There has been recent speculation in trade journals that landscape fabrics, while doing a excellent job of weed control, may have a detrimental effect upon ornamental plant growth. A study is in progress to investigate the manner in which applied landscape fabric affects soil aeration, soil temperature, and water infiltration rate over a period of 18 months. The experimental design is a split-plot with main plots identified as composted or non-composted areas. Within each main plot, the design is a randomized complete block with four blocks and three treatments per block (control, organic mulch, landscape fabric + organic mulch). Each plot has been planted with herbaceous perennials so as to allow analysis of treatment effects upon plant growth. Re-dox potential is measured on a weekly and infiltration rate is measured on a biweekly basis. Soil temperature within plots is monitored on a continuous basis. Preliminary results suggest that landscape fabrics have a detrimental effect on soil aeration and that this likely has a adverse effect upon plant growth. An attempt will be made in this study to contrast any adverse effects of landscape fabric use with the obvious benefits offered by increased weed control.
Paul H. Henry and She-Kong Chong
Amy O'Leary, Paul Henry and She-Kong Chong
There has been recent speculation in trade journals that landscape fabrics, while doing an excellent job of weed control, may have a detrimental effect on ornamental plant growth. A study is in progress to investigate the manner in which hardwood mulch and applied landscape fabric affect soil temperature, soil aeration, and water content over 18 months. Two experiments are in progress, one with compost incorporated at 50% soil volume, the other with no compost incorporation. The experimental design is a randomized complete block with four treatments (mulch, fabric, fabric plus mulch, and control) and four plants per plot. Each plot has been planted with herbaceous perennials so as to allow analysis of treatment effects on plant growth. Soil temperature within plots is monitored on a continual basis. Soil aeration is measured every two weeks using installed oxygen tubes. Water content is measured using time domain reflectometry 24 and 48 h after a significant rainfall event. Preliminary results suggest that hardwood mulch and landscape fabric are similar in their effect on soil water content 0 to 48 h after a significant rainfall event. However, after 48 h, hardwood mulch increases soil water retention compared to landscape fabric.
Joyce A. Swenson, S. Alan Walters, Michael E. Schmidt and She-Kong Chong
Water management is often the key to successful vegetable culture. Various mulching/tillage systems are often utilized in tomato production, depending upon the available resources of a particular grower, to achieve better water use efficiency. A study was conducted to compare six different mulching/tillage systems to observe the influence of these systems on soil water retention as well as on `Fabulous' tomato (Lycopersicon esculentum Mill.) production. Winter ryegrass and wheat were the cover crops utilized and were mowed with the following six treatments then applied: 1) Conventional tillage (CT), 2) black plastic over conventional tillage (BP), 3) no-till with cover crop sprayed with Glyphosate prior to transplanting (NT-GLY), 4) strip-till with cover crop sprayed with Glyphosate prior to transplanting (ST-GLY), 5) no-till in which cover crop was mowed periodically during the growing season (NT), and 6) strip-till with cover crop mowed periodically during the growing season (ST). This test was conducted under severe drought conditions (45.4 mm of rain from 1 July to 30 Sept. 1999) with plants receiving no supplemental water via irrigation at any time throughout the study. Soil moisture was measured periodically throughout the growing season at a depth of 20 cm; soil and mulch surface temperatures were taken at similar timings as soil moisture. Soil moisture levels during the growing season indicated different patterns of water depletion when comparing the six treatments. There was no significant difference between the winter rye and wheat with respect to water depletion or tomato yields. Lower early tomato yields under NT, ST, NT-GLY, and ST-GLY indicate that cooler soil conditions, while aiding in the retention of soil moisture, delay early tomato production when compared to the warmer soil conditions found under CT and BP. Results also indicate that late season harvests under NT and ST systems produce predominantly cull fruits with a high incidence of blossom-end rot. The NT-GLY and ST-GLY systems tended to produce comparatively lower levels of cull fruit and blossom-end rot in late season harvests than any of the other six treatments.