Preliminary research on seed production and nutrient content for certain quinoa varieties in a saline-sodic soil

The aim of the present study was to compare the potential seed yield of eight quinoa varieties, to explore their mineral composition of seeds and to identify superior varieties in two locations with different soil properties. Compared with neutral soil conditions, seed yield in the marginal (saline-sodic) soil was decreased by 45 %. Under the latter soil conditions seed yield was negatively correlated with crop density, indicating that a considerable yield loss was due to poor and uneven plant density caused by adverse soil properties. Among the varieties, 'RU-5-PQCIP-DANIDA-UNA' produced the highest seed yield (>20 dt ha(-1)) when grown under neutral soil conditions. Under marginal conditions, the above-mentioned variety and 'N 407' produced seed yields up to 10 dt ha(-1) whereas the rest reached yields of only about 5 dt ha(-1). The majority of the varieties accumulated significantly more protein (20%) in the seeds under saline-sodic soil conditions (lower yielding environment). The varieties originated from South America were superior in accumulating protein in the seeds at both locations. Mineral contents of calcium (Ca), magnesium (Mg), zinc (Zn) and manganese (Mn) in the seeds were significantly higher in the neutral soil. No differences were found for phosphorous (P), iron (Fe), copper (Cu) and boron (B) between the two locations. The South American varieties were again superior in mineral composition. Adaptation of certain quinoa varieties even under marginal environments seems promising for seed production and/or protein and mineral content in the seeds. Agronomic data are needed in a due course, over a higher number of locations and/or various climatic conditions.