Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Change tillage practicesBiodiversity loss: Eleven studies from Canada, Europe, Mexico, or the USA measured effects of reduced tillage on soil animals or microbes. Of these, four (including three replicated trials (three also randomized and one also controlled)) found more microbes, more species of earthworm, or higher microbe activity under reduced tillage. One replicated trial found increased numbers of soil animals and earthworms under reduced tillage. One controlled, replicated trial found mixed effects on microbe diversity depending on time of sampling. Two, (including one controlled, replicated trial) found no effect of reduced tillage on earthworm activity or microbe activity. Compaction: Five studies from Australia, Canada, and Europe measured the effect of controlled traffic and reduced tillage on compacted soils. Of these, two (including one before-and-after trial and one replicated trial) found reduced compaction and subsequent effects (reduced water runoff, for example) under controlled traffic, and one also found that crop yields increased under no-tillage. Three replicated trials, including one site comparison study, found higher compaction under reduced tillage. Drought: Three replicated trials from Europe and India (one also randomized) found the size of soil cracks decreased, and ability of soil to absorb water and soil water content increased with conventional ploughing and sub-soiling. Erosion: Nine replicated trials from Brazil, Europe, India, Nigeria and the USA, and one review showed mixed results of tillage on soil erosion. Seven trials (one also controlled and randomized) showed reduced soil loss and runoff under reduced tillage compared to conventional ploughing. One trial showed no differences between tillage systems, but demonstrated that across-slope cultivation reduced soil loss compared to up-and-downslope cultivation. Two trials showed that no-tillage increased soil loss in the absence of crop cover. Soil organic carbon: Twelve studies from Australia, Canada, China, Europe, Japan and the USA compared the effect of no-tillage and conventionally tilled systems on soil organic carbon. All (including two randomized, five replicated, two randomized, replicated, and one controlled, randomized, replicated) found higher soil organic carbon in soils under a no-tillage or reduced tillage system compared to conventionally tilled soil. One review showed that no-tillage with cover cropping and manure application increases soil organic carbon. One randomized, replicated trial from Spain found greater soil organic carbon in conventionally tilled soil. One replicated trial from Canada found no effect of tillage on soil carbon. Soil organic matter: Fifteen studies from Canada, China, Europe, Morocco, and the USA measured effects of reduced tillage on soil organic matter content and nutrient retention. Of these, eight studies (including four replicated (two also randomized), two site comparisons (one also replicated) and one controlled) found maintained or increased soil organic matter and improved soil structure under reduced tillage. Four trials (including two replicated and two site comparison studies) found higher nutrient retention under reduced tillage. One controlled, replicated trial found less carbon and nitrate in no-till compared to conventionally tilled soil, but conventionally tilled soil lost more carbon and nitrate. One controlled, randomized, replicated trial and one replicated trial found mixed effects of reduced tillage on soil nitrogen levels. Yield: One replicated study from Canada found lower yields under minimum or no-tillage compared to conventional tillage, and one controlled, randomized, replicated study from the USA found higher yields when subsoiling was done. One randomized, replicated study from Portugal found no effect of tillage treatment on yield. SOIL TYPES COVERED: anthrosol, calcareous silt loam, chalky, clay, clay loam, fine sandy loam, loam, loamy-clay, loam - sandy loam, loam – silt-loam, loamy sand, loamy silt, non-chalky clay, sandy, sandy clay loam, sandy loam, sandy silt-loam, silt loam, silty, silty-clay, silty clay loam, silty loam.Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F906https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F906Wed, 02 Oct 2013 11:37:18 +0100Collected Evidence: Collected Evidence: Amend the soil with manures and agricultural compostsBiodiversity loss: Three controlled, replicated studies from the UK and USA found higher microbial biomass when manure or compost was applied, and higher microbial respiration when poultry manure was applied. Erosion: One controlled, randomized, replicated study from India found lower soil loss and water runoff with manure application in combination with other treatments. Nutrient management: Four studies from Canada, Spain, the UK and the USA measured the effect of a variety of manure types on soil nutrient levels. Of these, three randomized, replicated studies (two also controlled) found reduced nutrient loss and higher nitrogen levels when farmyard or poultry manure was applied. One also found lower nutrient loss when farmyard manure (rather than poultry manure or slurry) was applied in winter rather than autumn. One controlled replicated study found higher nitrate leaching. Soil organic carbon: Four studies (including three controlled, replicated studies (one also randomized) and a review) from India, Japan and the UK found higher carbon levels when manures were applied. Soil organic matter: One controlled, randomized, replicated study from Turkey found higher organic matter, larger soil aggregations and a positive effect on soil physical properties when manure and compost were applied. Two studies from Denmark and Germany found no effect of manure on organic matter levels. Yield: Four controlled, replicated studies (including three also randomized) from India, Spain and Turkey found higher crop yields when manures or compost were applied. One study found higher yields when manure were applied in combination with cover crops. Soil types covered: Clay loam, fine sandy-silty loam, loam, loamy, sandy loam, sandy clay loam, silty loam, and sandy silt loam. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F911https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F911Thu, 03 Oct 2013 11:10:07 +0100