N. G. Juma

University of Alberta | UAlberta · Department of Renewable Resources

This file contains a list of refereed primary journal articles and chapters of Dr. Noorallah G. Juma Classified By Subject Areas 1. Plant Root and Soil Phosphatase Activity 2. Mineralization and Immobilization of N in Soil 3. Microbial-Faunal-Plant Interactions in Soil 4. Plant Root Dynamics and Rhizodeposition 5. Dynamics of Carbon and Nitrogen...

Interrelationships between soil structure/texture, soil biota/soil organic matter and crop productivity occur from a scale of micrometres to metres. In this paper an attempt has been made to integrate and quantify these interrelationships by using the themes of C and N mineralization and porosity using data from soils in western Canada. Although th...

Field Experiments conducted over the past 100 years in the Canadian Prairie provinces have resulted in voluminous agronomic knowledge that has propelled Canada to become a major exporter of agricultural products. Hundreds of scientific publications have been produced and this knowledge is now being used to address emerging issues such as climate ch...

Agriculture manipulates energy fluxes, nutrient dynamics and hydrologic cycles. Descriptions of nutrient cycling and decomposition in agro-ecosystems are site-specific and thus generalizations are of limited validity unless processes and regulatory mechanisms are considered. Consequently, this chapter discusses organic matter status of agricultural...

The Story of Soil Science in Alberta: A Guided Tour of Soil Resources at the University of Alberta. The soil monoliths and artifacts are organized by clusters on the second, third and fourth floors of the Earth Sciences Building, University of Alberta. The document has many visuals of the items in the collections. Enjoy!

1. Large herbivores are known to spatially concentrate and alter the form of nitrogen (N) in grassland systems, which can modify aboveground plant chemical composition and productivity, and result in shifts in grazing pressure in these areas. Root responses to grazing under high N inputs may facilitate these changes, but their responses are less we...

J.D. Newton Soil Science Collection (1921-1998) John Dawson Newton was born in Plaisance Quebec, in 1894. He graduated from McGill University with a B.Sc. (Agric.) in 1917, and received his Ph.D. from the University of California in 1922. He was a member of the Agronomy Department at the University of British Columbia from 1918 to 1920, and concurr...

This is an article which has the biographies and academic achievements of Soil Science pioneers, Drs. F. A. Wyatt and J. D. Newton, at the University of Alberta. The following recognitions were obtained from the Board of Governors, University of Alberta: The Alberta Soil Monolith Collection in Room 2-36 Earth Sciences Building, University of Alber...

Soil Monolith Exhibition Edmonton Inspires II: An Exhibition from the University of Alberta Museums The Department of Museums and Collections Services is pleased to announce the opening of Edmonton Inspires II, the second of a two-part University of Alberta Museums exhibition that runs from 25th November to 18th December 2004, at the FAB Galler...

Factors controlling soil organic matter (SOM) dynamics in soil C sequestration and N fertility were determined from multi-site analysis of long-term, crop rotation experiments in Western Canada. Analyses included bulk density, organic and inorganic C and N, particulate organic C (POM-C) and N (POM-N), and CO2-C evolved during laboratory incubation....

This document is a complilation of the Landscape Ecology Seminar Series sponsored by the Department of Renewable Resources & the Office of Vice-President (Research), University of Alberta. Dr. Noorallah Juma was the seminar series coordinator for a period of 7 years from 1995 to 2001. Dr. Ross Wein was the coordinator for the subsequent year. The a...

Soil C contents can be raised by land use practices in which rates of C input exceed those of C oxidation. Rates of C inputs of soil can be raised by continuous cropping, especially with perennial legumes, and by soil amendments, especially manure. We have summarized our understanding of the processes by which changes in soil C content are determin...

We related C input and management to soil organic C (SOC) dynamics over 51 yr (1939-1990). We used two rotations from the Breton Classical Plots at Breton, Canada, on a Typic Cryoboralf: (i) wheat (Triticum aestivum L.)-fallow (WF) and (ii) wheat-oat (Avena sativa L.)-barley (Hordeum vulgare L.)-hay (primarily alfalfa, Medicago sativa L.)-hay (WOBH...

