VIRGINIA POLYTECHNIC INSTITUTE

THE INFLUENCE OF ROOTS’S ON KENTUCKY BLUEGRASS EFFECTED BY SALT IN IRRIGATION WATER BY Dr. R. E. Schmidt Turf Ecology and Research Virginia Polytechnical Institute OBJECTIVE To ascertain if treating Kentucky bluegrass with biostimulants will reduce the impact of irrigation with salty water. METHODS Kentucky bluegrass was grown under greenhouse conditions in 270 cc plastic cups filled with a silt loam soil. When the grass was in the two-leaf stage, it was treated with ROOTS® (a fortified seaweed extract) in 61 liters of water per ha at 290 k Pa with a compressed air sprayer. A 20-20-20 soluble fertilizer was applied at time of seeding to supply 0.8 kg nitrogen per ha. Three days after the ROOTS® was applied, 50 ml. of water containing no added salt was applied everyday to.each cup. The salt concentration was increased at two-week intervals from 500 to 1500 to 2000 urn hos/crn for the low salt regimes. For the salt regime, the concentration was doubled. All treatments were arranged in an experimental randomized block design and replicated three times. After six weeks of irrigating with different amounts of salt water, the turf ground cover and leaf water potential of the differently treated turf was estimated. Leaf water potential was determined using a hydraulic pump to develop pressure in a closed leaf chamber. The higher the pressure needed to extract water from the leaf, the lower the water content of the leaf. Soil was then washed from the roots. Foliage and roots were separated, dried and weighed. All data were subjected to a statistical analysis of variance. RESULTS Shoots, roots, ground cover and leaf water content decreased with salt concentration of the irrigation water. Shoot dry weight of ROOTS®-treated turf was higher than the control, but not significantly when no salt was added to the irrigation water (Fig. 1). ROOTS®, under low and high salt concentration, enhanced foliar growth. The dry weight of the grass roots was enhanced with ROOTS® application, regardless of salt concentration of the irrigation water (Fig. 2). Although leaf water content of the non-treated grasses was consistently lower than the ROOTS® treated grass, statistical significance was obtained only when salt, or low salt treatments, were applied (Fig. 3). This indicated that the high salt application was extreme. Ground cover was enhanced with ROOTS® treatment for all salt concentrations (Fig. 4). Turf treated with ROOTS® and irrigated with high salt water produced the same ground cover as plots not treated with ROOTS® and irrigated with no salt added water. These data strongly suggest that turf treated with ROOTS® will tolerate the negative impact of irrigating with high concentrations of salt water.

THE INFLUENCE OF ROOTS’S ON KENTUCKY BLUEGRASS

EFFECTED BY SALT IN IRRIGATION WATER

Dr. R. E. Schmidt

Turf Ecology and Research

Virginia Polytechnical Institute

OBJECTIVE

To ascertain if treating Kentucky bluegrass with biostimulants will reduce the impact of irrigation with salty water.

METHODS

Kentucky bluegrass was grown under greenhouse conditions in 270 cc plastic cups filled with a silt loam soil. When the grass was in the two-leaf stage, it was treated with ROOTS® (a fortified seaweed extract) in 61 liters of water per ha at 290 k Pa with a compressed air sprayer. A 20-20-20 soluble fertilizer was applied at time of seeding to supply 0.8 kg nitrogen per ha.

Three days after the ROOTS® was applied, 50 ml. of water containing no added salt was applied everyday to.each cup. The salt concentration was increased at two-week intervals from 500 to 1500 to 2000 urn hos/crn for the low salt regimes. For the salt regime, the concentration was doubled. All treatments were arranged in an experimental randomized block design and replicated three times.

After six weeks of irrigating with different amounts of salt water, the turf ground cover and leaf water potential of the differently treated turf was estimated. Leaf water potential was determined using a hydraulic pump to develop pressure in a closed leaf chamber. The higher the pressure needed to extract water from the leaf, the lower the water content of the leaf.

Soil was then washed from the roots. Foliage and roots were separated, dried and weighed. All data were subjected to a statistical analysis of variance.

RESULTS

Shoots, roots, ground cover and leaf water content decreased with salt concentration of the irrigation water. Shoot dry weight of ROOTS®-treated turf was higher than the control, but not significantly when no salt was added to the irrigation water (Fig. 1). ROOTS®, under low and high salt concentration, enhanced foliar growth.

The dry weight of the grass roots was enhanced with ROOTS® application, regardless of salt concentration of the irrigation water (Fig. 2).

Although leaf water content of the non-treated grasses was consistently lower than the ROOTS® treated grass, statistical significance was obtained only when salt, or low salt treatments, were applied (Fig. 3). This indicated that the high salt application was extreme.

Ground cover was enhanced with ROOTS® treatment for all salt concentrations (Fig. 4). Turf treated with ROOTS® and irrigated with high salt water produced the same ground cover as plots not treated with ROOTS® and irrigated with no salt added water.

These data strongly suggest that turf treated with ROOTS® will tolerate the negative impact of irrigating with high concentrations of salt water.