No-Tillage Production of Transplanted Crops in High Cover Crop Residues
Due to increased regulations and loss of farmland, fewer acres in the South are available for production of transplanted crops (vegetables and tobacco) than in the past. Of the available acreage, some is not suitable for production because the slope is too great for conventional production practices.
In the early 1990s, a no-tillage (NT) system was developed for producing transplanted crops that, compared to conventional tillage (CT) methods, uses fewer chemicals, reduces erosion, utilizes cover crops for moisture management, and allows transplanting, spraying and harvesting at times when CT methods don’t allow access to the field.
Demonstrate NT, compared to CT, production systems for transplanted crops in three regions of Virginia.
Farmer cooperators with a sincere interest in NT production systems and a past history of farming excellence were selected by the project coordinators. Aiding in the selection were Cooperative Extension Service (CES) and Natural Resources Conservation Service (NRCS) agents in the three regions of Virginia (Mountain, Piedmont, and Coastal Plains)
Cover crops were seeded in the fall prior to summer transplanting of the vegetable crop. Efforts were made to produce high levels (2 to 4 tons dry matter/acre) of cover crop residues. Prior to transplanting, cover crops were sprayed with Gramoxone Extra and rolled, creating a flat uniformly thick cover of residues over the entire field.
In all cases, the NT vegetables were transplanted with a Subsurface Tiller-Transplanter (SST-T) that was originally developed by Dr. Ronald Morse of Virginia Tech University in the early 1990s. The SST-T has a high-clearance design to minimize dragging of crop residues and, in one pass across the field, it subsurface tills a narrow in-row area, sets the transplants in the narrow tilled strip, compacts the loosened soil around the transplant, and precision bands fertilizer on both sides of the row.
Although weeds were often more severe in the NT fields, using one or a combination of the following cultural practices can successfully control weeds in NT fields: high-density (multiple row) plantings, pre-emergence and post-emergence herbicides, hand weeding, and NT cultivators. Soil temperatures are cooler under cover crop residues; thus early spring plantings are not advised, unless raised beds and/or in-row residue cleaners are used. Because cover crop mulches enhance soil moisture, incidence of slugs can be higher in NT systems. Use of slug baits and other treatments may be necessary if slug problems are severe.
The no-tillage system of transplanting crops (vegetables and tobacco) is a viable production option. When using the SST-T, establishment and survival of plants were excellent; in most cases, equal or better than that obtained in comparable conventional fields.
No-till crop yields are as high or higher than that found in CT fields, except in situations where weeds are not controlled in NT fields.
When weeds are adequately controlled, there are four distinct advantages of using NT systems versus. CT:
Soil and water are conserved. Less irrigation water is needed when using high-residue, NT systems.
Flexibility of field operations is increased. Because the soil is untilled (firm) and covered with crop residues, farmers have greater access to their fields following rain.
In unirrigated fields, high-residue mulches generally increase yields in dry years.
Fruit quality is often higher in NT fields because surface crop residues serve as a protective barrier between the fruit and soil, reducing rotting and blemishes.
Outreach included four field days and production of a videotape and manual (in the final stages of preparation) entitled The No-tillage Advantage–A Profitable and Sustainable Alternative for Transplanted Crops. The four successful field days were held July 1996 at Hillsville (Mountain Region); July 1996 at Suffolk (Coastal Plains) Region; August 1996 at Williamsburg (Piedmont Region); October 1997 at Glade Spring (Mountain Region). An average of 35 farmers and agricultural service providers attended each field day.