Phosphorus fertilizer form and application frequency affect soil P availability, chickpea yield, and P use efficiency under drip fertigation

Abstract

Background Phosphorus (P) fertilizer properties and nutrient management strategies substantially affect soil P availability as well as uptake and consequently crop yield. Aims The present study aims to study the potential use of inorganic soluble polyphosphates (Poly‐P) as slow‐release fertilizer under drip fertigation. Methods A pot experiment was conducted using an alkaline soil. Two Poly‐P fertilizers, differing in their polymerization rate (Poly‐53 with 53% and Poly‐100 with 100% Poly‐P of the total‐P content), were compared to an orthophosphate (Ortho‐P) and a treatment without P application (control) under three drip fertigation frequencies (Fsow: P fertilizer applied at sowing, Fweek: once a week, and F3days: every 3 days). Soil samples were taken at 40 days after sowing and at harvest from 3 layers (0–5, 5–10, and 10–20 cm) to determine P availability in soil (Olsen‐P) and its relocation into deeper soil layers. Furthermore, plant growth, yield, P uptake, P use efficiency, as well as water productivity were investigated. Results Soil P availability varied significantly between fertilizer forms and fertigation frequencies. At higher polymerization rate of the Poly‐P fertilizer, P becomes less mobile in the soil, but its availability is maintained until harvest. The analysis of Olsen‐P at harvest showed that the higher P availability in soil was obtained with Poly‐P forms with higher values in the 0–5 and 5–10 cm soil layers than in the 10–20 cm. In addition, weekly fertigation (Fweek) revealed the best results in terms of P availability compared to other P fertigation regimes, and all P fertilizers significantly improved chickpea grain yield, seed quality, and water productivity, compared to the unfertilized control. Conclusion Poly‐P fertilizers can be recommended as an effective source of phosphorus for plants, due to their slow‐release properties. Using Poly‐P, the frequency of P application through the drip fertigation system can be reduced while ensuring high crop yields.

Photosynthetic performance and nutrient uptake under salt stress: Differential responses of wheat plants to contrasting phosphorus forms and rates

“…However, phosphorus uptake by plants, in the form of phosphate ions, depends on soil physicochemical parameters ( Pereira et al., 2020 ), the application method and its frequency ( Rady et al., 2018 ; Chtouki et al., 2022 ), the root exudation and architecture ( Khourchi et al., 2022a ), and the rhizosphere microbial activity ( Wahid et al., 2020 ). In this regard, different studies have proven the effectiveness of phosphate solubilizing bacteria (PSB) in improving crop yield due to improved P levels in the soil ( Khourchi et al., 2022b ).…”

A review on phosphorus drip fertigation in the Mediterranean region: Fundamentals, current situation, challenges, and perspectives

“…P drip fertigation consists of the application of small and frequent P rate during the growing season, which limits the time of P fertilizer exposure to soil minerals and improve P availability in the soil and its uptake by plant roots. Moreover, P drip fertigation can easily schedule P application rates to coincide with crop nutrient requirements during the growing season [ 15 ].…”

“…Unlike ortho-P fertilizers, which are immediately assimilable by plants after being applied to the soil, poly-P fertilizers must be gradually hydrolyzed into the ortho-P form in order to be absorbed by plant roots [ 15 ]. The hydrolysis of poly-P to ortho-P in soil takes time and is controlled by several factors including root exudates, soil microorganisms, soil pH and properties, poly-P fertilizer chemical properties (polymerization rate and degree, chain length), and agronomic practices [ 15 , 41 ].…”

“…Unlike ortho-P fertilizers, which are immediately assimilable by plants after being applied to the soil, poly-P fertilizers must be gradually hydrolyzed into the ortho-P form in order to be absorbed by plant roots [ 15 ]. The hydrolysis of poly-P to ortho-P in soil takes time and is controlled by several factors including root exudates, soil microorganisms, soil pH and properties, poly-P fertilizer chemical properties (polymerization rate and degree, chain length), and agronomic practices [ 15 , 41 ]. In general, hydrolysis of poly-P to ortho-P occurs by successively decreasing the degree of polymerization of poly-P to tetraphosphate (P 4 O 13 6− ),tripolyphosphate (P 3 O 10 5− ), then pyrophosphate (P 2 O 7 4− ), and finally orthophosphate (PO 4 3− ) [ 42 ].…”

“…Most studies evaluating the use efficiency of dry P fertilizer found that crops take up only 10–25 % of the applied P within the same growing season [ 13 ]. Recently, phosphorus drip fertigation has been proposed as an efficient agricultural practice to improve P use efficiency by crops, as it delivers nutrients when and where plants need them [ 14 , 15 ]. However, the effectiveness of P drip fertigation systems as well as the impact of P fertigation on crop physiology and productivity still fluctuate and depend on a variety of factors including soil properties, fertilizer characteristics, as well as P application strategies [ [16] , [17] , [18] ].…”