Premium
Comparison of Phosphorus Fertilization Diagnostic Methods of Potato in Mollisols
Author(s) -
Zamuner E. C.,
Lloveras J.,
Echeverria H.
Publication year - 2016
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2015.0467
Subject(s) - mollisol , human fertilization , agronomy , soil water , phosphorus , fertilizer , environmental science , crop , yield (engineering) , crop yield , udic moisture regime , chemistry , biology , soil science , loam , materials science , organic chemistry , metallurgy
The aim of this research was to provide tools for the profitable and environmentally friendly P fertilization of potato ( Solanum tuberosum L.) crops. The objectives were: (i) to examine the relationships between the available soil phosphorus index (Pav), as determined by Bray1, Mehlich 3, Olsen, and CaCl 2 in Mollisols, and potato yields and (ii) to identify the P fertilization rates required to obtain the maximum agronomic yields, considering the environmental risk of P loss. The study was conducted from 2005 to 2014 in soils with a wide range of initial available P levels (8.6–50.0 mg kg −1 Bray1; from a depth of 0 to 20 cm in which irrigated potato crops fertilized with P were cultivated. The linear‐plateau, quadratic‐plateau, and Cate–Nelson models were used to analyze crop responses to P and to determine the phosphorus threshold (Pt) required to identify soils with positive responses to P fertilization. The Pt was 32 mg kg −1 for Bray1 and Mehlich 3, 11 mg kg −1 for Olsen and 2.8 mg kg −1 for CaCl 2 . Recommended P rates were defined based on the initial soil Pav index, the quantity of P removed by the crop for a specific yield, the P required to increase the initial soil P to the Pt, and the environmental Pt. Soil Bray1 determined postharvest confirmed that the P fertilizer recommendation was appropriate in Mollisols soils. Core Ideas The relationships between potato yield responses and available soil P were examined. The available soil P threshold was determined with the Bray1, Mehlich 3, Olsen, and CaCl 2 tests. The P rate required to maximize the potato yield while avoiding environmental pollution was defined based on empirical information.