P.C. Brookes's research while affiliated with Zhejiang University and other places

Publications (122)

Article
Full-text available
Uncertainty remains over what properties of biochar and which groups of microorganisms are responsible for the direction and magnitude of observed biochar-induced priming effects (PE). We selected maize straw, grass, peanut shells and sugar cane as feedstocks to produce biochar at 300, 400 and 500°C by slow pyrolysis, and carried out an 80-day soil...
Article
Full-text available
David Jenkinson was one of the most influential soil scientists of his generation, bringing new insights into the transformations of organic matter and nitrogen in soil. He spent the majority of his career at Rothamsted Research, Harpenden, UK. His studies were influential regarding the role of soil carbon stocks in the context of climate change an...
Article
Full-text available
Biochar has been widely proposed to be valuable in the sequestering of carbon (C) in soil due to its chemical and biological recalcitrance. However, whether biochar could cause soil positive priming effects (PEs), which offset the effects of soil organic C sequestration, has raised a very controversial issue and debate recently. Changed soil proper...
Article
Nanoparticles are ubiquitous in soil, and their quantity and stability play important roles in the fate, transport and bioavailability of contaminants in the environment. In this research, four soil nanoparticles (SNPs) were extracted from typical soil of different regions in China. Three different kinds of natural organic matter (NOM) were subsequ...
Article
Full-text available
Additions of organic amendments to soil not only compensate for decreased soil C, but also contribute to energy requirements for conserving biological activity levels. The soil microbial biomass displays some highly conserved, and possibly unique, characteristics that do not permit a classic interpretation of microbial metabolic parameter data. The...
Article
Biochars generated from swine manure, fruit peels, Phragmites australis and Brassica rapa were applied to a Psammaquent and a Plinthudult. The Phospholipid (PLFA) markers indicating different microbial communities and available concentrations of elements (K, Ca, Na, Mg, Al, Cr, Cu, Zn, Cd, Pb, Ni, As, Mn, Fe, B, Mo) were measured. Relationships bet...
Article
There is limited information on zinc (Zn2+) adsorption and desorption by different types of soil, especially acidic ones following amendment with manure- and lignocellulose-derived biochars. The novelty of this research is a comparison of the mechanisms of adsorption and desorption of Zn2+ by different types of acidic soil amended with biochar deri...
Article
Aims Replenishment of soils with carbon (C) produced during photosynthesis plays an important role in global C cycling. Nitrogen (N) fertilization is critical for rice production, but its effects on the deposition of photosynthesis-derived C into soil C pools is poorly understood. To address this, we used continuous 14C-labeling to quantify the dep...
Article
Full-text available
Many soil microbes exist in biofilms. These biofilms are typified by variable quantities of extracellular polymeric substances (EPS: predominantly polysaccharides, glycoconjugates, and proteins) and the embedded microbial cells. A method to measure soil-EPS (the biofilm exclusive of microbial cells) has not yet been described. The present work inve...
Article
Full-text available
This study compares a traditional agricultural approach to minimise N pollution of groundwater (incorporation of crop residues) with applications of small amounts of biodiesel co-product (BCP) to arable soils. Loss of N from soil to the aqueous phase was shown to be greatly reduced in the laboratory, mainly by decreasing concentrations of dissolved...
Article
Elevated CO2 respiration rates have been observed in soils treated with complex mixtures versus single low molecular weight (LMW) organic substrates, and it has been postulated that a more diverse range of soil microorganisms responds to increasingly complex mixtures of LMW organic substrates. To test this hypothesis, 13C-labelled substrates (glyci...
Article
Autotrophic microorganisms, which can fix atmospheric CO2 to synthesize organic carbon, are numerous and widespread in soils. However, the extent and the mechanism of CO2 fixation in soils remain poorly understood. We incubated five upland and five paddy soils from subtropical China in an enclosed, continuously 14CO2-labeled, atmosphere and measure...
Article
Autotrophic microorganisms, which can fix atmospheric CO2 to synthesize organic carbon, are numerous and widespread in soils. However, the extent and the mechanism of CO2 fixation in soils remain poorly understood. We incubated five upland and five paddy soils from subtropical China in an enclosed, continuously 14CO2-labeled, atmosphere and measure...
Article
Full-text available
Biochar has been widely proposed as a soil amendment, with reports of benefits to soil physical, chemical and biological properties. To quantify the changes in soil microbial biomass and to understand the mechanisms involved, two biochars were prepared at 350 °C (BC350) and 700 °C (BC700) from Miscanthus giganteus, a C4 plant, naturally enriched wi...
