Response of high density energy plantation of Eucalyptus tereticornis to basal nitrogen source, dose and phosphorus application on an alluvial soil
1993
S.S. Grewal | Kehar Singh | M.L. Juneja
On a sandy loam alluvial soil (UdicUstocrepts) of the foothill of north India, response of high density fuelwoodplantation (10,000 ha-1) of Eucalyptus tereticornis to three levels of basal N (0, 25, 50g per plant) from two sources, prilled urea (PU, 46% N) and super granules (SG,1 g of urea briquettes, 46% N) was studied for one rotation of 3.5 y. Phosphorus andzinc sulphate at 25 and 10 g per plant respectively were uniformly applied to all thetreatments. There were no significant growth responses to the nitrogen source. Theapplication of 25 N-PU and 50 N-PU increased air dry pole biomass by 22.2 and43.0% and annual discounted (12% rate of interest) cash returns by 36 and 64%over control at 42 months of age. The plantation accumulated 373, 17 and 241 kgha-1 from the available nutrient pool of 1340, 201 and 1015 kg ha-1 of N, P and Kinitially present in 0-300 cm soil depth. The soil profile indicated a deficit of 98 and204 kg ha-1 of available N and K but a gain of 59 kg ha-1 of available phosphorus.Although the leaf litter turnover and other probable additions narrowed down theoverall nutrient deficit created by Eucalyptus harvest, it was unlikely that suchnutrient-poor soil can support additional rotation without balanced fertilization. Assuch, tree farming was economicaly more viable than rainfed agriculture undermoisture and nutrient stress conditions of this tropical region.
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