Pak. J. Bot., 39(1): 151-160, 2007. | Back to Contents | ||||
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Updated: 09-07-09 | ||||
DOSE RESPONSE EFFECT OF NITROGEN AND PHOSPHORUS ON FORAGE QUALITY, YIELD AND ECONOMIC RETURN OF RANGELANDS TAHIR POLAT, BEKIR BÜKÜN1* AND MUSTAFA OKANT Abstract: A two-year experiment was conducted in Karacadag rangeland, Sanliurfa,
Turkey to evaluate Nitrogen (N) and Phosphorus (P) fertilization on
forage quality and plant species composition and to determine their
economic impact on animal production. Treatments were 0, 50, 100, 150
and 200 kg ha-1 of N and 0, 50, 100, and 150 kg ha-1
of P fertilizer doses. Nitrogen and Phosphorus fertilization significantly
influenced the composition of plants. Botanical composition of experimental
fields was recorded as 25 legume, 22 grass and 27 species from other
families. The results show large interaction between P and N due largely
to the fact that legume species are relatively abundant fertilization
reduced legume proportion; however, P fertilizer increased the proportion
of legume in vegetation. Adverse effect of N on growth of legume resulted
in significantly crude protein decrease in forage. In both years, overall
mean dry matter yield increased with increase in N and P applications.
Highest dry matter yield production was 3407 kg ha-1 in 150
kg ha-1 of P and 200 kg ha-1 of N as compared
to control treatment which had a 1152 kg ha-1. Average mean
crude protein concentration was 110 g kg-1 for control plots,
while it decreased to 106, 102, 104 and 103 g kg-1 in 50,
100, 150 and 200 kg ha-1 of N applications, respectively.
Crude protein concentrations were significantly enhanced with increasing
P fertilizer amounts. Maximum crude protein concentration was 140 g
kg-1 obtained from P150+N0 treatments.
The average crude protein yield was 126.7 kg ha-1 in control
plots and maximum crude protein yield was from P150+N200
treatment as 464.1 kg ha-1. Overall results indicated
that, the most profitable treatment was P150+N200
and average calculated benefit was 644 € per hectare.
Department of Agronomy, Faculty of Agriculture, Harran University,
63040 Sanliurfa, Turkey. |
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