Germination and growth of Puccinellia tenuiflora in saline-sodic soil under drip irrigation

Field experiments were conducted to investigate the effects of drip irrigation on seed germination and Puccinellia tenuiflora growth in saline-sodic soils in the Songnen Plain, northeast China. The experiment included five treatments in which the soil matric potential (SMP) at 0.2 m depth was controlled at -5, -10, -15, -20 and -25 kPa after the P. tenuiflora germinated. Consequently, the total water applied increased with increased matric potential. The results showed that drip irrigation influenced the water content, electrical conductivity of saturated-soil extract (ECe) and pH distributions, and inhibited the buildup of salts in the root zone, which enabled seeds to germinate and emerge. The ECe and pH in the whole soil profiles decreased as the SMP increased. After two years of the experiment, the tiller numbers, height, spike number and length, aboveground biomass and coverage of P. tenuiflora all increased greatly; and the growth of -15 and -20 kPa treatments were better than other treatments. Taken together, these results indicate that drip irrigation can be used to provide suitable conditions for the germination of P. tenuiflora seeds in the Songnen Plain and induce good growth, and the SMP of -15 and -20 kPa at a depth of 0.2 m immediately under a drip emitter can be used as an indicator for saline-sodic P. tenuiflora grassland restoration in Songnen Plain. The results provide theoretical and technological guidance for reclamation and use of salt-affected soil, as well as for easy and quick restoration and reconstruction of saline-sodic grasslands. (C) 2012 Elsevier B.V. All rights reserved.