How relationships between soil organic matter parameters and soil structure characteristics are affected by the long-term fertilization of a sandy soil

Geoderma ◽  
2019 ◽  
Vol 342 ◽  
pp. 75-84 ◽  
Author(s):  
Vladimír Šimanský ◽  
Martin Juriga ◽  
Jerzy Jonczak ◽  
Łukasz Uzarowicz ◽  
Wojciech Stępień
2020 ◽  
Vol 17 (24) ◽  
pp. 6457-6474
Author(s):  
Marcus Schiedung ◽  
Severin-Luca Bellè ◽  
Gabriel Sigmund ◽  
Karsten Kalbitz ◽  
Samuel Abiven

Abstract. Pyrogenic organic matter (PyOM) is a major and persistent component of soil organic matter, but its mobility and cycling in soils is largely unknown. We conducted a column experiment with a topsoil and subsoil of a sand and a sandy loam to study the mobility of highly 13C labeled ryegrass PyOM (>2.8 at. %), applied as a layer on a 7 cm long soil column, under saturated conditions. Further, we used fresh and oxidized PyOM (accelerated aging with H2O2) to identify changes in its migration through the soil with aging and associated surface oxidation. Due to the isotopic signature, we were able to trace the PyOM carbon (PyOM-C) in the soil columns, including density fractions, its effect on native soil organic carbon (nSOC) and its total export in percolates sequentially sampled after 1000–18 000 L m−2. In total, 4 %–11 % of the added PyOM-C was mobilized and <1 % leached from the columns. The majority of PyOM-C was mobilized with the first flush of 1000 L m−2 (51 %–84 % of exported PyOM-C), but its export was ongoing for the sandy soil and the loamy subsoil. Oxidized PyOM showed a 2–7 times higher mobility than fresh PyOM. In addition, 2-fold higher quantities of oxidized PyOM-C were leached from the sandy soil compared to the loamy soil. Besides the higher mobility of oxidized PyOM, its retention in both soils increased due to an increased reactivity of the oxidized PyOM surfaces and enhanced the interaction with the soil mineral phase. Density fractionation of the upper 0–2.3 cm, below the PyOM application layer, revealed that up to 40 % of the migrated PyOM was associated with the mineral phase in the loamy soil, highlighting the importance of mineral interaction for the long-term fate of PyOM in soils. The nSOC export from the sandy soil significantly increased by 48 %–270 % with addition of PyOM compared to the control, while no effect was found for the loamy soil after the whole percolation. Due to its high sorption affinity towards the soil mineral phase, PyOM can mobilize mineral-associated soil organic matter in coarse-textured soils, where organo-mineral interactions are limited, while finer-textured soils have the ability to re-adsorb the mobilized soil organic matter. Our results show that the vertical mobility of PyOM in soils is limited to a small fraction. Aging (oxidation) increases this fraction but also increases the PyOM surface reactivity and thus its long-term retention in soils. Moreover, the migration of PyOM affects the cycling of nSOC in coarse soils and thus influences the carbon cycle of fire-affected soils.


Soil Research ◽  
1993 ◽  
Vol 31 (1) ◽  
pp. 39 ◽  
Author(s):  
RG Mclaren ◽  
GSP Ritchie

A soil copper fractionation was carried out on soils sampled from plots in a long-term copper fertilizer trial on a lateritic sandy soil in Western Australia. At copper application rates up to 8.25 kg copper sulphate ha-1, a high proportion of the applied copper was initially associated with the soil organic matter. During the course of the trial (20 years), a substantial proportion of this copper became redistributed to a residual soil fraction, i.e. the residue remaining after extractions to remove organic matter and iron oxides. However, significant redistribution of copper with time was not detected in plots with a higher rate of copper application (19.25 kg copper sulphate ha-1). The change in distribution of copper at the lower copper application rates appeared to be only partly responsible for a corresponding decrease observed in EDTA-extractable soil copper during the trial. The changes with time in the nature of fertilizer copper applied to this soil are considered to be responsible for the previously observed decline in plant availability of such copper.


2012 ◽  
Vol 63 (2) ◽  
pp. 42-45 ◽  
Author(s):  
Vladimír Šimanský

Assessment of Soil Structure Under Monoculture of Vines Long-term impact of vine growing on the soil structure stability was studied in three wine-growing areas of Slovakia. In Leptosols, the highest content of water-stable aggregates was determined. This soil type had the lowest vulnerability of soil structure as well. In Chernozems, the highest stability of soil structure was determined, while on the other hand, in Fluvisols, soil structure had the highest vulnerability. Between rows of vines in comparison to rows of vines a more favourable soil structure was determined. In vineyards, the soil structure state depends on the quantity and stability of soil organic matter, as well as particle size distribution.


2019 ◽  
Vol 135 ◽  
pp. 396-406 ◽  
Author(s):  
Bryony E.A. Dignam ◽  
Maureen O'Callaghan ◽  
Leo M. Condron ◽  
Jos M. Raaijmakers ◽  
George A. Kowalchuk ◽  
...  

Author(s):  
Haiming Tang ◽  
Chao Li ◽  
Lihong Shi ◽  
Li Wen ◽  
Kaikai Cheng ◽  
...  

