科研之友
微信
新浪微博
Facebook
分享链接
摘要
Soil water repellency (SWR) caused by organic coatings on soil particles can lead to serious loss in crop production and turfgrass quality. In laboratory experiments, we tested the novel concept of direct application of enzymes to alleviate SWR. In a biofuel research project on fungal pre-treatment of switchgrass (Panicum virgatum L.) for improved saccharification, enzymatic co-products (mainly laccase mixed with other trace enzymes) were produced based on fermentation periods of 18, 36, 54, and 72 days. We characterised enzyme activities of the 18-72-day crude enzyme extracts (CEE) and applied undiluted or diluted solutions (dilutions of 5-, 10-, and 100-fold) to eight air-dried, SWR soils from several golf courses. These soils exhibited water drop penetration times (WDPT) of 345-7439 s (i.e. moderately to very strongly hydrophobic) and all showed a large decrease in SWR to WDPT <60 s after application of undiluted CEE and various dilutions of CEE for 3 days with a 1 : 1 soil : solution ratio (10 g air-dried soil and 10mL CEE solution). The observed decrease in WDPT was positively related to increased enzyme activity level for each soil in an exponential or logarithmic relationship. Most of the improvement in SWR was observed within 1 day. Enzyme activity was maintained to varying degrees in the soil solution for up to 5 days. These preliminary results suggest that it may be feasible to use direct enzyme application from CEE, as a biomass fermentation byproduct, for remediation of hydrophobic soils, which could also offer a cost benefit for biomass fermentation.
