The effect of biochar with different feedstock materials on the English grain aphid Sitobion avenae Fab. (Hemiptera: Aphididae)

Abstract

Biochar applications to soils remain to be explored for their effect on herbivorous insects on crops. Our laboratory experiments examined the effect of three types of biochar (derived from straw of corn, Zea mays L., wheat, Triticum aestivum L., or rice, Oryza sativa L.) by four amendment rates (0, 1.5%, 3% or 5%) on reproduction of Sitobion avenae Fab. on wheat. In addition, a three-year field experiment was carried out to evaluate the role biochar application played in suppressing S. avenae populations. The laboratory experiments showed that biochar amendments decreased aphid lifetime fertility and population growth. The negative effect varied in magnitude depending on both biochar type and amendment rate, tending to be stronger both at the 5% rate than at lower rates and for corn than for rice and wheat straw-derived biochar. The field experiment did not show a consistent effect of biochar application on aphid population size across three years, while demonstrating a distinct suppressing effect in the third year after biochar application. Our results from laboratory study suggest that biochar application can impair S. avenae fertility and population growth potential, yet our field experiment provides insufficient evidence in suggestive of the decisive role biochar application plays in suppressing aphid populations.