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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #321425
Title: Cover cropping and no-tillage improve soil health in arid irrigated cropping systems

Author
item MITCHELL, JEFF - University Of California
item SHRESTHA, ANIL - California State University
item MATHESIUS, KONRAD - University Of California
item SCOW, KATE - University Of California
item SOUTHARD, RANDY - University Of California
item Haney, Richard
item SCHMIDT, RADOMIR - University Of California
item HORWATH, WILLIAM - University Of California

Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cover crops are an important tool to increase fertility in soil. However, their adoption in some areas of the country has been limited due to the concern that they will not provide an increase in fertility for the time and expense involved in establishing a cover crop system. This research shows that cover crops can greatly enhance the fertility of California soil given time and a sustained commitment to a cover crop system. Impacts of no-tillage and cover crops on soil health evaluated in California’s San Joaquin Valley were the following: 1) Increased surface soil C and N with cover crops and no-tillage in arid San Joaquin Valley. 2) Impacts of no-tillage and cover crops are soil depth-dependent and 3) there are benefits from cover cropping and no-tillage seen for arid regions.

Technical Abstract: The impact on soil health of long-term no-tillage (NT) and cover cropping (CC) practices, alone and in combination, was measured and compared with standard tillage (ST) with and without cover crops (NO) in irrigated row crops after 15 years of management in the San Joaquin Valley, CA. Soil aggregation, rates of water infiltration, content of carbon, nitrogen, water extractable organic carbon (WEOC) and nitrogen (WEON), residue cover, and biological activity were all increased by NT and CC practices relative to STNO. However, effects varied by depth with NT increasing soil bulk density by 12% in the 0 – 15 cm depth and 10% in the 15 – 30 cm depth. Higher levels of WEOC were found in the CC surface (0 – 5cm) depth in both spring and fall samplings in 2014. Surface layer (0 – 15 cm) WEON was higher in the CC systems for both samplings. Tillage did not affect WEON in the spring, but WEON was increased in the NT surface soil layer in the fall. Sampling depth, CC, and tillage affected 1-day soil respiration and a soil health index assessment, however the effects were seasonal, with higher levels found in the fall sampling than in the spring. Both respiration and the soil health index were increased by CC with higher levels found in the 0 – 5 cm depth than in the 5 -15 and 15 – 30 cm depths. Significant improvements in soil chemical, physical and biological properties indicated that adoption of management practices using NT and CC would benefit farmers who adopt these conservation agriculture systems in arid irrigated soils.