JWSS - Journal of Water and Soil Science

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In a completely randomized design, the effects of six different additive compounds including limestone, hydrochloric acid, zeolite, aluminum sulfate, pad ammoniac, and fatty acids on nitrogen, pH, temperature, moisture, water soluble phosphorus, and microbial count of litter of broiler chicken were investigated. Each compound was added at a level of one kg/m² of litter. Six–hundred-and-sixteen (616) day- old broiler chickens (both sexes) were divided into 28 groups, 22 chicks per group. Four replications were allocated to each treatment from 1 to 56 days. All groups were fed with the same diet. Litter moisture was not affected by the treatment. Experimental treatments significantly (p<0.05) influenced the litter pH on day 21. The lowest pH was obtained with aluminum sulfate and the highest pH was obtained with limestone. At the end of the experimental period, all treatments had nearly the same pH levels. Litter temperature was not affected by the treatments . Experimental treatments had a significant (p<0.05) effect on litter nitrogen and bacterial count. Correlation between litter pH and nitrogen was significant and negative (r = -0.95, p<0.05). Effect of treatments on soluble P was significant and the lowest soluble P belonged to aluminum sulfate and pad ammoniac. Correlation between soluble P and pH was positive (r = 0.48, p<0.05). The results showed that some chemical compounds can be used to reduce litter pH, nitrogen, and soluble P and their effectiveness diminishes as chicks grow older.

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The soil potassium status and effect of soil physical and chemical properties on it were investigated using 109 surface soils (0-30cm) from four regions in Guilan province. Neutral molar ammonium acetate extractable K (K-NH₄OAc), boiling molar nitric acid extractable K (K-HNO₃) and water soluble K were determined. Results showed that CEC and clay were normally frequency distributed while distribution frequency of other variables such as silt organic carbon and pH were not normal and have significant skew and kurtosis. In addition sand, K-NH₄OAc and K-HNO₃ has logarithmic normal distribution. Water-soluble potassium was affected by sand, pH, O.C and K-NH₄OAc (R²_a=0.73**). Ammonium extractable potassium was affected by soluble potassium, non-exchangeable potassium and CEC (R²_a=0.72**). Boiling nitric acid was affected by exchangeable potassium and silt (R²_a=0.55**). Geographic distribution of K-NH₄OAc data shows amount of it in central parts of Guilan, particularly Sepidrood river watershed is more than other regions. Fomanat region soils have the less clay, CEC, K-NH₄OAc and K-HNO₃. According this study about 68.8 percent of Guilan soils was classified in the range of medium to very low potassium status.