EUCALYPTUS-TERETICORNIS CULTIVATION WITH SOIL AMENDMENTS IN A NATRIC USTOCHREPT OF A SEMIARID REGION OF NORTHWESTERN INDIA

A field experiment was conducted with gypsum, pyrite, and ferric sulfate (industrial iron effluent) amendments at a Eucalyptus tereticornis Sm. plantation in a Natric Ustochrept soil of a semiarid region of northwestern India. Amendments were applied in amounts of 9, 18, and 27 kg per pit and were mixed in a 1 m2 area 30 cm deep. The soil surface was covered with a 1.5-meter wide polythene sheet, leaving a 15-cm wide strip (0.225 m2) in the center for planting and infiltration of rain and irrigation water. Mortalities of E. tereticornis were 80% in untreated soil, 50% in gypsum, 24% in pyrite, and 17% in ferric sulfate treatments. An application of pyrite increased plant height (H) and diameter (D) and produced about a 2.6 times higher biomass volume (D2H) per unit land area as compared to gypsum, 9.6 times higher than that of untreated soil. Ferric sulfate produced a 3.1 times higher biomass volume as compared to gypsum and 11.3 times higher than the untreated soil. Gypsum produced only a 3.7 times higher biomass as compared to untreated soil. The results of various soil physical and chemical measurements suggested that the superiority of pyrite or ferric sulfate over gypsum amendment in reducing mortality and increasing biomass production of E. tereticornis is primarily the result of improving the soil's physical conditions.