Microbial biomass, organic matter mineralization and nitrogen in soils from long‐term experimental grassland plots (Palace Leas meadow hay plots, UK)

The Palace Leas meadow hay plots have received different annual manure and fertilizer applications since 1897 and represent the second oldest permanent grassland experiment in the world. Although the soil properties have diverged as a result of the experimental treatments since 1897, the soil organic carbon (SOC) contents of the plots have remained largely unchanged between the 1980s and 2006. In this study we have determined the effects of contrasting manure and fertilizer treatments on the total N contents of the soil, the recalcitrance of soil organic matter, the contributions made from different depths to the overall C mineralization, and the distribution of soil microbial biomass in the soil profiles. Relative to the control plot, which has received no manure or fertilizer additions since 1897, the two plots that have received manure or P plus K contain significantly more N, which in the case of the P plus K plot is consistent with abundant Trifolium spp. in the sward. The plot that has received farmyard manure (FYM) contained 11% more N than the control. The two plots that received large inputs of (NH4)2SO4 and which have consequently become highly acidic (around pH 4) contain 15–27% less N than the control despite the N addition and the accumulation of SOC in these plots. The plot that has only received P has also apparently lost total N (20%) relative to the control. The rates of C mineralization of the microbial biomass were closely related to total SOC contents but have been positively influenced by the increased N in the P plus K plot. Values for soil N, C mineralization rate and microbial C are reported because such data from sites that have been under known long‐term known land‐use are extremely rare and because there is increasing realization of the potential importance of soil data, especially biological characteristics, for monitoring environmental changes.

[1]  J. McNicol,et al.  Soil organic carbon contents in long‐term experimental grassland plots in the UK (Palace Leas and Park Grass) have not changed consistently in recent decades , 2009 .

[2]  D. Manning,et al.  Actinobacterial community dynamics in long term managed grasslands , 2009, Antonie van Leeuwenhoek.

[3]  L. Schipper,et al.  Large losses of soil C and N from soil profiles under pasture in New Zealand during the past 20 years , 2007 .

[4]  R. Lark,et al.  Carbon losses from all soils across England and Wales 1978–2003 , 2005, Nature.

[5]  Keith A. Smith,et al.  Soil and environmental analysis: modern instrumental techniques. , 2003 .

[6]  Ronald Amundson,et al.  The Carbon Budget in Soils , 2001 .

[7]  D. Hopkins,et al.  Carbon transformations during decomposition of different components of plant leaves in soil. , 2000 .

[8]  N. Batjes,et al.  Total carbon and nitrogen in the soils of the world , 1996 .

[9]  D. Hopkins,et al.  Size and activity of soil microbial communities in long-term experimental grassland plots treated with manure and inorganic fertilizers , 1996, Biology and Fertility of Soils.

[10]  E. Witter,et al.  Size of the soil microbial biomass in a long-term field experiment as affected by different n-fertilizers and organic manures , 1993 .

[11]  D. Hopkins,et al.  Chemical characterization and decomposition of organic matter from two contrasting grassland soil profiles , 1993 .

[12]  F. Beese,et al.  Miniaturized Method to Measure Carbon Dioxide Production and Biomass of Soil Microorganisms , 1992 .

[13]  E. D. Seneca,et al.  Loss on ignition and kjeldahl digestion for estimating organic carbon and total nitrogen in estuarine marsh soils: Calibration with dry combustion , 1991 .

[14]  D. Jenkinson,et al.  Model estimates of CO2 emissions from soil in response to global warming , 1991, Nature.

[15]  D. Hopkins,et al.  Decomposition of cellulose, soil organic matter and plant litter in a temperate grassland soil , 1990, Plant and Soil.

[16]  D. Hopkins,et al.  The influence of sward species composition on the rate of organic matter decomposition in grassland soil , 1988 .

[17]  P. Sequi,et al.  Comparison of Total Nitrogen by Four Procedures and Sequential Determination of Exchangeable Ammonium, Organic Nitrogen, and Fixed Ammonium in Soil , 1988 .

[18]  R. Shiel,et al.  Redistribution of nitrogen and phosphorus on Palace Leas meadow hay plots as a result of aftermath grazing , 1988 .

[19]  R. Shiel,et al.  The effects of weather and nutrition on the yield of hay from Palace Leas meadow hay plots, at Cockle Park Experimental Farm, over the period from 1897 to 1980 , 1987 .

[20]  R. Shiel.  Variation in amounts of carbon and nitrogen associated with particle size fractions of soils from the Palace Leas meadow hay plots , 1986 .

[21]  W. Post,et al.  Global patterns of soil nitrogen storage , 1985, Nature.

[22]  D. Rimmer,et al.  Changes in soil structure and biological activity on some meadow hay plots at Cockle Park, Northumberland , 1984, Plant and Soil.

[23]  V. Standen.  ASSOCIATIONS OF ENCHYTRAEIDAE (OLIGOCHAETA) IN EXPERIMENTALLY FERTILIZED GRASSLANDS , 1982 .

[24]  G. Schuman,et al.  Automated Total Nitrogen Analysis of Soil and Plant Samples1 , 1973 .

[25]  D. Hopkins,et al.  Comparison of d- and l-amino acid metabolism in soils with differing microbial biomass and activity , 1997 .

[26]  D. Powlson.  The soil microbial biomass - before, beyond and back , 1994 .

[27]  G. Sparling.  Ratio of microbial biomass carbon to soil organic carbon as a sensitive indicator of changes in soil organic matter , 1992 .

[28]  J. P. E. AND-N.  A PHYSIOLOGICAL METHOD FOR THE QUANTITATIVE MEASUREMENT OF MICROBIAL BIOMASS IN SOILS , 2022 .