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Nitrogen loss assessment and environmental consequences in the loess soil of China

Tong, Yanan (2003). Nitrogen loss assessment and environmental consequences in the loess soil of China. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae. Silvestria, 1401-6230 ; 284
ISBN 91-576-6518-4
[Doctoral thesis]

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Abstract

Attention is focused on fertilizer nitrogen loss and the environmental consequences in Shaanxi Province in loess region of China, including N losses to the atmosphere via ammonia volatilization, nitrification and denitrification, N losses to groundwater by leaching, and crop uptake by roots. Three soils were selected, Entisol, Anthrosol and Luvisol from north, central and south Shaanxi, respectively. Nitrification and NH4+ fixation were measured using a closed chamber method in the laboratory. Denitrification was tested in the laboratory with intact soil cores, C2H2 inhibition techniques. N2O emission was assessed via in situ measurement of N2O in the soil profile and at the soil surface in field experiments. Fertilizer use and crop yields obtained by the farmers were investigated on a large scale in Shaanxi Province. Transformation of fertilizer NH4+ to NO3- was within nine days in the Entisol and Anthrosols, but it took 40 days in Luvisol due to NH4+ fixation by clay minerals. In the pot experiment open to the wind and sunshine with different water content, applied N fertilizer recovery was 74.2% for the Luvisol and 61.3% for the Entisol. The results for the Luvisol showed lower nitrogen recovery as initial soil water content increased. When the fertilizer was incorporated, the recovery was 91.6% at 8% and 68.9% at 28% water content. Recovery increased with increasing soil clay content. Large amount of nitrate was accumulated at 200-400 cm depth in the soil profile and accounted for 362-543, 144-677 and 165-569 kg N ha-1 in terrace and bottom land in north Shaanxi, terrace land in Guanzhong and south Shaanxi, respectively. N2O measurements also showed that N2O spatial variation in the profile could be ranked as, 10 cm < 30 cm < 150 cm < 90 cm < 60 cm. Temporal variation was correlated with rainfall or irrigation. Closed chamber measurements or calculations from profile concentrations resulted in N2O emission of less than 1 kg N2O ha-1 y-1. An investigation showed that soil fertility in the Guanzhong area is high, but yield has not increased with increasing N fertilizer application during the last five years. Over-application of N fertilizer was very common in the Guanzhong area and ranged from 100 to 382 kg N ha-1 for wheat and from 106 to 530 kg N ha-1 for maize. The results of the experiments indicate that the N fertilizer recovery efficiency is about 30% and the consequences of N losses are seriously threatening the environment by leaching to the groundwater and by denitrification to the atmosphere.

Authors/Creators:Tong, Yanan
Title:Nitrogen loss assessment and environmental consequences in the loess soil of China
Year of publishing :September 2003
Volume:284
Number of Pages:47
Papers/manuscripts:
NumberReferences
ALLI. Tong, Y.A., O. Emteryd, D.Q. Lu & H. Grip. 1997. Effect of organic manure and chemical fertilizer on nitrogen uptake and nitrate leaching in a Eum-orthic anthrosol profile. Nutrient Cycling in Agroecosystems. 48(3): 225-229. II. Tong, Y.A., O. Emteryd, H. Grip & D.Q. Lu. Nitrification, Ammonium fixation, and Nitrogen recovery in two Chinese soils. Pedosphere. (Submitted, 2003). III. Lu, D.Q., Y.A. Tong, B.H. Sun & O. Emteryd. 1998. Effects of nitrogen fertilizer use on environmental pollution. Plant Nutrition and Fertilizer Sciences. 4(1): 8-15. (Translated from Chinese). IV. Liang, D.L., Y.A. Tong, O. Emteryd & S.X. Li. 2002. In situ measurements of N2O emissions from a loess soil profile. Acta Pedologica Sinica. 39(6): 802-809. (Translated from Chinese). V. Emteryd, O., Y.A. Tong, D.L. Liang, T. Magnusson & H. Grip. Heavy nitrogen fertilizer application and losses in the loess soils areas of China. (Manuscript).
Place of Publication:Umeå
ISBN for printed version:91-576-6518-4
ISSN:1401-6230
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:T Pollution > T01 Pollution
P Natural resources > P34 Soil biology
Subjects:Not in use, please see Agris categories
Agrovoc terms:nitrification, denitrification, leaching, environmental impact, pollution, nitrogen fertilizers, loess soils, china
Keywords:nitrification, denitrification, Nitrate leaching, N2O emission, environment pollution, Nitrogen fertilizer, loess soil
URN:NBN:urn:nbn:se:slu:epsilon-169
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-169
ID Code:351
Department:(S) > Institutionen för skogsekologi (930701-061231)
Deposited By: Yanan Tong
Deposited On:17 Sep 2003 00:00
Metadata Last Modified:02 Dec 2014 10:04

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