scholarly journals Effects of Grazing Intensity on Plant-Soil C: N: P Stoichiometry with Precipitation Changes During the Growing Season in Desert Grassland

2021 ◽  
Author(s):  
Wei Yan ◽  
Fengling Shi ◽  
Tao Wan
Keyword(s):  
Species Diversity ◽  
Plant Growth ◽  
Grazing Intensity ◽  
Desert Grassland ◽  
C:N:P Stoichiometry ◽  
Soil C ◽  
Plant Soil ◽  
Heavy Grazing ◽  
Significant Difference ◽  
The Impact

Abstract Background and aimsHigh-intensity grazing in the Mongolian grassland has led to the general deterioration of biodiversity and ecosystem functioning. Although abundant evidence shows that grazing affects the structure and function of grassland ecosystems, research on the impact of precipitation, especially under drought and overgrazing. MethodsWe examined the effects of heavy grazing, moderate grazing and no grazing on plant communities; plant and soil C, N and P contents; and plant and soil C:N:P stoichiometry in the desert grassland in different years with different amounts of precipitation. ResultsThere was no significant difference in the species diversity between the grazing and no grazing treatment, while the no grazing treatment was significantly higher than the heavy grazing treatment. Compared with the amounts in the no grazing and moderate grazing treatments, the N and P contents of the plants in the heavy grazing treatment were the highest, and the N content of the soil increased. There was a positive correlation between precipitation and the N and P contents of plants and the C and N contents of the soil at 0-10 cm and 10-20 cm. ConclusionsOur study suggest that a large amount of precipitation of plant growth will drive changes in the community species diversity. Grazing promoted the flow of N between plants and the soil, especially under heavy grazing. Under grazing stress, plants maintain the potential of compensatory growth, and precipitation in the peak season of plant growth induces rapid growth, suggesting that precipitation is an important factor driving grazing ecosystems.

scholarly journals Nitrogen availability modulates the host control of the barley rhizosphere microbiota

2019 ◽  
Author(s):  
Rodrigo Alegria Terrazas ◽  
Senga Robertson-Albertyn ◽  
Aileen Mary Corral ◽  
Carmen Escudero-Martinez ◽  
Katharin Balbirnie-Cumming ◽  
...  
Keyword(s):  
Plant Growth ◽  
Microbial Communities ◽  
Biological Processes ◽  
N Application ◽  
Plant Soil ◽  
Unplanted Soil ◽  
Bacterial Microbiota ◽  
Soil Feedback ◽  
The Impact ◽  
Barley Genotypes

AbstractBackgroundSince the dawn of agriculture, human selection on plants has progressively differentiated input-demanding productive crops from their wild progenitors thriving in marginal areas. Barley (Hordeum vulgare), the fourth most cultivated cereal globally, is a prime example of this process. We previously demonstrated that wild and domesticated barley genotypes host distinct microbial communities in their rhizosphere. Here, we tested the hypothesis that microbiota diversification is modulated by, and responds to, nitrogen (N) application in soil and assessed the impact of microbiota taxonomic and functional compositions on plant growth.MethodsWe grew two wild (H. vulgare ssp. spontaneum) and an ‘Elite’ domesticated (H. vulgare ssp. vulgare) barley genotypes in an agricultural soil treated with and without N inputs. By using a two-pronged 16S rRNA gene amplicon sequencing and comparative metagenomics approach, we determined the impact of N application on taxonomic composition and metabolic potential of the microbial communities exposed to limiting and replete N supplies. We then implemented a plant-soil feedback experiment to assess microbiotas’ recruitment cues and contribution to plant growth.ResultsN availability emerged as a modulator of the recruitment cues of the barley bacterial microbiota as evidenced by the increased number of bacterial genera differentially recruited between unplanted soil and rhizosphere communities under N-limiting conditions. This recruitment pattern mirrored the impact of the host genotype on rhizosphere bacteria. The characterisation of the assembled metagenomes of plants exposed to N-limiting conditions revealed a metabolic specialisation of the rhizosphere microbiota compared to unplanted soil controls. This specialisation is underpinned predominantly by bacteria and is manifested by the enrichment of a core set of biological processes sustaining the adaptation of polymicrobial communities such as N utilisation, quorum sensing and motility across genotypes. The quantitative variation in a group of these biological processes defined host signatures in the barley rhizosphere metagenome. Finally, a plant-soil feedback experiment revealed that the host-mediated taxonomic diversification of the bacterial microbiota is associated with barley growth under sub-optimal N supplies.ConclusionsOur results suggest that under N limiting conditions, a substrate-driven selection process underpins the assembly of barley rhizosphere microbiota. Host-microbe and microbe-microbe interactions fine-tune this process at the taxonomic and functional level across kingdoms. The disruption of these recruitment cues negatively impacts plant growth.

