Progress 10/01/06 to 09/20/11
Outputs
OUTPUTS: A field experiment with smooth bromegrass (Bromus inermis Leyss.) was laid out in the Experiment Farm of University of Alaska Fairbanks in May 2004. There were three fertilizer treatments: 1) Check (0 kg N/ha/year); 2) Low N (50 kg N/ha/year); and 3) High N (150 kg N/ha/year), and two cutting frequencies: one cutting per year and two cuttings per year. There were two objectives: 1) comparing N use efficiency in one and two cuttings of bromegrass in interior Alaska; and 2) evaluating different chemical methods to estimate potential mineralizable N in Alaska soils. The third objective was developed during the course of the experiment which was to characterize soil water soluble organic N under different land uses. Here are the summary of the outputs. The results showed that increase of N application rate increased biomass production of smooth bromegrass for both cutting regimes. Most of applied N was apparently recovered in the first cutting, in comparison, about 10 % N was recovered respectively from 50 and 150 kg N/ha treatments in the second cut. Delaying time in the first cut helped the grasses to recover an additional applied N in 150 kg N/ha treatment, but did little to improve crop N uptake for 50 kg N/ha treatment. The cumulative apparent N recovery from 150 kg N/ha application in early cut was less than 50%, the lowest among all treatments. 15N was applied in the fertilizer treatments to determine the fate of the applied N. Soil samples from the field experiment, and as well as from different land uses (CRP, forest, and agriculture) were taken. Two incubation experiments were conducted in the laboratory. In the first experiment, soils samples were extracted by water (22oC), 2M KCl, hot KCl (100oC), and 0.1 M NaOH. In the second experiment, soils samples were extracted with water (sequentially extracted by cold (22oC) and hot (80oC) water), 0.01M NaHCO3, 1 M HCl, and 1 M NaOH. The first incubation results showed that residual 15N fertilizer in soil was released in 4 weeks after incubation, indicating residual fertilizer N was still in labile N pool. Soluble organic N in soils before incubation was higher in agricultural soils than in forest and CRP soils. The water extracted N has a high correlation with bromegrass N uptake. The results of the second incubation experiment were also indicated that water soluble organic N had a high relationship with mineral N released over time. The quality of water extracted organic C and N were assessed by solution incubation, and by SUVA254, SUVA280, and fluorescence humification index (HI), and fluorescence components. In addition, factors (fresh soil samples vs. air-dried soil samples, land use changes etc.) that might affect the quantity and quality of water extractable organic C and N were determined. The results showed that air-drying can increase soil soluble organic C and N. Fluorescence EEM contour curves and parallel factor analysis indicated three components existed in soil water soluble organic matter (e.g. humic-, fulvic-, tyrosin-like materials). Also, the biodegradability of the water extracted organic N was related to HI and SUVA254, SUVA280. PARTICIPANTS: Dr. Mingchu Zhang, principal investigator, University of Alaska Fairbanks, School of Natural Resources and Agricultural Sciences, Department of High Latitude Agriculture, responsible for oversight and administration. Ph.D. student Ms. Aiqin Zhao is currently conducting research in the project TARGET AUDIENCES: Primarily, all Alaskan agronomic producers, both traditional and organic. Secondarily, all agronomic producers in circumpolar northern environments. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The information generated from this research project will provide 1) a soil test method that estimates potential minealizable N in soil, and the method is suitable for Alaska soil and can be used for fertilizer recommendation; 2) an optimal range of N fertilizer application rate in smooth bromegrass; and 3) an optimal windows of cutting for high quality hay. The information on optimal N application rate and cutting time from this research can be used to guide farmers to produce high quantity and quality hay for reindeers. This is especially important under the context of high fertilizer cost (due to high energy price) and the demands on high quality hay for expansion of reindeer industry in Alaska. In addition, the characterization of water soluble organic matter under different land uses further indicated that in Alaska, the water extractable organic N does relate to potential mineralizable N in soil disregard to different land uses. The spectral measurements such as humification index, SUVA254, and SUVA280 is related to biodegradable of soil soluble organic matter, indicating possibility of using such measurements for estimating potential mineralizable N in soil.
Publications
- M. Zhang, S. Sparrow, S. Seefeldt. 2006. Spectral characteristics of water extractable organic matter from soils of different land uses in a subarctic Alaska environment. Abstract in ASA-CSSA-SSSA 2006 International Annual Meetings Nov. 12-16. Indianapolis, Indiana.