Soil C contents can be raised by land use practices in which rates of C input exceed those of C oxidation. Rates of C inputs of soil can be raised by continuous cropping, especially with perennial legumes, and by soil amendments, especially manure. We have summarized our understanding of the processes by which changes in soil C content are determin...

Soil samples from differing cropping systems were amended with 15N-labeled plant residues having varying carbon to nitrogen (C:N) ratios to quantify N dynamics in a Gray Luvisolic soil. For non-amended cropping systems a significantly greater amount of total N was mineralized from the continuous legume (CL) than from the continuous grass (CG), barl...

(Introduction): Long-term monitoring is required to assess the effects of natural and anthropogenic processes on soil-quality attibutes. Long-term crop-rotation experiments were set up in the Canadian Prairies with the prime goal of improving crop yields and economic returns. These experiments can be used to assess changes in physical, chemical, an...

Resource quality and availability, microclimatic conditions, soil solution chemistry and soil structure significantly influence the size, composition, distribution and dynamics of soil biotic communities. Plant roots, and soil meso-and macro-fauna contribute to soil structure dynamics by altering existing macropores and voids, or by creating new ma...

The Canadian prairie, which accounts for about 80% of Canada's farmland, has large reserves of soil organic carbon (SOC). Changes in the size of the SOC pool have implications for soil productivity and for atmospheric concentrations of CO2, an important `greenhouse gas'. We reviewed recent findings from long-term research sites to determine the imp...

(INTRODUCTION): Most Cryoboralfs in Canada occur in the northern interior plains of Manitoba, Saskatchewan and Alberta. The largest area occurs in Alberta (20 million hectares), of which about 5.7 million hectares are potentially arable. About 3.2 million hectares are occupied and about 1.6 million hectares are cultivated.8 Cultivated Cryoboralfs c...

This appendix has data for the Breton Plots. The data are organized by headings: site location, site description, experimental design, management schedule, soil properties, crop yields, climate. The appendix (chapter) is published on a 3.5" disk accompanying the volume

Agronomic practices impace total organic C (TOC), microbial C (MBC), light fraction (LFC) and potentially mineralizable C in soils. Experiments were conducted at the University of Alberta Breton Plots to determine the impact of crop rotations (2-year wheat-fallow, and 5-year wheat, oat, barley, forage, and forage) and treatments (check, NPKS fertil...

Agronomic practices are vital for reclamation of eroded soils. Soil erosion was simulated by removing 0, 10, and 20 cm of topsoil from plots on a Gray Luvisol and a Black Chernozem in central Alberta. Three amendment treatments (‘topsoil + fertilizer’, ‘manure + fertilizer’ and continuous fertilizer) were superimposed on the plots where 20 cm topso...

(Introduction) Soils are open, dynamic systems which occur as three dimensional natural bodies on the landscape. The organic component of soil consists of living organisms, undecomposed and partially decomposed organic matter and humified organic substances. Decomposition of organic matter is controlled by organisms, physical environment, and resou...

This chapter develops a mechanistic understanding of the impact of the soil biota, especially soil fauna, on biochemical transformation of carbon in soil, humification of organic carbon (OC) in soil, humus forms in soils, and distribution of humus in soil compartments and profiles. The structure of plant and animal residues shows that neosynthesis...

Proper management of crops on Gray Luvisols requires knowledge of net soil nitrogen (N) mineralization during the growing season. Soil samples from a long-term field experiment at Beaverlodge, Alberta, were used to determine the kinetics of net N mineralization in soil samples from different crop rotations. The cropping systems established in 1968...

We studied the impact of continous barley and a 4-year rotation consisting of fababean, barley after fababean, barley intercropped with field pea, and barley after the intercrop on the soil biological properties of a Gray Luvisol. The crop rotations were estabilshed in 1988 and fertilizer N was not applied to any plots. The plots were sampled five...

The Breton Plots research site is owned and operated by the University of Alberta located at latitude 53 07' N and longitude 114 28' W near the town of Breton (Alberta, Canada). The research site currently holds five long-term rotations and tillage experiments. The oldest plots, the Breton Classical Plots, were initiated in 1930 with the objective...

