Introduced tree legumes Indigofera Zollingeriana to enhance potential carrying capacity of Brachiaria Humidicola Pasture in coconut plantations

Abstract

Coconut commodity is still one of the economic back-bone of society, especially Indonesia is currently the largest copra producer in the world. Ruminant productivity in Indonesia is determined by forages availability along the year. Mostly of forage fed to animals is derived from local grasses species which is low quality and contains around 5% of crude protein (CP), lower than ideal protein content on ruminant diet. A kind of tropical grass namely Brachiaria humidicola well adapted under mature coconuts, persist under free grazing as practice by the farmers, drought resistant and good performance as tropical pasture but crude protein content of this grass fluctuated and in some cases was lower than minimum requirement in ruminant diet. Furthermore, carrying capacity of a pasture based on Brachiaria humidicola, in a coconut plantation, could provide only the needs of total digestible nutrient for cattle with body weight not exceeding 250 Kg. Crude protein content could be increased via costly and non-environmental friendly nitrogen fertilizer. Herbaceous legumes species integrated as mixed pasture failed to persist due to aggressiveness of this grass. On the other hand, there are some kind of tree legumes available in Indonesia i.e., Indigofera zollingeriana, highly relished by ruminant. The aims of this research was to study the ability of I. zollingeriana tree legumes to produce leaves as source of protein and dry matter to enhance the carrying capacity of tropical pasture and the productivity of cattle integrated in coconut plantation. The purpose of the results of this research is to be a base line for the next research program to build a model of field ration formulation of integrated forages production under coconuts plantation. This study was conducted in the experimental station of Assessment Institute Agricultural Technology (AIAT) of North Sulawesi, located 12 km from Manado City. This research consists of two experiments separately, from agronomic traits and animal nutrition aspect. Results of this research from agronomic aspect of both forages species grown together on the space of land at planting spacing (PS) of I. zollingeriana 1.5 x 1.5 meter showed dry matter yield higher than others PS treatments. From animal feeds point of view B. humidicola solely could provide dry matter, crude protein and TDN for cattle with body weight 250 Kg, and I. zollingeriana provides crude protein almost double more than the grass species. It means that both species all together in the same field could provide animal feeds for cattle with higher body weight.