scholarly journals Dynamics of nitrogen and active nitrogen components across seasons under varying stand densities in a Larix principis-rupprechtii (Pinaceae) plantation

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5647 ◽  
Author(s):  
Junyong Ma ◽  
Hairong Han ◽  
Wenwen Zhang ◽  
Xiaoqin Cheng
Keyword(s):  
Plant Biomass ◽  
Management Practice ◽  
Light Condition ◽  
Stem Density ◽  
Active Nitrogen ◽  
Microbial Biomass Nitrogen ◽  
Environmental Indices ◽  
Soil Temperatures ◽  
Tree Stem ◽  
N Pool

Changes in the concentration of soil nitrogen (N) or its components may directly affect ecosystem functioning in forestry. Thinning of forest stands, a widely used forestry management practice, may transform soil nutrients directly by altering the soil environment, or indirectly by changing above- or belowground plant biomass. The study objectives were to determine how tree stem density affects the soil N pool and what mechanisms drive any potential changes. In this study, N and its active components were measured in the soil of a Larix principis-rupprechtii plantation across two full growing seasons, in 12 (25 × 25 m) plots: (low thinning, removal of 15% of the trees, three plot repetitions), moderate thinning (MT) (35% removal) and heavy thinning (HT) (50% removal) and no thinning control. Environmental indices, like the light condition, soil respiration, soil temperatures, and prescription, were measured in the plots also. Results indicated that soil total nitrogen (STN) was affected by tree stem density adjustments in the short-term; STN generally increased with decreasing tree stem density, reaching its highest concentration in the MT treatment before decreasing in HT. This pattern was echoed by the DON/STN ratio dissolved organic nitrogen (DON) under MT. A lower DON/STN was measured across the seasons. Microbial biomass nitrogen (MBN) and the SOC/STN (soil organic carbon (SOC)) ratio and density treatments influenced MBN concentration and inhibited SOC/STN. MT tended to accumulate more STN, produce lower DON/STN and had a generally higher microbial activity, which may be partly ascribed to the higher MBN value, MBN/STN ratio and lower DON/STN. The water conditions (soil moisture), light and soil temperatures could partly be responsible for the N pool dynamic in the different density treatments.

scholarly journals Moderate thinning increases soil nitrogen in a Larix principis-rupprechtii (Pinaceae) plantations

2018 ◽  
Author(s):  
Junyong Ma ◽  
Hairong Han ◽  
Wenwen Zhang ◽  
Xiaoqin Cheng
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practice ◽  
Light Condition ◽  
Stem Density ◽  
Soil N ◽  
Microbial Biomass Nitrogen ◽  
Soil Temperatures ◽  
Tree Stem ◽  
N Pool

Changes in the concentration of soil N or its components of the soil may directly affect forestry ecosystem functioning. Thinning of forest stands, a widely used forestry management practice, may transform soil nutrients directly by altering the soil environment, or indirectly by changing above- or belowground plant biomass. The study objectives were to determine how tree stem density affects the soil N pool and what mechanisms drive any potential changes. In this study, N and its active components were measured beneath a Larix principis-rupprechtii plantation across two entire growing season and under 12 25*25m plots: LT (low thinning forests, removal of 15% of the trees, three plot repetitions), MT (35% removal) and HT (50% removal) and contrast: CK (no thinning control). The environmental index like the light condition, soil reoperation, soil temperatures and prescription was measured in the plots. Results indicated that STN (soil total nitrogen) was affected by tree stem density adjustments in short-term, STN generally increased with decreasing tree stem density, reaching its highest concentration in the MT treatment before decreasing in HT; this pattern was echoed by DON/STN (DON, dissolve organic nitrogen), under MT, a lower DON/STN was measured across the seasons; and MBN (microbial biomass nitrogen) and the SOC/STN (SOC, soil organic carbon) ratios, density treatments had an influence on MBN concentration and inhibited SOC/STN (SOC, soil organic carbon). MT tended to accumulate more STN and produce lower DON/STN and generally higher microbial activity, which may be partly ascribed to the higher MBN value, MBN/STN ratio and lower DON/STN; and the water condition (water content, surface runoff and sediment loads) and light and soil temperatures may partly be responsible to the N pool dynamic in the different density treatments.

scholarly journals Moderate thinning increases soil nitrogen in a Larix principis-rupprechtii (Pinaceae) plantations

2018 ◽  
Author(s):  
Junyong Ma ◽  
Hairong Han ◽  
Wenwen Zhang ◽  
Xiaoqin Cheng
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practice ◽  
Light Condition ◽  
Stem Density ◽  
Soil N ◽  
Microbial Biomass Nitrogen ◽  
Soil Temperatures ◽  
Tree Stem ◽  
N Pool

