Phosphorus fertilisation in the life cycle, forage and seed production of bur clover (Medicago hispida Gaertn) in Camacani Puno

Abstract

The highland grasslands of Peru are the basis for livestock feeding. The bur clover (Medicago hispida Gaertn) is a naturalised legume that grows among agricultural crops, producing excellent forage and providing nitrogen; however, it is undervalued to the point of being uprooted because it is considered a weed. This study aimed to evaluate the influence of phosphorus fertilisation on the duration of the life cycle, forage yield, seed production and seed quality of bur clover and was carried out at 3842 m of elevation. Five experimental treatments (0, 40, 60, 80 and 100 kg ha^-1 of P₂O₅) were established under a randomized complete block design. After emergence, clover plants reached fruit maturity in less time (164 days) with doses of 80 and 100 kg ha^-1 of P₂O₅. The highest yields of green matter (7,116 and 6,351 kg ha^-1) and total dry matter (1,914 and 1,658 kg ha^-1) were also obtained with fertilisation of 80 and 100 kg ha^-1 of P₂O₅. Phosphorus fertilisation did not influence plant height (p ≥ 0.05) while seed yield (120 kg ha^-1) and weight of 100 seeds (0.42 g) were influenced by 80 kg ha^-1 of P₂O₅ treatment and the germinating power of the bur clover seeds. Seed production was affected by the natural fall of ripe fruits to the ground and the low germination of seeds due to their hardness.