DOI: 10.5061/dryad.sxksn03bq
title: Data from: Strategic tillage of no-till decreased surface and subsurface losses of dissolved phosphorus

description: No-till is a cultivation practice in which plant seeds are applied in soil
 without completely breaking up the surface of agricultural fields as,
 e.g., in plowing. When growing annual crops, no-till is considered the
 most effective way of controlling erosion and associated nutrient losses
 to surface waters. The downside of long-term no-till, especially in soils
 with modest inherent erosion, is phosphorus (P) enrichment of the
 uppermost soil surface layer that causes an increase in dissolved P loss,
 i.e., the most potent fraction of P losses causing eutrophication of
 surface waters. As a remedy to dissolved P losses, occasional tillage,
 also termed strategic tillage, of long-term no-till fields has been
 suggested. We made strategic tillage of clay soil that has been under
 no-till management for a decade and measured surface and subsurface P
 losses during the following 4 yr. The study was made on a field, divided
 into four 0.5-ha plots, in SW Finland. Surface and subsurface (tile
 drainage) waters are collected and sampled for analyses
 flow-propositionally. These supplemental data contain a description of the
 field site and quarter-year sums of surface and subsurface discharges of
 water, dissolved P, particulate P, and total P. Also, the outcomes of
 statistical testing of the data are included. We found that strategic
 tillage effectively (by about 60%) decreased the losses of dissolved P via
 surface and subsurface discharge pathways. When the strategic tillage was
 done in summer and a new crop was sown a week later, erosion-associated
 particulate P losses only increased by about 10%. At the study site,
 strategic tillage was preferred over continuous no-till and annual plowing
 when searching for the least water eutrophication-fuelling tillage
 methods.
description: The data are from a 2-ha field in SW Finland where surface and
 subsurface discharges are measured and sampled. In the field, three
 tillage options were applied: annual plowing, continuous no-till, and
 no-till that was plowed one time in the summer of 2018. Included in the
 data are discharge water volumes and P losses via surface and subsurface
 pathways during four years. The data are calculated as quarter-year sums
 from Aug 2018 to Aug 2022.
description: # Data from: Strategic tillage of no-till decreased surface and subsurface
 losses of dissolved phosphorus [Access this dataset on
 Dryad](DOI:10.5061/dryad.sxksn03bq) These datasets accompany the above
 publication, presenting details on the field setup, numbers behind the
 data presented in figures and statistical analyses, and details on
 statistical testing results. Files are ordered in four folders: * Figures
 FigS1_FigS3 and captions: \-- FigS1 (jpg) shows the Jokioinen/Kotkanoja
 fields's subsurface drainage layout, dimensions of the field, and a
 photo showing how flow-proportional water samples are collected \-- FigS2
 (jpg) shows quarter-year sums of precipitation and mean air temperature
 during the study, number of successive days with at least 10 cm of snow
 cover each winter during the study, and maximum snow depth (with date) \--
 FigS3 (jpg) presents the cumulative discharge of total P during the study;
 shown are surface, subsurface, and their summed losses \-- Figure captions
 (txt) explain data shown in the figures S1, S2, and S3 included in this
 folder * Weather data referred to in the article is not included here (due
 to conflicting license) but can be downloaded at the website of the
 Finnish Meteorological Institute:
 [https://en.ilmatieteenlaitos.fi/download-observations](https://en.ilmatieteenlaitos.fi/download-observations) (choose site: Jokioinen, Ilmala). * Tables S5_S8 Water and P discharges: \-- Table S5 (CSV) gives quarter-year sums of surface and subsurface (tile drainage) water discharges from the four 0.5-ha plots during the study (2018-2022) \-- Table S6 (CSV) gives quarter-year sums of surface and subsurface losses of dissolved reactive phosphorus (DRP) from the field plots during the study \-- Table S7 (CSV) gives quarter-year sums of surface and subsurface losses of particulate phosphorus (PP) from the field plots during the study \-- Table S8 (CSV) gives quarter-year sums of surface and subsurface losses of total phosphorus (TP) from the field plots during the study * Tables S9_S11 Statistical testing: \-- Table S9 (CSV) shows differences in slope estimates for water discharge and P losses (summed surface and subsurface losses) during the control (Sept 2008 - May 2018) and study (Jul 2018 - Aug 2022) periods \-- Table S10 (CSV) lists slope estimates for water discharge and P losses (summed surface and subsurface losses) during the control (2008-2018) and study (2018-2022) periods \-- Table S11 (CSV) gives adjusted p-values of cross-comparisons of slope differences (Supplemental Table S10) in the control (2008-2018) and study (2018-2022) periods Used units: Precipitation and water discharges are given in mm Temperatures are given in degrees Celsius Phosphorus losses are given in grams per hectare ## Description of the data and file structure Weather data are linked with water and nutrient discharges as the study was conducted field-scale under natural precipitation. To obtain these data, go to [https://en.ilmatieteenlaitos.fi/download-observations](https://en.ilmatieteenlaitos.fi/download-observations) (site: Jokioinen, Ilmala). Data are given as continuous quarter-year sums of water and P discharges for the period Sept 2008 to Aug 2022. These can be used, e.g., for the evaluation of phosphorus loss models. ## Sharing/Access information Weather data (not included in this zip file) were derived from the open database of the Finnish Meteorological Institute and their Jokioinen observatory located about 600 m from the study site. Other data were produced by the Natural Resources Institute Finland, Jokioinen unit.