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Assessment of cropping‐system impact on soil organic matter levels in short‐term field experiments
Author(s) -
Brock Christopher,
KniesDeventer Hannah,
Leithold Günter
Publication year - 2011
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/jpln.201100147
Subject(s) - arable land , environmental science , soil carbon , cropping , sampling (signal processing) , soil science , organic matter , soil water , soil organic matter , term (time) , cropping system , agronomy , chemistry , geography , crop , computer science , physics , archaeology , filter (signal processing) , organic chemistry , quantum mechanics , biology , computer vision , agriculture
It has been suggested that short‐term field experiments are not suitable for the quantitative assessment of cropping‐systems impact on soil organic matter (SOM) levels in arable soils, as expectable temporal changes are very small compared to a large spatial variation of SOM background levels. However, applying an optimized sampling design based on repeated sampling in small plots, we were able to detect soil total carbon (STC) and nitrogen (STN) changes in the magnitude of ≈ 1% (STC) and ≈ 2% (STN) of background levels with only four replications, respectively. Gradually enlarging the sample size up to n = 24 did not considerably improve change detectability with STC, but with STN ( n = 15 allowing for the dection of ≈ 1% change of background levels). The common calculation of minimum detectable differences (MDD) based on a state analysis of SOM levels instead of repeated measurements considerably underestimated change detectability.