The extent of nitrate leaching in cultivated soils of Alberta is unknown. We studied how long- and short-term agricultural practices influenced nitrate leaching in a cryoboreal subhumid soil-climate of north-central Alberta. The study used plots from three crop rotation-tillage studies at Breton on an Orthic Gray Luvisol, and from one at Ellerslie...

Though legumes are beneficial in crop rotations, there is limited information on how tillage system-crop sequence interactions influence crop yield and N production. To see if biomass and N yields in short-term legume-based rotations under zero tillage (ZT) and low-input (LI) production methods can equal those in cereal monocultures under ZT and co...

(Introduction): In order to predict the rates and amounts of gaseous emission from soils, it is necessary to quantify dynamics of C and N in soils. Over the past 100 years, four main approaches have been used to study the nature of soil organic matter: (i) acid hydrolysis; (ii) classical humic fractionation techniques; (iii) particle size fractiona...

The rates of decomposition of roots and root-derived materials are needed to assess the contribution of these materials to sequestration of organic carbon in soil. The objective of this study was to examine the kinetics of different forms of C in a Black Chernozem, with roots in situ under two barley cultivars, using 14C pulse-labeling and incubati...

A productive soil needs a favorable structure and an efficient nutrient cycling system. Management practices which simultaneously enhance these functions can lead to sustainable land use. The objective of this study was to develop concepts which can be used to link C and N cycling and soil structure formation by using the following model: (1) each...

Total soil N and N mineralization rate partially characterize the influence of various cropping systems on the growth of sequent crops in a rotation. The objectives of this study were to (1) quantify the relationship among cropping system, total N and mineralizable N, and (2) compare amount of N mineralized under controlled laboratory conditions wi...

The production and utilization of root-derived C is fundamental to the functioning of ecosystems. The objectives of this experiment were to quantify the amount of root-released C produced by two barley (Hordeum vulgare L.) cultivars, to evaluate the direct and indirect effects of shoot C, root C and root length on the root-released C and to quantif...

Soil water limits plant growth in the Canadian Prairie Provinces. Effcient use of soil water is, therefore, paramount in crop production. Two 2-yr field studies were conducted (i) to determine the effects of crop selection and cropping practice on the temporal and spatial distribution of soil water and (ii) to quantify water use and water-use effic...

Root research has been hampered by a lack of good methods and by the amount of time involved in making measurements. The use of the minirhizotron as a quantitative tool requires comparison with conventional destructive methods. This study was conducted in the greenhouse to compare the minirhizotron technique with core and monolith methods in quanti...

Quantification of root dynamics by destructive methods is confounded by high coefficients of variation and loss of fine roots. The minirhizotron technique is non-destructive and allows for sequential root observations to be made at the same depth in situ. Observations can be stored on video tape which facilitates data handling and computer-aided im...

If mathematical models of decomposition and transformation processes are to be rigorously validated, they should be tested against the microbial dynamics from which these processes arise. A mathematical model was constructed from kinetic equations for microbial activity reported in the literature and in earlier models, and was tested against C and...

The mineralization of C and N in soils involves the dynamic behaviour of the microbial biomass. This behaviour was reproduced in a simulation model which was used to study microbial growth and mineralization following soil amendments with labelled glucose and crop residues. Temporal trends of simulated microbial C and N associated with these amendm...

Work with barley cultivars had shown that barley root and shoot mass dynamics were affected by the cultivars used, and root length followed similar trends as root mass but decreased much faster than root mass between heading and ripening stages. A field experiment was made on a Typic Cryoboroll in 1990 with two barley cultivars to study the above-...

The rebuilding of soil organic matter is a continual process which involves the physical breakdown, biochemical transformation and biophysical stabilization of organic material. The growth and death of organisms results in the uptake (immobilization) and release (mineralization) of macro- and micro-nutrients and in the formation of new organic matt...

Cropping systems which conserve soil, water and nutrients are needed on the Canadian prairies. The objectives ofthis study were: (1) to assess the effects ofurea injection on N partitioning in barley-soil systems under conventional (CT) and zero tillage (ZT); and (2) to measure the dynamics of fertilizer and soil N over the growing season. Twelve m...

