Forecast-Informed Irrigation Scheduling for Maximizing Nutrient and Water Use Efficiency in Humid Climates: Experimental Results in Corn and Cotton
Abstract
Irrigation not only provides a much-needed buffer to maintain yields in the event of droughts, but also impacts a plants ability to uptake and crucial nutrients like nitrogen. Lower soil moisture during dry stretches impacts plants' ability to uptake nitrogen, thus resulting in low nutrient use efficiency (NUE). On the other hand, heavy rainfall results in water logging and surface runoff, which leads to nutrient leaching and runoff. This makes nutrients unavailable for plants, resulting in lower NUE, poor yields, and water quality impacts. However, existing irrigation scheduling methods rarely account for the impact that soil moisture levels have on NUE. This study developed an irrigation support methodology using real-time soil water availability, crop physiological status, water needs, and short-term weather forecasts information from National Weather Service. A rule-based approach based on soil moisture depletion and short-term weather forecasts was then used to trigger irrigation to avoid both depleted and excess water conditions. This method was tested in two years of field trials to quantify its impacts on yield, NUE, and water use efficiency (WUE) in corn and cotton under three irrigation treatments (rainfed, traditional, and forecast-informed irrigation) and four nitrogen application treatments (increments of 80lb for corn and 40lb for cotton).The forecast informed precision irrigation treatment was found to prevent soil moisture loss beyond the critical level and waterlogging conditions in the field. This resulted in improved yield, NUE, and WUE when compared to traditional irrigation scheduling.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMGC44E..05S