Effects of Tillage Practices on Cotton Double Cropped with Wheat1

Abstract

AbstractTo reduce production cost, reduce land erosion and increase profits per acre, double cropping and reduced tillage are becoming a part of production systems across the United States. Tillage studies with double crop (DC) wheat (Triticum aestivum L.) and cotton (Gossypium hirsutum L.) were conducted at two Georgia locations, Tifton (1982–1984) and Plains (1981–1984). At Tifton, continuous tillage treatments (same treatments on the same plot every year) were: a winter fallowed full‐season (FS) check; no‐tillage (NT), cotton planted into straw and stubble; burn no‐tillage (BNT), plots burned, no other tillage; maximum tillage (MXT), plots burned and bottom plowed; minimum tillage (MTH), plots burned and disc harrowed; and minimum tillage (MTRH), plots burned, subsoiled, and bedded (riphip). The treatments at Plains were non‐continuous (test rotated to new area each year) and did not include a FS or MTRH treatment. The DC cotton at Tifton showed a significant yield reduction when compared with the FS cotton, regardless of DC tillage treatment. Within tillage treatments, continuous MXT, MTH, or MTRH had no significant effect on cotton yield, but the average yield of the tilled treatments over years was significantly better than those of the NT and BNT treatments. In certain years the BNT treatment yield was equal to some of the tilled treatments. Yield of the BNT treatment was significantly better than the NT treatment. At Plains, the average yields of the BNT, MTH, and NT treatments were not significantly different, but the BNT was significantly better than the MXT treatment. The MXT and MTRH treatments produced a higher lint percent than FS, but there were no differences in the DC tillage treatments at Tifton. Boll size and fiber characteristics were similar for DC and FS cotton at Tifton. The MXT treatment at Plains produced larger bolls than did the other treatments, but there was no treatment effect for lint percent and fiber properties. Wheat yields at Tifton were not affected by cotton tillage treatments.