Data
Full-text available
Soil contains approximately 2344 Gt (1 gigaton = 1 billion tonnes) of organic carbon globally and is the largest terrestrial pool of organic carbon. Small changes in the soil organic carbon stock could result in significant impacts on the atmospheric carbon concentration. The fluxes of soil organic carbon vary in response to a host of potential env...
Chapter
Nearly all soil organic matter is extensively humified, with some fractions existing for more than 1,000 years. Soil microorganisms are surrounded by about 50 times their mass of soil organic matter but can only metabolise it very slowly (‘basal mineralisation’ rate). Here, we show that the rate-limiting step in soil organic matter mineralisation i...
Article
Full-text available
Elucidating the biodiversity of CO2-assimilating bacterial communities under different land uses is critical for establishing an integrated view of the carbon sequestration in agricultural systems. We therefore determined the abundance and diversity of CO2 assimilating bacteria using terminal restriction fragment length polymorphism and quantitativ...
Article
Information on the input, distribution and fate of photosynthesized carbon (C) in plant–soil systems is essential for understanding their nutrient and C dynamics. Our objectives were to: 1) quantify the input to, and distribution of, photosynthesized C by rice into selected soil C pools by using a C14 continuous labelling technique and 2) determine...
Article
Full-text available
The efficiency of the fumigation extraction method on the determination of soil microbial biomass carbon and ninhydrin-N was tested in three different soils (UK grassland, UK arable, Chinese arable) amended with black carbon (biochar or activated charcoal). Addition of activated charcoal to soil resulted in a significant decrease in K2SO4 extractab...
Poster
Phosphorus (P) is essential to all living organisms (Ehrlich, 1990), to crop plant production, microbial growth and function (Rorty, 1946; Brookes et al. 1982). Soil microbial biomass (SMB) represents about 2-3% of the total amount of soil organic matter and drives the cycling of organic matter and nutrients in soil including P (Jenkinson and Ladd,...
Poster
Phosphorus (P) is essential to all living organisms (Ehrlich, 1990), to crop plant production, microbial growth and function (Rorty, 1946; Brookes et al. 1982). Soil microbial biomass (SMB) represents about 2-3% of the total amount of soil organic matter and drives the cycling of organic matter and nutrients in soil including P (Jenkinson and Ladd,...
Article
The preparation of soil for measurement of properties such as microbial biomass P involves the removal of plant roots. Any soil attached to the roots (root-attached soil) is also removed. In a very poorly drained silty clay loam under grassland we found that the root-attached soil contained more than twice the quantity of bicarbonate extractable P...
Article
Our aim was to determine whether the smaller biomasses generally found in low pH compared to high pH arable soils under similar management are due principally to the decreased inputs of substrate or whether some factor(s) associated with pH are also important. This was tested in a soil incubation experiment using wheat straw as substrate and soils...
Article
The drying and re-wetting of soils can result in the modification of the amounts and forms of nutrients which can transfer, via leachate, from the soil to surface waters. We tested, under laboratory conditions, the hypothesis that the rate of re-wetting of a dried soil affects the solubilisation and concentrations of different forms of phosphorus (...
Article
Effects of changing pH along a natural continuous gradient of a UK silty-loam soil were investigated. The site was a 200 m soil transect of the Hoosfield acid strip (Rothamsted Research, UK) which has grown continuous barley for more than 100 years. This experiment provides a remarkably uniform soil pH gradient, ranging from about pH 8.3 to 3.7. So...
Article
Most investigations into the effects of changing soil pH on microbial activity use, from necessity, soils taken from different sites so that soil physical and chemical properties are confounded. Studies along continuous gradients of soil pH within a single soil type are rare, simply because so few exist, in UK or even worldwide. Here we report meas...
Article
Soil organic matter comprises all dead plant and animal residues, from the most recent inputs to the most intensively humified. We have found that traces of fresh substrates at microg g(-1) soil concentrations (termed 'trigger molecules') activate the biomass to expend more energy than is contained in the original 'trigger molecules'. In contrast,...
Article
Biological and chemical stabilization of organic C was assessed in soils sampled from the long-term experiments at Rothamsted (UK), representing a wide range of carbon inputs and managements by extracting labile, non-humified organic matter (NH) and humic substances (HS). Four sequentially extracted humic substances fractions of soil organic matter...
Article
Phosphorus (P) gradually accumulates in surface soils if there is a continuous input of inorganic P fertilizers, manures and composts. In turn, P is lost from soil through runoff and leaching, which lead to increased P concentrations in surface and ground waters. Previous work showed that, in Northern European agricultural soils, below a certain Ol...
