Distribution of Water and Ions in Soils Irrigated and Fertilized from a Trickle Source1
- B. Bar-Yosef and
- M. R. Sheikholslami2
Simultaneous distributions of water, NO3-N and P in clay and sandy soils irrigated daily from a trickle source were studied in the laboratory. Hydraulic conductivity data, water retention curves and adsorption isotherms to the soils were determined to enable verification of mathematical models against the experimental results obtained under various conditions. It was found that when adding identical amounts of water, but increasing the trickle discharge rate in the sandy soil from 250 to 2,500 ml/hour, the vertical movement of the wetting front increased and the horizontal movement decreased. In a sequence of three cycles of irrigation with a nutrient solution, losses of nitrate were observed in the clay soil, probably due to denitrification processes. The restricted mobility of the phosphate ions, even in the sandy soil, implies that a preirrigation mixing of P in the soil, supplemented by its addition to the irrigation solution, is necessary to obtain a uniform P concentration in the soil volume.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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