Soil Microbial Community Structure and Physicochemical Properties in Amomum tsaoko-based Agroforestry Systems in the Gaoligong Mountains, Southwest China

Abstract

Amomum tsaoko is cultivated in forests of tropical and subtropical regions of China, and the planting area is expanding gradually. However, little attention has been paid to the impact of A. tsaoko cultivation on the soil characteristics of the regions. We analyzed the effects of the A. tsaoko-forest agroforestry system (AFs) on the composition of soil microbial communities with increasing stand ages. We also compared the soil physicochemical properties, microbial biomass, and phospholipid fatty acid (PLFA) composition between native forest (NF) and AFs. The results showed that the level of total carbon, nitrogen, and organic matter dramatically dropped in AFs with increasing stand ages. pH affected other soil properties and showed close correlation to total carbon (P = 0.0057), total nitrogen (P = 0.0146), organic matter (P = 0.0075), hydrolyzable nitrogen (P = 0.0085), available phosphorus (P < 0.0001), and available potassium (P = 0.0031). PLFAs of bacteria (F = 4.650, P = 0.037), gram-positive bacteria (F = 6.640, P = 0.015), anaerobe (F = 5.672, P = 0.022), and total PLFA (F = 4.349, P = 0.043) were significantly affected by different treatments, with the greatest value for NF treatment, and least value for AF5. However, the microbial biomass declined during the initial 5 years of cultivation, but it reached the previous level after more than 10 years of cultivation. Our research suggests that AFs is a profitable land-use practice in the Gaoligong Mountains and that AFs showed a recovering trend of the soil nutrient condition with increasing stand ages. However, the severe loss of nitrogen in the soil of AFs requires additional nitrogen during cultivation to restore it to pre-cultivation levels.

Assessment of genetic diversity in Amomum tsao-ko Crevost & Lemarié, an important medicine food homologous crop from Southwest China using SRAP and ISSR markers

“…Amomum tsao-ko Crevost & Lemarié, commonly known as black cardamom, is a perennial evergreen tufted herb belonging to the family Zingiberaceae. It is mainly distributed in Southwest China and Northern Vietnam at altitudes ranging from 1300 to 1800 m and is a type of economic crop that grows in humid forests (Liu et al 2019 ; Wu and Raven 2000 ). The dried ripe fruit of A. tsao-ko (Cao-guo in Chinese) is often used to treat internal resistance to cold and dampness, epigastric distension, fullness and vomiting, and malaria among other ailments (Lim 2013 ; Shi et al 2014 ).…”

Development of 23 novel microsatellite markers of Amomum tsao-ko (Zingiberaceae) based on restriction-site-associated DNA sequencing

“…Amomum tsao-ko, commonly known as black cardamom, is a perennial evergreen tufted herb belonging to the family Zingiberaceae. It is mainly distributed in Southwest China and Northern Vietnam, and found at altitudes ranging from 1300 to 1800 m. It is a type of economical crop that can grow in humid forests in tropical and subtropical areas [1,2]. Yunnan province is the main A. tsao-ko-producing area in China, contributing to 95% of the nation's output [3].…”

Correlation Analysis of Compounds in Essential Oil of Amomum tsaoko Seed and Fruit Morphological Characteristics, Geographical Conditions, Locality of Growth

“…In China, it is randomly planted in the southeast of Yunnan province, mainly in the moist, broadleaved forests. In the last 200 years, to increase the consumption and gradual disappearance of the wild (or natural) population, the cultivated area has expanded [13]. Now, there is about 90% producing area of A. tsaoko in Yunnan province [14].…”