A 3-year field study (1986–88) was conducted in central Alberta to discover how diverse soil-plant systems function under cryoboreal subhumid conditions. Barley, fescue, faba (field) bean and a barley/field pea intercrop were grown continuously on different soils at Ellerslie and Breton using two distinct tillage methods. The agronomic performance,...

The objective of this study was to quantify the shoot and root mass, shoot mass/root mass ratios, and root lengths of four barley (Hordeum vulgare L.) cultivars (Abee, Bonanza, Harrington and Samson) grown in a Black Chernozem in north-central Alberta. The cultivars were grown using a randomized complete block design with three replicates and were...

Mathematical modelling of a microcosm experiment provided a rigorous link between soil organism populations and the processes in the C and N cycles for a clay loam soil. In order to check the internal consistency of the model, we tested its performance with the data set obtained for a sandy loam. We empirically lowered the value of the half saturat...

Modelling in soil ecological research is a means of linking the dynamics of microbial and faunal populations to soil processes. The objectives of this study were (i) to simulate bacterial-protozoan interactions and flows of C and N in clay loam Othic Black Chernozemic soil under laboratory condtions; and (ii) to quantify the flux of C and N (inputs...

Texture affects pore space,bacterial and protozoan populations and their activity in soil. The objective of this study was to test the hypothesis that protozoa grazing on bacteria increase the mineralization of bacterial C and N more in coarse-textured soils than in fine-textured soils. The microcosm experiment consisted of samples from three steri...

Soil texture affects pore space, and bacterial and protozoan populations in soil. In the present study we tested the hypothesis that bacteria are more protected from protozoan predation in fine-textured soils than in coarse-textured soils because they have a larger volume of protected pore space available to them. The experiment consisted of three...

One way to conserve fertilizer N in the plant-soil system is to immobilize it at the time of application by adding a readily available C source and to rely on the microorganisms to remineralize it to meet crop N demand during the season. The present study was conducted to determine the effects of microbial activity due to glucose amendment at the t...

Barley-field pea intercrops have been shown to increase N yield when grown under cryoboreal subhumid conditions. In this study, we extended previous research by testing the hypotheses that (1) the intercropped field pea fixes a greater proportion of its shoot and root N than does sole-cropped field pea; (2) N is transferred from the annual legume t...

Quantification of root dynamics by destructive methods is confounded by high coefficients of variation arising from the spatial heterogeneity of roots. This often results in a poor estimation of root dynamics. The minirhizotron technique is nondestructive and allows for rapid and sequential root observations to be made at the same depth in situ. An...

Carbon assimilated by plants is recovered in the tissues of the shoot, root and in root released organic materials, e,g, root exudates. Van Veen et al. (1991), summarizing the previous work, concluded that the root exudation had the lowest degree of certainty compared to other root processes. Moreover, there is a lot of information on the effect of...

A 4-yr rotation was initiated in 1989 at Ellerslie (Black Chernozem) and at Breton (Gray Luvisol) in central Alberta with the objective of evaluating the impact of annual legumes in reducing the use of fertilizer N om short-term rotations. Crops grown in rotation without the addition of fertilizer N, consisted of fababean (for silage), followed by...

Nitrogen fertilization is used in reclaiming elemental sulphur (S0) laden soils. Nitrogen and S dynamics in limed. S0-laden, forested Gray Luvisols exposed to S0 and lime during the 5 yr before sampling was assessed in a 14-week experiment in a growth chamber. Ammonium sulphate labelled with 15N was added to soils in pots with and without plants (L...

Above- and below-ground net primary productivity is the major energy and nutrient pathway in ecosystems and is crucial for constructing ecosystem budgets. Production studies concerned with crops almost exclusively concentrate on production of plant parts of direct economical interest. e.g. grain or hay yield. Thus, information of net primary produc...

Growing legumes with cereals may increase both yield and protein of livestock-feed crops as well as the quantity of N returned to soil. This study examined: (i) if barley-field pea intercropping has advantage over sole barley (Hordeum vulgare L.) for grain and N yield and (ii) the interactions between fertilizer N and seeding densities of barley an...