Changes in the concentration of soil N or its components of the soil may directly affect forestry ecosystem functioning. Thinning of forest stands, a widely used forestry management practice, may transform soil nutrients directly by altering the soil environment, or indirectly by changing above- or belowground plant biomass. The study objectives were to determine how tree stem density affects the soil N pool and what mechanisms drive any potential changes. In this study, N and its active components were measured beneath a Larix principis-rupprechtii plantation across two entire growing season and under 12 25*25m plots: LT (low thinning forests, removal of 15% of the trees, three plot repetitions), MT (35% removal) and HT (50% removal) and contrast: CK (no thinning control). The environmental index like the light condition, soil reoperation, soil temperatures and prescription was measured in the plots. Results indicated that STN (soil total nitrogen) was affected by tree stem density adjustments in short-term, STN generally increased with decreasing tree stem density, reaching its highest concentration in the MT treatment before decreasing in HT; this pattern was echoed by DON/STN (DON, dissolve organic nitrogen), under MT, a lower DON/STN was measured across the seasons; and MBN (microbial biomass nitrogen) and the SOC/STN (SOC, soil organic carbon) ratios, density treatments had an influence on MBN concentration and inhibited SOC/STN (SOC, soil organic carbon). MT tended to accumulate more STN and produce lower DON/STN and generally higher microbial activity, which may be partly ascribed to the higher MBN value, MBN/STN ratio and lower DON/STN; and the water condition (water content, surface runoff and sediment loads) and light and soil temperatures may partly be responsible to the N pool dynamic in the different density treatments.

scholarly journals Effects of mowing on N<sub>2</sub>O emission from a temperate grassland in Inner Mongolia, Northern China

2013 ◽  
Vol 10 (12) ◽  
pp. 19219-19243
Author(s):  
L. Zhang ◽  
Q. Wang ◽  
H. J. Laanbroek ◽  
C. Wang ◽  
D. Guo ◽  
...  
Keyword(s):  
Inner Mongolia ◽  
Management Practices ◽  
Plant Biomass ◽  
Management Practice ◽  
Northern China ◽  
Litter Production ◽  
N2o Emissions ◽  
Microbial Biomass Nitrogen ◽  
Relationship Analysis ◽  
N2o Fluxes

Abstract. Grazing and mowing are two common practices for grassland management. Mowing is now recommended as an alternative to traditional grazing for grassland conservation in Inner Mongolia, northern China. Many studies have revealed that both mowing and grazing may alter ecosystem properties in various ways. However, little attention has been paid to the effect of mowing on trace gas emissions, especially on N2O flux. In this study, we conducted an experiment to investigate the effects of mowing on N2O fluxes from a semiarid grassland in Inner Mongolia. The mowing experiment, which started in 2003, comprised four mowing intensity treatments, i.e. mowing heights at 2, 5, 10 and 15 cm above the soil surface, respectively, and a control of non-mowing, with five replicates. Gas fluxes were measured through a closed static chamber technique during the growing seasons (usually from May to September, depending on local climate at the time) of 2008 and 2009, respectively. Our results showed that mowing decreased N2O emissions, above-ground biomass and total litter production. N2O emissions were greater in May and June than in other sampling periods, regardless of treatments. A co-relationship analysis suggested that variations in seasonal N2O fluxes were mainly driven by variations in soil moisture and microbial biomass nitrogen, except in July and August. In July and August, above-ground plant biomass and soil total nitrogen became the major drivers of N2O fluxes under the soil temperatures between 16 °C and 18 °C. Overall, our study indicated that the introduction of mowing as a management practice might decrease N2O emissions in grasslands, and both mowing height and soil properties affected the magnitude of the reduction. Our findings imply that grasslands, along with proper management practices, can be a N2O sink mitigating the rise of N2O in the atmosphere.

scholarly journals Formation of Crop Yields of Energy Crops Depending on the Soil and Weather Conditions

2021 ◽  
Vol 24 (1) ◽  
pp. 41-47
Author(s):  
Maroš Korenko ◽  
Volodymyr Bulgakov ◽  
Vasyl Kurylo ◽  
Maksym Kulyk ◽  
Alexander Kainichanko ◽  
...  
Keyword(s):  
Alternative Energy ◽  
Crop Yields ◽  
Plant Biomass ◽  
Weather Conditions ◽  
Energy Crops ◽  
Forest Steppe ◽  
Stem Density ◽  
Energy Productivity ◽  
Giant Miscanthus ◽  
The Impact

