Abstract
The available N of 27 soils from England and Wales was assessed from the amounts of N taken up over a 6-month period by perennial ryegrass grown in pots under uniform environmental conditions. Relationships between availability and the distribution of soil N amongst various fractions were then examined using multiple regression. The relationship: available soil N (mg kg−1 dry soil)=(Nmin×0.672)+(Ninc×0.840)+(Nmom×0.227)−5.12 was found to account for 91% of the variance in available soil N, where Nmin=mineral N, Ninc=N mineralized on incubation and Nmom=N in macro-organic matter. The N mineralized on incubation appeared to be derived largely from sources other than the macro-organic matter because these two fractions were poorly correlated. When availability was expressed in terms of available organic N as % of soil organic N (Nao) the closest relationship with other soil characteristics was: Nao=[Ninc×(1.395−0.0347×C∶Nmom]+[Nmom×0.1416], where C∶Nmom=C∶N ratio of the macro-organic matter. This relationship accounted for 81% of the variance in the availability of the soil organic N.
The conclusion that the macro-organic matter may contribute substantially to the available N was confirmed by a subsidiary experiment in which the macro-organic fraction was separated from about 20 kg of a grassland soil. The uptake of N by ryegrass was then assessed on two subsamples of this soil, one without the macro-organic matter and the other with this fraction returned: uptake was appreciably increased by the macro-organic matter.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
Allen S E, Grimshaw H M, Parkinson J A and Quarmby C 1974 Chemical Analysis of Ecological Materials. Blackwell Scientific Publication, Oxford, 565 p.
Andrew C S and Fergus I F 1976 Plant nutrition and soil fertility. In Tropical Pasture Research. Eds. N H Shaw and W W Bryan. pp 101–133. Commonwealth Agricultural Bureaux, Farnham Royal.
Barley K P 1955 The determination of macro-organic matter in soils. Agron. J. 47, 145–147
Bremner J M 1965 Inorganic forms of nitrogen. In Methods of Soil Analysis Part 2. Ed. C A Black. pp 1179–1237. American Society of Agronomy, Madison.
Clement C R and Williams T E 1962 An incubation technique for assessing the nitrogen status of soils newly ploughed from leys. J. Soil Sci. 13, 82–91.
Choudhri M B and Stevenson F J 1957 Chemical and physicochemical properties of soil humic colloids. III. Extraction of organic matter from soils. Soil Sci. Soc. America Proc. 21, 508–513.
Follett M J and Ratcliff P W 1963 Determination of nitrite and nitrate in meat products. J. Sci. Food Agric. 14, 138–144.
Garwood E A, Clement C R and Williams T E 1972 Leys and soil organic matter. III. The accumulation of macro-organic matter in the soils under different leys. J. Agric. Sci. Cambridge 78, 333–341.
Gehrke C W, Kaiser F E and Ussary J P 1968 Automated spectrophotometric method for nitrogen in fertilizers. J. Assoc. Official Analytical Chemists 51, 200–211.
Henricksen A and Selmer-Olsen A R 1970 Automatic methods for determining nitrate and nitrite in water and soil extracts. Analyst 95, 514–518.
Jones M J and Parsons J W 1972 The effect of soil factors on the extraction of soil organic matter by anhydrous formic acid. J. Soil Sci. 23, 119–127.
Kalembasa S J and Jenkinson D S 1973 A comparative study of titrimetric and gravimetric methods for the determination of organic carbon in soils. J. Sci. Food and Agric. 24, 1085–1090.
Keeney D R 1982 Nitrogen — availability indices. In Methods of Soil Analysis, Part 2. Chemical and Microbiological Properties. Agronomy Monograph No. 9 Ed. A L Page. pp 711–734. American Society of Agronomy, Madison, Wisconsin.
McGill W B, Hunt H W, Woodmansee R G and Reuss J P 1981 Phoenix, a model of the dynamics of carbon and nitrogen in grassland soils. In Terrestrial Nitrogen Cycles. Eds. F E Clark and T Rosswall. Ecological Bulletins (Stockholm) 33, 49–115.
Power J F 1968 Mineralization of nitrogen in grass roots. Soil Sci. Soc. 32, 673–674.
Richards I R and Hobson R D 1977 The relationships between nitrogen supply and the nitrogen yield of cut grass swards. J. Agric. Sci. Cambridge 88, 289–292.
Smith J H and Peterson J R 1982 Recycling of nitrogen through land application of agricultural, food processing and municipal wastes. In Nitrogen in Agricultural Soils. Ed. F J Stevenson. pp 791–831. Agronomy Monograph No. 22. American Society of Agronomy, Madison.
Stanford G 1982 Assessment of soil nitrogen availability. In Nitrogen in Agricultural Soils. Ed. F J Stevenson. pp 651–688. Society of Agronomy, Madison.
Warren G P 1988 Use of acetylene to improve the reliability of the assessment of soil nitrogen mineralized on aerobic incubation. Soil Biol. Biochem. 20, 119–121.
Whitehead D C 1970 The Role of Nitrogen in Grassland Productivity. Commonwealth Agricultural Bureaux, Farnham Royal, 202 p.
Whitehead D C 1984 Interactions between soil and fertilizer in the supply of nitrogen to ryegrass grown on 21 soils. J. Sci. Food Agric. 35, 1067–1075.
Whitehead D C 1986 Sources and transformations of organic nitrogen in intensively managed grassland soils. In Nitrogen Fluxes in Intensive Grassland Systems. Eds. H G Van der Meer, J C Ryden and G C Ennik. pp 47–58. Martinus Nijhoff, Dordrecht.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Warren, G.P., Whitehead, D.C. Available soil nitrogen in relation to fractions of soil nitrogen and other soil properties. Plant Soil 112, 155–165 (1988). https://doi.org/10.1007/BF02139991
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02139991