ABSTRACT
@#【Objective】 To study the effects of soil environment on the growth, yield, and quality of Sharen (Amomi Fructus) under different planting patterns. 【Methods】 Soil physical and chemical indices and enzyme activities in four periods including early flowering (March), full flowering (June), fruit ripening (September), and late fruit picking (December), were measured under three planting patterns including natural forest, greenhouse, and rubber forest in Xishuangbanna, China. The changes in soil indices during the growth periods of Sharen (Amomi Fructus) under different planting patterns were analyzed, and the differences in plant growth, yield, and quality under different planting patterns were explored. Pearson correlation analysis was used to analyze the relationship between soil indices and Sharen (Amomi Fructus) growth, yield, and quality. Principal component analysis was used to investigate the effects of soil environment under different planting patterns on Sharen (Amomi Fructus) growth, yield, and quality. 【Results】 The soil moisture, available potassium content, and urease activity of the three planting patterns of Sharen (Amomi Fructus) increased initially and decreased afterwards throughout the year; pH and organic matter content showed little change in the whole year. Exchangeable manganese content and acid phosphatase activity gradually increased throughout the year. Hydrolyzed nitrogen content, exchangeable calcium content, available zinc content, protease activity, and sucrase activity decreased initially and increased afterwards throughout the year. Exchangeable magnesium content, available iron content, and catalase activity decreased annually. Total nitrogen content, total phosphorus content, and available phosphorus content fluctuated throughout the year. The total potassium content under natural forest and greenhouse planting decreased throughout the year, while the total potassium content under rubber forest showed an upward trend all year round. The organic matter content, total nitrogen content, total potassium content, available potassium content, available zinc content, urease activity, acid phosphatase activity, and catalase activity under greenhouse were significantly lower than those under natural and rubber forests (P < 0.05). Correlation analysis showed that plant growth, yield, and quality of Sharen (Amomi Fructus) were significantly correlated with soil organic matter, total nitrogen, hydrolyzed nitrogen, total phosphorus, available phosphorus, total potassium, available potassium, exchangeable manganese, exchangeable magnesium, exchangeable calcium, available zinc, urease, acid phosphatase, and invertase (P < 0.05). The results of the principal component analysis indicated that the soil environment of Sharen (Amomi Fructus) under natural forest was the best, followed by rubber forest and greenhouse. The order of its advantages and disadvantages is consistent with the growth index of Sharen (Amomi Fructus), but contrary to the yield of Sharen (Amomi Fructus), indicating that the soil environment directly affects the growth index and nutritional components of plants. 【Conclusion】 Different planting patterns of Sharen (Amomi Fructus) have different soil nutrient content, and the change rules in the growths period are not similar, with some differences. Soil indices have impacts on plant growth, yield, and quality of Sharen (Amomi Fructus). Soil ecological environment is positively correlated with the growth characteristics of Sharen (Amomi Fructus) plants, but has no direct correlation with yield and quality.
ABSTRACT
Nitrogen is one of the most frequently used fertilizers in growth of Chinese medicinal plants(CMP). As in many other ecosystems, CMP ecosystem is also composed of plant-herbivore-natural enemy(tritrophic) interactions. Nitrogen fertilizer influences the growth and reproduction of CMP, and it is also able to heavily shape the ecosystem functions of CMP ecosystem through bottom-up forces. Understanding the specific effects of nitrogen fertilizer towards each trophic level will be beneficial to improve the resistance of CMP to herbivore and enhance the control efficiency of nature enemies to herbivore, and eventually, maximize the yield and quality of CMP. Most papers published on nitrogen use in plants focused mainly on the impact of nitrogen fertilization on CMP yield and quality. Influences of nitrogen application on CMP ecosystem get little attention at present. Therefore, this review summed up the potential effects of nitrogen fertilization on CMP ecosystem from perspectives of soil and tritrophic interactions. First of all, nitrogen fertilizer might decrease soil microbial biomass and altered the community structures of soil bacteria, fungi and protozoa. Negative effects of nitrogen fertilizer were found on biodiversity of soil bacteria and protozoa. Different fungi species respond differently to nitrogen fertili-zers. Nitrogen deposition can also decrease the soil pH. Decreases in soil microbial diversity and soil acidification can cause negative effects on CMP growth. In addition, nitrogen fertilizer could regulate the pest resistance of CMP including constitutive and inducible resistance. Both positive and negative effects of nitrogen application were found on pest resistance of CMP. Moreover, the development and predation of natural enemies were influenced by nitrogen deposition. Nitrogen influences natural enemies in many ways including plant volatiles, plant nutrient and structure and the supplementary food quality. Nectar and honeydew of plants and preys serve as important food source for natural enemies especially in early season when preys are still not available. Finally, the interactions between herbivores and their natural enemies were also shaped by nitrogen fertilizer in many aspects like increasing the nutritional content of prey and changing control efficiency of natural enemies. Some herbivores have evolved a strategy to sequester secondary metabolites which they absorbed from plant during their feeding. Studies showed that sequestration efficiency of secondary metabolites in prey could also be regulated by nitrogen. Parasitic, emergence, reproduction rate and longevity of parasites were found positively correlated with nitrogen deposition. Hopefully this study will shed light on practicable and economical application of nitrogen in cultivation of CMP.
Subject(s)
China , Ecosystem , Fertilizers , Nitrogen , Plants, Medicinal , SoilABSTRACT
Objective To study soil environment characteristics of high_mortality areas of esophageal cancer in Three Gorge dam region. Methods To contrast the disparity of soil type,soil use,and basic characteristics,in particular microelement contents in high_mortality area and low_mortality area of esophageal cancer. Results Calcareous purple soils distributed dominantly in high_mortality area,and soil pH and CaCO3 content was high,and soil fertility low. While paddy soils occupyed mainly in low_mortality area,and pH and CaCO3 content was low however soil fertility high.Moreover,the microelement contents in soils in high_mortality area were lower than those in low_mortality area apparently. Conclusion Mortality of esophageal cancer was closely relative to the contents of some microelements in the soil environment.