Abstract Soil organic matter (SOM) and its fractions play an important role in maintaining or improving soil quality and soil fertility. Therefore, the effects of a 34-year long-term fertilizer regime on six functional SOM fractions under a double-cropping rice paddy field of southern China were studied in the current paper. The field experiment included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM) and without fertilizer input as control (CK). The results showed that coarse unprotected particulate organic matter (cPOM), biochemically, physically–biochemically and chemically protected silt-sized fractions (NH-dSilt, NH-μSilt and H-dSilt) were the main carbon (C) storage fractions under long-term fertilization conditions, accounting for 16.7–26.5, 31.1–35.6, 16.2–17.3 and 7.5–8.2% of the total soil organic carbon (SOC) content in paddy soil, respectively. Compared with control, OM treatment increased the SOC content in the cPOM, fine unprotected POM fraction, pure physically protected fraction and physico-chemically protected fractions by 58.9, 106.7, 117.6 and 28.3%, respectively. The largest proportion of SOC to total SOC in the different fractions was biochemically protected, followed by chemically and unprotected, and physically protected were the smallest. These results suggested that a physical protection mechanism plays an important role in stabilizing C of paddy soil. In summary, the results showed that higher functional SOM fractions and physical protection mechanism play an important role in SOM cycling in terms of C sequestration under the double-cropping rice paddy field.


1986 ◽  
Vol 66 (2) ◽  
pp. 273-285 ◽  
Author(s):  
J. F. DORMAAR ◽  
C. W. LINDWALL ◽  
G. C. KOZUB

A field was artificially eroded by levelling in 1957 and then continuously cropped to barley for 7 yr. Subsequently, a wheat-fallow experiment was conducted from 1965 to 1979 to determine the effects of four fertilizer treatments and green manure (yellow sweet clover) on restoring the productivity to soil that had been "eroded" to various depths. After 22 yr and 14 crops, the productivity of the land from which soil was removed has been improved but not fully restored. Although green manuring with yellow sweet clover improved soil structure, wheat yields were not improved because of competition for soil moisture and poorer in-crop weed control in this part of the rotation. The addition of 45 kg N plus 90 kg P2O5 per hectare in each crop year to sites from which 8–10, 10–20, or 46 + cm of soil had been removed resulted in yield increases of 18, 46, and 70%, respectively, over the unfertilized check of each treatment; the average yields were 104, 91, and 70%, respectively, of the undisturbed, unfertilized (check) treatment. On "erosion" treatments where only 8–10 cm of soil were removed, 45 kg N plus 22 kg P2O5 per hectare were sufficient to restore the productivity. Precipitation apparently had a greater effect than fertilizer application on wheat yields. The loss of organic matter and associated soil structure characteristics seemed to be critical factors contributing to yield losses associated with soil erosion. These results show that it is more practical to use management practices that prevent soil erosion than to adopt the practices required to restore eroded soil. Key words: Soil erosion, topsoil loss, water-stable aggregates, soil organic matter, green manure, precipitation


2001 ◽  
Vol 81 (3) ◽  
pp. 349-355 ◽  
Author(s):  
D. F. E. McArthur ◽  
P M Huang ◽  
L M Kozak

Research has suggested a link between the bioavailability of soil Cd and total soil organic matter. However, some research suggested a negative relationship between total soil organic matter and bioavailable soil Cd while other research suggested a positive relationship. This study investigated the relationship between soil Cd and both the quantity and quality of soil organic matter as influenced by long-term cultivation. Two Orthic Chernozemic surface soil samples, one from a virgin prairie and the other from an adjacent cultivated prairie, were collected from each of 12 different sites throughout southern Saskatchewan, Canada. The samples were analyzed for total organic C, total Cd, Cd availability index (CAI), and pH. The nature of the soil organic matter was investigated with 13C Cross Polarization Magic Angle Spinning Nuclear Magnetic Resonance spectroscopy (13C CPMAS NMR). The total soil Cd, CAI, and total soil organic C of the cultivated soils were significantly lower than those of the virgin soils whereas the opposite trend was observed for the soil pH and the aromaticity of the organic C. The reduced CAI in the cultivated soils was related to the increase in both the soil pH and the aromaticity of the organic C. No relationship was found between the CAI and the soil organic C content, but a significant positive correlation was found between total organic C and total Cd in both the virgin and the cultivated soils. As well, a significant positive correlation was found between the fraction of total Cd removed from the soil after long-term cultivation and the corresponding fraction of organic C removed. Key words: Long-term cultivation, soil organic matter, 13C CPMAS NMR, cadmium


2013 ◽  
Vol 10 (3) ◽  
pp. 2089-2103 ◽  
Author(s):  
T. Wutzler ◽  
M. Reichstein

Abstract. Interactions between different qualities of soil organic matter (SOM) affecting their turnover are rarely represented in models. In this study, we propose three mathematical strategies at different levels of abstraction to represent those interactions. By implementing these strategies into the Introductory Carbon Balance Model (ICBM) and applying them to several scenarios of litter input, we show that the different levels of abstraction are applicable at different timescales. We present a simple one-parameter equation of substrate limitation that can straightforwardly be implemented into other models of SOM dynamics at decadal timescale. The study demonstrates how substrate quality interactions can explain patterns of priming effects, accelerate turnover in FACE experiments, and the slowdown of decomposition in long-term bare fallow experiments as an effect of energy limitation of microbial biomass. The mechanisms of those interactions need to be further scrutinized empirically for a more complete understanding. Overall, substrate quality interactions contribute to both understanding and quantitatively modelling SOM dynamics.


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