Rothamsted

The fact that is not radioactive means that it can be used safely in experiments in the field, but it also means that much patient work is needed to obtain results. The approach is demanding in terms of time, equipment, and skilled manpower, but it has made a great contribution to the understanding of the nitrate problem. The results that are outlined here are from experiments made by staff at Rothamsted, but key contributions have also come from Scotland and France. " The majority of the Rothamsted experiments involved winter wheat, but oilseed rape, potatoes, beans, and sugar beet were also grown. The soil is a factor in nitrate leaching, and three types were used, the flinty, silty clay loam at Rothamsted, a sandy loam at Woburn in Bedfordshire and a heavy sandy clay at Saxmimdham in Suffolk. 

Up to Harvest. Oilseed rape and field beans are used as break crops for winter wheat on a variety of soils, and potatoes are used on the lighter soils. Sugar beet may also be grown, but this depends not only on the soil but also on the proximity of a sugar beet processing factor. Four Rothamsted-based experiments compared the effectiveness of winter wheat and winter oilseed rape in their use of labelled nitrogen fertilizer. Potatoes were included in two of these experiments and sugar beet and field beans in one experiment each. Two criteria based on the... 

Rainfall at Rothamsted was first analysed for nitrate and ammonium about 120 years ago, but not very much was found. Between 1877 and 1915 the total deposition of nitrogen was 227kgha about 6 kgha per year on average. By 1990, measurements at four sites in south-east England " showed that the annual... 

Table 1 Deposition of NH to plate eolleetors (expressed as kg NH -Nha yr ) reeorded by Hall and Miller at Rothamsted ...

Figure 2 Comparison of measured wet deposition of ammonium at Rothamsted, England with model estimates by Asman et al for regions whieh assume ehanges in emissions are only due to differenees in animal numbers. (Taken from Sutton et al ).

T. M. Addiscott, Rothamsted Experimental Station, Harpenden, Hertfordshire AL5 2JQ, UK... 

Brenchley, W.E. Warington, K. (1958). The Park Grass Plots at Rothamsted 1856-1949. Harpenden Rothamsted Experimental Station. 

D. S. Jenkin.son, P. B. S. Hart, J. H. Rayner, and L. C. Parry, Modelling the turnover of organic matter in long-term experiments at Rothamsted. INTECOL Bull. 15 1 (1987). 

Barnett, V., T. Lewis, and V. Rothamsted, Outliers in Statistical Data, 3rd edition, Wiley, New York, NY, 1994. 

To calculate carbon sequestration potentials, accurate measures of carbon inputs and outputs are needed. Long-term management studies may provide information needed in SOC maintenance calculations (VandenBygaart et al. 2003 McVay et al. 2006 Richter et al. 2007). One of the oldest management studies conducted in the world is the Rothamsted long-term study. Information on this study is available at http //www.rothamsted.bbsrc.ac.uk/resources/LongTermExperiments.html. Links to other long-term studies are available at http //ltse.env.duke.edu/resources/links. 

The Rothamsted Carbon Model (RothC) uses a five pool structure, decomposable plant material (DPM), resistant plant materials (RPM), microbial biomass, humified organic matter, and inert organic matter to assess carbon turnover (Coleman and Jenkinson 1996 Guo et al. 2007). The first four pools decompose by first-order kinetics. The decay rate constants are modified by temperature, soil moisture, and indirectly by clay content. RothC does not include a plant growth sub-module, and therefore NHC inputs must be known, estimated, or calculated by inverse modeling. Skjemstad et al. (2004) tested an approach for populating the different pools based on measured values. 

Acknowledgments We wish to thank Peter Heise-Pavlov for his assistance in sampling gland swabs, Ron and Sue Stannard at Julatten, Australia, for the storage of the samples and Lynda Ireland at Rothamsted Research, UK, for the technical assistance during the analyses of the samples. 

Biological Chemistry Division Rothamsted Research, Harpenden Hertfordshire AL5 2JQ UK... 

If the dissipation rate of a chemical is slower than the rate at which the chemical is applied in a soil, then the concentration of the chemical will increase, reaching a limit above which the soil may not be suitable for food production. A study by Jones et al. [25] at Rothamsted Experimental Station showed that the concentration of PAHs in the topsoil had been increasing steadily over the last century, with the total PAH increasing by about four-fold. 

The release of K into solution from the solid phase is important in plant nutrition, and it has been extensively studied at Rothamsted as at other agricultural research stations throughout the world. We have been interested in the process both from the practical standpoint of determining the availability of K to crops, and from the more fundamental view of understanding its... 

P.W. Arnold (1-3) was an early pioneer of the work at Rothamsted. The present research programme was begun by 0. Talibudeen (4-6), with whom I began collaboration in 1974. This paper summarises our results and my more recent work on exchange equilibria (4-16). 

Figure 2. The differential enthalpy of Ca 2K exchange (d(AHx/dx) as a function of fractional K saturation for the Batcombe series soils from various plots of the Broadbalk Classical Experiment at Rothamsted. 

ROSS, G.J.S. (1980) Maximum likelihood program. Harpenden Rothamsted Experimental Station... 

Johnston AE, Goulding KWT, Poulton PR (1986) Soil acidification during more than 100 years under permanent grassland and woodland at Rothamsted. Soil Use Manage 2 3-10 Kahn SU (1982) Bound pesticides residues in soil and plant. Residue Rev 84 1-25 Kan AT, Chen W, Tomson MB (2000) Desorption kinetics from neutral hydrophobic organic compounds from field contaminated sediment. Environ Pollution 108 81-89 Kang SH, Xing BS (2005) Phenanthrene sorption to sequentially extracted soil humic acids and humans. Environ Sci Technol 39 134-140... 

---