A sufficient and balanced nutrient supply is vital for achieving high yields of good quality. The DEMO trial was established in order to highlight the effects of organic, mineral and zero fertilisation on plant development as well as on yields and yield quality. In this demonstration trial, symptoms of nitrogen, phosphorus and potassium deficiency are impressively on show in six crops grown in parallel.
Trial Design
The trial was set up in 1989 in Zurich-Reckenholz on a plot located in the transition zone between a gleyic Cambisol and a eutric Cambisol. In eight fertilisation treatments, nitrogen, phosphorus and potassium are applied in different forms and quantities: in mineral form in the ‘PK’, ‘NP’, ‘NK’, ‘NPK’ and ‘NPK + lime’ treatments, and in organic form in the ‘manure’ and ‘slurry’ treatments. The ‘zero fertilisation’ treatment serves as the control. All crops of the seven-year crop rotation (spring wheat – sugar beet – silage maize – potatoes – winter barley – two years of temporary ley) are cultivated in parallel in seven rotating strips. The trial does not contain spatial replications, but all crops are repeated annually thanks to the crop-rotation sequences.
Measurements
Soil pH and available macronutrients in the topsoil (0-0.2m depth) are measured annually. In addition, yields and nutrient content of the main and by-products are determined, and nutrient removals and budgets are calculated.
The yields of all crops are similar among the ‘NPK’, ‘NPK + lime’ and ‘slurry’ treatments. Winter and spring crops, however, respond differently to different nutrient deficiencies: insufficient nitrogen supply limits yields of winter barley, whilst potassium is critical for spring wheat, maize and potatoes. Sugar beet is the only crop hat responds to phosphorus deficiency with significant yield losses.
Symptoms of Nutrient Deficiencies
In early summer, symptoms of nutrient deficiencies can be observed simultaneously in various crops. A tour of the trial between the end of May and end of June will thus be most impressive.
Contact
Key data
Topic: Fertilisation, plant nutrition
Site: Zurich-Reckenholz
Location: 47.425666, 8.516497;
443 m a.s.l.
Start year: 1989
Design: non-replicated, 7 parallel crops
Soil type (WRB): deep gleyic Cambisol
Soil texture: Loam (20% clay, 33% silt, 47% sand, 2% org. C)
Precipitation: 1050 mm
Temperature: 9.4 °C
Further Information
Last modification 28.04.2021
