Phosphorus and potassium fertilizing of lucerne
1990
Orphanos, P.I. (Agricultural Research Inst., Nicosia (Cyprus))
The results are presented of a PK fertilizer experiment in which 20, 40, 60 or 80 kg P/ha in combination with 0, 220, or 440 kg K/ha were tested with lucerne (alfalfa) grown on plots of known fertilizer history at Morphou Government farm over the period 1969-72. A rate of 60 kg P/ha was sufficient for maximum yield (about 20 t DM/ha in the second year) irrespective of initial soil P status (1.2, 3.8 or 13.9 ppm bicarbonate-extractable P in the 0-15 cm soil layer) but K did not influence yield (lowest exchangeable K value in the 0-15 cm soil layer 185 ppm). Increasing P fertilizing increased P concentration in the DM harvested to about 0.3%, slightly decreased K concentration, but did not influence N concentration. Similarly, increasing K fertilizing increased K concentration in the DM harvested from 1.5% without K fertilizing to 3.0%. One ton of the DM harvested contained 35 kg N, 3.0 kg P and 25 kg K
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