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Soil arthropods play an important role in nutrient cycling and maintenance of soil structure, and their abundance and diversity provide an indication of the biological quality of soil. Land application of livestock manure provides crop nutrients and may also impact the soil arthropod community. This study was conducted to quantify soil arthropod abundance and diversity for a period of one year following swine manure application via broadcast or injection. Arthropods were extracted from plot soil samples using Berlese funnels, identified and counted, and the QBS index (Qualita Biologica del Suolo) was calculated for each soil sample. Collembola (Hypogastruridae and Isotomidae) populations were greater (p < 0.05) in the broadcast plots than the injection or control plots. Pseudoscorpiones were more abundant (p < 0.05) in the injection treatment compared to the broadcast and control treatments. Acari populations and the QBS index were not significantly impacted by manure application.

In Iowa, producers achieve an adequate growing season for high yielding corn (Zea mays L.) by beginning field activities in a timely fashion. Subsurface drainage allows for early field activities by improving trafficability and decreasing excess water stress to crops on poorly drained soils. Drainage water management practices reduce drainage volumes and nitrate (NO3) loss by maintaining the water table closer to the ground surface when compared to conventional drainage systems. The objective of this study was to determine the effect of shallow, controlled, conventional, and no drainage on depth to water table, volumetric water content, and soil temperature during a 51-day period, from mid-April through May, to evaluate if drainage water management practices delay planting. At the Iowa State University Southeast Research Farm near Crawfordsville, Iowa, we evaluated eight large-scale research plots with two replicates for each of the four drainage treatments over the 51-day planting period during 2012 to 2015. Each plot was planted half to soybeans (Glycine max [L.] Merr.) and the other half to corn, and the halves rotated every year in accordance with a typical corn–soybean rotation. Conventional and controlled drainage significantly lowered (p

Subsurface tile drainage is a commonly used agricultural practice in Iowa croplands. Little is known about the effect of drainage on soybean (Glycine max) disease. Field and greenhouse studies were conducted to study the effect of drainage on seedling health. A field experiment was conducted at the Iowa State University research farm near Crawfordsville, Iowa, in 2012 and 2013. Four treatments were compared: conventional drainage (CvD, subsurface drains installed 1.2 m [3.9 ft] deep with 18 m [59 ft] spacing), shallow drainage (SD, 0.76 m [2.5 ft] deep with 12.2 m [40 ft] spacing), controlled drainage (CtD, 1.2 m [3.9 ft] deep and 18 m [59 ft] spacing with a water table control structure located at the outlet), and no drainage (ND, no artificial drainage). A greenhouse experiment was conducted three times to compare two soil sources (ND and CvD soil from the field experiment), two soybean cultivars (Ripley and Williams 82), and three watering intensities (low, moderate, and saturated). Plants were sampled at the second trifoliate stage to assess root rot severity, root dry weight, root size, and Fusarium spp. incidence in roots. In the field, root rot severity was significantly (p