Effect of long-term irrigation patterns on phosphorus forms and distribution in the brown soil zone

Abstract

Continuous application of P fertilizers under different irrigation patterns can change soil phosphorus (P) chemical behavior and increase soil P levels that are of environmental concern. To assess the effect of long-term different irrigation patterns on soil P fractions and availability, this study examined sequential changes in soil organic P and inorganic P from furrow irrigation (FI), surface drip irrigation (SUR), and subsurface drip irrigation (SDI) in the brown soil zone (0–60 cm) during 1998 to 2011. Analyses of soil P behavior showed that the levels of total P are frequently high on top soil layers. The total P (TP) contents of the entire soil profiles under three irrigation treatments were 830.2–3180.1 mg/kg. The contents of available P (AP) were 72.6–319.3 mg P/kg soil through soil profiles. The greatest TP and AP contents were obtained within the upper soil layers in FI. Results of Hedley’s P fractionation indicate that HCl-P is a dominant form and the proportion to TP ranges from 29% to 43% in all three methods. The contents of various fractions of P were positively correlated with the levels of total carbon (TC), total inorganic carbon (TIC), and calcium (Ca), whereas the P fractions had negative correlation with pH in all soil samples. Regression models proved that NaHCO3-Po was an important factor in determining the amount of AP in FI. H2O-Po, NaHCO3-Po, and NaOH-Pi were related to available P values in SUR. NaHCO3-Po and NaOH-Po played important roles in SDI. The tomato yield under SUR was higher than SDI and FI. The difference of P availability was also controlled by the physicochemical soil properties under different irrigation schedule. SUR was a reasonable irrigation pattern to improve the utilization efficiency of water and fertilizer.

Evaluation of irrigation suitability potential of brewery effluent post treated in a pilot horizontal subsurface flow constructed wetland system: implications for sustainable urban agriculture

“…The concentrations of phosphorus in the effluent are usually about 10 mgL -1 , which is beneficial to plant development ( Hanjra et al, 2012 ). In contrast, its continuous application for irrigation can change soil phosphorous behavior and become another environmental concern from agricultural runoff ( Liu et al, 2017 ). Additionally, phosphorus can cause eutrophication or toxicity in other habitats ( Jaramillo and Restrepo, 2017 ).…”

Geospatial Distribution of Some Phosphorus and Potassium Forms as Influenced by Period of Irrigation in the Kano River and the Hadejia Valley Irrigation Schemes, Nigeria.

“…Frequent application of fertilizer P during the year-round production and the availability of cations to bind it as insoluble fraction may have facilitated the higher build up of TP in the areas with longer histories of irrigation in both the schemes. Liu et al (2017), found out that among all forms of irrigation they evaluated, furrow irrigation led to the greatest accumulation of TP at topsoil layer.…”

“…From the figure, however, it could be discerned that the predominance of higher concentrations is at non-irrigated area and at areas with fewer years of irrigation. Addition of large volume of water to the soil as is the practice in both the schemes may favour accumulation TP as postulated by Liu et al (2017). According to them long term irrigation may harden the soil and restrict the mobilization and transport of P into soil profiles.…”

“…Chepkwony et al (2001), indeed showed an increased P-availability for plants after soil drying and re-wetting. Liu et al (2017), have also indicated that high water content under frequent irrigation leads to greater P mobility and loss through runoff. Frequent application of fertilizer P during the year-round production and the availability of cations to bind it as insoluble fraction may have facilitated the higher build up of TP in the areas with longer histories of irrigation in both the schemes.…”

A Review of the Category, Mechanism, and Controlling Methods of Chemical Clogging in Drip Irrigation System

“…Drip irrigation is an effective technology for increasing P availability [18]. However, phosphorus fertilizer contains HPO 4 2− that would react with Ca 2+ and Mg 2+ , which can form the insoluble CaHPO 4 or MgHPO 4 precipitates and lead to drip irrigation clogging [53,54].…”