Addition of organic amendments derived from invasive apple snails alleviated soil acidification, improved soil nitrogen and phosphorus effectiveness, microbial growth and maize yield in South China

Abstract

Pomacea canaliculata (apple snail) is an invasive agricultural pest posing serious threats to aquatic crop production and wetland ecosystem function in Asia. The shell of P. canaliculata is composed of calcium carbonate (CaCO3), while its soft tissue is protein-rich (carbon (C) and nitrogen (N) sources). Thus, P. canaliculata has the potential to be used as a source of organic soil amendments. Here, we evaluated the effectiveness of snail derivatives (powder, including shells and soft tissues of the snails) as organic soil amendments to improve the productivity of an acidic dryland soil in South China. Snail powder (SP) was incorporated into the soil at application rates of 0–50 g kg−1, followed by planting of maize. Our results showed that SP addition significantly increased soil pH (up to 7.25–7.95), alleviated soil acidification. Moreover, SP addition improved soil N, phosphorus (P) effectiveness, and dissolved organic carbon (DOC) content, increasing biomass of actinobacteria and arbuscular mycorrhizal fungi (AMF) to stimulate microbial growth. Notably, SP addition increased height (up to 42.4 %), biomass (up to 117.6 %) and yield (up to 118.9 %) of maize, with 10 g kg−1 SP optimal for plant productivity. However, the optimal application rate and buffer time for field application of SP warrant further study. Our findings demonstrate the potential of SP resource utilization for acidic soil remediation and the invasive snail P. canaliculata control.