Chameleon soil moisture sensors alternative crops climate change quinoa cowpea Mekong River Delta
Saline intrusion and freshwater scarcity is now common in the Mekong River Delta (MRD) Vietnam resulting in dry season rice crop failure. There is a need to identify suitable alternative crops that are fast maturing, water efficient and/or saline tolerant and optimise the practical irrigation of these crops. A glasshouse trial examined the suitability of quinoa (Chenopodium quinoa Kruso white), cowpea (Vigna unguiculata Red Caloona) and soybean (Glycine max Richmond) for growth in conditions representing of salinity and drought experienced in the MRD. Plants were irrigated with either fresh or saline (up to 4 g L−1) water. Chameleon soil moisture sensors were used to trigger irrigation events, either constantly (water potential 0 to single bond22 kPa) or intermittently (irrigating when the water potential was below single bond50 kPa). Water use, soil salinity, plant performance and stress parameters were measured. Saline treatments significantly affected the yield of all three species; however, quinoa grew in saline conditions for the longest duration. Cowpea and quinoa tolerated irrigation with 4 g L−1 during reproductive phases, whilst soybean experienced leaf chlorosis and premature senescence with saline irrigation. Cowpea was negatively affected by intermittent irrigation with higher proline concentrations in younger leaves. Chameleon sensors improved irrigation efficiency and could be used to aid farmers in developing irrigation schedules in agricultural producing regions affected by water shortages. High salinity during reproductive growth phases hindered the accuracy of the Chameleon sensors and thus their use would be most adventitious in vegetative stages to improve water use efficiency before salinity peaks.
Details
Title
Investigating the suitability of Chameleon soil moisture sensors to improve water use of upland crops under conditions of temporal salinity
Authors/Creators
Brooke Kaveney - Charles Sturt University
Khoi Chau Minh - Can Tho University
Minh Dang Duy - Can Tho University
Kim Phuong Nguyen Thi - Can Tho University
Cao Dinh An Giang
Ed Barrett-Lennard - Murdoch University, Centre for Sustainable Farming Systems