Document Type : Research Paper
Authors
1
Soil Science Department, College of Agriculture and natural Resources, University of Tehran, Karaj, P.O.Box 4111, Iran
2
Soil Science Department, Faculty of Agriculture, University of Tehran, Karaj, Iran.
3
Soil Science Department, ّFaculty of Agriculture, College of Agriculture and Natural Resources, University of Tehran, Karaj, P.O.Box 4111, Iran
4
Department Of Agronomy, College of Agriculture and Natural Resources, University of Tehran, Karaj, P.O.Box 4111, Iran
Abstract
The aim of the study is to combine organic, inorganic materials and selected microorganisme to modify the physical, chemical and biological characteristics of a non-saline sandy Entisol (0-20 cm), from NajmAbad Karaj aeolian sediments. This research was conducted in the frame of factorial Completely Randomized Design with three levels of bentonite 0, 20 and 40 Ton ha-1 respectively, carboxymethyl cellulose 0, 3 and 5 g kg-1 respectively and mixture of two isolates of endophytic bacteria (Pseudomonas sp) and rhizosheath (Pantoea agglomerans) at three levels respectively 0, 20, and 40 mL kg-1 and a total of 27 treatments with 3 replications (81 samples). Multivariate statistical methods including Principal component Analysis (PCA), hierarchical clustering, and two-step clustering were used. Based on Two-step clustering, available Fe (RI=1), mean weighted diameter (RI=0.99), field capacity (RI=0.97), total N (RI=0.87), available K (RI=0.83), and dehydrogenase (RI=0.8) were identified as the most important (RI) variables. Variables including Fe available with a range of 1.75 to 7.08 mg kg-1, mean weight diameter with a range of 0.31 to 1.15 mm, total nitrogen with a range of 0.014 to 0.06%, field capacity with a range of 8.03 to 12.82%, available K with a range of 280.8 to 416.66 mg kg-1 and dehydrogenase enzyme with a range of 0.07 to 0.148 μgTPF g soil 24 h-1, had the highest effect in the clustering treatments. The results of this study showed that treatments B20C5M20, B40C5M10, B40C5M20, B40C3M20 and B40C3M10 have better performance to modify certain soil properties compared to other treatments.
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