Nitrogen and phosphorous fertilizer improve pastures naturally growing under hazelnut trees

Abstract

This three-year study (2003-2005) aimed to improve the yield and quality of pastures growing naturally that are colonized by naturally occurring vegetation without agricultural input under hazelnut (Corylus sp.) orchards in the middle and eastern Black Sea regions of Turkey. There were eight treatments: 1) control; 2) fertilizer only (triple superphosphate 44% and calcium ammonium nitrate 26%) (80 kg ha(-1) P and 60 kg ha(-1) N in Samsun; 100 kg ha(-1) P and 80 kg ha(-1) N in Ordu; 100 kg ha(-1) P and 40 kg ha(-1) N in Giresun); 3) lime only (calcium carbonate 94%) (3.0 t ha(-1) lime in Samsun; 4.5 t ha(-1) lime in Ordu and Giresun); 4) early cut only; 5) soil aeration only; 6) fertilizer + lime; 7) fertilizer + lime + early cut; 8) fertilizer + lime + soil aeration, laid out in a randomized complete block design with four replicates at each location. The highest dry matter (DM) yield of kg ha(-1) and crude protein content (%) was obtained from the treatments that included fertilizer. There was no difference in DM production between any of the combination treatments that involved fertilizer and the fertilizer alone treatment. Only lime and aeration applications also increased yield compared to control, but not as much as did any treatment including fertilizer. Crude protein content of the pasture ranged from 13.3 to 18.1% across locations. Nitrogen and phosphorus fertilizer are recommended to improve DM yields and herbage quality for pastures under hazelnut orchards.