AbstractThe article presented discusses the need to use plant biomass made of energy crops grown in marginal soils as an alternative energy source. Variability of biometric indicators of the plant vegetative parts (productivity elements) was experimentally established: stem quantity per area unit and stem height depending on the soil and weather conditions. Based on the five-year research, there was observed a significant influence of soil and climatic growing conditions (average daily air temperature; rainfall; soil fertility) on formation of crop energy productivity. Results showed that the variability of stem density and height; dry phytomass productivity of millet switchgrass and giant miscanthus during observed years depended on the studied factors. Correlation-regression analysis proved and characterized the influence of soil and climatic conditions during the growing season of energy crops on the yield of dry phytomass of millet switchgrass and giant miscanthus in the central part of the Ukraine forest-steppe. The impact proportion share of weather conditions and plant productivity elements on the level of energy crops yields was calculated.

scholarly journals Cross-Sectional Imaging of Tree Stem Density Distribution using Gamma-Ray Tomography Technique

2019 ◽  
Vol 1198 (2) ◽  
pp. 022012 ◽  
Author(s):  
Wibisono ◽  
Bayu Azmi ◽  
Sastra Kusuma Wijaya ◽  
Prawito ◽  
Firliyani Rahmatia Ningsih
Keyword(s):  
Density Distribution ◽  
Gamma Ray ◽  
Stem Density ◽  
Cross Sectional ◽  
Cross Sectional Imaging ◽  
Sectional Imaging ◽  
Tree Stem

The effect of the site of seed potato production on subsequent sprout growth and tuber yield

1979 ◽  
Vol 92 (1) ◽  
pp. 227-233 ◽  
Author(s):  
D. C. E. Wurr
Keyword(s):  
Seed Production ◽  
Tuber Yield ◽  
Negative Relationship ◽  
Potato Production ◽  
Stem Density ◽  
Seed Potato Production ◽  
Sprout Length ◽  
Soil Temperatures ◽  
Final Yield ◽  
Sprout Growth

SummaryIn 1974 and 1975 certified Scottish seed tubers were multiplied at four sites of different altitude which had different mean soil temperatures. The progeny tubers were subsequently grown to produce a ware crop at Wellesbourne in 1975 and 1976. In 1975, the effects of the site of seed production on sprout growth and tuber yield of the ware crop were small though there was an indication of a negative relationship between total tuber yield and the temperature at each site. In 1976 the effect of the site of seed production was more marked. The total sprout length per tuber of both the varieties used was greatest from the hottest site and least from the coolest site. In the field the final yield of both varieties was lowest from the hottest site and greatest from the coolest site of seed production. There was no indication that the effect of the site of seed production on tuber yield occurred as a result of differences in stem density.

scholarly journals A Comparison of Prism Plots and Modified Point-Distance Sampling to Calculate Tree Stem Density and Basal Area

2006 ◽  
Vol 23 (3) ◽  
pp. 218-221 ◽  
Author(s):  
Ian D. Thompson ◽  
Darcy A. Ortiz ◽  
Christopher Jastrebski ◽  
Daniel Corbett
Keyword(s):  
Boreal Forest ◽  
Distance Sampling ◽  
Basal Area ◽  
Forest Stand ◽  
The Other ◽  
Stem Density ◽  
Normal Density ◽  
Forest Stands ◽  
Point Distance ◽  
Tree Stem

Abstract Two common methods of measuring forest stand woody stem attributes include prism plots for basal area and modified point-distance for stem density. The data from each method can be used for the other calculation; that is, prism data can provide stem density, and point-distance datacan provide estimated basal area. We examined data from the same 10 stands using the two techniques to determine whether the results for each calculation were comparable and/or consistent. There was a significant correlation between the estimated tree (defined as stems >10 cm) basal areas,and between tree stem densities, derived from the two methods (P < 0.01). Prism plots provided significantly higher estimated tree stem densities (+23.5%; P < 0.05) compared to estimates from the point-distance technique, but there was no difference between estimated treebasal area. For all stems, that is also including stems <10 cm dbh, there was no difference between the two methods for estimated basal area or stem density. There was no correlation between total stem densities derived from the two methods. This is likely because the prism plot method(two-factor metric prism) sampled relatively few trees with small diameters, whereas the point distance technique, as used, sampled small trees independently from trees using a diameter distinction. When we removed two young stands with <50 trees/ha, there was no difference in estimatesof stem density. We concluded that, for boreal forest stands with a normal density of trees (i.e., >10 cm dbh and 900 to 3,000 stems/ha), either method would provide comparable estimates of stem density and basal area. We found no time difference in conducting surveys using either method.

scholarly journals Tomato Rootstocks Mediate Plant-Water Relations and Leaf Nutrient Profiles of a Common Scion Under Suboptimal Soil Temperatures

2021 ◽  
Vol 11 ◽  
Author(s):  
Steven T. Bristow ◽  
Leonardo H. Hernandez-Espinoza ◽  
Maria-Sole Bonarota ◽  
Felipe H. Barrios-Masias
Keyword(s):  
Hydraulic Conductivity ◽  
Stomatal Conductance ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Plant Biomass ◽  
Leaf Gas Exchange ◽  
Root Anatomy ◽  
Shoot Biomass ◽  
Root Hydraulic Conductivity ◽  
Soil Temperatures

