Many soils of the southern U.S. are highly weathered and acidic because of the age of the parent material and the warm, moist climate. This region faces some of the most erosive rainfall in the country. On the positive side, the growing season (200-260 days) is often used to raise more than one crop per year (multi-cropping), which can enhance residue production and add soil organic benefits.
Crops in this region include cotton, soybeans, peanuts, corn, wheat, grain sorghum, rice, sugarcane, tobacco and a variety of horticultural crops from melons to green beans.

This region includes:
Alabama
Arkansas
Florida
Georgia
Mississippi
North Carolina
Oklahoma (eastern)
South Carolina
Tennessee
Texas (eastern)
Virginia

Challenges
The warm climate speeds decomposition of crop residue and can claim as much as 75% of the initial cover by the time the next crop is planted. Lack of residue at planting time is compounded by the fact that soybeans and cotton (two of the more common crops in the region) are low residue-producers. In addition, some cotton pest management strategies require removing or burying cotton stalks to comply with bowl-weevil eradication programs, reducing or eliminating residue benefits.
Many soils in the region have restrictive layers (horizons) approximately 7-14 inches deep, which can prevent the movement of water and growth of roots down into the soil profile.

Possible solutions
Cover crops can be one of the most effective ways to add residue to a production system. The most common covers in the south are hairy vetch, wheat, rye, crimson clover, and winter annual weeds. Cover crops not only help reduce erosion, they add organic matter to the soil and help conserve moisture. Because these legumes contribute nitrogen for the next crop, it is possible to reduce the amount of nitrogen fertilizer required.

No-till or strip-till cotton production is on the rise in the south.

Cover crops can deplete soil moisture for a cash crop that follows unless the cover is killed 10-14 days before planting the cash crop. Dual-use cover crops reduce production costs. The common wheat-soybean double cropping system takes advantage of wheat as a cover crop as well as a cash crop.
Innovative cropping strategies include planting grain sorghum or tropically-adapted corn hybrids late enough that they allow crimson clover to naturally reseed in a no-till system. Crimson clover planted in the fall and followed with no-till soybeans will allow the clover to reseed. Corn can then be planted into the reseeded clover and soybean residue in spring of the second year to take full advantage of nitrogen supplied by both legumes (soybeans and clover).
For soils with restrictive layers, in-row chiseling or subsoiling should be used to facilitate more rapid infiltration of rainfall and improve deeper plant rooting. This concept, coupled with planting into the subsoiled strip, (on a "clean" seed bed) is commonly referred to as "strip-till." Some producers chisel or subsoil annually, while others do so every 2-3 years.
The downside to suboiling is the need for high horsepower. However, some research suggests that soil improvements from continuous high-residue farming could eventually make deep tillage unecessary. Prospects of increased infiltration rates and rooting depths are aided by multi-cropping as well as fewer trips with heavy equipment.

Note:
Mow cotton stalks higher (6-8 inches or more) so they will bend easily and prevent problems with cattle or farm vehicle tires.

For more region-specific information on conservation tillage, send for one of the publications listed on page 35.