INVESTIGATIONS WITH FERTILIZATION OF VEGETABLE CROPS GROWN ON THREE DIFFERENT LOW MOOR (MUCK) SOILS
This report contains a short summary on the study of the fertilization requirements of cauliflowers and lettuce grown on low moor soils from three locations and of onions grown in field conditions. Prior to experiments the soils were used for grass production. The characteristics of the soils are given in table 1.
From the year 1967 the experiments are conducted in greenhouse (pot experiments), outdoors in microplots (field bins - containers made of concrete with water permeable bottoms, reaching 1 meter below the soil surface, filled with 5 cubic meters of peat soil) and in field conditions on natural low moor soil.
Prior to treatment the soils in greenhouse and microplots were fertilized with major nutrients to the level of 200 mg N, 600 mg P2O5, and 600 mg K2O per one liter of soil. Limed treatments received CaCO3 in amounts necessary to rise the pH to 6.5. Molybdenum in the rate of 0.5 mg Mo/liter soil was applied as ammonium molybdate - (NH4) Mo7O24· 4H2O. Copper as cupric sulphate - CuSO4. 5H2O - was applied in the rate of 10 mg Cu/liter of soil.
The experiments indicate the following response to micro- and major nutrient fertilization:
Cauliflower. On two soils a strong response to molybdenum fertilization was observed. Without Mo fertilization the crop was a complete failure and the young cauliflower plants died up within 8 weeks after emergency. Normal growth and satisfactory yield was obtained with the application of molybdenum. Liming at the rate of about 20 tons of CaCO3 per hectare gave similar results as Mo fertilization but only in the young stage of growth (prior to the initiation of curds). At harvest maturity lime treated cauliflowers showed a non-significant yield decrease in a greenhouse experiment, and a highly significant yield decrease in a microplot experiment. The average curd yields in microplots on limed treatments was 50 grams as compared to 260 grams on plots treated with ammonium molybdate.
The results from the year 1968 indicate that young cauliflower plants grown prior to transplanting into the field, in a soil well supplied with molybdenum, produced normal yield regardless of the molybdenum status of the field. No response to molybdenum was observed on the third soil type. Copper did not affect the growth and the yield of cauliflower