Productivity, quality, economics and nutrients uptake by natural pasture as influenced by introduction of Stylosanthes species, phosphorus and potash levels under annona (Annona squamosa) trees

摘要

Introduction of Stylosanthes hamata in natural pasture under annona (Annona squamosa L.) trees was found significantly superior in terms of total dry forage (3.20, 3.89 and 3.95 tonnes/ha) and crude protein yield (255.9, 311.7 and 305.1 kg/ha) than S. scabra in first, second and third years, respectively. Dry forage yield (3.26, 3.86 and 3.98 tonnes/ha) and fruit quality of annona (TSS degrees B 26.4) was significantly increased with the application of 40 kg P2O5 + 30 kg K2O/ha as compared to control treatment. However, crude protein yield (269.9, 321.1 and 325.5 kg/ha) and fruit yield (5.72, 6.11 and 7.60 kg/tree) was significantly increased up to 60 kg P2O5 + 45 kg K2O/ha. Application of phosphorus and potash also had a positive effect on maintenance of legumes population in natural pasture. Persistence of legumes were 86.9 and 81.6% in the treatment where phosphorus and potash were applied @ 60 P + 45 K kg/ha as compared to control treatment (75.7 and 63.3%) during the second and third years, respectively. Maximum net returns and benefit: cost ratio were obtained by introduction of S. hamata along with application of 60 kg P2O5/ha +45 kg K2O/ ha in natural pasture under annona trees during all the 3 years. Nutrients uptake by different species were also increased with the application of phosphorus and potash in natural pasture.