The Possible Replacement of Calcite by Calcareous Sludge of Paper Mill in Amending Cultivated Soil of White Mulberry (Ichinoife Variety) (Report‪)‬

Introduction The most common management practice to ameliorate acid soils is the surface application of lime and other calcareous materials (Bolan et al., 2003). The main aim of soil liming is to neutralize acidic inputs and for recovering the buffering capacity to the soil (Ulrich, 1983). Applications of industrial wastes as fertilizer and soil amendment have become popular in agriculture. One of these wastes is calcareous sludge of the paper industry. Paper mill sludge is produced as a by-product of paper production such that disposal of this material presents a problem for the mill (Battaglia et al., 2007; Calace et al., 2005; Mahmood and Elliot, 2006). Disposal by land filling, the most common disposal method, is costly and faces increasingly stringent environmental regulations (Feldkinchner et al., 2003). Lime sludge is the solid waste produced as part of the process that turns wood chips into pulp for paper. The major component of lime mud is calcium carbonate (CaC[O.sub.3]) and it is estimated that about 0.47 [m.sup.3] of lime mud is generated to produce 1ton of pulp (Wirojanagud et al., 2004). Mohammadi Torkashvand (2010) compared the effect of sulfuric acid and paper mill sludge on the produced compost quality of municipal wastes. He found that both amendments increased the agronomic value of the produced compost quality, but using sulfuric acid is suitable in fewer amounts (20 ml/kg fresh organic wastes; decomposable municipal wastes). The paper mill sludge had more effect on total nitrogen of the produced compost than the sulfuric acid. For land application of sludge produced from pulp mills, Simpson et al. (1982) reported that combined kraft paper mill secondary sludge-fly ash applied at a rate of 108 metric dry ton [ha.sup.-1] significantly increased the yield of fescue and corn. A four years field study in Alberta (Macyk, 1996) recommended an agronomically sound decomposed pulp mill sludge application rate of 40-80 ton [ha.sup.-1] for brome grass. Kannan and Oblisami (1990) also concluded in a similar research that paper alkaline waste along pulp with paper in irrigating sugarcane fields is leading to reduced growth. High consumption of sludge (10 ton/ha) also caused reduced plant yield. Leon et al. (2006) during a research concluded that the use of paper sludge as soil modifiers significantly caused decreased rot in beans in sludge treatments compared with control. They found that the decrease in disease resulted from a change in properties of soil biology (Leon et al., 2006). Curnoe et al. (2006) identified the positive effects of factory lime sludge paper on maize yield. Gaskin and Morris (2004) indicated that lime mud has the potential to be used as an agricultural liming material because of its capability to neutralize soil acidity (increased soil pH) and to add calcium and magnesium to the soil. Although high moisture content of lime mud creates more shipping and handling difficulties than typical dry agricultural liming materials (Mahmoudkhani et al., 2004), this obstacle can be overcome as sludge dewatering technology improves (Chen et al., 2002 and Yin et al., 2004). The objectives of the present study were (i) to determine the effect of paper mill sludge on some chemical properties of soil (pH, EC, AB-DTPA extractable P, K, Fe, Mn and Zn) and growth of berries as compared with calcite lime and, (ii) to evaluate the value of the waste as an agricultural lime material.