Comparison of Nitrification in Poplar and Metasequoia Plantations

1. Comparison of Nitrification in Poplar and MetasequoiaPlantations By: Antionette Fowlkes Mentors: Dr. Elica Moss, Dr. Shengzuo Fang and Prof. Ye Tian

2. Outline I. Research II. Cultural Experience

3. Introduction • Poplar and Metasequoia plantations are usually established at riparian land for timber production and for maintaining healthy aquatic ecosystems as buffer zones • Poplars are broad-leaved deciduous trees with rounded contours. There are various species of poplar growing in a range of soil types under different situations. • Metasequoia is a fast-growing, deciduous tree. It is one of three species of conifers known as redwoods.

4. Introduction What is Nitrification? • Nitrification is the process by which ammonium is oxidized to nitrite NO2 and nitrate NO3 by ammonia-oxidizing bacteria • Nitrification occurs in a two step process: • Step one of nitrification is a ammonium oxidizing bacteria that oxidize ammonia to nitrite via hydroxylamine • Step two of nitrification is nitrite oxidizing bacteria into nitrite to nitrate • Soil nitrification processes include: Autotrophic nitrification Heterotrophic nitrification

5. Soil Quality • Importance of Soil Moisture • Soil moisture is key in controlling the exchange of water and heat energy between the land surface and atmosphere through evaporation through and plant transpiration • Importance of Microbial biomass • Soil microbial biomass is an early indicator of changes that may occur in the long term with regards to soil fertility • Importance of Soil pH • Soil pH measures the acidic and alkaline soils and has a fundamental effect on plant growth and nutrient availability

6. Overview of Nitrification

7. Goal & Objective • To compare the characteristics of soil N nitrification and Ammonium Nitrate between Poplar and Metasequoiaplantations in riparian zone. It includes: • to evaluate the relative importance of autotrophic and heterotrophic nitrification in Poplar and Metasequoia plantations.

8. Experimental Site • Research Sites • National Wetland Park (119°15′ E，33°22′ N) in Baoying, Yangzhou City, Jiangsu Province

9. Materials and Methods Field Work • Fresh soil samples (0-10 cm and 10-20 cm) were taken from 3 random soil profiles in each plantation on June 13, 2013 • Samples were collected and taken to the laboratory and stored at 4 °C until analyses

10. Materials and Methods Soil Preparation • Soil samples were prepared by grinding through a 2 mm-sieve • Samples were then bagged stored at 4 °C until analyses

11. Materials and Method Soil pH • Ten grams of soil were measured in triplicates • 50 mL of water was then addedand stirred • After 30 minutes pH was measured

12. Materials and MethodsGravimetric Water Content (Soil Moisture) • Initially the weight of a small mason jars were recorded • Approximately 18.5 g of fresh, sieved soil was measured in triplicate and added to each jar • Soil samples were then oven dried at 65°C for 48 hours

13. Materials and MethodsMicrobial Biomass N • Five grams of soil were measured in triplicates • Two milliliters of KCl (potassium chloride) was added to each soil sample • Samples were covered and secured with Styrofoam and placed on shaker and allowed to mix for 30minutes

14. Materials and MethodsIncubation Period • Ten grams of fresh soil was weighed, placed in small mason jars and triplicated in four groups based on substrates • 1mL of Ammonium Chloride was added to Group A1 • 1mL of Glycine was added to Group A2 • 1mL of Nitrapyrin was added to Group A3 • 1mL of Actidione was added to Group A4 • Sample were incubated for one week on the ammonium nitrate analyzer

15. Data & Results

16. Data & Results

18. Discussion & Conclusion • Previous studies indicate that soil nitrification is regulated by several factors • Temperature • Moisture • Microbial biomass • pH • Both sites have an annual mean temperature of 14.4 ℃ and are similar in pH and moisture content • However, the Poplar plantation is slightly higher in microbial biomass N and net Nitrification than that of the Metasequoia plantation, indicating more microbial activity

19. Discussion & Conclusion • Studies show there is a high net nitrification rate when glycine and ammonium chloride substrates are added to soil samples • Studies also show there is a higher net nitrification rate in the Poplar vs. the Metasequoiaplantations • Studies show that acidic soils that have glycine is nitrified more readily than ammonium chloride • Alkaline soil rates are about the same this is due to • the optimal rate of nitrification requires some what alkaline conditions

20. Actidione is an antibiotic that is known to be and inhibitor to microbial growth • In conclusion, a possible reason for the higher MBN and net N nitrification in the Poplar plantation may be because the trees are rapid-growing, but relatively short-lived, which suggest that leaves frequently fall, causing high organic matter, leading a higher MBN and thus a higher net N nirtification

22. My Cultural Experience

23. People

24. Places

25. Food

26. A Special Thank You • Alabama Agricultural and Mechanical University • Nanjing Forestry University • National Science Foundation • Dr.Elica Moss • Dr. Shengzuo Fang • Professor Ye Tian • Graduate Students of Dr. Fang • Jonjala Jackson Questions & Answers