Article
Our aim was to compare the soil microbial biomass concentration and its activity (measured as CO2–C evolved) following the rewetting and aerobic incubation of soils which have previously been stored air-dry for different periods. Some of the soils have been stored in the Rothamsted sample archive for 103 years, others were comparable freshly sample...
Article
Studies of single soil organisms, while useful in specialized cases, e.g. Rhizobia and mycohrrizae, do not yield information on the functioning of the soil ecosystem. This is because most important soil processes, e.g. carbon and nitrogen mineralization, depend upon interactions between entire suites of organisms, many of which still await identifi...
Article
The soil microbial biomass survives as a largely dormant population for long periods without fresh substrates, depending for growth upon a rapid uptake of substrates when they become available. Currently, little investigation has been made into the mechanisms involved in the transition from dormancy to activity. We found that additions of trace amo...
Article
Our aim was to determine whether the soil microbial biomass, which has developed naturally over many years in a given ecosystem, is specially adapted to metabolize the plant-derived substrate C of the ecosystem within which it developed or whether the nature of recently added substrate is the more important factor. To examine this, soils from three...
Article
Full-text available
Our aim was to determine whether the soil microbial biomass, which has developed naturally over many years in a given ecosystem, is specially adapted to metabolize the plant-derived substrate C of the ecosystem within which it developed or whether the nature of recently added substrate is the more important factor. To examine this, soils from three...
Article
During the first few days after rewetting of an air-dried soil (AD-RW), microbial activity increases compared to that in the original moist soil, causing increased mineralisation (a flush) of soil organic carbon (C) and other nutrients. The AD-RW flush is believed to be derived from the enhanced mineralisation of both non-biomass soil organic matte...
Article
Our aim was to determine if soil ergosterol concentration provides a quantitative estimate of the soil fungal biomass concentration, as is usually assumed. This was done by comparing soil ergosterol measurements with soil fungal biomass (fungal biomass C) concentrations estimated by microscopic measurements and by the selective inhibition technique...
Article
Full-text available
The effects of past applications of farmyard manure (FYM, applied from 1942 to 1967), metal contaminated sewage sludge (applied from 1942 to 1961) and mineral fertilizer (NPK, applied from 1942 until now) on the microbial biomass and community structure in a sandy loam, arable soil from the Woburn Market Garden Experiment, UK, were investigated in...
Article
The effects of past applications of farmyard manure (FYM, applied from 1942 to 1967), metal contaminated sewage sludge (applied from 1942 to 1961) and mineral fertilizer (NPK, applied from 1942 until now) on the microbial biomass and community structure in a sandy loam, arable soil from the Woburn Market Garden Experiment, UK, were investigated in...
Article
Adenosine triphosphate (ATP) was measured in soil profiles taken from two areas of deciduous woodland on Rothamsted Farm, one near neutral, one acidic. Biomass carbon (C) was calculated from these measurements. Comparison of the results with others taken from the literature showed that an exponential function m=e−(rbd) gave a close fit to the assem...
Article
Phosphorus (P) quantity-intensity relationships are central to the solubility and release of P from soil to water. Relationships between P extractable by 0.5 M NaHCO extractable P (Olsen P; quantity, Q) and P extractable by 0.01 M CaCl(2) (CaCl(2)-P; possible predictor of soil solution or drainage water P; intensity, I) are curvilinear: above a cer...
Article
Full-text available
The aim is to assess whether soil microbial biomass carbon (biomass C) could be used as an indicator of environmental change in natural and semi-natural ecosystems. Biomass C was measured by fumigation–extraction in soils from two sites at Rothamsted. One was a plot from the Broadbalk Wheat Experiment, given inorganic fertiliser and chalk, which ha...
Article
Full-text available
This study compared phosphorus (P) speciation and the relationship between bicarbonate extractable (Olsen) P and 0.01 M CaCl2 extractable P (a measure of potentially mobile P) in soils from plots of the Park Grass experiment started in 1856 at IACR-Rothamsted, UK and with and without nitrogen as (NH4)2SO4 and with and without calcium carbonate (CaC...
Article
Martens [Soil Biol. Biochem. 33 (2001) 701] recently reported that Jenkinson and Oades [Soil Biol. Biochem. 11 (1979) 193] method for measuring adenosine 5′ triphosphate (ATP) in soil leads to serious underestimations. We have now compared the Jenkinson and Oades extraction technique, which corrects for incomplete extraction of ATP by reference to...
