Intercropping wheat with ancestral non-mycorrhizal crops in a volcanic soil at early growth stage

Claudia Castillo1, Jaime Solano1, Mauricio Collinao1, Rocío Catalán1, Pedro Campos2, Paula Aguilera1, Ewald Sieverding3, and Fernando Borie1, 4*
Intercropping is especially relevant for low-income farmers when crop production is developed in soils under the new scenario produced by climatic change, mainly water shortage and low availability of nutrients especially P. An example of this would happen in volcanic soils of Southern Chile with high P fixing capacity and where most cereals are cropped. The aim of this study was to compare the benefits obtained on soil biochemical properties and on wheat (Triticum aestivum L.) growth when sowed under monoculture or intercropped with non-mycorrhizal plants such as quinoa (Chenopodium quinoa Willd.), buckwheat (Fagopyrum esculentum Moench), canola (Brassica napus L.) and white lupin (Lupinus albus L.) Wheat plants parameters such as shoot growth and morphological root traits together with some soil biological and chemical characteristics were measured after 30 and 44 d of plant growing in pots under controlled conditions. Results showed nonsignificant differences on growth parameters (i.e., height and shoot/root biomass) and P acquisition between monocrop and intercropped wheat. Conversely, wheat root morphological traits namely total length, root area, and forks were greatly reduced (around 50%) regardless of plant species. Intercropping tended to increase P availability and significantly reduced rhizosphere soil pH, with the lowest levels observed for wheat-canola combination (from 7.5 to 5.6). Intercropping produced a slight reduction in mycorrhizal colonization but increased over 100% viable spores’ number and exerted a variable effect on the microbial C-biomass, with greater values observed in wheat-canola combination (1.49 mg g-1). These results encourage us to deepen the use of some new plant combinations in family farming carried out in volcanic soils.
Keywords: Companion plants, P nutrition, quinoa, root traits, smallholders.
1Universidad Católica de Temuco, Facultad de Recursos Naturales, Departamento de Ciencias Agropecuarias y Acuícolas, Rudecindo Ortega 02950, Temuco, Chile.
2Instituto de Investigaciones Agropecuarias, INIA Carrillanca, PO Box 929, Temuco, Chile.
3University Hohenheim, Institute of Plant Production and Agroecology in the Tropics and Subtropics, Stuttgart, Germany.
4Núcleo Científico Tecnológico en Biorecursos (BIOREN-UFRO), Universidad de la Frontera, PO Box 54-D, Temuco, Chile.
*Corresponding author (fborie@uct.cl).