scholarly journals Phosphorus leaching in sandy soils .II. Laboratory studies of the long-term effects of the phosphorus source

Soil Research ◽  
1988 ◽  
Vol 26 (1) ◽  
pp. 191 ◽  
Author(s):  
DM Weaver ◽  
GSP Ritchie ◽  
GC Anderson
Keyword(s):  
Sandy Soils ◽  
Summer Rainfall ◽  
Weather Conditions ◽  
Application Rate ◽  
Long Term Effects ◽  
Sequential Fractionation ◽  
Inorganic P ◽  
Coastal Superphosphate ◽  
Extractable P

Long-term phosphorus (P) losses and gains in sandy soils continuously fertilized with either ordinary superphosphate or coastal superphosphate (a granulated mixture of superphosphate, rock phosphate and elemental sulfur) or previously fertilized with superphosphate were investigated under leaching conditions in columns in the laboratory. The soils were subjected to 10 consecutive cycles designed to simulate the mediterranean weather conditions in the Harvey region of the Coastal Plain of Western Australia. Each cycle consisted of a wet phase during which the equivalent of 850 mm of rainfall was leached through the soil and a drier phase during which the soil was incubated in the presence of moisture equivalent to summer rainfall (150 mm). Dissolved inorganic P in the leachate was used as a measure of P loss. A sequential fractionation procedure (a resin extraction followed by 0.5 M sodium bicarbonate, 0.1 M sodium hydroxide and 0.1 M sulfuric acid extractions) and total inorganic and organic P were used to measure changes in P levels in the soils. Phosphorus losses from the previously fertilized soils decreased logarithmically with increasing number of cycles. Total inorganic P and resin-extractable P were able to explain >94% of the variation in P losses. Addition of either fertilizer increased the amount of P leached from the soil and 10-40% more P was leached by adding superphosphate rather than coastal superphosphate. The percentage of the cumulative P lost by leaching decreased with increasing application rate of both fertilizers when expressed as a percentage of the cumulative water plus citrate-soluble P added. Addition of either fertilizer increased the amount of acid-extractable P, but coastal superphosphate had a much greater effect than superphosphate. Leaching losses of P were influenced by fertilizer solubility in the short term (< 1 year). In the long term, however, the water plus citrate-insoluble P in the fertilizers also contributed to P losses by leaching.

scholarly journals Phosphorus leaching in sandy soils .I. Short-term effects of fertilizer applications and environmental conditions

Soil Research ◽  
1988 ◽  
Vol 26 (1) ◽  
pp. 177 ◽  
Author(s):  
DM Weaver ◽  
GSP Ritchie ◽  
GC Anderson ◽  
DM Deeley
Keyword(s):  
Soil Solution ◽  
Environmental Conditions ◽  
Management Practices ◽  
Sandy Soils ◽  
Summer Rainfall ◽  
Application Rate ◽  
Short Term ◽  
Coastal Superphosphate ◽  
Soil Solutions ◽  
Soil Solution P