- Zhang, M., Zhongqi He, Aiqin Zhao, Dinku M. Endale, and Harry H. Schomberg. 2011. Soil water extractable carbon and nitrogen impacted by tillage and manure application. Soil Science, 176:307-312
- Zhang, M., S. D. Sparrow, R. V. Veldhuizen, and d. t. masiak. 2011. Soil quality under different land uses in a subarctic environment in Alaska. Journal of Land Use Science 1-13
- Zhang, M., Z. He, and A. Zhao. 2011. Ultraviolet-visible absorption features of water extractable humic fractions of animal manure and relevant compost. pp In Z. He (ed.) Environmental Chemistry of Animal Manure. Nova Science Publishers, Inc. Hauppauge, N.Y. USA (in press)
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: purpose To estimate potential N released from a soil is the foundation for improving fertilizer N use efficiency. To estimate potential mineralizable N from a soil, a chemical extraction method is often used. In this study, total N in water and hot water extractions were used to estimate potential mineralizable N from Alaska soil. Fourteen soil samples were collected from Fairbanks, Delta Junction, and Palmer areas, they represented major land uses, agricultural production systems, and soil types. progress Fourteen soil samples (air dried, < 2 mm in size) were incubated in laboratory at 15oC (mean temperature from May to September) and 80% field capacity. Destructive samples were taken at 0, 1, 2, 4 6, 9, 12, 16 and 24 weeks after initialization of the incubation. The samples taken from incubation were extracted by 2 M KCl for mineral N (NH4-N + NO3-N). Prior to the incubation, the 14 soil samples were respectively extracted by deionized water, and deionized hot water (80oC) (soil:solution = 1:7.5). The total N and C and mineral N (mostly NH4-N) in the extractant were determined. PARTICIPANTS: Dr. Dan Olk USDA-ARS National Soil Tilth Laboratory 2150 Pammel Drive Ames, IA 50011 Email olk@nstl.gov Phone 515-294-8412 and all NC-1032 states. Bob Van Veldhuizen and darleen masiak, Research Associates. Partners and contacts: Charles Knight, North Region Manager and Inspector, AK DNR, Divison of Agriculture TARGET AUDIENCES: Research communities, soil laboratories, fertilizer agencies, producers, federal and state agencies: USDA/ARS and NRCS, State Department of Natural Resources Division of Agriculture. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
impact The results showed that mineral N released from the incubation was well correlated with the total N from the hot deionized water extraction (r2 = 0.80, p < 0.05 ), and to a less degree correlated with the deionized water extraction (r2 = 0.47, p < 0.05), indicating that hot water extraction may serve as an index for potential mineralizable N for subarctic soils.
Publications
- Zhao, Aiqin and Mingchu Zhang. 2010. Effect of land use on water soluble organic C and N in subarctic environment. Organic Geochemistry (submitted).
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: A field experiment with smooth bromegrass (Bromus inermis Leyss.) was begun at the Fairbanks Experiment Farm of the University of Alaska Fairbanks in May 2004. There were three fertilizer treatments: 1) Contnrol (0-30-30); 2) Low N (50-30-30); and 3) High N (150-30-30), and two cutting frequencies: one cutting per year and two cuttings per year. In the spring 2006, 15N enriched urea (10%) was applied in 1 m x 1 m microplots. Plant samples from the microplots were taken in June, July and August in 2006, 2007 and 2008. Soil samples were taken from each of one-quarter areas of the microplots in August in 2006, 2007 and 2008. Soil samples with the N15 treatment were incubated at 90% field capacity and at 15 degree C for 200 days. Destructive soil samples were taken at different time intervals to determine N15 release of applied fertilizer N in soils. The samples were extracted by distilled water, in N15 soil samples before and after extraction was determined. To further understand water extractable labile organic N and C in high latitude soils, another incubation experiment was conducted with soils samples from three land uses (CRP, forest, and agriculture). Water extractable N and C, mineral N, fluorescence emission and excitation matrices of water extractable C and N in incubated samples taken in different times are to be determined. Characterization of water extractable C and N from three land uses prior to incubation was completed. In addition, urease inhibitor Agrotain was applied on bromegrass fields to determine if Agrotain can reduce nitrogen loss through ammonia volatilization. PARTICIPANTS: Mingchu Zhang, Principal Investigator. Associate Professor, University of Alaska Fairbanks, School of Natural Resources and Agricultural Sciences, Department of High Latitude Agriculture. Responsible for oversight and administration. Dan Olk USDA-ARS National Soil Tilth Laboratory 2150 Pammel Drive Ames, IA 50011 Email olk@nstl.gov Phone 515-294-8412 and all NC-1032 states. Bob Van Veldhuizen and darleen masiak, Research Associates. Partners and contacts: Charles Knight, North Region Manager and Inspector, AK DNR, Divison of Agriculture TARGET AUDIENCES: Research communities, soil laboratories, fertilizer agencies, producers, federal and state agencies: USDA/ARS and NRCS, State Department of Natural Resources Division of Agriculture. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Results showed that residual 15N fertilizer in soil was released in 4 weeks after incubation, indicating residual fertilizer N was still in the labile N pool. Soluble organic N in soils before incubation was higher in agricultural soils than in forest and CRP soils in fresh soil samples. Air-drying and sieving processes can increase soil soluble organic C, but these increases mostly occurred in soluble carbon fractions less than 1 kD. Fluorescence EEM contour curves and PARAFAC analysis indicated three components in soluble organic C, they were humic-, fulvic-, tyrosin-like materials. The urea inhibitor study showed that both in fall and spring applied urea can be lost through ammonia volatilization when Agrotain was not used. The goal for the project is to provide ways to manage nitrogen fertilizers by determining that labile N pool from soils receiving different N application rates, soils under different land uses, and the use of Agrotain to prevent N loss.
