The effect of soil properties and level of fertilizer application on the dissolution of sechura rock phosphate in some soils from Brazil, Colombia, Australia and Nigeria

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 219 ◽  
Author(s):  
JC Hughes ◽  
RJ Gilkes

The extent and rate of dissolution of Sechura rock phosphate in 30 soils from Brazil, Colombia, Australia and Nigeria were measured. There was an initial rapid dissolution within 1 day, and this was followed by slower dissolution up to 124 days. For all soils an increase in the level of rock phosphate resulted in a smaller proportion dissolving. After 31 days, the percentage dissolved differed widely between soils and for rock phosphate application levels of 0.34 and 34 mg g-1 soil ranged over 0-100%, and 0-21% respectively. Pyrophosphate and oxalate-extractable iron and aluminium were important soil properties for predicting the amount of rock phosphate dissolution; pH, organic carbon, silt content and exchangeable calcium were subsidiary predictive properties for some soils.

2002 ◽  
Vol 32 (8) ◽  
pp. 1381-1392 ◽  
Author(s):  
Michael D Bock ◽  
Ken CJ Van Rees

Greater utilization of hardwood species and societal concerns over maintenance of ecological integrity have provided impetus for forest managers to consider alternative silvicultural practices in boreal mixedwood forests. The objective of this study was to quantify the effects of five mechanical site preparation (MSP) treatments on soil properties and understory vegetation of mixedwood stands in the Northwest Territories (NWT). Soil and understory vegetation conditions in treatments (3 years post-MSP treatment) and adjacent uncut forest controls were sampled. Significant Shearblade – Grizz R-ex and Shearblade treatment soil property effects were consistently found. Increases in bulk density (307%) and decreases for total organic carbon (92%); total nitrogen (86%); cation exchange capacity (74%); and exchangeable calcium (72%), magnesium (67%), and potassium (75%) in the soil surface (0–12.8 cm) were observed. Increases in mineral soil pH (1.0 units), total organic carbon (94%), cation exchange capacity (20%), and exchangeable calcium (35%) and magnesium (56%) were also found. Dissimilarity of the understory community with that of the uncut forest increased as follows: uncut forest < harvested only < Meri–Crusher = Grizz R-ex < Shearblade – Meri-Crusher < Shearblade – Grizz R-ex < Shearblade. This research suggests that winter shearblading should be utilized only where it is necessary to achieve specific management objectives.


Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 455
Author(s):  
Rebecca M. Swab ◽  
Nicola Lorenz ◽  
Nathan R. Lee ◽  
Steven W. Culman ◽  
Richard P. Dick

After strip mining, soils typically suffer from compaction, low nutrient availability, loss of soil organic carbon, and a compromised soil microbial community. Prairie restorations can improve ecosystem services on former agricultural lands, but prairie restorations on mine lands are relatively under-studied. This study investigated the impact of prairie restoration on mine lands, focusing on the plant community and soil properties. In southeast Ohio, 305 ha within a ~2000 ha area of former mine land was converted to native prairie through herbicide and planting between 1999–2016. Soil and vegetation sampling occurred from 2016–2018. Plant community composition shifted with prairie age, with highest native cover in the oldest prairie areas. Prairie plants were more abundant in older prairies. The oldest prairies had significantly more soil fungal biomass and higher soil microbial biomass. However, many soil properties (e.g., soil nutrients, β-glucosoidase activity, and soil organic carbon), as well as plant species diversity and richness trended higher in prairies, but were not significantly different from baseline cool-season grasslands. Overall, restoration with prairie plant communities slowly shifted soil properties, but mining disturbance was still the most significant driver in controlling soil properties. Prairie restoration on reclaimed mine land was effective in establishing a native plant community, with the associated ecosystem benefits.


Heliyon ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. e06074
Author(s):  
Workineh Ejigu ◽  
Yihenew G.Selassie ◽  
Eyasu Elias ◽  
Matebe Damte

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuhua Shan ◽  
Min Lv ◽  
Wengang Zuo ◽  
Zehui Tang ◽  
Cheng Ding ◽  
...  

AbstractThe most important measures for salt-affected mudflat soil reclamation are to reduce salinity and to increase soil organic carbon (OC) content and thus soil fertility. Salinity reduction is often accomplished through costly freshwater irrigation by special engineering measures. Whether fertility enhancement only through one-off application of a great amount of OC can improve soil properties and promote plant growth in salt-affected mudflat soil remains unclear. Therefore, the objective of our indoor pot experiment was to study the effects of OC amendment at 0, 0.5%, 1.0%, 1.5%, and 2.5%, calculated from carbon content, by one-off application of sewage sludge on soil properties, rice yield, and root growth in salt-affected mudflat soil under waterlogged conditions. The results showed that the application of sewage sludge promoted soil fertility by reducing soil pH and increasing content of OC, nitrogen and phosphorus in salt-affected mudflat soil, while soil electric conductivity (EC) increased with increasing sewage sludge (SS) application rates under waterlogged conditions. In this study, the rice growth was not inhibited by the highest EC of 4.43 dS m−1 even at high doses of SS application. The SS application increased yield of rice, promoted root growth, enhanced root activity and root flux activity, and increased the soluble sugar and amino acid content in the bleeding sap of rice plants at the tillering, jointing, and maturity stages. In conclusion, fertility enhancement through organic carbon amendment can “offset” the adverse effects of increased salinity and promote plant growth in salt-affected mudflat soil under waterlogged conditions.


