The possible replacement of calcite by calcareous sludge of paper mill in amending cultivated soil of white mulberry (Ichinoife variety)

Abstract Paper mill sludge is produced as a by-product of paper production such that disposal of this material presents a problem for the mill. Disposal by land filling, the most common disposal method, is costly and faces increasingly stringent environmental regulations. In this study, the possibility of using paper sludge lime instead of calcite lime had been investigated in berry orchard improvement under cultivation of sericulture in two phases. In the first phase, the effect of different amounts of paper mill sludge on some chemical properties of soil was investigated in an incubation study at the period of 90 days. The results showed that the proportional amount of paper sludge increased pH and decreased soil iron and manganese, but will lead to increased soil phosphorus. In a field experiment (second phase), control treatment and three treatments in the amounts of lime sludge applied at the rate of 2.5, 5 and 10 ton/ha; and a treatment with 2.5 tons/ha of calcite in the form of a completely randomized block design in the mulberry orchard of the Silkworm Research Center had been carried out. The results indicated that the amount of paper sludge, 2.5 and 5 tons/ha, along with calcite lime treatments, leaf dry matter yield and gross protein content in leaves significantly increased compared to control, but with regard to yield, percentage of protein and nutrient uptake, treatment of sludge lime were more appropriate than calcite lime treatment

Growth of olive saplings in different media containing artificial and natural super absorbents at two irrigation intervals

A factorial experiment was conducted to evaluate the impact of super absorbents and organic wastes of rice, olive marc, vermicompost and farmyard manure on the soil water holding capacity and the growth of plant based on randomized complete block design with 13 treatments at two irrigation intervals 5 and 10 days. The olive saplings with same heights and better appearances were planted in an open space roofed with a plastic cover with a height of 3 m to avoid the effects of rainfall and snowfall on the results. Stockosorb superabsorbent and weighted zeolite and the rest of bulk materials were mixed. Results showed that the substrate containing 10 g/kg soil of zeolite and the substrate including 20% vermicompost +15% rice wastes +15% manure +50% soil had the best yield and can modify the effect of 10 days irrigation interval compared to the 5 days