Browse on keywords: soil quality earthworms
Search results on 06/18/13
1782. Dutt, A.K.. 1948. Earthworms and soil aggregation.. J. Am. Soc. Agron. 40:407-410.
Earthworms increased water-stable aggregates; addition of alfalfa hay had the largest effect; better than straw or forest leaves; earthworm casts were 3 times as stable as 0-3" soil, for field, pasture, and forest; aggregation with straw additions was increased, with no effect of earthworms. T: water, stable aggregates and organic additions.
6389. Smith, D.. 1990. Earthworms: digging out the facts.. Farm Journal Mid-January.
A no-till farmer considered earthworms the single most important factor for success of his system in Illinois. He used a simple infiltration test to demonstrate their impact. Infiltration rates remained high after several years of no-till even though soil bulk density had increased. Lime applications affected pH to a greater depth in a no-till field than a tilled field, probably due to earthworm action. Fields that were chisel plowed had only 25% as many worms the following spring as no-till or ridge-till fields.
10436. Haines, P.J. and N.C. Uren. 1990. Effects of conservation tillage farming on soil microbial biomass, organic matter and earthworm populations, in northeastern Victoria.. Austral. J. Expt. Agric. 30:365-371.
Wheat was grown continuously for 7 years with conventional tillage and direct drilling (no-till). There was a significant gradient of organic matter under no-till. In the surface 2.5 cm, biomass C and N, and N mineralization were 35, 30, and 62% greater, respectively, than under conventional tillage. No-till did not significantly increase soil organic C or N. Of the estimated 7.8 t/ha of C added to the soil from crop residues, 4% was retained in the top 7.5 cm at the time of sampling. Microbial biomass varied considerably with season. The biomass of earthworms in the top 10 cm under no-till was more than twice that of conventional tillage, while total worm numbers increased significantly when wheat residue was retained versus burned.