Soil aggregates and organic matter dynamics in short, medium and long term cover crops based land use system

Introducing cover crops to corn and soybean cropping systems have both ecological and agricultural benefits. However, the magnitude of the provided benefits can be influenced by a number of biotic and abiotic factors. Among these factors, the type of cover crops, soil properties, topographic characteristics and duration of using cover crops. The objective of the present study was to investigate the effects of cover crops on soil dry aggregate size distribution (DASD), particulate soil organic matter (POM) and soil organic matter (SOM) in experiments with different durations of cover crop use and diverse topography. The data were collected at LTER experimental fields at Kellogg Biological Station. The treatments comprised conventional and reduced input with rye and red clover cover crops in short (1 yr), medium (6 yr) and long-term (24 yr) systems. The results of the study revealed that DASD was not affected by cover crop syetems, whereas POM and SOM were significantly improved in long-term cover crop based management, but  statistically at par in short-and medium term experimental fields. POM and SOM were higher in depression than slope and summit positions regardless of the presence of cover crops in the system. The present study showed that in topographically diverse fields of coarse textured Alfisols, it may require >10 years of using cover crops to observe improvements in soil C variables and soil aggregation that can be detected statistically.

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LTER ASM 2012 poster