Publications
- No publications reported this period
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: A field experiment with smooth bromegrass (Bromus inermis Leyss.) was laid out in the Experiment Farm of University of Alaska Fairbanks in May 2004. There were three fertilizer treatments: 1) Check (0-30-30); 2) Low N (50-30-30); and 3) High N (150-30-30), and two cutting frequencies: one cutting per year and two cuttings per year. In the spring 2006, 15N enriched urea (10%) was applied in the fertilizer treated plots in 1 m x 1 m microplots. Plant samples from the microplots were taken in June, July and August in 2006, 2007 and 2008. Plant samples were dry and ground and 15N concentration is currently being determined. Currently, a Ph.D. student is conducting the research to characterize soil mineraliable N from bromegrass hay field. Soil samples were taken from each of the one-quarter area of the microplots in August in 2006, 2007 and 2008. Plant samples were taken in 2008 growing season and were ground. Plant samples of 2006, 2007, and 2008 are currently being analyzed for total N and 15N concentration. Soil samples of 2006 were ground, and passed a 2-mm sieve. Five grams of soil samples were incubated at -5 and 15oC temperature. The total time for incubation is 200 days to determine the potential mineralizable N. During incubation, destructive soil samples were taken at different time intervals. The samples were extracted by distilled water, 2 M KCl, hot HCl, and 0.1 M NaOH, mineral N, total N and 15N concentration in solution will be determined. The experiment is still being conducted. Organic N compounds before and after extraction are characterized by 15N NRM instrument. The analysis is currently conducted in a research service laboratory out site of the University of Alaska, and the results are yet to come. Two additional experimental designs have been finished for this project after multiple pre-experimental trials for determining proper protocols. The first is an experiment to determine freezing and thaw impact on N mineralization, and the second is a fluorescence experiment to determine the components of water soluble nitrogen in a time series. PARTICIPANTS: Dr. Mingchu Zhang, principal investigator, University of Alaska Fairbanks, School of Natural Resources and Agricultural Sciences, Department of High Latitude Agriculture. Responsible for oversight and administration. TARGET AUDIENCES: Primarily, all Alaskan agronomic producers, both traditional and organic. Secondarily, all agronomic producers in circumpolar northern environments. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The project will provide tools for fertilizer recommendation for crop production in Alaska. This will help us to improve nutrient management in arable land of Alaska, and to understand N dynamics in natural ecosystems.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: A field experiment with smooth bromegrass (Bromus inermis Leyss.) was laid out in the Experiment Farm of University of Alaska Fairbanks in May 2004. There were three fertilizer treatments: 1)Check (0-30-30); 2)Low N (50-30-30); and 3)High N (150-30-30), and two cutting frequencies: one cutting per year and two cuttings per year. In the spring 2006, 15N enriched urea (10%) was applied in the fertilizer treated plots in 1 m x 1 m microplots. Soil samples were taken from one quarter of the microplot area in August of 2006 and 2007. Plant samples were dried and ground for analysis of total nitrogen and 15N concentration. Soil samples collected in 2006 were air dried and pulled through a 2 mm sieve. A five gram subsample was incubated at -5 and 15 degree C for a total time period of 200 days to determine the potential mineralizable nitrogen. During incubation, destructive soil samples were taken at different time intervals. The soil samples were treated using the distilled water
2 M KCl, hot HCl, and 0.1 M NaOH extraction methods to determine the mineral nitrogen, total nitrogen and 15N concentration in solution.
PARTICIPANTS: Dr. Dan Olk USDA-ARS National Soil Tilth Laboratory 2150 Pammel Drive Ames, IA 50011 Email olk@nstl.gov Phone 515-294-8412 and all NC-1032 states. Bob Van Veldhuizen and darleen masiak, Research Associates. Partners and contacts: Charles Knight, North Region Manager and Inspector, AK DNR, Divison of Agriculture
TARGET AUDIENCES: Research communities, soil laboratories, fertilizer agencies, producers, federal and state agencies: USDA/ARS and NRCS, State Department of Natural Resources Division of Agriculture.
PROJECT MODIFICATIONS: None
Impacts
The project will provide tools for fertilizer recommendation for crop production in Alaska, and for assessing enhanced nitrogen mineralization in natural ecosystems under climate change scenario. The will help us to improve nutrient management in arable land of Alaska, and to understand nitrogen dynamics in natural ecosystems.
Publications
- No publications reported this period
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