Soil physical properties, water depletion and crop development under traditional and conservation tillage in southern Spain

A long-term tillage trial was conducted (1981 to 1987) on loamy textured soils to quantify changes in runoff, soil loss and some soil physical properties due to conservation tillage practices. Two sites were established, one at Cowra on a sandy loam textured soil, and the other at Grenfell on a loamy textured soil. The tillage treatments imposed were direct drilling (DD), reduced tillage (RT) and traditional tillage (TT), with grazing at both sites, and a direct drilling ungrazed (NT) treatment at Cowra only. Runoff and soil loss were measured using a rainfall simulator, and sorptivity (S), saturated hydraulic conductivity (Ksat), bulk density to 40 mm (BD4) and 100 mm (BD10), organic carbon (OC) and water stable aggregates (WSA) were measured annually. Runoff decreased significantly in the minimum soil disturbance treatments (NT and DD) at Cowra. Runoff did not decrease in the stubble incorporation treatments despite a significant increase in OC and WSA. Decreases in runoff were due to the development and maintenance of porosity, particularly macropores. Changes in other soil physical properties were generally not significant owing to temporal variability. The regression relationship between OC and WSA, although significant, had little practical value because of high prediction error. Although improvements in soil physical properties were measured, a period of at least five years of cropping at both sites was required before they became significant and consistent.

Download Full-text

Soil Physical Properties and Potato Yield in No-till, Subsurface-till, and Conventional-till Systems

HortTechnology ◽

10.21273/horttech.9.2.240 ◽

1999 ◽

Vol 9 (2) ◽

pp. 240-247 ◽

Cited By ~ 13

Author(s):

Charlotte Mundy ◽

Nancy G. Creamer ◽

L. George Wilson ◽

Carl R. Crozier ◽

Ronald D. Morse

Keyword(s):

Physical Properties ◽

Sandy Loam ◽

Conservation Tillage ◽

Potato Production ◽

Soil Physical Properties ◽

Plant Population ◽

Growth And Yield ◽

Greenhouse Study ◽

Ct System ◽

Potato Growth

Conservation tillage using residue from a cover crop grown before potato (Solanum tuberosum L.) production has been infrequently and inconclusively studied. The objectives of this study were to 1) conduct a field study to evaluate soil physical properties, and potato growth and yield, in conventional-tillage (CT), no-tillage (NT), and subsurface-tillage (SST) systems and 2) conduct a greenhouse study to evaluate the effect of soil bulk density (ρb) on potato growth and yield. Potatoes (`Atlantic') were planted into residue of sorghum-sudangrass [Sorghum bicolor (L.) Moench × S. sudanense (Piper) Staph] at two sites in eastern North Carolina—Plymouth into Portsmouth fine sandy loam and Lewiston into Norfolk sandy loam. Potatoes in the NT and SST system emerged more slowly than potatoesplanted conventionally. There were no differences in plant population or size by 8 weeks after planting at Plymouth, but plant population and size were less in NT and SST systems at Lewiston. Reducing tillage also affected soil compaction, increased soil moisture early in the season at both sites, and increased ρb at Lewiston. Yield of U.S. No. 1 potatoes planted in NT and SST systems were comparable to potatoes planted in a CT system at Plymouth, but were less than potatoes planted in a CT system at Lewiston. There were no differences in yield between potatoes planted with NT and SST. In the greenhouse study, ρb did not affect leaf area or tuber yield or tuber grade. Specific sites and soils may allow for comparable potato production with no or SST, but further research, conducted on different soil types would promote further understanding of the impacts of reducing tillage in potato production.

Download Full-text