The overall objective of our research program at the University of Alberta is to develop new management systems which conserve soil for sustained agricultural production. Above-ground productivity and selected soil properties under conventional and alternate cropping systems were studied using four crops (barley, barley-field pea intercrop, fababea...

EPIC (Erosion-Productivity Impact Calculator) is a comprehensive model developed to evaluate the relationship between soil erosion and soil productivity. This study evaluated the ability of the EPIC model in simulating evapotranspiration, nitrogen transformations, and barley yield at Ellerslie, Alberta, during 1987 and 1988. In general, EPIC provid...

Dynamics of barley N, mineral N, and organic N were compared at Ellerslie (Black Chernozem, Typic Cryoboroll) and Breton (Gray Luvisol, Typic Cryoboralf) in central Alberta, using 15N-urea. On average, shoot N and shoot 15N recoveries at Ellerslie (14.1 g m–2, 36%) were greater than at Breton (4.5 g m–2, 17%). Root N (g m–2) did not significantly d...

Carbon distribution in shoots, roots, microbial C an soil organic C was measured in barley plots on a Ba;ck soil at Ellerslie and a Gray Luvisol at Breton. Less C was found at Breton than Elleslie in all components with the exception of root C which was similar at both sites. A smaller proportion of soil organic C was found in kinetically more acti...

Intercropping cereals with legumes may increase the protein content of crops grown for livestock feed as well as the quantity of N returned to soil. In central Alberta, we studied: a) grain and nitrogen yield of barley-field pea and barley grown on a Black Chernozem and on a Gary Luvisol, b) interactions between N fertlizer and seeding densities of...

This study compared the dynamics of shoots, roots, microbial biomass and faunal populations in two different soils cropped to barley. The dynamics of microbial C, protozoa, nematodes, acari, collembola, shoot and root mass were measured between July and October under barley at Ellerslie (Black Chernozem, Typic Cryoboroll) and Breton (Gray Luvisol,...

This study was undertaken to compare some aspects of carbon cycling in a Gray Luvisol at Breton and a Black soil at Ellerslie, Alberta cropped to barley. Comparisons of the above and below-ground allocation of carbon, distribution of carbon in soil, and microbial use of carbon were made between sites. Shoot C, root C, microbial biomass C, soil orga...

The distribution of12C and14C and dynamics of14C in barley plots were studied after pulse labelling with14CO2. Barley was grown in microplots on a Black soil at Ellerslie and a Gray Luvisol at Breton, Alberta and was sampled on four dates between July 31 and October 20. The quantity of12C in shoots, microbial biomass, and soil was greater at Ellers...

The kinetic and thennodynamic parameters of phosphomonoesterases of soils and of corn (Zea mays L.) and soybean (Glycine max L.) roots were evaluated. The optimum pH values for acid phosphatase activity in corn and soybean roots were 4 and 5, respectively. Roots of these plants did not contain alkaline phosphatase activity: therefore, the alkaline...

Because of the importance of organic phosphates as sources of P for plants, this work was performed to study the hydrolysis of nine organic phosphates by sterile, intact corn (Zea mays L.) and soybean (Glycine max L.) roots. Results showed that the rates of hydrolysis ofp-nitrophenyl phosphate (PNP) in buffered solutions by roots of three varieties...

Studies with sterile root materials showed that the optimum pH values of phosphatase activity in three varieties of each of corn (Zea mays L.) and soybean (Glycine max. L.) were 4 and 5, respectively. The activity on either side of the optimum pH fell sharply, and there was no activity at pH 9. Thus, these roots contain acid but no alkaline phospha...

The dynamics of microbial biomass, nematode and microarthropod populations were studied in oat (Avena sativa L.) and second-year alfalfa (Medicago sativa L.) plots of a 5-yr rotation at Breton, Alberta. Plots were sampled at monthly intervals between July and October 1984. First cut of alfalfa was taken in early July. On average shoot biomass was h...