Environments with short growing seasons and variable climates can have soil temperatures that are suboptimal for chilling-sensitive crops. These conditions can adversely affect root growth and physiological performance thus impairing water and nutrient uptake. Four greenhouse trials and a field study were conducted to investigate if rootstocks can enhance tomato performance under suboptimal soil temperatures (SST). In a controlled greenhouse environment, we exposed four commercial rootstocks (Estamino, Maxifort, RST-04-106-T, and Supernatural) grafted with a common scion (cv. BHN-589) to optimal (mean: 24°C) and SST (mean: 13.5°C) and compared their performance with the non-grafted BHN-589 cultivar. Several root and shoot physiological traits were evaluated: root hydraulic conductivity and conductance, root anatomy, leaf gas exchange, leaf δ13C, shoot C and N, and biomass. Under field conditions, the same five phenotypes were evaluated for canopy growth, normalized difference vegetation index (NDVI), leaf nutrients, biomass, and yield. Under SST, root hydraulic conductivity (Lp) and conductance (KR), stomatal conductance (gs), and plant biomass decreased. Hydrostatic Lp decreased more than osmotic Lp (Lp∗hyd: 39–65%; Lp∗os: 14–40%) and some of the reduced conductivity was explained by the increased cortex area of primary roots observed under SST (67–140%). Under optimal soil temperatures, all rootstocks conferred higher gs than the non-grafted cultivar, but only two rootstocks maintained higher gs under SST. All phenotypes showed greater reductions in shoot biomass than root biomass resulting in greater (∼20%) root-to-shoot ratios. In the field, most grafted phenotypes increased early canopy cover, NDVI, shoot biomass, and fruit yield. Greenhouse results showed that Lp∗os may be less affected by SST than Lp∗hyd and that reductions in Lp may be offset by enhanced root-to-shoot ratios. We show that some commercial rootstocks possess traits that maintained better rates of stomatal conductance and shoot N content, which can contribute toward better plant establishment and improved performance under SST.

scholarly journals Examination the effects of different herbicides on the soil microorganisms of a calcareous chernozem

2010 ◽  
pp. 121-126
Author(s):  
Zsolt Sándor
Keyword(s):  
Microbial Biomass ◽  
Agricultural Production ◽  
Crop Production ◽  
Soil Microorganisms ◽  
Plant Biomass ◽  
Microbial Biomass Carbon ◽  
The Other ◽  
Co2 Production ◽  
Test Plant ◽  
Microbial Biomass Nitrogen

Pesticides play a key role in fighting weeds, pests and parasitic fungi. According to surveys, pests reduce the yield of agricultural crops by 35% worldwide. Pests, fungi and weeds account for 14%, 12% and 9% yield loss, respectively (Gáborjányi et al., 1995). Chemicals have contributed to increasing and maintaining the yields of crop production for decades. Today, agricultural production (in spite of many efforts) is unthinkable without the use of pesticides (herbicides, insecticides and fungicides). On the other hand, these chemicals contribute to the pollution of the atmosphere, surface and underground waters, and agricultural soils, especially if they are applied improperly.The sustainable agricultural production pays attention to environment-friendly cultivation-technologies; but at the same time it makes an effort to produce good quality and economical products. The examination of the herbicides’ secondary effects, fits into this chain of idas namely, how the herbicides affect – stimulating or inhibiting – the soil microbiological processes, prevention of soil fertility.In the course of the experimental work the effect of herbicides on soil biological properties were examined in different maize (Zea mays) cultures. We wanted wished to know that how the herbicides affect the quantity change of soil microorganisms, the life of different physiological groups of bacteria and the activity of microorganisms. A small pot experiment was set up in 2008 with the application of two herbicides - Acenit A 880 EC and Merlin 480 SC – in the breeding house of the Department. The moisture content and nutrient supply were at optimal level in the experiment.On the basis of results the following can be stated: 1. It can be stated that the two herbicides and all their doses affected negatively the number of total soil bacteria, theinhibiting effects were significant. The quantity of microscopical fungi increased by the effect of Merlin 480 SC and decreased in the treatments of Acenit A 880 EC.2. The Acenit A 880 EC had stimulating effect on the nitrate mobilization. The CO2-production was stimulated by the basic doses of herbicides; the other treatments did not influence the CO2-production significantly.3. The quantity of microbial biomass-carbon –except for only one treatment- decreased significantly by the effect of herbicides. Besides it, the quantity of microbial biomass-nitrogen increased significantly in the treatments of Acenit A 880 EC.4. The biomass of test plant decreased in the treatments of herbicides, their quantities were smaller than in the control. In the pots treated by Merlin 480 SC, parallel with the increase of doses decreased the quantity of plant-biomass.

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