Effects of nitrogen sources on the growth and nitrogen uptake of waterhyacinth (Eichhornia crassipes (Mart.) Solms) in the model paddy fields
2000
Honmura, T. (Kagoshima Univ. (Japan)) | Miyauchi, N.
This fundamental experiment was designed for a better use of abandoned paddy fields to prevent their devastation by cultivating waterhyacinth and using its harvested materials as feedstuff, and to study the influence of the sources of nitrogen on the growth and nitrogen uptake of waterhya cinth in the model paddy field of closed water system. The sources of nitrogen were ammonium (NH4-N), nitrate (NO3-N), amide (NH2-N) and the animal waste (pigpen waste). These equivalent weight for 40ppm levels of nitrogen fertilizers were added to the water for basal dressing and every 10 days, and the plants were harvested sixty days after the transplanting. Plants grew well in both the NH2-N and the animal waste groups when estimated from numbers, dry matter (DM) weights of the plants. The amount of nitrogen uptake were higher in both the NH2-N and the animal waste groups than the NH4-N and the NO3-N groups. Changes in pH of culture waters indicated that the NH4-N decreased (acidic) and the N03-N increased (slightly basic) during the cultivation, and both the NH2-N and the animal waste groups changed gradually. EC of the NH4-N and the NO3-N increased in accordance with manuring, however the NH2-N and the animal waste groups increased little
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