Can using a strip-tilled cover cropping system followed by surface mulch practice enhance organisms higher up in the soil food web hierarchy?

Field trials were conducted in 2008 and 2009 to evaluate the potential of using sunn hemp (SH), Crotalaria juncea, and marigold (MG), Tagetes patula, in a strip till cover cropping system (STCC) followed by clipping SH and MG to provide surface mulch (SM). The overall objective was to examine if the STCC + SM could improve the structure of the soil food web compared to bare ground (BG) system where weeds were maintained at minimum level prior to planting. Cucumber (Cucumis sativus) and winter gourd (Benincasa hispida) were planted as cash crops in 2008 and 2009, respectively. Both the SH and MG in STCC + SM system suppressed herbivorous nematodes through the end of 2008 and up to mid-term crop cycle in 2009. The abundance of bacterivorous and fungivorous nematodes were consistently greater in SH plots during both trials. The structure index was significantly greater in SH treatment plots in 2009, indicating a more structured soil food web than BG treatment. SH and MG plots resulted in higher (P < 0.05) abundances of collembolans and predatory mites, respectively. Although crop yields were similar among treatments in 2008, winter gourd yield was significantly higher in SH during 2009. Possible mechanisms of why using the SH STCC + SM system resulted in improved soil food web structure in a relatively short time frame is discussed.

• Strip-till cover cropping and organic mulch enrich soil nutrient throughout a crop.
• Sunn hemp and marigold in STCC + SM system suppressed plant-parasitic nematodes.
• After 2 years of STCC + SM practice, SH finally increased structure index in year 2.
• STCC+SM also increased abundance of meso- and macroarthropods in the soil.
• Winter gourd yield was significantly higher in SH plots in year 2.