A comparison of soil moisture sensors for space flight applications |
| |
Authors: | Norikane J H Prenger J J Rouzan-Wheeldon D T Levine H G |
| |
Institution: | Biosystems and Agricultural Engineering Department, University of Kentucky, Lexington, KY 40546-0276, USA. jnorikane@bae.uky.edu |
| |
Abstract: | Plants will be an important part of future long-term space missions. Automated plant growth systems require accurate and reliable methods of monitoring soil moisture levels. There are a number of different methods to accomplish this task. This study evaluated sensors using the capacitance method (ECH2O), the heat-pulse method (TMAS), and tensiometers, compared to soil water loss measured gravimetrically in a side-by-side test. The experiment monitored evaporative losses from substrate compartments filled with 1- to 2-mm baked calcinated clay media. The ECH2O data correlated well with the gravimetric measurements, but over a limited range of soil moisture. The averaged TMAS sensor data overstated soil moisture content levels. The tensiometer data appeared to track evaporative losses in the 0.5- to 2.5-kPa range of matric potential that corresponds to the water content needed to grow plants. This small range is characteristic of large particle media, and thus high-resolution tensiometers are required to distinguish changing moisture contents in this range. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|