Modeling of phosphorus dynamics in contrasting agroecosystems using long-term field experiments

Abstract

Morel, C., Ziadi, N., Messiga, A., Bélanger, G., Denoroy, P., Jeangros, B., Jouany, C., Fardeau, J. C., Mollier, A., Parent, L. E., Proix, N., Rabeharisoa, L. and Sinaj, S. 2014. Modeling of phosphorus dynamics in contrasting agroecosystems using long-term field experiments. Can. J. Soil Sci. 94: 377–387. Long-term field experiments on phosphorus (P) fertilization were originally designed to study crop needs in different soil types by analyzing the effects of several rates of P fertilization on yields, their P concentrations and dynamics of plant-available soil P. The objective of this study was to test a computer-based model to simulate the P dynamics at the field scale using plant database and analyzing for plant-available P by a hierarchical process-based approach. It predicts both the concentration (CP) of phosphate ions (Pi) in soil solution and the associated Pi amounts that in time equilibrate with Pi in solution. Five experiments, representative of contrasting soil types, land-use, and climates were selected. Our model equilibrates the change in plant-available P in the upper soil layer to the P budget between annual P inputs and outputs. Rates of P fertilization affected simulations following the same expected pattern across sites. Field-observed and simulated values are in good agreements in all sites. The field-observed variations of CP per unit of P budget ranged from 0.007 to 2.49 (µg P L−1) (kg P ha−1)−1. The predictions are of the same order of magnitude. Predictions were compared with empirical long-term data and mismatches were discussed. This investigation highlights the scientific interest of long-term field P experiments to test and validate models describing P dynamics at the scale of the agricultural fields under different agricultural management practices.

Phosphorus in agricultural soils: drivers of its distribution at the global scale

“…Following the approach commonly used at the global scale (Wang et al, 2010;Goll et al, 2012), we did not represent explicitly a pool of orthophosphate ions (H 2 PO À 4 and HPO 2À 4 ) in the soil solution, while it is the main form of P taken up by the plant roots. Morel et al (2014)) because soluble P is not commonly measured by the Hedley method. Parameters involved in equations describing P in soil solution should be optimized against measurements complementary to those made by the Hedley method (e.g.…”

“…32 P labelling and isotopic dilution approaches; e.g. Morel et al (2014)) because soluble P is not commonly measured by the Hedley method. While this not straightforward, we think that such representation would be more process-based.…”

Modeling the forest phosphorus nutrition in a southwestern Swedish forest site

“…The sorption/desorption process of P refers to all the inorganic P ion exchange processes (except weathering) between the soil solution and soil matrix. The desorption rate (P ions moving from the soil matrix to soil solution, r des , mg P m -3 d -1 ) is modeled as the change of total sorbed Pi in the soil matrix between two time steps (Stroia et al 2007;Messiga et al 2012;Morel et al 2014). It is then constrained by the sorption capacity of the soil layer within the time step (Pr 1d , mg P m -3 soil):…”

“…ForSAFE also offers pedotransfer functions (Eq. B4.5 -B4.7) to estimate the parameters based on the physical-chemical properties of the soils from selected studies (Stroia et al 2007;Achat et al 2010;Morel et al 2014;Stroia et al 2011;Messiga et al 2012).…”

Phosphorus Sorption Kinetics in Reclaimed Lignite Mine Soils under Different Age Stands ofRobinia pseudoacaciaL. in Northeast Germany

“…Therefore, it is important to understand the kinetics of P sorption in this "initial soil" in order to describe the P bioavailability and P mobility. Several studies have been carried out on soil P sorption and desorption kinetics in agroecosystems [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43], and various techniques have been employed to investigate P (de)sorption from soils [29,30,32,44,45]. However, few studies [22,46] concentrated on P sorption in mining soils.…”