ChileanJAR

Two experiments on grassland oversowing were carried out throughout the 1970-73 seasons in Southern chile (X Region).
The first trial took place in a marginal area of the Experiment Station Remehue characterized by a natural sward of Agrostin tenuis, Arrhenatherum elatius var. bulbosum, rubus ulmifolius and other, on a "Trumao" soil with regular type of slope. The sward was oversown using a Connor Shea unit with a mixture of Trifolium subterraneum, Thifolium repens, Lolium perenne and Dactylis glomerata, together with an annual topdressing of 50-32-74 and 32 units at P₂O₅, N, K₂O and S per hectare, respectively. A second experiment was carried out in two localities (Calimahuida and La Trampa) on soils of a reddish brown lateretic zone and in a third locality at the Experiment Station Remehue. the oversowing of red clover (Trifolium pratense) alone and the mixed oversowing red clover, perennial ryegrass and cocksfoot, or red clover, cocksfoot and fescue (Festuca arundinacea) with a topdressing of 90-50-45 and 2.6 units of P₂O₅, S, N, and B were compared with the natural sward receiving the same topdressing. Botanical composition of the sward was determined before and after oversowing, the sward being classified as "Excellent", "Good", "Medium", "Bad" and "Very Bad". The swards used in the first trial were classified as "Very Bad" and those of the second trial in all there localities were "Bad". Oversowing did not markedly improve the condition of the sward, all of which were classified as "Bad".
It is concluded that the techinique for oversowing the pasture studied here is of limited use and can be probably better recommended, in particular of soils with regular or good fertility and a low population of Agrostis tenuis.