scholarly journals The role of salal in forest regeneration problems in coastal British Columbia: problem or symptom?

2008 ◽  
Vol 84 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Cindy E Prescott ◽  
Toktam Sajedi
Keyword(s):  
Mycorrhizal Fungi ◽  
Forest Regeneration ◽  
Field Experiments ◽  
Fundamental Problem ◽  
Optimal Solution ◽  
Long Term Results ◽  
Organic N ◽  
Growth Responses ◽  
Gaultheria Shallon ◽  
Ericaceous Shrub

The ericaceous shrub, salal (Gaultheria shallon Pursch) is associated with forest regeneration problems on a variety of site types along the west coast of North America. On dry sites, salal is a serious competitor for water; on wet (cedar-salal) sites, salal is thought to limit nutrient availability to trees by competing, interfering with mycorrhizae and "short-circuiting" the nitrogen cycle through production of phenolic compounds. Short-term field experiments and laboratory and greenhouse studies provided some evidence of each of these effects. However, long-term results from a suite of silvicultural trials and associated ecological studies indicated that salal is not the fundamental problem for regenerating conifers on cedar-salal sites. Fertilization of cedar-salal sites caused a large and sustained response in tree growth regardless of the presence of salal, and growth responses to salal removal were much smaller than fertilization responses. Greenhouse experiments indicated that salal does not have allelopathic effects on germination or growth of conifer seedlings. In laboratory studies, salal did not demonstrate a greater capacity to take up organic N forms than the conifers, and molecular studies uncovered a vast diversity of mycorrhizal fungi associated with salal and hemlock roots. Together these findings indicate that the nutrient "short-circuiting" hypothesis, based on assumptions about ericoid versus non-ericoid mycorrhizal plants does not adequately describe the nutrition of plants in these ecosystems. We conclude that salal should be viewed as a symptom of the underlying problem of poor nutrient supply on cedar-salal sites, and that fertilization, rather than salal control, is the optimal solution for improving forest regeneration on these sites. Key words: ericaceous shrubs, fertilization, scarification, allelopathy,mycorrhizae, Gaultheria shallon, nitrogen

scholarly journals Effects of Organic Nutrient Amendments on Weed and Crop Growth

Weed Science ◽  
2015 ◽  
Vol 63 (3) ◽  
pp. 710-722 ◽  
Author(s):  
Neith G. Little ◽  
Charles L. Mohler ◽  
Quirine M. Ketterings ◽  
Antonio DiTommaso
Keyword(s):  
Field Experiments ◽  
Organic Amendments ◽  
Crop Growth ◽  
Growth And Yield ◽  
Organic N ◽  
Nutrient Ratios ◽  
Growth Responses ◽  
Common Lambsquarters ◽  
Giant Foxtail ◽  
Application Rates

Sufficient fertility is important for crop growth and yield but supplying a balanced amount of N, P, and K with compost and manure is a challenge and nutrient imbalances can benefit weeds more than crops. The goal of this study was to compare the aboveground growth responses of common northeastern U.S. crops and weeds to addition of composted poultry manure (CPM). A secondary goal was to test whether the observed growth responses to CPM could be attributed to the three macronutrients—N, P, and K—supplied in the CPM. Two field experiments were conducted over 2 yr. Species grown were corn, lettuce, kale, Powell amaranth, common lambsquarters, giant foxtail, and velvetleaf. Plants were grown in soil amended with CPM or single-nutrient organic N, P, and K fertility amendments. Single-nutrient P treatments with bone char did not adequately mimic P supply from CPM. In both years, biomass of all weeds studied increased with CPM amendment rate. Powell amaranth was the most responsive to CPM addition, increasing 1,775 and 159% from the control to the highest CPM rate in 2010 and 2011, respectively. Corn biomass increased by 22% with CPM rate in 2010 but did not increase with CPM rate in 2011. Lettuce biomass increased with CPM amendment rate (175% in 2010 and 109% in 2011), but due to the increased weed biomass at high CPM amendment rates, good weed control will be necessary to maintain this yield benefit. The increase in growth of Powell amaranth, common lambsquarters, and giant foxtail with CPM amendment was not due to N or K, and may have been influenced by P or another factor in the CPM. Velvetleaf was the only species that exhibited increased biomass with N addition (as blood meal), similarly to the increase with added CPM, suggesting the velvetleaf growth response to CPM was due to N in the CPM. The results show that nutrient ratios should be considered when applying organic amendments, because application rates of organic amendments that meet the crop's needs for one nutrient may oversupply other nutrients. Overfertilization will not benefit crop yield, but the results of this study show that high organic fertility application rates are likely to increase weed growth.

