Differential Fertilisation of Pine Plantations on Acid Forest Soils

SYNOPSIS An approach to mapping plantation sites for fertilisation at different rates is discussed and compared with the generally accepted recommendations of 35 kg per hectare P. Fertilisation of sites in the Tsitsikamma Key Area with a rooting depth of 500 mm or greater resulted in a saving of potentially misapplied phosphate of 24%. Fertilising based on a regression model for increasing the soil Bray 2 levels to 12 mg/kg resulted in a further potential saving of 46%. based on a map of predicted rates computed from soil characteristics using a mean rate. of 18,9 kg/ha P: Variables studied showed spatial dependence and so we recommend the use of geostatistics in survey planning and mapping as this allows more efficient use to be made of spatial data. Results from this paper show promise for improving the forestry manager's flexibility and aiding his decision-making.

Hali tarjima qilinmagan