Research yields of conservation tillage (CT) snap beans (Phaseolus vulgaris L.) and sweet corn (Zea mays L. var. rugosa Bonaf.) have been less than those produced under conventional tillage. This has been due to soil conditions at planting, the cover crop used, weed control and a lack of proper design in equipment for CT. However, some growers have been successful with CT for sweet corn using hairy vetch (Vicia villosa Roth.) as the cover crop. On-farm demonstrations of CT with cabbage (Brassica oleracea L. Capitata Group), pumpkins (Cucurbita pepo L.), tomatoes (Lycopersicon esculentum Mill.) and watermelons [Citrullus lanatus (Thunb) Matsum. & Nak.] have been successful and with good management it is commercially feasible under Tennessee conditions. Advantages include reduced soil erosion, cleaner products, more efficient application of crop protection chemicals, quicker planting after rainfall, lower energy costs and facilitation of harvest in wet weather. Disadvantages include reduced weed control, modifications of existing equipment, less uniformity in seed coverage and problems with transplanting, cover crop residue in mechanically harvested crops, possible delays in early harvest of fresh market crops due to delayed maturity and limited application of soil protective chemicals.
Alvin D. Rutledge
Lewis W. Jett and Timothy P. Talbot
A cultural practice that can modify and conserve the soil environment is needed in sweetpotato [Ipomoea batatas (L.) Lam.] production. The objective of this research was to evaluate conventional and conservation tillage of sweetpotato with four cover crop species (fallow, ryegrass, rye, and wheat). The cover crops were seeded in late Oct. 1995, and the sweetpotato transplants (`Beauregard') were transplanted at two dates the following spring (May and June). Conservation tillage significantly lowered soil temperature (10 cm depth) during storage root initiation and development. Moreover, each cover crop significantly reduced weed emergence and soil erosion. The ryegrass conservation tillage treatment significantly increased marketable yield of sweetpotato in the first planting date, while rye and wheat performed equally well in the second planting date. In the second planting date, white grub (Phyllophaga ephilida Say) injury to storage roots was significantly higher in the conservation tillage treatments. However, conservation tillage seems to be a viable alternative to the conventional method of sweetpotato production.
G.D. Hoyt, D.W. Monks, and T.J. Monaco
Conservation tillage is an effective sustainable production system for vegetables. No-till planters and transplanters and strip-till cultivation equipment are presently available for most vegetables. Lack of weed management tools (herbicides, cultivators, etc.) continues to be the cultural practice that limits adaptability of some vegetables to conservation tillage systems. Nitrogen management can be critical when grass winter cover crops are used as a surface residue. Advantages of using conservation tillage include soil and water conservation, improved soil chemical properties, reduction in irrigation requirements, reduced labor requirements, and greater nutrient recycling. However, disadvantages may include lower soil temperatures, which can affect maturity date; higher chemical input (desiccants and post-emergence herbicides); potential pest carryover in residues; and enhancement of some diseases.
Jeffrey P. Mitchell, Karen M. Klonsky, Eugene M. Miyao, Brenna J. Aegerter, Anil Shrestha, Daniel S. Munk, Kurt Hembree, Nicholaus M. Madden, and Thomas A. Turini
of “conservation tillage” approaches that reduce the frequency of tillage in tomato production systems have been evaluated and are now beginning to be used by tomato producers. The term “conservation tillage” as defined by the University of California
Guangyao Wang and Mathieu Ngouajio
dispersal ( Hausbeck and Lamour, 2004 ; Ristaino and Johnston, 1999 ). Cover cropping, combined with conservation tillage, can leave enough residue on the soil surface to minimize contact of the soil by fruit. Ristaino et al. (1997) showed that no
Maren J. Mochizuki, Anusuya Rangarajan, Robin R. Bellinder, Harold M. van Es, and Thomas Björkman
Conservation tillage systems minimize soil disturbance and maintain 30% cover with surface residue ( SSSA, 2005 ). Despite potential improvements in soil physical and biological properties, the adoption of conservation tillage practices for
D.S. NeSmith, G. Hoogenboom, and D.V. McCracken
Three summer squash (Cucurbita pepo L.) cultivars were grown using conventional tillage and no-till soil management practices during 1991 and 1992 in the mountain regions of Georgia. Soil bulk density and N content as well as crop dry weight, leaf area, and yield were monitored to assess the potential for using conservation tillage in squash production. Soil bulk density of the surface (0 to 10 cm) layer under no-till exceeded. that under conventional tillage at planting by 0.25 Mg·m-3, and 1 month after planting by as much as 0.16 Mg·m-3. However, growth-limiting bulk densities (>1.45 Mg·m-3) did not occur. Total soil N to a 30-cm depth was similar for the two tillage regimes. There were no significant cultivar × tillage interaction effects on plant dry weight, leaf area, or crop yield. Total yields were similar for the two tillage regimes; however, early yield during 1991 was 27% less using no-till. There is potential for the use of conservation tillage in summer squash production in the southeastern United States. However, the current lack of registered herbicides for weed control and possible early market price incentives are likely disadvantages to widespread acceptance of such cultural practices.
