TY - JOUR
T1 - State-space description of field heterogeneity
T2 - Water and nitrogen use in cotton
AU - Li, Hong
AU - Lascano, Robert J.
AU - Booker, Jill
AU - Ted Wilson, L.
AU - Bronson, Kevin F.
AU - Segarra, Eduardo
PY - 2002
Y1 - 2002
N2 - Field heterogeneity in soil texture and site elevation (SE) may affect crop water and N use. A 2-yr (1998-1999) study was concluded on the Texas High Plains to determine the interdependence between management (irrigation and N fertilization), soil heterogeneity (texture, soil water, and NO3-N) and topography, and their impact on cotton (Gossypium hirsutum L.) lint yield and N uptake. Treatments were irrigation at 50 and 75% estimated cotton evapotranspiration (ET) and N rates at 0, 90, and 135 kg ha-1. Soil water content (SWC), lint yield, N uptake, and N fertilizer recovery, measured as a function of management and space, were higher on low positions. Mixed model analysis showed that irrigation was significant on SWC, lint yield, and N uptake (P < 0.05) each year. The N treatment had no effect on lint yield or N uptake in 1998 because of high soil residual NO3-N, and the model residual was significant for all measured variables (P < 0.0001). Sand, SWC, lint yield, and N uptake were negatively correlated with SE (r ≥ -0.64). In 1998, lint yield, SWC, clay, sand, and SE were cross correlated within 60 to 80 m. Multivariate state-space analysis showed that lint yield at position i was weighted on lint yield, SWC, clay, sand, and SE at previous position i - 1. It is concluded that 75% ET and N rate at 90 kg ha-1 would be the basis to consider variable water and N rates related to field conditions, and the state-space model quantified spatial interdependence between irrigation, fertilization, and field heterogeneity.
AB - Field heterogeneity in soil texture and site elevation (SE) may affect crop water and N use. A 2-yr (1998-1999) study was concluded on the Texas High Plains to determine the interdependence between management (irrigation and N fertilization), soil heterogeneity (texture, soil water, and NO3-N) and topography, and their impact on cotton (Gossypium hirsutum L.) lint yield and N uptake. Treatments were irrigation at 50 and 75% estimated cotton evapotranspiration (ET) and N rates at 0, 90, and 135 kg ha-1. Soil water content (SWC), lint yield, N uptake, and N fertilizer recovery, measured as a function of management and space, were higher on low positions. Mixed model analysis showed that irrigation was significant on SWC, lint yield, and N uptake (P < 0.05) each year. The N treatment had no effect on lint yield or N uptake in 1998 because of high soil residual NO3-N, and the model residual was significant for all measured variables (P < 0.0001). Sand, SWC, lint yield, and N uptake were negatively correlated with SE (r ≥ -0.64). In 1998, lint yield, SWC, clay, sand, and SE were cross correlated within 60 to 80 m. Multivariate state-space analysis showed that lint yield at position i was weighted on lint yield, SWC, clay, sand, and SE at previous position i - 1. It is concluded that 75% ET and N rate at 90 kg ha-1 would be the basis to consider variable water and N rates related to field conditions, and the state-space model quantified spatial interdependence between irrigation, fertilization, and field heterogeneity.
UR - http://www.scopus.com/inward/record.url?scp=0036121490&partnerID=8YFLogxK
U2 - 10.2136/sssaj2002.5850
DO - 10.2136/sssaj2002.5850
M3 - Article
AN - SCOPUS:0036121490
VL - 66
SP - 585
EP - 595
JO - Soil Science Society of America Journal
JF - Soil Science Society of America Journal
SN - 0361-5995
IS - 2
ER -