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Meta‐Analysis of Phosphorus Loss from No‐Till Soils
Author(s) -
Daryanto Stefani,
Wang Lixin,
Jacinthe Pierre André
Publication year - 2017
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2017.03.0121
Subject(s) - particulates , tillage , environmental science , surface runoff , soil water , leaching (pedology) , phosphorus , agriculture , conventional tillage , water quality , hydrology (agriculture) , agronomy , soil science , chemistry , ecology , biology , geotechnical engineering , organic chemistry , engineering
Agriculture is a significant contributor to phosphorus (P) enrichment in aquatic ecosystems. No‐till (NT) farming has been proposed as an alternative approach to conventional tillage (CT) in reducing soil P export, but published data have shown contrasting impacts, likely due to the interacting effects of different physical (climate region, rainfall variability, transport pathway, slope gradient) and management variables (NT duration, crop species). We conducted a meta‐analysis to understand the extent to which each of these variables controls the concentration and load of different P fractions (dissolved P, particulate P) in agricultural runoff and leaching. In comparison with CT, particulate P loss was significantly lower with NT adoption (45 and 55% reduction in concentration and load, respectively), but an increase in dissolved P loss was observed. The extent of the reduction or increase, however, varied with different physical and management variables. In comparison with CT, for example, NT was not effective in reducing particulate P concentration during wet years and particulate P load on steep slopes (4–9%). Total P concentration was also similar with CT at sites under prolonged NT duration (∼10 yr) and at NT fields planted with soybean [ Glycine max (L.) Merr.]. Our results underscore the need to consider the covarying physical and management factors when assessing the potential of NT farming in controlling P loss in the environment. The limited impact of NT on dissolved P loss remains a serious impediment toward harnessing the water quality benefits of this management practice. Core Ideas No‐till was effective in reducing particulate P loss but increased dissolved P loss. NT covaried with several physical and management variables in affecting P loss. NT must be combined with other land management strategies to reduce dissolved P loss.