Article
The turnover times of soil microbial biomass carbon (biomass C) and phosphorus (biomass P) were estimated from the declines in biomass 14C and 32P following the addition to soil of 14C-labelled glucose with added KH232PO4 or with the separate addition of ryegrass which had been doubly labelled with 14CO2 and KH232PO4 (both at 1000 μg C and about 10...
Article
Full-text available
In many intensive agroecosystems continued inputs of phosphorus (P) over many years can significantly increase soil P concentrations and the risk of P loss to surface waters. For this study we used solid-state 31P nuclear magnetic resonance (NMR) spectroscopy, high-power decoupling with magic angle spinning (HPDec-MAS) NMR, and cross polarization w...
Article
The microbial biomass in moist aerobic soils has an adenosine 5′-triphosphate (ATP) concentration of around 8–12 μmol ATP g−1 biomass C and an adenylate energy charge (AEC) of between about 0.8–0.95, both typical of micro-organisms undergoing exponential growth in vitro. In fact, only a very small fraction of the biomass can be in this condition at...
Article
Full-text available
Phosphorus (P) loss from agricultural land to surface waters is well known as an environmental issue because of the role of P in freshwater eutrophication. Much research has been conducted on the erosion and loss of Pin sediments and surface runoff. Recently, P loss in sub-surface runoff via agricultural drainage has been identified as environmenta...
Chapter
This book is divided into 6 sections: organic matter and sustainability; modelling soil organic matter dynamics - global challenges; soil organic matter management - the roles of residue quality in C sequestration and N supply; the role of soil organic matter and manures in sustainable nutrient cycling; implications of soil biodiversity for sustain...
Article
Two ways of measuring substrate-induced respiration (SIR) following addition of glucose to soil, viz. solid glucose or glucose in solution, were tested on 13 soils sampled from arable, grassland and woodland sites ranging from pH 3.2 to 7.5. Generally similar patterns of CO2 evolution were found between soils following addition of glucose as liquid...
Article
Two UK grassland soils, one from Rothamsted (24% clay) and the other from Woburn (8% clay) were incubated at 25°C, unamended or amended with ryegrass followed by fumigation 20 d later followed by a further 20 d incubation. Other portions of the Rothamsted grassland soil were treated separately with a fungicide (Captan), a bacteriocide (Bronopol), o...
Article
Ammonium and nitrate production were measured at 2 h following addition of arginine solution (0.3 mg g−1 soil) to 13 unamended soils. The amounts of NH4–N, NO3–N and total inorganic N (i.e. NH4–N+NO3–N) produced were closely related to soil ATP content, biomass C measured by the fumigation–extraction method (FE) and CO2 evolution measured by substr...
Article
Soil microbial biomass carbon (biomass C) and its activity were measured in soil from Gabuzkoa (Spain) contaminated with heavy metals from a mine spoil tip. Soil was collected along a natural gradient of heavy metal contamination characterized by different organic C contents, clay contents, cultivation and topography. Biomass C and ninhydrin-N were...
Article
The aim was to investigate whether soils developed under tropical conditions had different organic matter and microbial biomass dynamics than soils developed under temperate ones. Three soils formed under temperate climatic conditions (U.K.) and three under tropical conditions (Brazilian) were selected to be as comparable as possible in terms of or...
Article
Full-text available
The effects of 19 years of cumulative annual field application of five pesticides (benomyl, chlorfenvinphos, aldicarb, triadimefon and glyphosate), applied at, or slightly above, the recommended rates in 25 combinations, on soil microbial biomass and the mineralization of soil organic matter were investigated. Soil samples were taken 1 month after...
Article
A transient ATPase was produced when a grassland soil was incubated with glucose (5000 μg glucose C g−1 soil) and inorganic N. The activity of this enzyme reached a maximum after about 2 days, declining to ambient levels by 10 days. Its formation was strongly repressed by the addition of inorganic phosphate during the incubation with glucose and N....
Article
Thirteen soils, differing in pH, clay content, soil organic C and management, were kept at 25°C either unamended, amended with ryegrass (2% w/w) or amended with ryegrass and then fumigated for 10 or 20 d. The amount of soil microbial biomass was then determined in each soil by the fumigation-extraction method (FE), substrate-induced respiration (SI...
Article
Full-text available
The effects of two ergosterol biosynthesis-inhibiting fungicides, epoxiconazole and triadimefon (at 2 and 20 ×, and 1 and 10 × field rate, respectively), and of straw amendment on ergosterol and microbial biomass C in a sandy loam soil, were investigated. Initial soil ergosterol and microbial biomass C contents were about 1.6 μg g−1 and 330 μg g−1...