Micromorphology of the Rhizosphere and its Influence on the uptake of Plant Nutrients
Former Ph.D. Scholar, University College of North Wales (Now Bangor University), Bangor, Caerns, Wales, U.K. ; Ex-Scientist (Soil Science), Indian Council of Agriculture Research (ICAR), New Delhi; Ex- Professor, University of Petroleum and Energy Studies (UPES), Dehradun, Uttarakhand, India & Ex-Senior Professor (International Business & Dean (Research), Asia-Pacific Institute of Management, New Delhi
Abstract
The paper highlights the historic background of Rhizosphere investigations focusing on Root-Soil Interface activities in terms of micro-morphology, using
advanced micro-morphological investigation techniques and tools such as high-resolution microscope, scanning electron microscope, electron-probe
X-ray-analyser technique, X-Ray Diffraction Technique, Thin Micro-Autoradiography using Kodak thin myler films onto thin sections with optical polish < 1.0
micron. The second part of the paper refers to a number of factorial pot experiments with French beans (Phaseolus vulgaris L) as test crop, involving three
nitrogen sources (viz. ammonium phosphate, choline phosphate and calcium chloride) at 2 N levels (500 ppm n and 1000 ppm N), 2 initial soil pH levels
adjusted at pH 7 & pH 8 and two growth (G) stages (21 days and 42 days) were conducted under a standard growth chamber condition ( temperature 280C,
light intensity 10, 000 LUX, R.H. 60%). Following dry ashing (4750C) shoots and roots were analysed for H2PO4-2 (Phospho- molybdate method ( Jackson,
1964) Ca2+, Mg2+ , K+ ,Na+, NH4+ , NO3- , Cl¬¬-), dithinate-citrate extractable Fe2+ , Mn2+ , Zn2+ ( Mehra and Jackson, 1960 ). The analytical values of
soil (rhizosphere and non-rhizosphere) and root and shoot parameters were subject to Analysis of Variance Tests (ANOVA Test) to determine significant
differences of based on single factors of factorial combinations and reveal ‘main effects’ and interactions. The summary of results of these experiments is
briefly summarized in the relevant sections of the paper