Statistical dependencies of fertilizing with humate fertilizers on productive and qualitative indicators of forage from meadow legume crops.

On the basis of the data received from the research experiment conducted with bird's-foot-trefoil, red clover and sainfoin, fertilized with humate fertilizers on the territory of the experimental field of Research Institute of Mountain Stockbreeding and Agriculture -- Troyan during the period 2013-2015, correlation dependencies and regression equations were constructed. A positive correlation dependence was established between: the phosphorus content and the height of fertilizer meadows with legumes (r = 0.90); the content of nitrogen-free extractable substances and the relative share of the stems (r = 0.86); and the crude protein and the percentage share of leaves (r = 0.80). This proves the positive effect of fertilizing with boron and molybdenum humate on growth and development of legumes, the accumulation of nutrients in the forage. The regression equations derived prove the possibility of predicting the crude protein content from the share of leaves in the grass stand (R² = 0.64), the phosphorus content from the height of the stems (R² = 0.81) and of the nitrogen-free extractable substances from the relative share of the stems (R² = 0.75), in the grass stands. Two-factor analysis of variance showed the high impact of the conditions of the year (η = 68.69) on the dry matter yield. [ABSTRACT FROM AUTHOR]