The Effect of Different Pistachio Wastes Biochar Application on Some Fertility Properties of a Loam Soil

In this research, the short-term beneficial effect of using different pistachio wastes biochars on improving some fertility properties of a loam soil was investigated. Therefore, the effects of two factors 1) types of amendments added to the soil, including biochars of pistachio mildew (PM), pistachio hard skin (PHS) and wood of 20-year pistachio trees (W) papered at 600o C (with amount of %5 by wt), and 2) time of incubation (1, 2, 3, 4, 5 months), were investigated on pH, electrical conductivity, soluble potassium, nitrate and availability of iron, copper, manganese and zinc. This experiment was performed as factorial based on the completely randomized design with three replicates. The results of this study showed that the application of biochars and different incubation times does not have a significant effect on soil pH. But, the threated soils at all incubation times showed a significant increase in electrical conductivity and organic carbon as compared to the control treatment. Addition of biochars and incubation time increased significantly potassium content of the soil solution, so that the treated soils had an increase of approximately two times solution potassium as compared to the control. Application of biochars to the soil caused an increase in nitrate retention and a decrease in nitrate solution as compared to the control sample. Biochars application led to a significant increase in iron content and irregular increase in zinc, copper and manganese. The availability of these elements in the soil decreased by time due to reduction of biochar decomposition and transformation of those elements from available into less available forms.