TY - JOUR
T1 - Robust increases of land equivalent ratio with temporal niche differentiation
T2 - A meta-quantile regression
AU - Yu, Yang
AU - Makowski, David
AU - Stomph, Tjeerd Jan
AU - van der Werf, Wopke
PY - 2016
Y1 - 2016
N2 - Intercropping has been shown to be land use efficient, but there is a large variation in the land equivalent ratio (LER) among studies. We used quantile regression to estimate the effect of temporal niche differentiation and its interaction with other key characteristics of intercropping, i.e., crop type combination, N fertilizer, relative density, and intercropping pattern, using data from the intercropping literature. Quantile regression characterizes the entire distribution of the response metric by estimating quantiles of this distribution. This method gives a comprehensive characterization of the diversity of the response in the population. In this study, the effect of temporal niche differentiation on the LER was positive and significant across all quantiles (10, 15, …, 85, 90%). The response of the LER to temporal niche differentiation was similar in C3 –C3 and C3 –C4 intercrops except at low quantiles (below 20%), where a stronger response was found in C3 –C4 than in C3 –C3 intercrops. There was a negative effect of N fertilizer on the LER in the absence of temporal niche differentiation at all tested quantiles. At low LER (quantiles
AB - Intercropping has been shown to be land use efficient, but there is a large variation in the land equivalent ratio (LER) among studies. We used quantile regression to estimate the effect of temporal niche differentiation and its interaction with other key characteristics of intercropping, i.e., crop type combination, N fertilizer, relative density, and intercropping pattern, using data from the intercropping literature. Quantile regression characterizes the entire distribution of the response metric by estimating quantiles of this distribution. This method gives a comprehensive characterization of the diversity of the response in the population. In this study, the effect of temporal niche differentiation on the LER was positive and significant across all quantiles (10, 15, …, 85, 90%). The response of the LER to temporal niche differentiation was similar in C3 –C3 and C3 –C4 intercrops except at low quantiles (below 20%), where a stronger response was found in C3 –C4 than in C3 –C3 intercrops. There was a negative effect of N fertilizer on the LER in the absence of temporal niche differentiation at all tested quantiles. At low LER (quantiles
U2 - 10.2134/agronj2016.03.0170
DO - 10.2134/agronj2016.03.0170
M3 - Article
AN - SCOPUS:84994881674
VL - 108
SP - 2269
EP - 2279
JO - Agronomy Journal
JF - Agronomy Journal
SN - 0002-1962
IS - 6
ER -