The consequences of previous as well as current environmental conditions and management practices on the potential for phosphorus (P) to be lost by drainage from sandy soils in the short term (< 1 year) were studied in the laboratory and the field. The potential for P losses by drainage was estimated by measuring soil solution P levels and rapidly released P. Rapidly released P was measured by determining the concentration of dissolved inorganic P contained in filtered (<0.45 pm) soil solutions after incubating soil at saturation for 15 min at ambient temperature. In the laboratory, sandy soils were incubated with ordinary superphosphate, coastal superphosphate (a granulated mixture of equal parts of superphospate, rock phosphate and elemental sulfur) or lime-superphosphate (a lime-reverted superphosphate with 18% kiln dust) and sequentially desorbed with deionized water. The effects of the extent of leaching, fertilizer type, application rate and the time of contact with the soil on soil solution P levels were investigated. The influence of annual pasture death and summer rainfall on rapidly released P in soils that had been pre-treated by leaching were also investigated. Phosphorus concentrations decreased logarithmically in the successive supernatants of the sequentially desorbed soils. More P was desorbed from soils incubated with superphosphate and lime-superphosphate than soil incubated with coastal superphosphate. At each level of pre-leaching, the P concentrations in the soil solution increased with increasing time. The level, to which the P concentration in the soil solution increased at each time, decreased with increased extent of pre-leaching. The addition of P fertilizers increased the concentration of P in the soil solution. The concentrations increased with increasing application rate and were much higher for superphosphate than for coastal superphosphate; however, there was little effect of contact time on soil solution P levels. Rapidly released P levels after leaching increased during a period of no further leaching. Additional moisture or plant material during this period of no further leaching increased the rate and extent to which rapidly released P increased. Monitoring of rapidly released P in the 0-2, 2-5, 5-10 and 10-20 cm layers of field plots, with and without applications of superphosphate, showed that sampling depth, water flow path, fertilizer management, rainfall pattern and background P levels would affect the estimate of short-term P losses. Rapidly released P in the 0-2 cm layer varied markedly with time and was higher (P < 0.05) than that in lower soil layers. Rapidly released P increased after the winter and spring rains diminished and then decreased after the rains commenced again at the end of the summer. A possible annual cycle of P in sandy soils in a mediterranean climate is postulated by considering the laboratory and field data in combination.

Relationship between phosphorus fractions and properties of highly calcareous soils

Soil Research ◽  
2007 ◽  
Vol 45 (4) ◽  
pp. 255 ◽  
Author(s):  
Ebrahim Adhami ◽  
Hamid Reza Memarian ◽  
Farzad Rassaei ◽  
Ehsan Mahdavi ◽  
Manouchehr Maftoun ◽  
...  
Keyword(s):  
Calcareous Soils ◽  
Hydroxylamine Hydrochloride ◽  
Inorganic Phosphorus ◽  
Influential Factor ◽  
Sequential Fractionation ◽  
Inorganic P ◽  
Soil P ◽  
Fractionation Procedure ◽  
Extractable P ◽  
P Content

Inorganic phosphorus (P) sequential fractionation schemes are applicable techniques to interpret soil P status. The present study was initiated to determine the origin of various P fractions in highly calcareous soils. Inorganic P forms were determined by a sequential fractionation procedure extracting with NaOH (NaOH-P), Na citrate-bicarbonate (CB-P), Na citrate 2 times (C1-P and C2-P), Na citrate-ascorbate (CAs-P), Na citrate-bicarbonate-dithionite (CBD-P), Na acetate (NaAc-P), and HCl (HCl-P). Results showed that NaOH-P was negatively correlated with active iron oxides. CB-P was positively correlated with silt content and negatively related to citrate-bicarbonate-dithionite extractable Fe (Fed). This result illustrates the weathering effect on Ca-P, with Ca-P content declining as a consequence of weathering. A negative correlation was observed between C1-P and citrate ascorbate extractable Fe (FeCAs). Second citrate extractable P (C2-P) was negatively related to calcium carbonate equivalent and positively related to hydroxylamine-hydrochloride and neutral ammonium acetate-hydroquinone extractable Mn (Mnh and Mnq). Fine silt (Fsilt) was the most influential factor affecting CAs-P. It seemed citrate-dithionite-bicarbonate extractable Al (Ald), Mnh, and Mnq have been sinks for CBD-P, while free iron oxide compounds (Feo, Fec, and FeCAs) were a major contributing factor for the formation of NaAc-P. Stable P compounds (HCl-P) of highly calcareous soils originated from coarse silt (Csilt) and hydroxylamine-hydrochloride extractable Mn (Mnh).

scholarly journals Biochar remediation of soil: linking biochar production with function in heavy metal contaminated soils  

2021 ◽  
Author(s):  
A Taraqqi-A-Kamal ◽  
Christopher J. Atkinson ◽  
Aimal Khan ◽  
Kaikai Zhang ◽  
Peng Sun ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Soil Remediation ◽  
Contaminated Soils ◽  
Environmental Issues ◽  
Application Rate ◽  
Long Term Effects ◽  
Soil Function ◽  
Soil Functionality ◽  
Insight Into

