TY - JOUR

T1 - Modeling N fertilization impact on water cycle and water use efficiency of maize, finger-millet, and lablab crops in South India

AU - Almawazreh, Albara

AU - Uteau, Daniel

AU - Subbarayappa, C. T.

AU - Buerkert, Andreas

AU - Lehmann, Sybille

AU - Peth, Stephan

N1 - ACKNOWLEDGMENTS We would like to thank Dr. Malte Horvat and BSc. Michael Tobias Fuchs for their contributions to installing the sensor network, sampling, and laboratory analysis. We also would like to thank the working group of Prof. Michael Wachendorf from the Department of Grassland Science and Renewable Resources at the University of Kassel for sharing the leaf area index data with us; Dr. M. N. Thimmegowda, Professor of Agro-Meteorology at University of Agricultural Sciences, Bengaluru, for providing us with the weatherdata; and Mr. Ansgar Weuthen and Dr. Heye Bogena from Jülich research institute for their technical support in maintaining the soil sensors network. This study was funded by the DFG (German Research Foundation) in the frame of theresearch unit FOR2432 “Social-Ecological Systems in the Indian Rural-Urban Interface: Functions, Scales, and Dynamics of Transition” under project number 279374797 and its Indian partner project “The Rural-Urban Interface of Bengaluru: A Space of Transitions in Agriculture Economicsand Society” awarded by the Department of Biotechnology (DBT), Ministry of Science of Technology, Governmentof India.

PY - 2024/3/16

Y1 - 2024/3/16

N2 - The understanding of the impact of nitrogen (N) fertilization on the field water cycle and corresponding water use efficiency (WUE) is very important for optimizing fertilization rates and conserving stressed water resources. We modeled soil moisture dynamics of maize (Zea mays L.), finger millet (Eleusine coracana Gaertn.), and lablab [Lablab purpureus (L.) Sweet] plots using calibrated HYDRUS-1D model on two experimental sites (rain-fed and irrigated) for three seasons under different N treatments. The results indicate that the effects of N depended on plant specific properties such as N-fixation and drought tolerance, and on plant available water content governed by soil structure and rainfall seasonal variability. Maize WUE of plots which received 150 kg/ha of urea (46 (Formula presented.) N) were 10–30 kg/ha/mm higher than plots which received none; likewise, millet that received 50 kg/ha of urea had a 7–10 kg/ha/mm higher WUE than control plots in both experiments. However, differences in water cycle components were noticeable between N treatments only in the rain-fed experiment, where higher N levels led to around 60 and 30 mm higher transpiration, 30 and 20 mm lower evaporation, and 30 and 15 mm lower percolation per season for maize and millet, respectively. In 2018, which was the driest year, the difference in maize WUE between the high and low N treatments was only 1 kg/ha/mm, which corresponded with low actual to potential transpiration ratios ((Formula presented.)). This indicates higher sensitivity of maize to water stress compared to the other crops. The results of lablab indicate a positive impact of N fertilization on WUE only under water-limited conditions.

AB - The understanding of the impact of nitrogen (N) fertilization on the field water cycle and corresponding water use efficiency (WUE) is very important for optimizing fertilization rates and conserving stressed water resources. We modeled soil moisture dynamics of maize (Zea mays L.), finger millet (Eleusine coracana Gaertn.), and lablab [Lablab purpureus (L.) Sweet] plots using calibrated HYDRUS-1D model on two experimental sites (rain-fed and irrigated) for three seasons under different N treatments. The results indicate that the effects of N depended on plant specific properties such as N-fixation and drought tolerance, and on plant available water content governed by soil structure and rainfall seasonal variability. Maize WUE of plots which received 150 kg/ha of urea (46 (Formula presented.) N) were 10–30 kg/ha/mm higher than plots which received none; likewise, millet that received 50 kg/ha of urea had a 7–10 kg/ha/mm higher WUE than control plots in both experiments. However, differences in water cycle components were noticeable between N treatments only in the rain-fed experiment, where higher N levels led to around 60 and 30 mm higher transpiration, 30 and 20 mm lower evaporation, and 30 and 15 mm lower percolation per season for maize and millet, respectively. In 2018, which was the driest year, the difference in maize WUE between the high and low N treatments was only 1 kg/ha/mm, which corresponded with low actual to potential transpiration ratios ((Formula presented.)). This indicates higher sensitivity of maize to water stress compared to the other crops. The results of lablab indicate a positive impact of N fertilization on WUE only under water-limited conditions.

UR - http://www.scopus.com/inward/record.url?scp=85188438217&partnerID=8YFLogxK

U2 - 10.1002/vzj2.20319

DO - 10.1002/vzj2.20319

M3 - Article

AN - SCOPUS:85188438217

JO - Vadose zone journal

JF - Vadose zone journal

SN - 1539-1663

ER -