Tree species rather than type of mycorrhizal association drives inorganic and organic nitrogen acquisition in tree-tree interactions

2021 ◽  
Author(s):  
Robert Reuter ◽  
Olga Ferlian ◽  
Mika Tarkka ◽  
Nico Eisenhauer ◽  
Karin Pritsch ◽  
...  
Keyword(s):  
Tree Species ◽  
Mycorrhizal Fungi ◽  
Prunus Avium ◽  
N Uptake ◽  
Organic N ◽  
Acer Pseudoplatanus ◽  
N Sources ◽  
Mycorrhizal Association ◽  
N Acquisition ◽  
Inorganic And Organic

Abstract Mycorrhizal fungi play an important role for the nitrogen (N) supply of trees. The influence of different mycorrhizal types on N acquisition in tree-tree interactions is, however, not well understood, particularly with regard to the competition for growth-limiting N. We studied the effect of competition between temperate forest tree species on their inorganic and organic N acquisition in relation to their mycorrhizal type (i.e., arbuscular mycorrhiza or ectomycorrhiza). In a field experiment, we quantified net N uptake capacity from inorganic and organic N sources using 15N/13C stable isotopes for arbuscular mycorrhizal tree species (i.e., Acer pseudoplatanus L., Fraxinus excelsior L., and Prunus avium L.) as well as ectomycorrhizal tree species (i.e., Carpinus betulus L., Fagus sylvatica L., and Tilia platyphyllos Scop.). All species were grown in intra- and interspecific competition (i.e., monoculture or mixture). Our results showed that N sources were not used complementarily depending on a species´ mycorrhizal association, but their uptake rather depended on the competitor indicating species-specific effects. Generally, ammonium was preferred over glutamine and glutamine over nitrate. In conclusion, our findings suggest that inorganic and organic N acquisition of the studied temperate tree species is less regulated by mycorrhizal association, but rather by the availability of specific N sources in the soil as well as the competitive environment of different tree species.

scholarly journals Impact of Integrated Agronomic Practices on Soil Fertility and Respiration on the Indo-Gangetic Plain of North India

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 402
Author(s):  
Rama Kant Dubey ◽  
Pradeep Kumar Dubey ◽  
Rajan Chaurasia ◽  
Ch Srinivasa Rao ◽  
Purushothaman Chirakkuzhyil Abhilash
Keyword(s):  
Soil Respiration ◽  
Soil Quality ◽  
Mycorrhizal Fungi ◽  
Field Experiments ◽  
Block Design ◽  
North India ◽  
Gangetic Plain ◽  
Agronomic Practices ◽  
Soil Sustainability ◽  
Indo Gangetic Plain

