THE EFFECTS OF PHOSPHORUS FERTILIZATION AND HARVESTING STAGES ON FORAGE YIELD AND QUALITY OF PEA (PISUM SATIVUM L.)

摘要

The aim of this study was to determine the effects of five phosphorus rates (0, 30, 60, 90 and 120 kg ha-1) and three harvesting stages (beginning of flowering, full flowering, and seed filling) on forage yield and quality of pea (Pisum sativum L.). Dry matter (DM) yield, Cp ratio, CP yield, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), and relative feed value (RFV) were determined. Phosphorus rates and harvesting stages significantly affected most of the components determined for pea. According to two-year averages, phosphorus treatments increased DM yield, CP ratio, CP yield, TDN and RFV values but decreased ADF and NDF ratios. Harvesting at the late stages impaired the forage quality. While the contents of CP, TDN and RFV decreased with advancing growth, DM yield, CP yield, ADF and NDF contents increased. It has been concluded that it is more suitable to harvest forage peas in the seed filling stage and 60 kg ha~(-1) phosphorus rate is sufficient for the high dry matter and crude protein yield in Usak and similar regions.