1
Evaluation and Modeling of the Impact of
Environmentally Friendly Fertilization Techniques
A. Shaviv
Department of Water-Sail-Environment, Faculty of Agricultural Engineering,
Technion-IlT, Haifa, Israel. e-mail: agshaviv@tx.technin.ac.il
Tel: +972-4-8292602 Fax: +972-4-8324478
Abstract
Environmentally friendly fertilization practices (EFFPs) aim at maintaining high
use efficiency of nutrients, and particularly nitrogen, while reducing the
environmental hazards such as nitrate leaching or emission of NOx gases. This
presentation examines the agronomic and environmental impact of practices such
as fertilizer placement, the use nitrification inhibitors (NIs), and the use of
controlled-release N-fertilizers (CRNs). In the first part, experimental results
demonstrating the significance of EFFPs (based on a single application) are
presented. This is followed by a sensitivity analysis performed using a
comprehensive N dynamics model that accounts for the effects induced in soil
when using EFFPs. Modeling results emphasize the contribution of practices that
reduce nitrification rate to reduction of leaching losses of nitrate while
maintaining high yields. Most effective of the practices that were analyzed, using
the N dynamics model. was banding of CRNs, which significantly reduced nitrate
losses while maintaining optimal yields and nitrogen uptake.
1 Introduction
Increasing attention is being paid to "environmentally friendly" N-fertilization
practices (EFFPs) due to demands to maintain a cleaner environment and focus on
sustainable agriculture. Reduction of nitrification rates and the control over the
rate and the temporal pattern of nitrogen supply offer possible solutions for
increasing N use-efficiency (NUE) while reducing environmental pollution by
fertilizer N (Hauck, 1985; Shaviv, 1993, 2000; Shaviv and Mikkelsen, 1993). In
most soils this is expected to be a result of merely reducing excess nitrate in the
root zone, thus reducing N losses via leaching or denitrification. In addition,
exposing plants to ammonium-rich nutrition results in higher NUE and reduced
rhizosphere pH, which in turn can increase the availability of both P and
microelements (Amberger, 1989; Shaviv, 1993).
H. Rubin et al.
Preserving the Quality of Our Water Resources
© Springer-Verlag Berlin Heidelberg 2002
Evaluation and Modeling of the Impact of
Environmentally Friendly Fertilization Techniques
A. Shaviv
Department of Water-Sail-Environment, Faculty of Agricultural Engineering,
Technion-IlT, Haifa, Israel. e-mail: agshaviv@tx.technin.ac.il
Tel: +972-4-8292602 Fax: +972-4-8324478
Abstract
Environmentally friendly fertilization practices (EFFPs) aim at maintaining high
use efficiency of nutrients, and particularly nitrogen, while reducing the
environmental hazards such as nitrate leaching or emission of NOx gases. This
presentation examines the agronomic and environmental impact of practices such
as fertilizer placement, the use nitrification inhibitors (NIs), and the use of
controlled-release N-fertilizers (CRNs). In the first part, experimental results
demonstrating the significance of EFFPs (based on a single application) are
presented. This is followed by a sensitivity analysis performed using a
comprehensive N dynamics model that accounts for the effects induced in soil
when using EFFPs. Modeling results emphasize the contribution of practices that
reduce nitrification rate to reduction of leaching losses of nitrate while
maintaining high yields. Most effective of the practices that were analyzed, using
the N dynamics model. was banding of CRNs, which significantly reduced nitrate
losses while maintaining optimal yields and nitrogen uptake.
1 Introduction
Increasing attention is being paid to "environmentally friendly" N-fertilization
practices (EFFPs) due to demands to maintain a cleaner environment and focus on
sustainable agriculture. Reduction of nitrification rates and the control over the
rate and the temporal pattern of nitrogen supply offer possible solutions for
increasing N use-efficiency (NUE) while reducing environmental pollution by
fertilizer N (Hauck, 1985; Shaviv, 1993, 2000; Shaviv and Mikkelsen, 1993). In
most soils this is expected to be a result of merely reducing excess nitrate in the
root zone, thus reducing N losses via leaching or denitrification. In addition,
exposing plants to ammonium-rich nutrition results in higher NUE and reduced
rhizosphere pH, which in turn can increase the availability of both P and
microelements (Amberger, 1989; Shaviv, 1993).
H. Rubin et al.
Preserving the Quality of Our Water Resources
© Springer-Verlag Berlin Heidelberg 2002