『Abstract
Nitrate contamination is a significant unresolved environmental
issue for agriculture in the 21st century, with longstanding challenges
in its control and allocation to a specified territory. In order
to address these challenges, real-world meticulous irrigation
area studies are required. The objective of this investigation
is to analyze the evolution of nitrate contamination in relation
to agronomic and management changes within a traditionally irrigated
land. Specifically, the impact of changes in irrigation allowance
assignment, changes in irrigation method from rotation to on-demand
flood irrigation, and creation of water consumption accounts were
analyzed.
To this end, nitrogen monitoring and annual balances were carried
out in a small irrigated hydrological basin (95 ha) located in
Northeastern Spain throughout the years of 2001 and 2005-2008.
The evolution of the nitrate contamination index was also analyzed,
which relates the mass of nitrates exported to the fertilization
necessities of a specific irrigated area.
The results demonstrated that although changes in crop pattern
caused a 33% reduction in the nitrogen required through fertilization,
the fertilization rates applied are still double the necessities.
Changes in irrigation management decreased the mass of nitrates
exported by half and the nitrate contamination index by 24%, but
the nitrate levels present are still approximately double of those
registered in modern irrigation areas.
The changes implemented by the Irrigation District in the irrigation
management were effective. However, this study confirms that a
greater effort is still required to achieve adequate nitrogen
fertilization matching the crop necessities.
Keywords: Irrigation return flows; Nitrate contamination; Nitrogen
balance; Nitrogen application index』
1. Introduction
2. Description of study area
3. Methodology
3.1. Agronomic analysis
3.2. Nitrogen balance
3.3. Nitrate contamination produced by irrigation
4. Results and discussion
4.1. Agronomic analysis
4.2. Nitrogen balance
4.3. Nitrate contamination produced by irrigation
5. Conclusions
Acknowledgments
References