Simultaneous water, nitrogen use can enhance sustainability

Researchers from Universidad Politécnica de Madrid have studied diverse techniques to enhance the water- and nitrogen-use efficiency in cropping systems.
The results of the study carried out by two researchers from the Research Group on Agricultural Systems at Universidad Politécnica de Madrid show that management practices oriented towards reducing nitrogen losses and maintaining farm productivity should rely on optimizing nitrogen and water inputs at the same time.
These two elements have a fundamental effect on food sovereignty of many regions and on the reduction of the gap between the potential food and the actual food produced in the world.
Thus, the practices that seek to improve both efficiencies simultaneously are more successful than those that aim to optimize each element separately.
This study carried out by Miguel Quemada and José Luis Gabriel, researchers from Universidad Politécnica de Madrid, has assessed seven practices to improve both elements at the same time in cropping systems.
Firstly, when there is crop water deficit the use of nitrogen has to be adjusted to the actual demand of the stressed crop since the plant will grow only as far as the most limiting factor allows it (water in this case), thus the rest of nitrogen remains on the soil ready to disappear from the system.
Thirdly, researchers suggest the use of fertigation that consists in the application of dissolved nutrients into irrigation water, this technique has a great potential to adapt the punctual demand of water and nitrogen per plant.
Soil mulching is the fourth technique suggested in this study.
Besides, soil mulching can favor the conditions to achieve a higher mineralization of soil nitrogen and it can also increase water infiltration reducing the loss of both water and nitrogen caused by soil erosion.
Finally, the seventh practice studied is the monitoring of water and nitrogen availability by using remote and proximity sensors.