The Apelsvoll cropping system experiment VII. Runoff losses of soil particles, phosphorus, potassium, magnesium, calcium and sulphur
1996
Eltun, R. | Nordheim, O. (Planteforsk - Norsk Inst. for Planteforskning, Apelsvoll Forskingssenter, Kapp (Norway)) | Fugleberg, O.
In the Apelsvoll Cropping System Experiment, the environmental side-effects and productivity of six cropping systems, involving conventional, integrated and ecological arable and forage systems, are being investigated. The systems differ with regard to crop rotation, fertilization, soil tillage and plant protection, and they are established on model farms, equipped as field lysimeters for measuring drainage and surface runoff. In the present paper the drainage and surface losses of soil particles, phosphorus, potassium, magnesium, calcium and sulphate-sulphur over the first four-year cropping period are presented. The average annual losses of these variables were 28, 0.32, 7, 12, 159 and 30 kg ha-1, respectively. The results showed that arable cropping systems with autumn ploughing have higher erosion risks than arable systems with spring tillage or forage crop systems. It appeared that the losses of the present nutrients are less affected by the cropping systems than is nitrogen. However, crop management factors like time of soil tillage, time of manure application and type of plant cover in the autumn, affects the loss of phosphorus. Plant residues appeared to be importent sources for loss of phosphorus and potassium, while the loss of magnesium, calcium and sulphur seems to be primarely affected by fertilization. Because of variation in weather factors, there was a great annual variation in nutrient losses, which shows that long term observations are needed in order to obtain reliable data concerning nutrient losses from the various cropping systems.
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