Evaluation of phosphorus retention equations for Manitoba soils

2008 ◽  
Vol 88 (3) ◽  
pp. 327-335 ◽  
Author(s):  
D V Ige ◽  
O O Akinremi ◽  
D N Flaten

One of the key factors in phosphorus management is the P retention capacity (PRC) of the soil. In our previous study, we formulated several equations for estimating the phosphorus retention capacity of Manitoba soils. The objectives of the current study were to evaluate these equations using independent soil samples and to evaluate the influence of manure application on the predictive ability of these equations. Forty representative surface soil samples (20 soils with history of manure application and 20 without manure application history) were collected from across Manitoba. The P retention index (P150) and Langmuir adsorption maximum (Smax) were determined in the laboratory. The measured P retention capacities were then compared with those estimated using the formulated equations. Surprisingly, P150, which was obtained from a single measurement, was more robust than Smax that was obtained from at least 17 measurements as the equations provided a better estimate of P150 than Smax. Equations that were based on soil particle sizes (either percent clay or percent sand) provided poor estimates of soil PRC for the whole soil collection. However, when the soils were grouped on a pH basis, soil particle size worked better for soils with pH <7 than for soils with pH ≥7. The equations also worked better for soils with pH similar to those of the soils that were used to formulate the P retention equations. The accuracy of the predicted P sorption capacity improved with the manured soils due to the direct influence of manure application on soil properties that influence P retention such as Ca and Mg. Overall, the combination of CaM3, MgM3 and AlOx provided the best estimate of the PRC of Manitoba soils. Key words: Soil phosphorus, calcareous soils, phosphorus sorption, phosphorus retention, phosphorus retention capacity, estimating phosphorus retention capacity

2005 ◽  
Vol 85 (3) ◽  
pp. 417-426 ◽  
Author(s):  
D V Ige ◽  
O O Akinremi ◽  
D N Flaten ◽  
B. Ajiboye ◽  
M A Kashem

The establishment of the P retention capacity of soil in Manitoba is essential for effective management of P in the region. However, the methods for determining the P retention capacity for neutral to calcareous soils in the Eastern Prairies are not well developed. The objectives of this study were to determine the P retention capacity of Manitoba soils and to generate equations that relate these capacities to other soil properties. One hundred and fifteen archived surface soils were selected and their physico-chemical properties were measured. These soils were used to generate a single-point P adsorption index by equilibrating 2 g of soil in 20 mL of 0.01 M KCl solution containing either 150 (P150) or 400 (P400) mg P L-1. A subset of 26 of these soils was used for multipoint isotherms with P concentrations in the range of 0–1000 mg P L-1. The data obtained were fitted to the Langmuir isotherm and the adsorption indices were correlated with the various soil properties that were then used to developed predictive equations of the P retention capacity of the soil. The values of the adsorption index, P150, obtained from the single point adsorption study using 150 mg P L-1, ranged between 88 and 891 mg P kg-1, while that of P400 ranged between 100 and 1250 mg P kg-1. A better correlation was obtained between P150 and soil properties compared with P400. For the 26 soil subset, the adsorption indices, Smax1 to Smax 6, obtained from the Langmuir isotherm, ranged from 300 to 1330 mg kg-1. A good correlation was obtained between the single point index and the multipoint isotherm (r = 0.93). Hence, Smax for the 115 soils was estimated from the relationship between P150 and Smax 3 of the 26 soils. The best relationships between the adsorption parameters, P150 and Smax, and the soil properties were obtained with the sum of Mehlich-3 extractable Ca and Mg (R2= 0.66) and the sum of exchangeable Ca and Mg (R2= 0.64). Mehlich-3-Ca and -Mg each explained 56% of the variation, while clay content explained 40% of the variation in the P retention capacity of these soils. Unlike the widely reported influence of Al and Fe in acid soils, our study showed that the retention of P in Manitoba soils was influenced more by Ca and Mg and soil texture. Key words: Phosphorus, phosphorus retention capacity, phosphorus adsorption capacity, phosphorus sorption, single-point index


2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Lawrence OLU EKEBAFE1 ◽  
David E. Ogbeifun1 ◽  
Felix E. Okieimen1 ◽  
Osazoduwa M. Ekebafe2

AbstractThe effects of the application of the graft copolymers (Hydrolyzed starch-g-polyacrylonitrile (HSPAN) and Hydrolyzed starch-g-polyacrylic acid (HSPAA)) on the nitrogen (N) and phosphorus (P) retention capacity of soil was evaluated in this study. Soil nutrient (N and P) retention capacity tests was carried out at three graft copolymers application rates (3.0, 6.0, and 9.0g/kg soil) against a blank soil sample to which graft copolymers was not applied. Diammonium phosphate (DAP) at 0, 100, and 200mg in aqueous solution/kg soil were applied in triplicates. The soil samples were mixed thoroughly and allowed to air-dry. The residual N and P contents of the soil samples were determined and reported as the amounts of nutrients retained as a function of the graft copolymer and DAP application rates. The result of this study has clearly demonstrated the potential of the graft copolymers to alleviate problems related to nutrient loss from the soil media. Leaching of nutrients (N and P) in soil has been found to be reduced to minimal (0.46%N, and 1.13%P) with the application of hydrolyzed graft copolymer and the nutrients are thus available to plant for growth by suction pressure difference.


