Providing evidence to improve practice

Action: Water: Use no tillage instead of reduced tillage Mediterranean Farmland

Key messages

Water use (1 study): One replicated, randomized, controlled study from Spain found that crops used water more efficiently in plots with no tillage, compared to reduced tillage, in one of four comparisons.

Water availability (9 studies): Six controlled studies from Spain (five of which were replicated and randomized) found more water in soils with no tillage, compared to reduced tillage, in some or all comparisons. One replicated, randomized, controlled study from Spain found less water in soils with no tillage, compared to reduced tillage, in one of fifteen comparisons. Two replicated, randomized, controlled studies from Australia and Lebanon found similar amounts of water in soils with no tillage or reduced tillage.

Pathogens and pesticides (0 studies)

Nutrients (0 studies)

Sediments (0 studies)

Supporting evidence from individual studies

1 

A controlled study in 1994–1999 in a rainfed legume-cereal field near Barcelona, Spain, found more water in soils with no tillage, compared to reduced tillage. Water availability: More water was found in soils with no tillage, compared to reduced tillage (33 vs 29 mm mean topsoil water content in February–May). Methods: No tillage or reduced tillage was used on one plot each (90 x 30 m plots). A cultivator (August), a chisel plough (September), and a harrow and roller (November) were used for reduced tillage (depth not reported). Herbicide was used for no tillage (August). Herbicide was used in both plots in September and January, and fertilizer was added in October. Seeds were sown with a seed drill in December and crops were harvested in July. Crop residues were removed from all plots before tillage. Water was measured weekly (February–May, two time-domain reflectometer probes/plot, 20 cm depth).

 

2 

A replicated, randomized, controlled study in 2003–2005 on rainfed farms in the Ebro river valley, Spain, found more water in soils with no tillage, compared to reduced tillage. Water availability: More water was found in soils with no tillage, compared to reduced tillage, in 10 of 18 comparisons, in the two days after tillage (0.08–0.26 vs 0.05–0.23 g water/g soil). Methods: No tillage or reduced tillage was used on seven plots each (33–50 x 7–10 m plots), on a total of two farms, with multiple crops. A cultivator (15 cm depth) or chisel plough (25–30 cm depth) was used on plots with reduced tillage. Herbicide was used on plots with no tillage. Water was measured in soil samples (5 cm depth), at three times (0, 24, and 48 hours after tillage).

 

3 

A replicated, randomized, controlled study in 1996–2008 in a rainfed barley field in the Ebro river valley, Spain (same study as (5,6)) found more water in soils with no tillage, compared to reduced tillage. Water availability: More water was found in soils with no tillage, compared to reduced tillage (0.09–0.25 vs 0.06–0.21 g water/g dry soil). Methods: No tillage or reduced tillage was used on nine plots each (50 x 6 m). A cultivator was used for reduced tillage (10–15 cm depth, 50% incorporation of crop residues). Two-thirds of the plots were fertilized (60 or 120 kg N/ha). Water content was measured in soil samples (0–5 cm depth).

 

4 

A replicated, randomized, controlled study in 2005–2007 in a rainfed field in the central Bekaa Valley, Lebanon, found no difference in water content between soils with no tillage and soils with reduced tillage. Water availability: No difference in water content was found in soils with no tillage and soils with reduced tillage (11–32% water). Methods: No tillage or reduced tillage (shallow disc cultivation, 10 cm depth) was used in four plots each (14 x 6 m), in October. Barley, chickpeas, and safflower were planted in November. Barley and safflower were fertilized (60–100 kg N/ha). Soil water was measured at two depths (25 and 50 cm), on five dates from 30 March 2005–16 August 2006, with a time domain reflectometer.

 

5 

A replicated, randomized, controlled study in 1996–2009 in a rainfed barley field in the Ebro river valley, Spain (same study as (3,6)), found higher water-use efficiency in plots with no tillage, compared to reduced tillage, in one of four comparisons. Water use: Higher water-use efficiency was found in plots with no tillage, compared to reduced tillage, in one of four comparisons (6.0 vs 4.3 kg barley grain/mm rainfall). Methods: No tillage or reduced tillage was used on nine plots each (50 x 6 m plots). A cultivator was used for reduced tillage (10–15 cm depth, 50% incorporation of crop residues), in October or November. A seed drill and herbicide were used for no tillage. Two-thirds of the plots were fertilized (60 or 120 kg N/ha). Soil samples were collected five times/year (two samples/plot, 4 cm diameter soil auger, 0–100 cm depth) in 2005–2009. Mature barley was harvested in June 2006–2009.

