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United States Department of Agriculture

Agricultural Research Service

Title: Tillage and Cropping System Effects on Conditions of Soil Cropped to Grain Sorghum

Authors
item Alemu, Getachew - INST AGRIC RES, ETHIOPIA
item Unger, Paul
item Jones, Ordie

Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 29, 1996
Publication Date: N/A

Interpretive Summary: Soil and water conservation are important for dryland crop production in semiarid regions. In 1994, effects of soil conditions and grain sorghum yields were studied where continuous sorghum (CS) or winter wheat-grain sorghum-fallow (WSF) systems and no- (NT) or stubble mulch (SMT) tillage treatments had been used for 10 years. Treatments were CS-NT, CS-SMT, WSF- -NT, and WSF-SMT. A DISK treatment was also used in 1994. Residue cover before planting was over 70% with CS-NT and WSF-NT, 29% with CS-SMT, 12% with WSF-SMT, and 0% with DISK. Cover after planting was about 50% with CS-NT and WSF-NT, and other treatments had amounts similar to those before planting. Soil organic matter (OM) (0- to 20-cm depth), water-stable aggregation (WSA) (0-to 2-cm depth), and surface roughness were or tended to be greater on CS than on WSF plots. Organic matter was not affected by tillage, WSA was greater with SMT, and RR was greater with CS-NT. Use of disk tillage did not affect OM or WSA, but reduced surface roughness. Dry aggregates were smaller with NT than with other treatments. Plant- available water at planting ranged from 177 mm with DISK to 281 mm with WSF-NT, and tended to be greater for WSF than for CS. Infiltration tended to be greater on CS than on WSF plots, was not affected by tillage within cropping systems, and was less with DISK than with other tillage methods on CS plots. Poor weed control lowered grain yield with NT (1.54 Mg/ha) compared with SMT (2.24 Mg/ha) in CS plots. Yield was 3.94 Mg/ha with NT and 3.44 Mg/ha with SMT in WSF plots. This study showed that both tillage methods are suitable, but WSF is better than continuous cropping for dryland crop production in the semiarid U.S. southern Great Plains.

Technical Abstract: Soil and water must be conserved to sustain dryland crop production in semiarid regions. This study evaluated soil conditions and sorghum [Sorghum bicolor (L.) Moench] yields where continuous sorghum (CS) or winter wheat (Triticum aestivum L.)-grain sorghum-fallow (WSF) systems and no- (NT) or stubble mulch (SMT) tillage treatments were used for 10 years. Treatments were CS-NT, CS-SMT, WSF-NT, and WSF-SMT. A DISK treatment was imposed in 1994. Residue cover before planting was >70% with CS-NT and WSF-NT, 29% with CS-SMT, 12% with WSF-SMT, and 0% with DISK. Cover after planting was about 50% with CS-NT and WSF-NT, and amounts with other treatments were similar to those before planting. Soil organic matter (OM) (0- to 20-cm depth), water-stable aggregation (WSA) (0-to 2-cm depth), and random roughness (RR) were or tended to be greater on CS than on WSF plots. Tillage did not affect OM, WSA was greater with SMT, and RR was greater with CS-NT. DISK tillage for one season did not affect OM or WSA, but reduced RR. Dry aggregates were smaller with NT than with other treatments. Plant-available water at planting ranged from 177 mm with DISK to 281 mm with WSF-NT, and tended to be greater for WSF than for CS. Infiltration tended to be greater on CS than on WSF plots, was not affected by tillage within cropping systems, and was less with DISK than with other tillage methods on CS plots. Poor weed control lowered grain yield with NT (1.54 Mg/ha) compared with SMT (2.24 Mg/ha) in CS plots. Yield was 3.94 Mg/ha with NT and 3.44 Mg/ha with SMT in WSF plots. Both tillage methods are suitable, but WSF is better than continuous cropping for sustaining dryland crop production in the semiarid U.S. southern Great Plains.

Last Modified: 9/10/2014
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