Global agricultural production is accountable for the emission of ~30% of greenhouse gases. Therefore, the wide-scale adoptions of low-input, soil-friendly, and resource-conserving agronomic practices are imperative for the ‘planet healthy food production’ and also for reducing the carbon emissions from agricultural soil. In this context, the present study aimed to analyze the impacts of integrated agronomic interventions i.e., the application of arbuscular mycorrhizal fungi (AMF) + reduced tillage (RT), biochar + RT, and AMF + biochar + RT, on spatiotemporal variations in soil-quality and soil-sustainability indicators, including microbial and soil respiration, in the Indo-Gangetic Plain (IGP) of North India. For this, field experiments on the above-mentioned agronomic interventions were employed using three different staple crops (Zea mays, Vigna mungo, and Brassica juncea) growing in three different agro-climatic zones of IGP (Varanasi, Sultanpur, and Gorakhpur) in a randomized block design. Periodic data collection was done to analyze the changes in physiochemical, biological, and biochemical properties of the soil, and statistical analyses were done accordingly. Irrespective of the sites, the experimental results proved that the integrated application of AMF + biochar + RT in V. mungo resulted in the highest soil organic carbon (i.e., 135% increment over the control) and microbial biomass carbon (24%), whereas the same application (i.e., AMF + biochar + RT) in Z. mays had the maximum reduction in microbial (32%) and soil (44%) respiration. On the other hand, enhanced occurrence of glomalin activity (98%) was noted in Z. mays cropping for all the sites. Significant negative correlation between soil respiration and glomalin activity under AMF + biochar + RT (−0.85), AMF + RT (−0.82), and biochar + RT (−0.62) was an indication of glomalin’s role in the reduced rate of soil respiration. The research results proved that the combined application of AMF + biochar + RT was the best practice for enhancing soil quality while reducing respiration. Therefore, the development of suitable packages of integrated agronomic practices is essential for agricultural sustainability.

scholarly journals A Meta-Analytical Approach on Arbuscular Mycorrhizal Fungi Inoculation Efficiency on Plant Growth and Nutrient Uptake

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 370
Author(s):  
Murugesan Chandrasekaran
Keyword(s):  
Plant Growth ◽  
Arbuscular Mycorrhizal Fungi ◽  
Nutrient Uptake ◽  
Mycorrhizal Fungi ◽  
Host Plants ◽  
Plant Biomass ◽  
Meta Analysis ◽  
Arbuscular Mycorrhizal ◽  
Growth Responses ◽  
Mycorrhizal Plants

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts of higher plants which increase the growth and nutrient uptake of host plants. The primary objective was initiated based on analyzing the enormity of optimal effects upon AMF inoculation in a comparative bias between mycorrhizal and non-mycorrhizal plants stipulated on plant biomass and nutrient uptake. Consequently, in accomplishing the above-mentioned objective a vast literature was collected, analyzed, and evaluated to establish a weighted meta-analysis irrespective of AMF species, plant species, family and functional group, and experimental conditions in the context of beneficial effects of AMF. I found a significant increase in the shoot, root, and total biomass by 36.3%, 28.5%, and, 29.7%, respectively. Moreover, mycorrhizal plants significantly increased phosphorus, nitrogen, and potassium uptake by 36.3%, 22.1%, and 18.5%, respectively. Affirmatively upon cross-verification studies, plant growth parameters intensification was accredited to AMF (Rhizophagus fasciculatus followed by Funniliforme mosseae), plants (Triticum aestivum followed by Solanum lycopersicum), and plant functional groups (dicot, herbs, and perennial) were the additional vital important significant predictor variables of plant growth responses. Therefore, the meta-analysis concluded that the emancipated prominent root characteristics, increased morphological traits that eventually help the host plants for efficient phosphorus uptake, thereby enhancing plant biomass. The present analysis can be rationalized for any plant stress and assessment of any microbial agent that contributes to plant growth promotion.

Effects of potassium and sodium application to soil on growth and cation accumulation of herbage

1984 ◽  
Vol 35 (1) ◽  
pp. 85 ◽  
Author(s):  
GN Mundy
Keyword(s):  
Plant Tissue ◽  
Field Experiments ◽  
Equivalent Amount ◽  
Growth Responses ◽  
K Uptake ◽  
Low Level ◽  
Pasture Plants

The effects of potassium (K) and sodium (Na) applications to soil on growth and cation accumulation of herbage were investigated in pot and field experiments. The application of K to K-deficient soil was more efficient at increasing growth than was the application of Na; however, at suboptimal K availability, yield was increased by Na application. Growth responses to Na were restricted when the soil contained insufficient K to satisfy the minimum K requirement of pasture plants. The Na concentration of herbage was markedly reduced by K applications, whereas Na had little effect on K uptake. It was found that an application of Na to soil containing a low level of Na raised the Na concentration of herbage sufficiently to satisfy animal needs. Both K and Na reduced the calcium (Ca) and magnesium (Mg) concentration of herbage, although Na was less inhibitive than an equivalent amount of K. The decline in Ca and Mg in plant tissue with increasing concentrations of soil K and Na was exponential and, as the decline approached the asymptotic concentration, further increases in soil K and Na had only a small effect on Ca and Mg uptake. The implications of these findings are discussed.

