Providing evidence to improve practice

Action: Water: Add manure to the soil Mediterranean Farmland

Key messages

Water use (0 studies)

Water availability (3 studies): One replicated, randomized, controlled study from Turkey found more water in soils with added manure, compared to soils without added manure. Two replicated, controlled studies (one randomized) from Greece and the USA found similar amounts of water in soils with or without added manure.

Pathogens and pesticides (0 studies)

Nutrients (2 studies): One replicated, randomized, controlled study from Spain found more dissolved organic carbon, but similar amounts of nitrate, in runoff from plots with added manure, compared to plots without added manure. One replicated, randomized, controlled study from Spain found that more nitrate, ammonium, phosphorus, potassium, and organic matter was leached from soils with added manure, compared to soils without added manure.

Sediments (0 studies)

Supporting evidence from individual studies

1 

A replicated, controlled study in 1997–1998 in irrigated fallow land in California, USA, found similar amounts of water in soils with or without added manure. Water availability: Similar moisture content was found in soils with or without added manure (111 vs 101 g/kg). Methods: Plots (2 x 2 m) had added poultry manure (25 Mg/ha) or no added fertilizer (five plots for each). Manure was added in April 1987, February 1988, and October 1988 and was immediately incorporated into the soil (15 cm depth). Plots were irrigated weekly (100 mm/day). Five soil samples (25–100 mm depth) were taken from each plot.

 

2 

A replicated, randomized, controlled study in 1995–1999 in arable farmland in southern Turkey found more available water in soils with added manure, compared to soils without added manure. Water availability: More available water was found in soils with added manure, compared to soils without added manure (0.14 vs 0.09 cm3 water/cm3 soil). Methods: Cattle manure (25 t/ha) was added to three treatment plots (10 x 20 m), but not three control plots. Wheat, sweet peppers, and maize were grown in rotation. Soils were sampled in 1999, after harvesting the last wheat crop (0–30 cm depth). The difference between water retention at field capacity (–33 kPa) and at permanent wilting point (–1,500 kPa) was used to determine available water content.

 

3 

A replicated, randomized, controlled study in 2001–2005 in the Guadalquivir Valley, Andalusia, Spain, found more nutrients and sediments in runoff from soils with added manure, compared to soils without added manure, after rainfall. Nutrients: More nitrate, ammonium, phosphorus, and potassium were found in runoff from plots with added manure, compared to plots without added manure, after rainfall (60 mm rainfall/hour, nitrate: 0.15–0.40 vs 0.07–0.09; ammonium: 6–10 vs 1; phosphorus: 0.3–0.7 vs 0; potassium: 4.1–7.9 vs 1–1.4 mg/litre water) (140 mm rainfall/hour, nitrate: 0.42–0.85 vs 0.10–0.19; ammonium: 16–31 vs 2–3; phosphorus: 0.9–1.8 vs 0; potassium: 11.4–22.3 vs 0.9–2.5 mg/litre water). Sediments: More organic matter was found in runoff from soils with added manure, compared to soils without added manure, after rainfall (60 mm rainfall/hour: 7–10 vs 0 mg C/litre water; 140 mm rainfall/hour: 16–26 vs 0). Methods: There were four plots (9 x 9 m) for each of two treatments (5.8 or 11.6 t poultry manure/ha) and four control plots (no manure). The manure was added in October 2001–2004, and soils were ploughed (25 cm depth). Soils were watered to simulate rainfall in October 2002–2005 (60 or 140 mm rainfall/hour), and soil loss was measured in plots (1 x 1 m) that overlapped the borders of the treatment and control plots by 0.5 m.

 

4 

A replicated, randomized, controlled study in 2007–2009 in an irrigated onion field near Madrid, Spain, found that more dissolved organic carbon was leached from soils with added manure, compared to soils without added manure. Nutrients: Similar amounts of nitrate were leached from soils with or without added manure (1 vs 17 kg/ha). More dissolved organic carbon was leached from soils with added manure (5 vs 2 kg/ha). Methods: Plots (20 m2) had manure (a mixture of hen and goat manure) or no fertilizer (three plots each), added in 2007 and 2008 (110 kg N/ha). The manure was immediately incorporated into the soil (10 cm depth), using a rotocultivator. Plots were irrigated 1–2 times/week (608–618 mm/year). Drainage water was collected in ceramic cups (80 cm depth, 40 kPa) thirty times during the experiment.

 

5 

A replicated, randomized, controlled study in 2009 in an abandoned wheat field in Greece found similar amounts of water in soils with or without added manure. Water availability: Similar amounts of water were found in soils with or without added manure (8–15%). Methods: Plots (1 x 1 m) had added manure (4 kg/m2) or no added manure (four plots for each). Manure was added in January and incorporated into the soil with a mattock. Soil samples (three/plot, 3–20 cm depth) were collected in March and June.

 

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.