 

6 

A replicated, randomized, controlled study in 1996–2009 in a rainfed barley field in the Ebro river valley, Spain (same study as (3,5)), found more water in soils with no tillage, compared to reduced tillage, in some comparisons. Water availability: More water was found in soils with no tillage, compared to reduced tillage, in seven of 16 comparisons (120–215 vs 105–195 g water/g soil). Methods: No tillage or reduced tillage was used on nine plots each (50 x 6 m plots). A cultivator was used for reduced tillage (10–15 cm depth, 50% incorporation of crop residues), in October or November. A seed drill and herbicide were used for no tillage. Two-thirds of the plots were fertilized (60 or 120 kg N/ha). Soil samples were collected four times/year in 2005–2009 (0–100 cm depth).

 

7 

A replicated, randomized, controlled study in 2008–2013 in a rainfed wheat-sunflower-pea field near Seville, Spain, found more water in soils with no tillage, compared to reduced tillage. Water availability: More water was found in soils with no tillage, compared to reduced tillage, in one of three comparisons (0–5 cm depth, in early May 2013: 19.1% vs 9.15% soil moisture). Methods: No tillage or reduced tillage was used on three plots each (6 x 33.5 m plots). A chisel plough (25 cm depth), a disc harrow (5 cm depth), and herbicide were used for reduced tillage. A seed drill and herbicide were used for no tillage. Wheat, sunflowers, and peas were grown in rotation. Wheat was fertilized, but sunflowers and peas were not. Soil moisture was measured in May 2013 (0–5 cm depth, time-domain-reflectrometry probes) and early June (0–10 cm depth, gravimetric).

 

8 

A replicated, randomized, controlled study in 2010–2011 in a rainfed wheat field in Australia found similar amounts of water in soils with no tillage or reduced tillage. Water availability: Similar amounts of water were found in soils with no tillage or reduced tillage (161–168 vs 163–179 mm). Methods: No tillage or reduced tillage was used on three plots each (1.4 x 40 m plots) in 2010, when the plots were fallow. A rotary hoe (12 cm depth) was used for reduced tillage. Herbicide was used for no tillage. Wheat was grown on all plots in 2011. Fertilizer (150 kg/ha) and herbicides were used on all plots in 2011. Soil water was measured with a neutron moisture meter (1.5 m depth, between September 2010 and December 2011).

 

9 

A replicated, randomized, controlled study in 1987–2010 in rainfed cereal fields in the Ebro river valley, Spain, found less water in soils with no tillage, compared to reduced tillage. Water availability: Less water was found in soils with no tillage, compared to reduced tillage, in one of 15 comparisons (in Selvanera: 110 vs 150 mm volumetric water content). Methods: No tillage or reduced tillage was used on ten plot each (Peñalba: three plots each, 34 x 175 m plots, established in 2005; Agramunt: four plots each, 9 x 50 m plots, established in 1990; Selvanera: three plots each, 7 x 50 m plots, established in 1987). A cultivator (Peñalba: 10 cm depth; Agramunt: 15 cm) or a chisel plough (Selvanera: 15 cm) was used for reduced tillage. Herbicide was used for no tillage. Barley (Peñalba) or wheat (Agramunt and Selvanera) was planted in November 2009 with a seed drill (2–4 cm depth) and harvested in June–July 2010.

 

10 

A replicated, randomized, controlled study in 1994–2011 in a rainfed cereal-legume field near Madrid, Spain, found more water in soils with no tillage, compared to reduced tillage. Water availability: More water was found in soils with no tillage, compared to reduced tillage, in some comparisons (amounts of water and numbers of comparisons not reported). Methods: No tillage or reduced tillage was used on three plots each (10 x 25 m). A chisel plough and a cultivator were used for reduced tillage (15 cm depth) in October. A seed drill and herbicide were used for no tillage. Soil samples were collected 1–12 times/month, in November 2010–October 2011 (0–15 cm depth, 2.5 cm diameter).

 

Referenced papers

Please cite as:

Shackelford, G. E., Kelsey, R., Robertson, R. J., Williams, D. R. & Dicks, L. V. (2017) Sustainable Agriculture in California and Mediterranean Climates: Evidence for the effects of selected interventions. Synopses of Conservation Evidence Series. University of Cambridge, Cambridge, UK.