Soil moisture can demarcate the onset of agricultural drought in near real time
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Originally posted 2018-11-14 06:05:30.
With the increase in population, the demand for food is also increasing. The critical challenges in attaining food security include the adverse climatic changes and diminishing agricultural yield due to several factors such as agricultural drought, pests, and other diseases. The Agriculture drought is a condition when the available soil moisture becomes insufficient to support plant growth.
After precipitation, a certain amount of water is retained in the soil which dissipates due to evaporation or transpiration with the passage of time. The top 2 inches of the soil hold an infinitesimal fraction of the planet’s water1. Although the amount of water is small, because of its position at the interface between land and atmosphere it forms a crucial part of the global water cycle. Monitoring soil moisture over time can help to tackle adverse climatic changes and hence can help to reduce its effect on crop yield. It can also predict the condition of agricultural drought well in advance and thus provides a possibility of preparedness without compromising on the yield.
Conventional way of measuring soil moisture is to install soil moisture sensors in the ground which measures the volumetric water content indirectly by using properties of the soil, such as electrical resistance, dielectric constant, or interaction with neutrons etc. But this method is time-consuming and has limited coverage. Hence a number of methodologies are developed globally utilizing the satellite data to retrieve relative soil moisture which provides better coverage compared to the former method. Soil moisture data is provided by passive and active microwave sensors. Passive microwave sensors provide soil moisture globally at a coarser spatial resolution whereas active microwave sensors have a higher spatial but low temporal resolution (2–4 weeks). Using soil moisture data directly from any of these sensors will have compromised spatial or temporal resolution. Some of the applications where higher spatiotemporal resolution soil moisture data is useful are:
- Optimal irrigation in farms
- Improved flood risk estimation
- Monitor agricultural drought in near real time
- Likely crop Yield
- Irrigation Management
- Improved weather forecast
- Analyze the impact of an irrigation project
- Automatic billing of farm based on the actual irrigation