Effects of arbuscular mycorrhizal fungi, poultry manure compost, and cadmium on plant growth and nutrient absorption of Oryza sativa

Geomar Vallejos-Torres1, 2*, Nery Gaona-Jimenez1, Luis Ordoñez-Sánchez1, Carlos Lozano1, Alberto Alva Arevalo3, Andi Lozano3, Wilfredo Mendoza-Caballero4, Christopher Paredes5, Jorge Saavedra-Ramírez5, James Tuanama6, and César Marín2, 7
Compost produced with chicken manure and vegetable residues enriched with arbuscular mycorrhizal fungi (AMF) could become a sustainable agricultural strategy in biofertilization and bioremediation in rice (Oryza sativa L.) A completely randomized pot experiment was carried out to investigate the effects of AMF, humified composted poultry manure, and Cd on vegetative growth and elemental uptake of rice. After 90 d, rice treated with a combination of AMF and compost showed the highest plant growth. Overall, the best values in plant height, root length, chlorophyll content, and cation exchange capacity were obtained with the application of AMF and compost. In the absence of compost, Cd contamination significantly reduced AMF root colonization, while AMF alone increased root N, P, and K. Soil organic matter was higher when AMF, compost, and Cd were combined. Total soil P increased significantly with AMF inoculation (solely) compared to the rest of the treatments. The highest plant height (57.77 cm), root length (31.67 cm) and weight (167 g), shoot weight (74.67 g), and chlorophyll content (34.30 SPAD units) were achieved in the AMF-compost treatment. The highest values of root N (1.037%) and soil organic matter (2.66%) were obtained with the Compost-Cd treatment, which in turn presented lower Cd contents in roots and shoots. Cadmium inhibited morphological growth of the plant, biomass accumulation, and chlorophyll, but these parameters improved significantly with the application of AMF and compost, by facilitating the absorption of nutrients, particularly P.
Keywords: Arbuscular mycorrhizal fungi, cadmium, Oryza sativa, synergistic effects.
1Universidad César Vallejo, Cacatachi, San Martín, Perú.2Universidad Santo Tomás, Centro de Investigación e Innovación para el Cambio Climático (CiiCC), Valdivia, Chile.3Universidad Nacional de San Martín, Jr. Maynas Nº177, Tarapoto, San Martín, Perú.4Universidad Católica Sedes Sapientiae, Los Olivos, Lima, Perú.5Universidad Nacional Autónoma de Alto Amazonas (UNAAA), Alto Amazonas, Yurimaguas, Perú.6Universidad Nacional Agraria La Selva, Tingo María, Huánuco, Perú.7Vrije Universiteit Amsterdam, Amsterdam Institute for Life and Environment, Amsterdam, The Netherlands.*Corresponding author (gvallejost@gmail.com).