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.
Joyce A. Swenson, S. Alan Walters, Michael E. Schmidt and She-Kong Chong
Patrice Cannavo, Houda Hafdhi and Jean-Charles Michel
( Fig. 5 ). It varied from 1867 μm to 766 μm at Day 0 and Day 196, respectively. Table 2. Hydraulic model parameters of Eq.  for peat water retention curves ψ ( θ ). z Fig. 4. Soil water retention curves of peat substrate. The peat volumetric water
Jennifer L. Boatright, J.M. Zajicek and W.A. Mackay
Two experiments were conducted in which a polyacrylamide gel (Hydrosource, Western Polyacrylamide) was incorporated into 56 × 38-cm, raised, concrete beds, 20 cm deep, with a drain pipe in the center of each bed. In Expt. 1, treatments included (in grams of i.a. N) 0, 186, 372, or 558 plus 0 or 366 g hydrogel/m2, for a total of eight treatments. Each treatment was replicated three times. Petunia plants were transplanted into each plot for a total of 30 plants per treatment. Plants were kept well watered. Polymer incorporation had no effect on soil water retention, soil NO3 or NH4 retention, or plant growth. Expt. 2 included treatments of 0 or 186 g of ai N and 0 or 366 g hydrogel/m2. Each treatment was replicated six times with 10 plants per replication, resulting in a total of 60 plants per treatment. Minimal irrigation was imposed on treatments. This study demonstrated that under suboptimal conditions of minimal irrigation and fertilization, polymer incorporation significantly increased soil moisture (17%), NH4 retention (83%), and NO3 retention where additional N was added (64%) compared to soils without polymer.
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.
Paraskevi A. Londra
standard mathematical form for its determination. Although the soil water retention function can easily be determined by measuring water contents at different pressure heads, the unsaturated hydraulic conductivity measurement is often laborious, time
Sanjit K. Deb, Parmodh Sharma, Manoj K. Shukla, Theodore W. Sammis and Jamshid Ashigh
Computer Corp., Bourne, MA). These sensors were installed at 10- and 20-cm depths and connected to Hobo H8 data loggers (Onset Computer Corp.). Soil temperatures were recorded every 30 min. The soil water retention model of van Genuchten (1980) was used
Philip J. Brown, Lambert B. McCarty, Virgil L. Quisenberry, L. Ray Hubbard Jr. and M. Brad Addy
. Two methods to ascertain water distribution and movement in soil are SWC curves and K sat . SWC curves describe soil water retention at different matric potentials or depths ( Rowell, 1994 ). As the matric potential increases, a corresponding increase
Xiaoyan Dai, Donald M. Vietor, Frank M. Hons, Tony L. Provin, Richard H. White, Thomas W. Boutton and Clyde L. Munster
water retention compared with soil without CMB during production and after transplanting of sod ( Boyle et al., 1989 ; Johnson et al., 2006 ). Organic C applied as CMB or CMB-amended sod could contribute to greater short- and long-term C storage in
Dilma Daniela Silva and Richard C. Beeson Jr.
-derived soil water retention curves for a fine sand soil using tensiometric, resistance and capacitance methods Plant Soil 234 153 157 Rab, A. Fisher, P. Robinson, N. Kitching, M. Aumann, C. Imhof, M. Chandra, S. 2010 Plant available water capacity of dryland
Ronnie W. Schnell, Donald M. Vietor, Richard H. White, Tony L. Provin and Clyde L. Munster
reduced soil bulk density 19.7% for a loam soil and 16.7% for a clay soil, which increased water content and retention for both soils. In addition to benefits during sod production, increases in soil water retention for sod grown with compared to without