Yield increase of corn inoculated with a commercial arbuscular mycorrhizal inoculant in Brazil

ABSTRACT: Arbuscular mycorrhizal fungi (AMF) play an important role in plant growth. However, there are no reports of legally commercialized AMF-based inoculants for agricultural crops in Brazil. The objective of this research was to evaluate the agronomic efficiency of a Rhizophagus intraradices inoculant in combination with phosphate fertilization in grain yield of corn under different edaphoclimatic conditions in Brazil. Experiments were conducted in five Brazilian states (Goiás, Mato Grosso, Minas Gerais, Rio Grande do Sul and Santa Catarina) in a 2 x 3 factorial scheme, with two inoculation treatments (inoculated and non-inoculated seeds) and three doses of phosphate fertilization (0, 50 and 100% of the recommended P). At the end of the crop cycle (stages R4-R5), inoculation provided increases in biomass (average of 48%) regardless of the applied dose of P, higher P absorption, and 54% average increase in grain yield. In conclusion, the mycorrhizal inoculant increases biomass yield, P uptake and corn grain yield under different edaphoclimatic conditions in Brazil, especially in soils that originally had low or medium levels of available P.

摘要：丛枝菌根真菌（Arbuscular mycorrhizal fungi, AMF）对植物生长具有重要作用，但目前巴西尚未有合法商业化的农作物专用AMF接种剂的相关报道。本研究旨在评估根内根囊霉（Rhizophagus intraradices）接种剂与磷肥配施，在巴西不同土壤气候条件下对玉米籽粒产量的农艺效益。试验采用2×3析因设计，在巴西5个州（戈亚斯州、马托格罗索州、米纳斯吉拉斯州、南里奥格兰德州和圣卡塔琳娜州）开展，设置2种接种处理（种子接种与未接种）以及3个磷肥施用量梯度（分别为推荐施磷量的0、50%和100%）。在作物生育期R4-R5（乳熟至蜡熟期）结束时测定结果显示，接种处理可使玉米生物量平均提升48%，且不受施磷剂量影响，同时显著提高植株磷吸收量，籽粒产量平均提升54%。综上，在巴西不同土壤气候条件下，尤其是有效磷初始含量处于中低水平的土壤中，该菌根接种剂可显著提升玉米生物量、磷吸收量与籽粒产量。