Adult and juvenile nematode distribution and trophic group dynamics were studied in oat (Avena sativa L.) and alfalfa (Medicago sativa L.) plots of a 5-yr rotation at Breton, Alberta. Nematodes were separated into two groups: (i) adults including the late juveniles and (ii) juveniles. The adults and the late juveniles were further separated into fo...

Studies were conducted to determine the most suitable mathematical equation and the most appropriate method for calculating the values of the parameters of the equation describing the net N mineralization in soil. The cumulative net N mineralized in two treatments of a 15N labeled soil and five unlabeled Saskatchewan soils showed curvilinear trends...

Studies were conducted on a 15N-labeled Weirdale loam, a Dark Gray Chernozemic soil (Boralflc Boroll) to (i) determine the amounts of N released by several methods previously used to obtain an estimate of potentially mineralizable N, (ii) determine their 15N enrichment and extractability ratios, and (iii) compare the results from the above with the...

Several phosphatases are present in soils. The contribution of phosphatases in plant roots to phosphatases in soils is not well understood. This study was conducted to determine the fate of corn-root phosphatases in soils. Results showed that corn roots contain acid phosphatase (optimum pH = 4.0) and inorganic pyrophosphatase (optimum pH = 6.5), bu...

The disposition of 15N-aqua NH3, and 15N-solution urea in the presence and absence of a nitrification inhibitor [4-amino-1,2,4-triazole (ATC)] was measured under field conditions. ATC caused a 15% greater recovery of fertilizer N in the soil-plant system (95 vs. 80%) but no changes in wheat N uptake (37%). The 0- to 15 cm layer of ATC-treated soils...

Micro-organisms in soil play a major role in the soil-N cycle, transforming N compounds into available and unavailable forms, mobile and immobile forms, oxidized and reduced forms, and gaseous and solute forms. The N transformations of interest to this workshop were nitrification, denitrification, mineralization-immobilization, and biological N2 fi...

1. NAME OF MODEL: TRAMIN - Use of tracer and computer similation techniques to assess mineralization and immobilization of soil nitrogen. 2. SYSTEM MODELED: The model describes the mineralization and immobilization of soil nitrogen during microbial growth and decay under laboratory conditions. 3. OBJECTIVES: The objectives of this investigation w...

The disposition of fertilizer 15 N in the presence and absence of a nitrification inhibitor [4-amino-1,2,4-triazole (ATC)] was measured under field conditions. The 15 N labeled soil obtained from the field experiment was then used in the laboratory and greenhouse studies to measure microbial growth, concurrent mineralization and immobilization and...

The effects of environmental factors and differences in plant constituents on the microbial mineralization and immobilization of nitrogen were reasonably well known for individual soils by 1935. During the further study of these processes, it was found that ammonium is preferentially utilized by microorganisms, and tracers and mathematical equation...

The effects of environmental factors and differences in plant constituents on the microbial mineralization and immobilization of nitrogen were reasonably well known for individual soils by 1935. During the further study of these processes, it was found that ammonium is preferentially utilized by microorganisms, and tracers and mathematical equation...

The efficiency of fertilizer nitrogen (N) utilization by crops has been a major concern of agronomists for the lat 30 years. Allison (1966) concluded that the efficiency of any N carrier is a function of: (a) losses due to leaching, denitrification and volatilization; (b) immobilization of N; (c) the ratio of soil N/fertilizer N in the available N...

Several phosphatases are present in soils. This study was conducted to determine the distribution of phosphomonoesterases (acid and alkaline phosphatases). Results showed that the activities of these enzymes were associated with surface soils and that they decrease with depth. Acid phosphatase was predominat in acid soils, and alkaline phosphatase...

Studies to evaluate the effects on the activity of acid and alkaline phosphatases of 20 trace elements showed that all trace elements inhibit the activity of phosphatases in soils. Results showed that the relative effectiveness of the trace elements in inhibition of phosphatase activity depends on the soil. When the trace elements were compared by...

Acid and Alkaline phosphatase are enzymes which catalyze the hydrolysis of monoesters of orthophosphoric acid. These are classified as such because they have their optimum activities in the acid and alkaline pH ranges, respectively. Both enzymes are distributed widely in nature and have been isolated from microorganisms and animals. Plant tissues h...