Objectives To find a safe and effective way to alleviate pepper continuous cropping obstacle, the effects of applying dry powder of three crops seedlings on pepper seedling growth and rhizosphere soil biological characteristics.
Methods A pot experiment was conducted with four treatments: control treatment (CK, continuous cropping soil without application of plant dry powder), using mustard seedlings dry powder (M), barley young stem and leaf dry powder (B) and celery young stem and leaf dry powder (C).
Results Compared with CK, three other treatments promoted the growth and development of pepper seedlings. Among them, M and B treatmens had the best treatment effect, and the height of the pepper plant at 30 days after planting was higher than that in CK. At the same time, the three treatments promoted root growth of pepper, leading to significant differences in root length, root surface area and root volume. Processed pepper leaf PSⅡ maximum quantum yield (Fv/Fm), PSⅡ actual quantum yield Y (Ⅱ) and light chemical quenching coefficient (qP) improved, but the three treatments had little impact on non chemical quenching coefficient (NQP). The contents of chlorophyll a, chlorophyll b and chlorophyll a + b of M treatment were higher than those in other treatments by 25.3%, 45.4% and 30.6%, respectively. All three treatments improved the pH of pepper soil by 27.6%, 24.5% and 25.4% compared to CK, respectively. The three treatments increased the amount of soil actinomycetes, bacteria and total bacteria. The amount of actinomycetes increased by 71.9%, 73.8% and 67.5%, compared with CK, the amount of bacteria increased by 1.18%, 55.5% and 30.4% compared with CK, and the total amount of bacteria increased by 4.55%, 57.1% and 33.9% compared with CK. All three treatments reduced the amount of soil fungi by 69.8%, 68.1% and 75.8%, respectively. After the treatments, the activity of sucrase, acid phosphatase and polyphenol oxidase was significantly increased, but the activity of soil urease was significantly lower than that of control.
Conclusions The three crop dry powders all show the effect in promoting the growth and development of continuous cropping pepper, increasing the activity of soil invertase, acid phosphatase and polyphenol oxidase, increasing the number of soil bacteria and actinomycetes and reducing the number of fungi. Therefore their application is beneficial to improve soil environment and microorganism structure. Among the three tested dry powders, mustard seedlings dry powder has the best satisfactory effect.
DownLoad: