Effects of sewage sludge and inorganic fertilizer treatments on yield and botanical composition of a sown-pasture established over a degraded pasture

A sown-pasture was established in present study over a natural degraded pasture totally lost hay yield and quality. The research was carried out to investigate the effects of sludge and inorganic fertilizer treatments on yield and botanical composition between the years 2009 and 2011. Experiments were conducted in randomized block design with three replications. Cinque mixture of Medicago sativa L. (40%), Dactylis glomerata L. (15%), Bromus inermis Leyss. (15%),Festuca arundinacea Schreb (15%) and Festuca rubra L. (15%) was used as the plant material of the research.Fertilizer combinations were as follows: N1P1: annually 5 kg da-1 N + 7.7 kg da-1 P2O5; N2P2: annually 10 kg da-1 N + 15.3 kg da-1P2O5; N3P3: annually 15 kg da-1 N + 23.0 kg da-1 P2O5; N4P4: annually 20 kg da-1 N + 30.7 kg da-1 P2O5; N5P5: annually 25 kg da-1 N + 38.4 kg da-1 P2O5; SS1: annually 169 kg da-1 sludge; SS2: annually 337 kg da-1 sludge; SS3: annually 506 kg da-1 sludge; SS4: annually 668 kg da-1 sludge; SS5: annually 843 kg da-1 sludge; SS111: 3-years total of 506 kg da-1 sludge at soil preparation; SS222: 3-years total of 1012 kg da-1 sludge at soil preparation; SS333: 3-years total of 1517 kg da-1 sludge at soil preparation; SS444: 3-years total of 2003 kg da-1 sludge at soil preparation; and SS555: 3-years total of 2529 kg da-1sludge at soil preparation. Green herbage, dry matter and crude protein yields of the sown pasture established over a degraded natural pasture increased with increasing chemical fertilizer and sludge treatments compared to control. The highest green herbage, dry matter and crude protein yields were obtained from inorganic fertilizer treatments of N4P4 and N5P5 and sludge treatments of SS333, SS444 and SS555.