The focus of this study is on the soil physicochemical, biological, and microbiological processes altered by biochar application to heavy metal (HM) contaminated soils. The aim is to highlight agronomical and environmental issues by which the restorative capacity of biochar might be developed. Literature shows biochar can induce soil remediation, however, it is unclear how soil processes are linked mechanistically to biochar production and if these processes can be manipulated to enhance soil remediation. The literature often fails to contribute to an improved understanding of the mechanisms by which biochar alters soil function. It is clear that factors such as biochar feedstock, pyrolysis conditions, application rate, and soil type are determinants in biochar soil functionality. These factors are developed to enhance our insight into production routes and the benefits of biochar in HM soil remediation. Despite a large number of studies of biochar in soils, there is little understanding of long-term effects, this is particularly true with respect to the use and need for reapplication in soil remediation.  

scholarly journals Effects of Climate Change on Epidemics of Powdery Mildew in Winter Wheat in China

Plant Disease ◽  
2017 ◽  
Vol 101 (10) ◽  
pp. 1753-1760 ◽  
Author(s):  
Xiuli Tang ◽  
Xueren Cao ◽  
Xiangming Xu ◽  
Yuying Jiang ◽  
Yong Luo ◽  
...  
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Powdery Mildew ◽  
Winter Wheat ◽  
Weather Conditions ◽  
Early Spring ◽  
Long Term Effects ◽  
Temperature Changes ◽  
Disease Epidemics

Powdery mildew is a highly destructive winter wheat pathogen in China. Since the causative agent is sensitive to changing weather conditions, we analyzed climatic records from regions with previous wheat powdery mildew epidemics (1970 to 2012) and investigated the long-term effects of climate change on the percent acreage (PA) of the disease. Then, using PA and the pathogen’s temperature requirements, we constructed a multiregression model to predict changes in epidemics during the 2020s, 2050s, and 2080s under representative concentration pathways RCP2.6, RCP4.5, and RCP8.5. Mean monthly air temperature increased from 1970 to 2012, whereas hours of sunshine and relative humidity decreased (P < 0.001). Year-to-year temperature changes were negatively associated with those of PA during oversummering and late spring periods of disease epidemics, whereas positive relationships were noted for other periods, and year-to-year changes in relative humidity were correlated with PA changes in the early spring period of disease epidemics (P < 0.001). Our models also predicted that PA would increase less under RCP2.6 (14.43%) than under RCP4.5 (14.51%) by the 2020s but would be higher by the 2050s and 2080s and would increase least under RCP8.5 (14.37% by the 2020s). Powdery mildew will, thus, pose an even greater threat to China’s winter wheat production in the future.

scholarly journals Long-Term Biosolids Applications to Overgrazed Rangelands Improve Soil Health

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1339
Author(s):  
Cassidy M. Buchanan ◽  
James A. Ippolito
Keyword(s):  
Soil Health ◽  
Organic Amendments ◽  
Application Rate ◽  
Land Application ◽  
Health Index ◽  
Long Term Effects ◽  
Health Indices ◽  
Application Rates ◽  
Biosolids Application

Overgrazed rangelands can lead to soil degradation, yet long-term land application of organic amendments (i.e., biosolids) may play a pivotal role in improving degraded rangelands in terms of soil health. However, the long-term effects on soil health properties in response to single or repeated, low to excessive biosolids applications, on semi-arid, overgrazed grasslands have not been quantified. Using the Soil Management Assessment Framework (SMAF), soil physical, biological, chemical, nutrient, and overall soil health indices between biosolids applications (0, 2.5, 5, 10, 21, or 30 Mg ha−1) and application time (single: 1991, repeated: 2002) were determined. Results showed no significant changes in soil physical and nutrient health indices. However, the chemical soil health index was greater when biosolids were applied at rates <30 Mg ha−1 and within the single compared to repeated applications. The biological soil health index was positively affected by increasing biosolids application rates, was overall greater in the repeated as compared to the single application, and was maximized at 30 Mg ha−1. The overall soil health index was maximized at rates <30 Mg ha−1. When all indices were combined, and considering past plant community findings at this site, overall soil health appeared optimized at a biosolids application rate of ~10 Mg ha−1. The use of soil health tools can help determine a targeted organic amendment application rate to overgrazed rangelands so the material provides maximum benefits to soils, plants, animals, and the environment.

