Influence of cutting regimes and fertilization on the dry matter yield, total nonstructural carbohydrates reserves, and natural reseeding of Lotus corniculatus L.

Abstract

An experiment with different fertilizing and cutting regimes was conducted at the "Estação Experimental Agronômica - UFRGS", in Eldorado do Sul, RS, southern Brazil, from September 1988 to May 1989, with birdsfoot trefoil (Lotus corniculatus L.) cv. São Gabriel submitted to two fertilizer levels: 36-152-84 and 09-38-21 kg/ha of N-P₂O₅-K₂O, and five combined cutting treatments: 3 weeks of rest (intervals) and cuts made at 5 and 10 cm stubble height; 6 weeks of rest and cuts leaving a 5 cm stubble height; and cuts at 9 weeks interval leaving a stubble of 5 and 10 cm height. The trial was conducted under a split-plot experimental design with four replications. The two fertilizer levels did not influence dry matter (DM) yield, level of total nonstructural carbohydrate (TNC) reserves, natural reseeding and plant frequency. As far a cutting frequency is concerned, higher DM yields were obtained at the lowest cutting frequency and at the lower stuble height. The TNC stored in plant roots showed a decreasing pattern from the beggining of the experiment down to the end of it, for all experimental treatments, showing higher values for the less frequent cuttings at higher stubble. In terms of plant frequency in the area, it showed to be better for the less frequent cuttings, which allowed for a higher natural reseeding (65,8 and 50,2 kg/ha to 5 and 10 cm, respectively).