EURASIAN JOURNAL OF SOIL SCIENCE

189-196

Authors: Sana Ullah, M.Amjad Qureshi, M. Asif Ali, Fakhar Mujeeb, Sanaullah Yasin

Rhizobium besides its nodule formation characteristic with members of Fabaceae family has been recognized for its great root colonizing ability and growth hormone production potential. In addition to nitrogen fixation in legume plants, rhizobia considered as beneficial tools and act as plant growth promoting rhizobacteria (PGPR) with many non-legumes. Present study was elucidated to determine the comparative role of Rhizbium sp for growth promotion of sunflower. Rhizobia were isolated from five different legumes (mungbean, barseem, lentil, chickpea, and vegetable pea) and checked for their auxin production efficiency. Rhizobial isolates Cp-4 showed maximum auxin potential (5.37 µg mL-1IAA equivalents).Results showed that inoculation of all rhizobial isolates caused significant increase in growth and physiological parameters of sunflower plants. While prominent results were found with inoculation of mungbean rhizobial isolate Mb-2 which increases the chlorophyll a, N, P, fresh and dry matter of sunflower significantly by 8.34, 4.9, 36, 31, and 34%, respectively in comparison to un-inoculated control plants. Hence, present study concluded that Rhizobium sp can be successfully used as PGPR in non-legumes after thorough investigations.

206-215

Authors: Amit Bera

Soil erosion is a most severe environmental problem in humid sub-tropical hilly state Tripura. The present study is carried out on Muhuri river basin of Tripura state, North east India having an area of 614.54 Sq.km. In this paper, Universal Soil Loss Equation (USLE) model, with Geographic Information System (GIS) and Remote Sensing (RS) have been used to quantify the soil loss in the Muhuri river basin. Five essential parameters such as Runoff-rainfall erosivity factor (R), soil erodibility Factor (K), slope length and steepness (LS), cropping management factor (C), and support practice factor (P) have been used to estimate soil loss amount in the study area. All of these layers have been prepared in GIS and RS platform (Mainly Arc GIS 10.1) using various data sources and data preparation methods. In these study DEM and LISS satellite data have been used. The daily rainfall data (2001-2010) of 6 rain gauge stations have been used to predict the R factor. Soil erodibility (K) factor in Basin area ranged from 0.15 to 0.36. The spatial distribution map of soil loss of Muhuri river basin has been generated and classified into six categories according to intensity level of soil loss. The average annual predicted soil loss ranges between 0 to and 650 t/ha/y. Low soil loss areas (70 t/ha/y) of soil erosion was found along the main course of Muhuri River.

226-237

Authors: Faruque Ahmed, Md. Shoriful Islam, Md.Toufiq Iqbal

Biochar has the potential to improve soil fertility and crop productivity. A field experiment was carried out at the experimental field of Bangladesh Sericulture Research and Training Institute (BSRTI), Rajshahi, Bangladesh. The objective of this study was to examine the effect of biochar on soil properties, growth, yield and foliar disease incidence of mulberry plant. The study consisted of 6 treatments: control, basal dose of NPK, rice husk biochar, mineral enriched biochar, basal dose + rice husk biochar and basal dose + mineral enriched biochar. Growth parameters such as node/meter, total branch number/plant, total leaf yield/hectare/year were significantly increased in basal dose + mineral enriched biochar treated plot in second year compared with the other fertilizer treatments. In second year, the total leaf yield/hectare/year were also 142.1% and 115.9% higher in combined application of basal dose + mineral enriched biochar and basal dose + rice husk biochar, respectively, than the control treatment. The soil properties such as organic matter, phosphorus, sulphur and zinc percentage were significantly increased with both the (mineral enriched and rice husk) biochar treated soil applied with or without recommended basal dose of NPK than the control and only the recommended basal dose of NPK, respectively. Further, the lowest incidences of tukra (6.4%), powdery mildew (10.4%) and leaf spot (7.6%) disease were observed in second year under mineral enriched biochar treated plot than the others. The findings revealed that utilization of biochar has positive effect on the improvement of soil fertility and productivity as well as disease suppression of mulberry plant.

249-258

Authors: Ayten Namlı, Ahmad Mahmood, Bahar Sevilir, Emre Özkır

Application of chemical fertilizers besides economic concerns has been a reason of environmental and ecosystem degradation, so sustainable organic agriculture is becoming popular in researches and among farming communities. Phosphorus holds second position after nitrogen among macronutrients required for better plant growth and is needed in higher amounts. Meeting this high phosphorus input for better crop yields causes environmental problems like eutrophication, so phosphorus solubilizing bacteria (PSB) and plant growth promoting rhizobacteria (PGPR) are being emphasized to utilize phosphorus fixed in soil layers. This study was carried out to evaluate the effect of PSB on plant growth, soil biological properties including enzymes and soil respiration. Treatments including control, 50 mg kg-1 nitrogen, 50 mg kg-1 nitrogen and 12 mg kg-1 phosphorus applications reduced dosage of nitrogen 25 mg kg-1 with PGPR and 25 mg kg-1 nitrogen along with 0.12 g raw phosphate and PGPR. Results indicated that plant parameters like above and below ground plant biomasses (fresh and dry weight), plant nitrogen and phosphorus content were significantly enhanced in all the treatments when compared with the control. While soil pH in rhizosphere significantly increased with the treatments, bulk soil pH decreased with PGPR treatments when compared with all other treatments. EC values in rhizosphere and bulk soils were not significantly influenced with the treatments. Rhizospheric and bulk soil showed high amount of N, P and organic matter in PGPR treatments. Alkaline phosphatase and β-glucosidase activities were found significantly higher in the last treatment than the other treatments. Basal soil respiration was interestingly found higher in control soil but did not differ statistically from the other treatments. Concluding, application of PGPR with lower amounts of chemical fertilizers can reduce the use of chemical fertilizers and has also potential of improving soil health in long term aspects.

275-284

Authors: Sayed Roholla Mousavi, Feraidon Sarmadian, Zohreh Alijani, Abass Taati

Land evaluation, using a scientific method, is essential to recognize the potential and limitation of a given land for specific use in terms of its suitability, and certifies its sustainable use. The soil is such a source that its renewal takes a long time, so effective use of soil and land resources requires a thorough understanding of the effective morphological processes of soil forming in different regions. The current study identified available soil in the area in terms of interpretation of aerial photographs and Geopedological approach. After mapping the geoform area, 61 profiles of the designated area were drilled and sampling was done for all diagnostic horizons. Then, the samples were transported to the laboratory for Physico-chemical analysis. By the end of the profile classification process, which was based on the Soil Survey Staff (2014), the soil map, was prepared by integration of the soil data and the geoform map in ArcGIS software. There are several limiting factors for wheat in Qazvin plain, namely; electric conductivity (EC), gypsum, coarse fragment, soil depth, soil organic carbon (SOC), texture, calcium carbonate and climate. The map of the land units was prepared, and land requirements for the type of utility were calculated. Land suitability evaluation was performed according to FAO. The results showed that land unit’s number 17 and 18 were unsuitable (N1) for irrigating wheat with limiting factors such as; high levels of EC and gypsum in the studied profiles. Moreover, the land unit’s number 10, 20, and 23 are suitable (S1) for the wheat production and have the highest rate of predicted yield.