Effects Of Superabsorbent Polymers On Growing And Water-saving Of Turfgrass

In this research, we mixed STOCKSORB, a superabsorbent polymers, with soil to study its effects on growing and water-saving of five kinds of turfgass: 'Pixie' tall fescue, 'Nuglude' Kentucky bluegrass, 'Pickwick' perennial ryegrass, Japanese lawngrass and 'Savannah' bermudagrass,and observed the leaf stoma of six kinds of turfgrass: 'Pixie' tall fescue, 'Nuglude' Kenucky bluegrass, 'Pickwick' perennial ryegrass, Japanese lawngrass, 'Savannah' bermudagrass and Buffalograss with scanning electron microscope. The results indicate:1. STOCKSORB haven't any effect on germination capacity of 'Pixie' tall fescue, 'Nuglude' Kenucky bluegrass and 'Pickwick' perennial ryegrass, but can increase Japanese lawngrass and 'Savannah' bermudagrass germination capacity under sufficient water condition. 'Pixie' tall fescue didn't germinate under deficit irrigation, until irrigation was twenty-five times of STOCKSORB.2. In early days, turfgrass that were applied with STOCKSORB grew faster than those withoutSTOCKSORB, 'Pickwick' perennial ryegrass grew faster,but 'Nuglude' Kentucky bluegrass grew slower than control group(0g/m2) when the amount of STOCKSORB is 25g/m2. The growth rate of 'Nuglude' Kentucky bluegrass and Japanese lawngrass increased when STOCKSORB is 75g/m2, 'Savannah' bermudagrass was not affected by STOCKSORB.3. In condition of sufficient irrigation and without STOCKSORB, 'Pixie' tall fescue had the highest evapotranspiration(ET) rates(4.24mm/d).For 'Nuglude'Kentucky bluegrass the ET was 4.01mm/d, 'Savannah' bermudagrass was 3.76mm/d, 'Pickwick' perennial ryegrass was 3.59mm/d.Japanese lawngrass possessed the lowest ET (3.40mm/d) . The water requirement of five kinds of turfgrass in a year was'Pixie' tall fescue 890.4mm, 'Nuglude'Kentcuky bluegrass 842.1mm, 'Pickwick' perennial ryegrass 753.9mm, Japanese lawngrass 578mm, 'Savannah'bermudagrass 639.2mm.It can save water 28.9-67.2mm when STOCKSORB is applied in soil.4. In condition of deficit irrigation, the ET of 'Savannah'bermudagrass was the highest(4.17mm/d). The following is 'Pixie'tall fescue(4.14mm/d), 'Pickwick'perennial ryegrass(4.10mm/d), 'Nuglude'Kentucky bluegrass(3.64mm/d).Japanese lawngrass had the lowest ET(3.22mm/d).The ET of five kinds of turfgrass was not affected by STOCKSORB when the amount is 25,50,75g/m2, and when the amount is up to 100g/m2 the ET will increase.When water is limited,the water requirement of 'Pixie' tall fescue, 'Nuglude'Kentcuky bluegrass, 'Pickwick'perennial ryegrass, Japanese lawngrass,'Savannah'bermudagrass in a year was 869.4mm,764.4mm,861mm,547.4mm,708.9mm,It can save water 12.6-52.7mm when STOCKSORB is applied in soil.5. It was found that the stomata of buffalograss, Japanese lawngrass and 'Savannah'bermudagrass is ellipse shape.The stoma of buffalograss and 'Savannah'bemudagrass were covered with wax. The stoma of 'Nuglude'Kentucky bluegrass, 'Pickwick'perennial ryegrass and'Pixie' tall fescue is elongate or rectangle shape. The size of leave's stoma for three kinds of warm-season turfgrass are smaller than three kinds of cool-season turfgrass, but the density of warm-season turfgrass is larger than cool-season turfgrass.The turfgrass had less drought resistance with high stoma density than turfgrass with low stoma density.6. It is feasible to use superabsorbent polymers for turfgrass establishment,especially in north area with little precipitation but strong precipitation intensity. Superabsorbent polymers would make effect in certain soil water condition. Sufficient water is the main condition for applying superabsorbent polymers.7. The suitable amount of STOCKSORB used in 'Pixie' tall fescue is 25g/m2,and for 'Nuglude'Kentucky bluegrass is 75g/m2, for 'Pickwick'perennial ryegrass is 25-75 g/m2, for Japanese lawngrass is 75g/m2. It is better for superabsorbent polymers to mix with soil. At the same time, we should avoid superabsorbent polymers exposed in the air. And the superabsorbent polymers shoul...