Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, 94720, USA.
Department of Biology, California State University, Fresno, Fresno, CA, 93740, USA.
New Phytol. 2021 Jul;231(1):447-459. doi: 10.1111/nph.17306. Epub 2021 Apr 2.
Arbuscular mycorrhizal fungi (AMF) are keystone symbionts of agricultural soils but agricultural intensification has negatively impacted AMF communities. Increasing crop diversity could ameliorate some of these impacts by positively affecting AMF. However, the underlying relationship between plant diversity and AMF community composition has not been fully resolved. We examined how greater crop diversity affected AMF across farms in an intensive agricultural landscape, defined by high nutrient input, low crop diversity and high tillage frequency. We assessed AMF communities across 31 field sites that were either monocultures or polycultures (growing > 20 different crop types) in three ways: richness, diversity and composition. We also determined root colonization across these sites. We found that polycultures drive the available AMF community into richer and more diverse communities while soil properties structure AMF community composition. AMF root colonization did not vary by farm management (monocultures vs polycultures), but did vary by crop host. We demonstrate that crop diversity enriches AMF communities, counteracting the negative effects of agricultural intensification on AMF, providing the potential to increase agroecosystem functioning and sustainability.
丛枝菌根真菌（AMF）是农业土壤中的关键共生体，但农业集约化已经对 AMF 群落产生了负面影响。增加作物多样性可以通过积极影响 AMF 来缓解其中的一些影响。然而，植物多样性与 AMF 群落组成之间的潜在关系尚未得到充分解决。我们研究了在一个集约化农业景观中，更高的作物多样性如何通过积极影响 AMF 来影响 AMF，该农业景观的特点是高养分输入、低作物多样性和高耕作频率。我们通过三种方式评估了 31 个田间地点的 AMF 群落：丰富度、多样性和组成。我们还确定了这些地点的根系定殖情况。我们发现，多作物种植将可用的 AMF 群落推向更丰富和更多样化的群落，而土壤特性则构成 AMF 群落组成。AMF 根系定殖不受农场管理（单作与多作）的影响，但受作物宿主的影响。我们证明，作物多样性丰富了 AMF 群落，抵消了农业集约化对 AMF 的负面影响，为提高农业生态系统功能和可持续性提供了潜力。
