Effects of cattle dung deposition on energy and matter flows in bahiagrass (Paspalum notatum Fluegge) pasture, 6: Relationships between energy and nitrogen flows through the producer
1994
Hirata, M. (Miyazaki Univ. (Japan). Faculty of Agriculture)
This paper, using the previously-shown energy and nitrogen flows in the dung-free, dung-deposited and dung-surrounding places in a bahiagrass pasture grazed by dairy heifers, examined the relationships between the energy and nitrogen flows. The energy flows investigated were net primary production (Pe), energy grazed by the animals (Ge), energy transferred to the litter (Le) and energy stored n the plants (Se). The nitrogen flows investigated were nitrogen uptake (Un), nitrogen grazed by the animals (Gn), nitrogen transferred to the litter (Ln) and nitrogen stored in the plants (Sn). There were significant positive linear relation ships between Pe and Un, Ge and Gn, Le and Ln, and Se and Sn, when all the data were pooled. These overall relationships, owing to the meanings of the parameters of the regression equations, were considered to give us the information which is useful for predicting the energy and nitrogen flows in the system and for characterizing the system. The Pe/Un relationship was influenced by the dung resulting in an acceleration of Un, though the degree of influence varied with the time after the dung deposition, the distance from the dung and the time of the dung deposition. In contrast, the Ge/Gn relationship was hardly affected by the dung. These facts indicated little contribution of the dung-induced stimulation in the Un to the nitrogen content of grazed herbage
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