Effect of irrigation, intercrop, and cultivar on agronomic and nutritional characteristics of quinoa

Abstract

A field experiment was conducted to determine the effect of three irrigation regimes and three intercrop treatments on emergence, plant height, seed yield, protein, and mineral concentration of two quinoa (Chenopodium quinoa) varieties. The experiment was carried out using a strip plot, randomized complete block design in 2012 and 2013 on an organic farm in Pullman, WA. Irrigation significantly increased quinoa yield compared to dry land production. The fescue/clover intercrop produced higher biomass compared to clover/medic intercrop. Neither intercrop affected quinoa yield. The cultivar “Oro de Valle” had higher mineral concentration than “Cherry Vanilla” for Cu, Fe, and P concentration, but lower seed yield each year. An interaction was found between Mn seed concentration and intercrop treatment; however, different intercrop treatments did not seem to greatly affect other seed mineral concentrations. The intercrop provided cover in the field during the winter months, thus, decreasing soil erosion and providing green manure the following season. The fescue grass clover mix created more winter cover compared to the clover/medic intercrop whereas the clover and medic mixture increased quinoa seed protein.