2021 ◽  
Author(s):  
Yuehong Shi ◽  
Xiaolu Tang ◽  
Peng Yu ◽  
Li Xu ◽  
Guo Chen ◽  
...  

&lt;p&gt;Soil carbon turnover time (&amp;#964;, year) is an important indicator of soil carbon stability, and a major factor in determining soil carbon sequestration capacity. Many studies investigated &amp;#964; in the topsoil or the first meter underground, however, little is known about subsoil &amp;#964; (0.2 &amp;#8211; 1.0 m) and its environmental drivers, while world subsoils below 0.2 m accounts for the majority of total soil organic carbon (SOC) stock and may be as sensitive as that of the topsoil to climate change. We used the observations from the published literatures to estimate subsoil &amp;#964; (the ratio of SOC stock to net primary productivity) in grasslands across China and employed regression analysis to detect the environmental controls on subsoil &amp;#964;. Finally, structural equation modelling (SEM) was applied to identify the dominant environmental driver (including climate, vegetation and soil). Results showed that subsoil &amp;#964; varied greatly from 5.52 to 702.17 years, and the mean (&amp;#177; standard deviation) subsoil &amp;#964; was 118.5 &amp;#177; 97.8 years. Subsoil &amp;#964; varied significantly among different grassland types that it was 164.0 &amp;#177; 112.0 years for alpine meadow, 107.0 &amp;#177; 47.9 years for alpine steppe, 177.0 &amp;#177; 143.0 years for temperate desert steppe, 96.6 &amp;#177; 88.7 years for temperate meadow steppe, 101.0 &amp;#177; 75.9 years for temperate typical steppe. Subsoil &amp;#964; significantly and negatively correlated (p &lt; 0.05) with vegetation index, leaf area index and gross primary production, highlighting the importance of vegetation on &amp;#964;. Mean annual temperature (MAT) and precipitation (MAP) had a negative impact on subsoil &amp;#964;, indicating a faster turnover of soil carbon with the increasing of MAT or MAP under ongoing climate change. SEM showed that soil properties, such as soil bulk density, cation exchange capacity and soil silt, were the most important variables driving subsoil &amp;#964;, challenging our current understanding of climatic drivers (MAT and MAP) controlling on topsoil &amp;#964;, further providing new evidence that different mechanisms control topsoil and subsoil &amp;#964;. These conclusions demonstrated that different environmental controls should be considered for reliable prediction of soil carbon dynamics in the top and subsoils in biogeochemical models or earth system models at regional or global scales.&lt;/p&gt;


2011 ◽  
Vol 8 (12) ◽  
pp. 3661-3675 ◽  
Author(s):  
M. I. Stutter ◽  
D. G. Lumsdon ◽  
A. P. Rowland

Abstract. Moorland carbon reserves in organo-mineral soils may be crucial to predicting landscape-scale variability in soil carbon losses, an important component of which is dissolved organic carbon (DOC). Surface water DOC trends are subject to a range of scaling, transport and biotic processes that disconnect them from signals in the catchment's soils. Long-term soil datasets are vital to identify changes in DOC release at source and soil C depletion. Here we show, that moorland soil solution DOC concentrations at three key UK Environmental Change Network sites increased between 1993–2007 in both surface- and sub- soil of a freely-draining Podzol (48 % and 215 % increases in O and Bs horizons, respectively), declined in a gleyed Podzol and showed no change in a Peat. Our principal findings were that: (1) considerable heterogeneity in DOC response appears to exist between different soils that is not apparent from the more consistent observed trends for streamwaters, and (2) freely-draining organo-mineral Podzol showed increasing DOC concentrations, countering the current scientific focus on soil C destabilization in peats. We discuss how the key solubility controls on DOC associated with coupled physico-chemical factors of ionic strength, acid deposition recovery, soil hydrology and temperature cannot readily be separated. Yet, despite evidence that all sites are recovering from acidification the soil-specific responses to environmental change have caused divergence in soil DOC concentration trends. The study shows that the properties of soils govern their specific response to an approximately common set of broad environmental drivers. Key soil properties are indicated to be drainage, sulphate and DOC sorption capacity. Soil properties need representation in process-models to understand and predict the role of soils in catchment to global C budgets. Catchment hydrological (i.e. transport) controls may, at present, be governing the more ubiquitous rises in river DOC concentration trends, but soil (i.e. source) controls provide the key to prediction of future C loss to waters and the atmosphere.


2010 ◽  
Vol 113-116 ◽  
pp. 1332-1335 ◽  
Author(s):  
Ning Liu ◽  
Hong Bo He ◽  
Hong Tu Xie ◽  
Zhen Bai ◽  
Xu Dong Zhang

Fertilization is one of the essential managements to maintain and increase soil organic carbon (SOC) level in agroecosystems. It has been realized that fertilizer applications influenced the turnover of labile and refractory organic carbon pools in arable soil markedly. However, the dynamic of relatively refractory lignin in response to fertilization is still kept unclear. Therefore, the impact of long-term organic fertilization on the content and degradation degree of lignin in Mollisol was investigated. Lignin monomers were released by alkaline CuO oxidation method and quantified by gas chromatography (GC). At the time scale of decades, lignin was clearly accumulated in soil and the relative accumulation of lignin in SOC was evident after long-term organic fertilizer application. Compared with the unfertilized soil, lower acid to aldehyde ratios of vanillyl and syringyl units induced by organic fertilization suggested a lower degradation degree of lignin incorporated into soil to some extent. It could be concluded that long-term organic fertilization was an effective fertilizer practice for lignin accumulation in soil and SOC sequestration in Mollisol in northeast of China.


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