Testing Some Pedo-Transfer Functions (PTFs) in Apulia Region. Evaluation on the Basis of Soil Particle Size Distribution and Organic Matter Content for Estimating Field Capacity and Wilting Point

Abstract

The knowledge of soil water retention vs. soil water matric potential is applied to study irrigation and drainage scheduling, soil water storage capacity (plant available water), solute movement, plant growth and water stress. To measure field capacity and wilting point is expensive, laborious and is time consuming, so, frequently, matemathic models, called pedo-transfer functions (PTFs) are utilized to estimate field capacity and wilting point through physical-chemical soil characteristics. Six PTFs have been evaluated (Gupta and Larson, 1979;Rawls et al., 1982;De Jong et al., 1983;Rawls and Brakensiek, 1985;Saxton et al., 1986;Vereecken et al., 1989) by comparing measured soil moisture values with estimated ones at soil water matric potential of -33 and -1500 kPa. Soil samples were collected (361)

Development and Evaluation of Pedotransfer Functions to Estimate Soil Moisture Content at Field Capacity and Permanent Wilting Point for South African Soils

“…Within this context, biophysical models such as Aquacrop [2], AP-SIM [3], CropSyst [4], DSSAT [5], SPAW [6] and SWAT [7] are often applied to estimate crop yields, solute movements and irrigation water requirements. These biophysical models are also used for the assessment of water balance components such as drainage, runoff and evapotranspiration to support efficient management and allocation of resources in different countries of the world [1,[8][9][10][11][12]. These models are therefore becoming more important to solve numerous water-related challenges posed by climate change in the fields of agriculture, ecology, environment, hydrology and soil sciences [13,14].…”

“…The application of biophysical models requires knowledge of soil hydraulic properties at a high spatial resolution, specifically the soil moisture content at field capacity (FC, at −33 kPa) and permanent wilting point (PWP, at −1500 kPa) for each soil horizon [1,8,9,13,[15][16][17]. Water retention at FC and PWP are the two critical soil hydraulic properties that are required for the computation of plant-available water in the soil profile [12,13,17].…”

“…Generally, PTFs are developed using correlations between these readily available or easily measurable soil properties and measurements of water retention at different pressure heads. Many PTFs with different data input requirements have been developed and validated for the estimation of soil hydraulic properties [9,20,25,26,[28][29][30][31][32][33][34][35][36][37][38]. Some of these PTFs have been incorporated into biophysical models such as Aquacrop, CropSyst, DSSAT, SPAW and SWAT amongst others as the ready-to-use PTFs to fill in missing information of soil moisture content at FC and PWP [12,13,17].…”

“…Research on the evaluation of the existing PTFs has shown that they are often only reliable and applicable for regions with similar characteristics to those of their origins [9,12,13,[39][40][41][42]. The limited transferability of PTFs across different regions is attributed to the significant variations in geological, climatic and soil bio-physico-chemical properties across regions [14,18,43].…”

Using Classification Trees to Evaluate the Performance of Pedotransfer Functions

“…These researchers related PTF residuals with the median soil particle diameter and soil organic C. In general, most PTFs show some pattern of the residuals with both the soil particle median diameter and soil organic C content. Buccigrossi et al (2010) evaluated six previously published PTFs to estimate soil water retention at −33 and −1500 kPa. They correlated the input parameters with PTF residuals to identify those attributes that most affected PTF performance.…”