DYNAMICS OF SOME CHEMICAL AND PRODUCTIVE INDICATORS OF ANNUAL SPRING CEREALS UNDER THE CONDITIONS OF CENTRAL BALKAN MOUNTAINS IN BULGARIA

VLINGORSKI

Abstract. The comparative evaluation of annual spring forage cereals under the conditions of Central Balkan Mountains in Bulgaria (Troyan region) proved that over the period from 2002 to 2004, the highest dry matter yield was harvested from sudan–grass, followed by sorghum–sudan–grass hybrid and millet. All of them exceeded the standard crop (maize) by 37.71%, 29.29% and 21.04%, accordingly. The highest value (11.39%) of crude protein content was observed for oats and of crude fat content–for millet. Maximum values of crude ash, calcium and phosphorus in dry mass had the oats. The highest crude protein yield (0.74 t/ha) was obtained from millet, and it was 12.12% higher than maize (standard crop).

Key words: annual spring cereals, dry mass yields, forage chemical composition, crude protein yields, Central Balkan Mountains, Bulgaria.

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CORRELATIVE DEPENDENCES BETWEEN FORAGE CHEMICAL COMPOSITION AND CRUDE PROTEIN PRODUCTIVITY OF GRASS–LEGUME MIXTURE UNDER VARIABLE MINERAL FERTILIZING

V. LINGORSKI, Boryana CHURKOVA

Abstract. During the 2001–2003 period in RIMSA, Troyan the correlative relationships between forage chemical composition and crude protein productivity of grass mixture containing perennial ryegrass and birdsfoot trefoil under variable mineral fertilizing was investigated. The following variants in the experiment were included:

1. Unfertilized variant (standard); 

2. Annual soil mineral fertilizing with P80K80;

3. Annual soil fertilizing with N80P80K80;

4. 1st year–fertilizing with P80K80, 2nd year–fertilizing with N80P80K80, 3rd year–fertilizing with P80K80;

5. 1st year and 2nd year–fertilizing with P80K80, 3rd year–fertilizing with N80P80K80.

There were positive correlations during annual mineral fertilizing (var. 2 and var. 3) with crude protein productivity for only two of the chemical composition components–for var. 2 with regard to crude ash content (r=0.7695–strong) and calcium (0.8974–very strong), and for var. 3–weak correlation between crude ash (r=0.4179) and crude fibre (r=0.4731). There were positive correlations for var. 4 of variable mineral fertilizing regarding to crude ash content (r=0.2506–weak) and crude fibre (r=0.7178–middle). There were positive correlations for var. 5 with four of the indicators–calcium (r=0.4184–weak), crude ash (r=0.5319–middle), crude protein (r=0.2340–weak) and crude fat (r=0.0992–very weak correlation).

Key words: grass–legume mixture, variable mineral fertilizing, forage chemical composition, crude protein yields, correlative dependences.

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