2010 ◽  
Vol 61 (5) ◽  
pp. 507 ◽  
Author(s):  
Wenzhi Liu ◽  
Guihua Liu ◽  
Siyue Li ◽  
Quanfa Zhang

Water-level regulation results in alternating exposure and inundation of soils in reservoir fluctuation zones, which may significantly influence the phosphorus sorption and desorption processes in the soil. The present study investigated the phosphorus sorption and desorption properties of wetland soils in China's Danjiangkou Reservoir using a batch equilibrium technique. Results showed that the maximum phosphorus sorption ranged from 435 to 1429 mg kg−1, with an average of 771 mg kg−1. The maximum phosphorus sorption was found to be significantly related to amorphous iron (r = 0.883, P < 0.01) and pH (r = −0.333, P < 0.05), and the binding constant k was strongly correlated with the amorphous iron (r = 0.475, P < 0.01) and organic matter (r = −0.455, P < 0.01). The phosphorus desorption percentage varied from 8 to 44%, with a mean value of 24%. The present study implies that short-term inundation in reservoir fluctuation zones would result in soil phosphorus desorption to some extent, in spite of the considerable absorption ability in the exposure period. These results are useful for assessing the phosphorus retention capacity of wetland soils and optimising management strategies for water conservation in reservoir regions.


1969 ◽  
Vol 95 (1-2) ◽  
pp. 1-14
Author(s):  
José A. Dumas ◽  
Joaquín A. Chong ◽  
Magaly Cintrón ◽  
Luis Reinaldo Santiago

Five commercial greenhouses in the central mountainous zone of Puerto Rico were studied in order to identify changes in soil factors that affect P retention. Soils were collected both within and outside drainages at a 0- to 15-cm depth. Soil physicochemical properties varied in samples taken both within and outside drainages. The high Fe and Al content in the soils of this study suggested a high phosphorus retention capacity. Laboratory estimates of P retention parameters indicated differences in P sorption capacity among soils. Phosphorus retention parameters were highly correlated with citrate dithionite extractable Fe. The equilibrium P concentration was also correlated with citrate dithionate Al in soils outside drainages. This finding was due to the higher soil organic matter counterbalancing the soil P retention capability of Al, all of which indicates the importance of clearing all drainages of organic residues in order to avoid excessive movement of P outside the greenhouse premises.


2003 ◽  
Vol 67 (2) ◽  
pp. 645 ◽  
Author(s):  
T. S. Griffin ◽  
C. W. Honeycutt ◽  
Z. He

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 373
Author(s):  
Jonathan Suazo-Hernández ◽  
Erwin Klumpp ◽  
Nicolás Arancibia-Miranda ◽  
Patricia Poblete-Grant ◽  
Alejandra Jara ◽  
...  

Engineered nanoparticles (ENPs) present in consumer products are being released into the agricultural systems. There is little information about the direct effect of ENPs on phosphorus (P) availability, which is an essential nutrient for crop growthnaturally occurring in agricultural soils. The present study examined the effect of 1, 3, and 5% doses of Cu0 or Ag0 ENPs stabilized with L-ascorbic acid (suspension pH 2–3) on P ad- and desorption in an agricultural Andisol with total organic matter (T-OM) and with partial removal of organic matter (R-OM) by performing batch experiments. Our results showed that the adsorption kinetics data of H2PO4− on T-OM and R-OM soil samples with and without ENPs were adequately described by the pseudo-second-order (PSO) and Elovich models. The adsorption isotherm data of H2PO4− from T-OM and R-OM soil samples following ENPs addition were better fitted by the Langmuir model than the Freundlich model. When the Cu0 or Ag0 ENPs doses were increased, the pH value decreased and H2PO4− adsorption increased on T-OM and R-OM. The H2PO4− desorption (%) was lower with Cu0 ENPs than Ag0 ENPs. Overall, the incorporation of ENPs into Andisols generated an increase in P retention, which may affect agricultural crop production.


2021 ◽  
Vol 13 (8) ◽  
pp. 1519
Author(s):  
Kensuke Kawamura ◽  
Tomohiro Nishigaki ◽  
Andry Andriamananjara ◽  
Hobimiarantsoa Rakotonindrina ◽  
Yasuhiro Tsujimoto ◽  
...  

As a proximal soil sensing technique, laboratory visible and near-infrared (Vis-NIR) spectroscopy is a promising tool for the quantitative estimation of soil properties. However, there remain challenges for predicting soil phosphorus (P) content and availability, which requires a reliable model applicable for different land-use systems to upscale. Recently, a one-dimensional convolutional neural network (1D-CNN) corresponding to the spectral information of soil was developed to considerably improve the accuracy of soil property predictions. The present study investigated the predictive ability of a 1D-CNN model to estimate soil available P (oxalate-extractable P; Pox) content in soils by comparing it with partial least squares (PLS) and random forest (RF) regressions using soil samples (n = 318) collected from natural (forest and non-forest) and cultivated (upland and flooded rice fields) systems in Madagascar. Overall, the 1D-CNN model showed the best predictive accuracy (R2 = 0.878) with a highly accurate prediction ability (ratio of performance to the interquartile range = 2.492). Compared to the PLS model, the RF and 1D-CNN models indicated 4.37% and 23.77% relative improvement in root mean squared error values, respectively. Based on a sensitivity analysis, the important wavebands for predicting soil Pox were associated with iron (Fe) oxide, organic matter (OM), and water absorption, which were previously known wavelength regions for estimating P in soil. These results suggest that 1D-CNN corresponding spectral signatures can be expected to significantly improve the predictive ability for estimating soil available P (Pox) from Vis-NIR spectral data. Rapid and accurate estimation of available P content in soils using our results can be expected to contribute to effective fertilizer management in agriculture and the sustainable management of ecosystems. However, the 1D-CNN model will require a large dataset to extend its applicability to other regions of Madagascar. Thus, further updates should be tested in future studies using larger datasets from a wide range of ecosystems in the tropics.


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