Growth responses of Leymus chinensis (Trin.) Tzvelev to sheep saliva after defoliation

2010 ◽  
Vol 32 (4) ◽  
pp. 419 ◽  
Author(s):  
Xing Teng ◽  
Lei Ba ◽  
Deli Wang ◽  
Ling Wang ◽  
Jushan Liu
Keyword(s):  
Plant Growth ◽  
Aboveground Biomass ◽  
Field Experiments ◽  
Perennial Grass ◽  
Leaf Length ◽  
Leymus Chinensis ◽  
Growth Responses ◽  
Time Duration ◽  
Positive Effects ◽  
Leaf Weight

Many studies indicated that saliva from herbivores might be involved in plant growth responses when plants have been grazed. However, there is currently no general agreement on whether saliva can affect plant growth. Our aims were to determine the growth response of plants to sheep saliva after defoliation under diverse environmental conditions (different sward structures), and whether the effect of saliva is influenced by time (duration) after its application. We conducted field experiments with clipping treatments and the application of sheep saliva to the damaged parts of tillers to simulate sheep grazing on the perennial grass Leymus chinensis (Trin.) Tzvelev during the early growing seasons. Results demonstrated that clipping with saliva application significantly increased tiller numbers 8 weeks after treatments in comparison with clipping alone. A key finding is that the effect of sheep saliva on plant growth was short-lived. Clipping with saliva application increased leaf weight in the second week, while clipping alone had no effect. Moreover, clipping with saliva application promoted the elongation of new leaves (not the old ones) in the first week whereas clipping alone was ineffective. Results also showed that there were no differences between clipping with saliva application and clipping alone for relative height growth rate and aboveground biomass. Therefore, we concluded that saliva application to clipping treatment would produce an additional effect compared to clipping alone for the plant and the positive effects are time dependent. The additional effects primarily embodied in the individual level of plant, such as the changes of leaf weight and leaf length. Beyond the level, the effects of saliva only produced many more tiller numbers rather than the accumulation of aboveground biomass.

scholarly journals Residual Effect of Poultry Manure and Mineral N Application on Maize Production under Wheat-Maize Cropping System

2017 ◽  
Vol 5 (9) ◽  
pp. 1061
Author(s):  
Syed Azam Shah ◽  
Wisal Mohammad ◽  
Haroon Haroon ◽  
Adnan Anwar Khan
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Poultry Manure ◽  
Residual Effect ◽  
Grain Weight ◽  
Organic N ◽  
Wheat Crop ◽  
Silty Clay ◽  
Mineral N ◽  
1000 Grain Weight

The study was designed to asses the residual effect of organic N (Poultry Manure) and mineral N on maize crop in field experiments carried out on silty clay loam soil at NIFA, Tarnab, Peshawar, Khyber Pakhtunkhwa (KP) Pakistan during 2014-15. Combined dose of N from both sources were 120 kg ha-1 applied to wheat crop alone and in different combination making six treatments. Maize variety (Azam) was sown in Randomized complete block (RCB) design with four replications. Agronomic data, grains ear-1, 1000 grain weight, biomass grain yield data, N-uptake in maize grain and straw were recorded. Results showed that maximum grain ear−1, 1000 grain weight, biomass and grain yield was obtained from treatment where 25% N applied from poultry manure + 75% from mineral N source applied to previous wheat crop. Agronomic efficiency and nitrogen use efficiency were also found maximum in treatment where 75% poultry manure + 25% mineral N was applied. It was concluded from the study that residual effect of organic manure with mineral N in different ratios enhances crop productivity and soil fertility.

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