J.P. Mitchell, W.T. Lanini, S.R. Temple, E.V. Herrero, E.M. Miyao, P. Brostrom, R. Morse, and F. Thomas
Conservation tillage (CT) row crop production is currently not widely adopted in California. Recently, however, interest in evaluating the potential of CT systems to reduce production costs and improve soil quality is growing in many areas in the state. In 1997 and 1998, we evaluated four cover crop mulches (rye/vetch, triticale/vetch, Sava medic, and Sephi medic) in a CT-transplanted tomato system relative to the conventional winter fallow (CF) practice. In both years, yields were comparable to the CF under the triticale/vetch and rye/vetch mulches. Earthworm populations after 2 years of CT production were increased 2- to 5-fold under mulches relative to the CF system. Soil carbon was increased by 16% and 6% after 2 years of CT production under the triticale/vetch and rye/vetch mulches, respectively. Weed suppression under the triticale/vetch and rye/vetch was comparable to the CF with herbicide system early in the season in both years but was maintained through harvest in only one season. Soil water storage (0-90 cm) was similar at the beginning of the tomato season in triticale/vetch, rye/vetch, and fallow plots but was higher under the mulches during much of the last 45 days of the 1998 season. Further refinement of CT practices in California's vegetable production regions is needed before wider adoption is likely.
Suhas R. Ghate, Donald R. Sumner, and Sharad C. Phatak
Cucumber crop was established in conservation tillage from gel-sown germinated seed. Fungicides (flutolanil + metalaxyl) were mixed with gel or applied as a drench after seeding to control Rhizoctonia and Pythium seedling diseases. The benefit of mixing fungicides with gel was similar to drenching the seeded area with fungicides. There was no added advantage of using germinated seed for cucumber production in conservation tillage. In fact, germinated seed was more susceptible to fungal diseases in the absence of fungicides. Crop yield was greater in conventionally-prepared soil than in conservation tillage.
Ronald W. Garton
Processing tomatoes were planted on a sandy loam soil on raised beds which were prepared in a conventional method with a power bedder (PB), or with conservation tillage (CT). The CT treatments were prepared by using Glyphosate herbicide to burn-off a fall-seeded rye cover crop at either 10cm, 15cm or 30cm height. The center of the bed was tilled with a modified conservation tillage coulter caddy, prior to planting the tomatoes, to loosen the soil but leave the rye residue on the surface. Crop residue cover on the soil surface after planting the tomatoes increased from 9% in the PB treatment, to 63% with CT at 30cm. Increasing crop residue cover resulted in cooler soil temperatures during the day and warmer soil temperatures at night. Transplant survival and early growth was comparable between the tillage systems. Tomato yield was approximately 10% higher in the PB treatment than in the CT treatments. In the conservation tillage treatments, the tomato plants had lower total nitrogen concentrations in the petioles. Nitrogen immobilization by microbes in the decaying cover crop residue may have contributed to the lower petiole N concentrations, and the yield reduction.