ABSTRACT
Growth curve of the natural pasture in the Mount Andes foothills of the X Region of Chile

Nolberto Teuber K.1 y Humberto Navarro D.1
 

In theAndes foothills, on a Puyehuesoil (La Mosqueta Farm), the accumulated dry matterproduction curve, and the dialy growth and marginal growth rate of the naturalized pasture that grows in that area, were obtained. The studywas carried out between Octobar 1981 and February 1983. The evaluation was done by cutting with a mowing machine, leaving 375 kg D.M./ha of photosynthetic tissue after each cut. The pasture's growth was evaluated every 14 days, in the spring-summer, and every 21 days, in the autumnwinter periods. The plot size was 2.25 m2 , replieated four times for each cutting date. Two subsamples were taken; one to asses the botanical composition and the other (dried to 70ºC) to get the dry matter production.
The maximurn production of D.M. accumulated in spring- summer period was 5,778 and 8,131 kg/ha, in 1981/82 and 1982/83, respectively; but in autumn-winter, pasture growth was very low (116 kg D.M./ha), between April to August.
The yield accumulation curve was adjusted to III polinomial fuction
(Y= a+bx+cx2+dx3+ex4)
where "x" is the number of regrowth days and Y, the kg/ha of photosynthezising D.M.
The mean growth rate in spring, was 60-80 kg D.M./ha/day; in summer it was 8 to 12 kg D.M./ha/day; in winter it was below 1 kg D.M./ha/day; and cero between July to August.
The botanical composition was 42% of Agrostis tenuis Sibth., 15% of Anthoxanthum odoratum L. and 15% Holcus lanatus L. as the main grasses. Hypochoeris radicata L. and Plantago lanceolata L. considered together, were 11%. The only legume was Lotus uliginosus Schkuhr, with 4% of the natural pasture.

Keywords:
1 Estación Experimental Remehue (INIA), casilla 24-0, Osomo, Chile.