Short Term Effects of Soil Tillage and Animal Manure Application on Soil Fauna under Corn Cultivation

One of the important components of soil management systems for sustainable agriculture is soil tillage. Tillage affects soil organisms through changes in soil properties. Hence, knowledge of short and long term effects of tillage on soil organisms is important in choosing better management systems for a sustainable agriculture. In order to investigate the short term effects of soil tillage and cow manure application on soil fauna under corn cultivation, an experiment was carried out from April until September 2008, in Grizeh Research Station of Kurdistan Province in Iran. The soil is classified as the Grizeh soil series (Fine, Mixed, Thermic, Fluventic, Xerochrepts). Treatments consisted of three tillage systems including Conventional Tillage (CT) (moldboard plow + disking), Minimum Tillage (MT) (disking), and No Tillage (NT) as the main plots and three levels of cow manure (0, 20 and 40 ton/ha) as subplots, with three replications. Experimental design was Complete Block Design (RCB) as split plot arrangement. Soil samples were collected three times during the experiment. Corn cultivar SC704 was planted as a fodder crop. Soil bulk density (BD) was measured where earthworms, springtails, mites, and nematodes populations were counted as indicators of soil macro, meso, and micro-fauna, respectively. Results showed that in short term, the effect of different tillage systems on BD was not significant and had no pronounced effects on nematodes, mites, and springtails in a loamy-sandy loam soil. However, tillage system had significant effect on earthworm population. Cow manure had positive effects on soil nematode population and corn biomass.. As a general conclusion, using MT treatment and application of 40 ton/ha cow manure were found useful management practices from agronomic and biological viewpoints.