Germination of Seven Perennial Arid Land Species, Subjected to Soil Moisture Stress

Briede, Jan; McKell, C.

Seven perennial arid land species were studied for germination at low soilmoisture levels. The research was conducted to test the hypothesis that seeds ofarid land species could germinate at relatively low soil moisture. This wouldallow selection of strains that germinate at low soil moisture, improving directseeding success in ecosystem restoration projects. The method used allowedseeds to be in contact with soil. Soil moisture was kept at constant levels by apolyethylene glycol solution that was separated from the soil by a semi-permeablemembrane. Highest germination rates were 86%, 61'5% and 66% for Agropyroncristatum, Bassia prostrata and Sporobulus airoides at -0'2MPa respectively.Maximum germination rates for Atriplex canescens, Grayia brandegei andSphaeralcia sp. were at -0'8 MPa and were 22%, 38% ~d 9'5% respectively.Germination ofSarcobatus vermiculatus was intermediate with the two groups andshowed a maximum percentage of 37'5% at -0'4MPa. In general, germinationwas lowest at 0'0MPa or no soil moisture stress except with Sporobulus airoides.All seven species germinated readily at soil moisture stress and some speciesmaintained high germination levels as low as -1'6 MPa. In particular Bassiaprostrata and Agropyron cristatum showed little decline in germination withincreasing soil moisture stress. Data indicate that arid land species have anadaptation to germinate under some levels of soil moisture stress. Thus,establishment can be successful at low soil moisture levels near the surface oftheseed bed if soil moisture at lower levels of the soil is sufficient for growth anddevelopment.

Germination of Seven Perennial Arid Land Species, Subjected to Soil Moisture Stress

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