Molecular changes in particulate organic matter (POM) in a typical Chinese paddy soil under different long-term fertilizer treatments

2010 ◽  
Vol 61 (2) ◽  
pp. 231-242 ◽  
Author(s):  
P. Zhou ◽  
G. X. Pan ◽  
R. Spaccini ◽  
A. Piccolo
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Paddy Soil ◽  
Molecular Changes

The interaction between particulate organic matter and copper, zinc in paddy soil

2018 ◽  
Vol 243 ◽  
pp. 1394-1402 ◽  
Author(s):  
Jiyan Shi ◽  
Qianhua Wu ◽  
Cuiqing Zheng ◽  
Jianjun Yang
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Paddy Soil ◽  
Copper Zinc

Organic management and legume presence maintained phosphorus bioavailability in a 17-year field crop experiment

2013 ◽  
Vol 30 (3) ◽  
pp. 211-222 ◽  
Author(s):  
Courtney Gallaher ◽  
Sieglinde S. Snapp
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Particulate Organic Matter ◽  
P Uptake ◽  
Field Crop ◽  
Inorganic P ◽  
Soil P ◽  
P Fertilizer ◽  
Term Management

AbstractLegumes have been shown to enhance bioavailability of phosphorus (P) from sparingly soluble pools, yet this functional trait remains underutilized in agriculture, and is untested at decadal scales. Management and legume presence effects on temporal soil properties were evaluated in a 17-year field crop experiment using soil samples collected in 1992, 2000 and 2006. Management systems compared included: (1) conventional corn–soybean–wheat rotation (C–S–W), (2) organic (C–S–W+red clover), (3) alfalfa and (4) early successional field. To evaluate the effects of long-term management versus recent management (residues and P fertilizer) on P and bio-availability to soybean, subplots of soybean were established with and without P-fertilizer (30 kg P ha−1), and compared to subplots and main plot with the long-term system. We evaluated soil properties (C, total P, Bray extractable inorganic P, particulate organic matter phosphorus) and soybean P uptake, biomass and yield. Recent fertilizer P inputs had no detectable influence on soil P, and total soil P stayed stable at ~350 mg P kg−1, whereas inorganic P (Pi) declined from an initial value of 54 to an average of 35 mg P kg−1. A P balance was constructed and showed a net loss of −96.7 kg P ha−1 yr−1 for the organic system, yet Bray-Pi and soybean P uptake were maintained under organic production at similar levels to the conventional, fertilized system. Particulate organic matter P was 57, 82 and 128% higher in organic, alfalfa and successional treatments, respectively, compared to conventional. A similar pattern was observed for soil C, soybean yield and bioavailable P, which were 20–50% higher in the organic, alfalfa and successional systems relative to conventional. This study provides evidence that long-term management history influences bioavailability of P.

scholarly journals Long-term steady state <sup>13</sup>C labelling to investigate soil carbon turnover in grasslands

2007 ◽  
Vol 4 (3) ◽  
pp. 385-394 ◽  
Author(s):  
K. Klumpp ◽  
J. F. Soussana ◽  
R. Falcimagne
Keyword(s):  
Organic Matter ◽  
Steady State ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Residence Time ◽  
Particulate Organic Matter ◽  
Mean Residence Time ◽  
Carbon Turnover ◽  
13C Labelling

Abstract. We have set up a facility allowing steady state 13CO2 labeling of short stature vegetation (12 m2) for several years. 13C labelling is obtained by scrubbing the CO2 from outdoors air with a self-regenerating molecular sieve and by replacing it with 13C depleted (−34.7±0.03‰) fossil-fuel derived CO2 The facility, which comprises 16 replicate mesocosms, allows to trace the fate of photosynthetic carbon in plant-soil systems in natural light and at outdoors temperature. This method was applied to the study of soil organic carbon turnover in temperate grasslands. We tested the hypothesis that a low disturbance by grazing and cutting of the grassland increases the mean residence time of carbon in coarse (>0.2 mm) soil organic fractions. Grassland monoliths (0.5×0.5×0.4 m) were sampled from high and low disturbance treatments in a long-term (14 yrs) grazing experiment and were placed during two years in the mesocosms. During daytime, the canopy enclosure in each mesocosm was supplied in an open flow with air at mean CO2 concentration of 425 µmol mol−1 and δ13C of −21.5±0.27‰. Fully labelled mature grass leaves reached a δ13C of −40.8 (±0.93) and −42.2‰ (±0.60) in the low and high disturbance treatments, respectively, indicating a mean 13C labelling intensity of 12.7‰ compared to unlabelled control grass leaves. After two years, the delta 13C value of total soil organic matter above 0.2 mm was reduced in average by 7.8‰ in the labelled monoliths compared to controls. The isotope mass balance technique was used to calculate for the top (0–10 cm) soil the fraction of 13C labelled carbon in the soil organic matter above 0.2 mm (i.e. roots, rhizomes and particulate organic matter). A first order exponential decay model fitted to the unlabelled C in this fraction shows an increase in mean residence time from 22 to 31 months at low compared to high disturbance. A slower decay of roots, rhizomes and particulate organic matter above 0.2 mm is therefore likely to contribute to the observed increased in soil carbon sequestration in grassland monoliths exposed to low disturbance.

Long-term dynamics of organic matter and elements exported as coarse particulates from two Caribbean montane watersheds

2012 ◽  
Vol 28 (2) ◽  
pp. 127-139 ◽  
Author(s):  
T. Heartsill Scalley ◽  
F. N. Scatena ◽  
S. Moya ◽  
A. E. Lugo
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Headwater Streams ◽  
Structural Complexity ◽  
Base Flow ◽  
Coarse Particulate Organic Matter ◽  
North East ◽  
Storm Flow ◽  
Before And After

Abstract:In heterotrophic streams the retention and export of coarse particulate organic matter and associated elements are fundamental biogeochemical processes that influence water quality, food webs and the structural complexity of forested headwater streams. Nevertheless, few studies have documented the quantity and quality of exported organic matter over multiple years and under a range of conditions that includes both droughts and hurricanes. This study quantifies the export of coarse particulate organic matter (CPOM, > 12.7 mm), over 18 y in two headwater streams in north-east Puerto Rico. Daily exports ranged from 0 to over 170 g ha−1 d−1 and averaged 7.39 g ha−1 d−1, with similar amounts coming from leaves (3.5 g ha−1 d−1) and wood (3.2 g ha−1 d−1). Export of coarse particulate organic carbon was 3.0 g ha−1 d−1 which constitutes only 1.32% of carbon exports. Most litter falling into the streams was processed in place as only 2.3% of the leaf litter falling directly into these perennial channels was exported as CPOM. On average, 6 wk y−1 had no exports while events transporting more than 10 g ha−1 d−1 occurred every 2.8 mo. Instead of a single annual pulse as observed in deciduous systems, there were annual peaks in CPOM exports during May and September and less export during the drier period from December to February. Ratios of C:N in the exported material were highest in the driest month and lowest during rainy months, while leaf fluxes for nitrogen, phosphorus and calcium were highest in rainy months and lowest during February. Although median daily exports and exports during low- and base-flow periods were similar before and after Hugo, after 16 y exports during moderate- and high-flow periods were still less than those in the 2 y prior to the hurricane. Our observations indicate a system with high rates of internal processing that quickly returns to median daily conditions following hurricanes but requires several decades for storm-flow exports to return to pre-disturbance conditions and indicates that the long-term pattern of CPOM export is associated with the level of maturity of watershed vegetation.

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