Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Convert to organic farmingThis synopsis includes experimental tests of organic farming only. Comparative studies of existing organic systems are not included. Parasitism and mortality (caused by natural enemies): One of five studies (three replicated, controlled tests and two also randomised) from Europe, North America, Asia and Australasia found that organic farming increased parasitism or natural enemy-induced mortality of pests. Two studies found mixed effects of organic farming and two randomised, replicated, controlled studies found no effect. Natural enemies: Eight of 12 studies (including six randomised, replicated, controlled tests) from Europe, North America Asia and Australasia found more natural enemies under organic farming, although seven of these found effects varied over time or between natural enemy species or groups and/or crops or management practices. Three studies (one randomised, replicated, controlled) found no or inconsistent effects on natural enemies and one study found a negative effect. Pests and diseases: One of eight studies (including five randomised, replicated, controlled tests) found that organic farming reduced pests or disease, but two studies found more pests. Three studies found mixed effects and two studies found no effect. Crop damage: One of seven studies (including five randomised, replicated, controlled tests) found less crop damage in organic fields but two studies found more. One study found a mixed response and three studies found no or inconsistent effects. Weed seed predation and weed abundance: One randomised, replicated, controlled study from the USA found mixed effects of organic farming on weed seed predation by natural enemies. Three randomised, replicated, controlled studies from the USA found more weeds in organically farmed fields, but in one of these studies this effect varied between crops and years. One study found no effect. Yield and profit: Six randomised, replicated, controlled studies measured yields and found one positive effect, one negative effect and one mixed effect, plus no or inconsistent effects in three studies. One study found net profit increased if produce received a premium, but otherwise profit decreased. Another study found a negative or no effect on profit. Crops studied were apple, barley, beans, cabbage, carrot, gourd, maize, mixed vegetables, pea, pepper, safflower, soybean, tomato and wheat.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F717https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F717Thu, 30 May 2013 09:37:10 +0100