control: ① Elimination of disease residues. The diseased plants found under the forest should be cleared in time to prevent the spread of pathogens; ② physical prevention and control. Before the rainy season, timely cleaning of the drainage ditch in the plantation for drainage to avoid root rot. Moreover, by building a simple rain shelter on the ridge surface under the forest, it can regulate environmental humidity and play a role in physical prevention and control of diseases. ③ Biological control. Under-forest bases should adopt products such as bio-control bacteria, bio-derived fungicides, and plant elicitors specified in GB/T 19630 for disease prevention or treatment, and the use of chemical pesticides should be strictly prohibited.


plantation, it is necessary to remove the dead branches on the ridge surface, and remove weeds and excessive pine needles that are not conducive to the growth of *P. notoginseng*. From late December to February of the following year is the dormancy period of under-forest *P. notoginseng*, the fallen dead branches and leaves in the forest should be completely removed to keep the ridge clean and healthy, and the dead branches and leaves of aboveground parts of *P. notoginseng* should be cut (cut at >5 cm away from the pine needle).

#### **2.3 Principles of cultivation practice for Chinese medicinal herbs under the forest**

Ecological balance principle. Traditional Chinese herbs are mostly grown in the natural ecological system, with high biodiversity, natural growth of medicinal materials, light pests and diseases, high efficacy, and sufficient medicinal power. However, in the high-yield cultivation mode of farmland, the variety of medicinal materials is single, the biodiversity of farmland is reduced, the ecosystem is unbalanced, and the harm of harmful organisms is intensified, resulting in the decrease in quality and safety of medicinal materials. It is an effective way to reduce the harm of diseases and insects and improve the quality of medicinal materials by using the natural law of interspecies mutual restraint. Based on the principle of under-forest biodiversity interaction and ecological balance, the planting of shade-growing Chinese herbs and forest system were effectively combined to construct an efficient, stable, and diverse agroforestry system. On this basis, according to the regularity of occurrence and development of Chinese herbal medicine diseases, the rain-shelter cultivation system of under-forest Chinese herbal medicine can also be constructed. Rain-shelter cultivation can create microclimate conditions that are not conducive to the development of pathogen to achieve physical prevention and control of the plant pathogen [18].

Habitat coupling principle. The cultivation of under-forest Chinese herbs makes full use of the coupling characteristics of forest habitats (light, temperature, water, fertilizer, etc.) and the growth characteristics of Chinese herbal medicines and realizes the genuine and high-quality production of Chinese herbal medicines. The main principles of habitat coupling include: ① light coupling principle. Chinese herbs suitable for under-forest cultivation are shade plants originating from the lower forest vegetation, which are sensitive to strong light [29, 30]. Inappropriate light will affect the growth and quality of Chinese herbs. Under the condition of conventional farmland planting, it is necessary to artificially build a shading shed to simulate its suitable light environment, but it is difficult to simulate to achieve its optimal growth conditions. Under-forest planting of Chinese herbs only uses the light microenvironment naturally formed under forest vegetation, which is more conducive to the growth and quality formation of Chinese herbs [31, 32]. Thermal coupling principle. Chinese herbal medicines are usually sensitive to heat. The artificial shading shed built in farmland has poor buffering capacity for heat, which often leads to heat injury or freezing damage [33, 34]. Due to the shade of trees, the lower layer of forest vegetation has strong buffering capacity for temperature, which can effectively alleviate the stress caused by the fierce change of temperature on the growth of medicinal herbs [35, 36]. ③ Water coupling principle. Forest-shade Chinese herbs growing under the forest have wet-like characteristics. The dry environment is not conducive to their growth. The forest environment can improve the microclimate, slow down the flow of air, and reduce water evaporation, thereby improving the distribution and utilization of water. ④ Nutrient coupling principle. The soil nutrient balance is the material basis for maintaining the primary and secondary metabolic balance of medicinal herbs. At

present, the input of organic fertilizer is less and less in the farmland system, and the use of a large number of chemical fertilizers makes the problems of soil acidification and salinization increasingly prominent, resulting in the decline of efficacy, diseases and pests, and continuous cropping obstacles [37, 38]. In the agroforestry system, the roots and leaves of trees can provide a large amount of organic matter for the soil. The decomposition and accumulation of these organic matters can improve the fertility of the soil and provide sufficient nutrient supply for the healthy growth of Chinese herbs [39]. The soil rich in organic matter can also increase the diversity of microorganisms, promote the growth of beneficial microorganisms, and improve the stability of the soil ecosystem and antiviral ability [40]; in addition, understory soils rich in organic matter and microorganisms also produce some disease-resistant substances, which induce plant resistance and effectively reduce the occurrence of diseases [41].

The under-forest ecosystem has rich biodiversity, such as plant diversity, animal diversity, insect diversity, and microbial diversity. Plant–plant, plant-microorganism, plant–animal (insect), and other organisms in the under-forest system form a stable community through complex mutual generation and restriction relationship among the various organisms, which has strong ability to resist natural disasters.
