Impact of management practices on Minnesota's specialty crop production: from biochar to tillage practices

Abstract

Climate fluctuations have always been a risk to our ability to provide adequate food for the increasing global population. To reduce crop production uncertainties in this variable climate, two management practices were examined: biochar application and conservation ridge tillage. Different biochars, application rates, and soil types were evaluated for their effect on seedling emergence and plant growth of specialty crops. Increases and decreases were observed in seed emergence and plant growth rates from biochar amended soil in a greenhouse study. A slow pyrolysis corn cob biochar (5% w/w) improved seed emergence performance the greatest across five specialty crops in the 4 soil types, with increases in emergence ranging from 2 to 67%. Biochar weathering from previous trials also influenced plant growth responses, and eliminated initial negative growth effects. Yield from field plot studies were not significantly different between biochar and control treatments. No universal relationship between biochar and its impact on specialty crop growth were observed across different soil types. However, there was good correlation between the suppression in plant growth with lower availability of nitrate and higher amounts of sorbed organic compounds on the biochar. Biochar additions had the greatest positive plant impacts on sandy textured soils with low initial soil fertility, which increased growth and soil moisture retention.Secondly, the impacts of ridge and conventional tillage on the yield and quality of three sweet corn varieties, <italic>Overland</italic>, <italic>Protégé</italic>, and <italic>Ambrosia</italic> were investigated. <italic>Protégé</italic> had greater marketable yields when grown under ridge tillage compared to conventional tillage. During 2012, there were no significant differences noted between ridge and conventional tillage treatments. However, in 2013, ridge till increased cut corn yield and ear marketability compared to the conventional tilled plots, suggesting additional benefits that were not adequately captured in this 2 year study. This study suggests that increasing the soil moisture holding capacity (with biochar or other amendments) as well as utilizing ridge tillage offers a potential tool for agricultural production to buffer future climate uncertainties.