Long-term effects of mulch, fertilization and tillage on cassava grown in sandy soils in northern Colombia

1998 ◽  
Vol 57 (1) ◽  
pp. 45-56 ◽  
Author(s):  
L.F Cadavid ◽  
M.A El-Sharkawy ◽  
A Acosta ◽  
T Sánchez
Keyword(s):  
Sandy Soils ◽  
Long Term Effects

Mid-long term effects of no tillage and Ca-amendment on degraded acid soils under contrasting weather conditions

2018 ◽  
Vol 183 ◽  
pp. 83-92 ◽  
Author(s):  
Chiquinquirá Hontoria ◽  
Clara Gómez-Paccard ◽  
Eduardo Vázquez ◽  
Ignacio Mariscal-Sancho ◽  
Rafaela Ordónez-Fernández ◽  
...  
Keyword(s):  
Acid Soils ◽  
Weather Conditions ◽  
No Tillage ◽  
Long Term Effects

Long-term changes in Mehlich-3 extractable P and K in a sandy clay loam soil under continuous corn (Zea mays L.)

1995 ◽  
Vol 75 (3) ◽  
pp. 361-367 ◽  
Author(s):  
T. Q. Zhang ◽  
A. F. MacKenzie ◽  
B. C. Liang
Keyword(s):  
Zea Mays L ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Inorganic P ◽  
Sandy Clay Loam ◽  
Continuous Corn ◽  
Extractable P ◽  
Loam Soil ◽  
P Removal

Rates of change of soil nutrient levels during crop production can be used to evaluate the long-term economic value and sustainability of fertilizer practices. Objectives were to quantify changes in Mehlich-3 extractable P and K due to additions of inorganic and manure P and K in corn (Zea mays L.) production. Surface (0–20 cm) and subsoil (20–40 cm) samples were collected after harvest from 1984 to 1993 on a Chicot sandy clay loam soil (Grey Brown Luvisol) fertilized with two rates of inorganic P and K and with dairy manure. Manure P at 60 kg P ha−1 plus inorganic fertilizer P at 132 kg ha−1 yr−1 increased extractable P 1.0 kg for every 4.2 kg added P if only topsoil was considered, for every 3.2 kg added P if corn grain P removal was deducted, and for every 2.8 kg added P if subsoil increases were included but corn P uptake excluded, and 2.1 kg added P with subsoil P included and corn P removal deducted. Without manure, 132 kg P ha−1 yr−1 increased Mehlich-3 extractable P by 1.0 kg for every 8.1 kg P added, or 5.3 kg P added if corn P removal was deducted from added fertilizer P. At the low rate of 44 kg P ha−1 with manure P, Mehlich-3 levels increased by 1.0 kg P for every 5.2 kg added fertilizer P. Extractable P remained constant when inorganic fertilizer P was added without manure, probably because crop removals equalled fertilizer additions. Mehlich-3 extractable K increased in both top soil and subsoil at rates of 141 and 332 kg ha−1 yr−1 inorganic K except for the 141 K rate in the final four years when no manure was applied. When both soil depths were included and summed over all years, values of added K to increase extractable K by 1.0 kg ranged from 4.2 to 5.5 kg, regardless of source or rate of added K. To increase soil test P, manure combined with high P rates was more effective per unit added P than low P rates or added P without manure. Either form or rate of added K was equivalent in increasing extractable K. Key words: Long-term fertilization, continuous corn, organic manure P, inorganic P, Mehlich-3 extractable P, Mehlich-3 extractable K

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