Impact of Exogenous Plant Growth Regulators on Physiological Traits, Tendril and Flowering in Horsegram (Macrotyloma uniflorum Lam) under Kharif Season 

2021 ◽  
Author(s):  
R. Sivakumar
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Foliar Application ◽  
Leaf Temperature ◽  
Physiological Traits ◽  
Mepiquat Chloride ◽  
Kharif Season ◽  
Significant Difference ◽  
The Impact

Background: Horsegram is an important pulse crop grown as Rabi crop in Tamil Nadu. Kharif sown crop could not flowers may be because of more number of tendrils produced as compare to Rabi sown crop. Hence, an attempt was made to reduce the number of tendrils and induce flowering in horsegram during Kharif season by plant growth regulators. Methods: A field experiment was conducted to study the impact of plant growth regulators viz., salicylic acid (100 ppm), chlormequat chloride (CCC - 250 ppm), mepiquat chloride (250 ppm), tri iodo benzoic acid (TIBA - 200 ppm) and nitrobenzene (0.2%) on physiological traits and tendril growth associated with flowering in horsegram during Kharif. Different treatments were applied through foliar application at 25 Days after sowing. Result: Among the PGRs, foliar application of TIBA registered the lowest number of tendrils (2.3) followed by CCC (3.0) compared to other treatments. Higher root length of 16.8 cm and RWC of 82.3% was found in CCC treatment. CCC also registered the highest photosynthetic rate (27.15 µmol m-2 s-1), transpiration rate (18.06 mmol m-2 s-1) and lowest leaf temperature (26°C) compared to other treatments. The highest soluble protein content of 13.1 mg g-1 was also estimated in CCC treatment followed by mepiquat chloride (12.51 mg g-1). Sucrose phosphate synthase (SPS) activity did not show any significant difference between the treatments. Number of flowers buds formed per plant was zero and hence the flowering did not take place in any treatments. Among the plant growth regulators used, TIBA and CCC registered its positive action on reduced the number of tendrils and leaf temperature, but not enough to induce flowering under Kharif season.

scholarly journals Effects of slope aspect on altitudinal pattern of soil C:N:P stoichiometry in alpine forest of Tibet

2021 ◽  
Vol 269 ◽  
pp. 01012
Author(s):  
Jiangrong Li ◽  
Qiqiang Guo ◽  
Heping Ma ◽  
Weilie Zheng
Keyword(s):  
Soil Temperature ◽  
Altitudinal Gradient ◽  
Sampling Site ◽  
Slope Aspect ◽  
C:N:P Stoichiometry ◽  
Soil C ◽  
Soil P ◽  
Soil Nutrition ◽  
Significant Difference ◽  
Stoichiometric Ratios

Knowledge of altitudinal patterns in soil C, N and P distribution is important for understanding biogeochemical processes in mountainous forests, yet the influence of slope aspects on soil stoichiometry has been largely neglected in previous studies. In this paper, a total number of 150 topsoil samples at four altitudes (3700, 3900, 4100, 4380 m a.s.l.) on sunny and shady slopes of Sygera mountains in the Southeastern Tibet were collected. Soil C, N and P contents, and pH, were measured. Soil temperature, moisture and richness of plant species were investigated at each sampling site. The results showed that: 1) in sunny slope, soil C, N and P concentrations increased with the increase in altitude, whereas soil C:N, C:P, and N:P decreased along the altitudinal gradient on s. Soil moisture was the main regulator of soil nutrition and stoichiometric ratios. 2) In shady slope, soil C and N contents had no significant difference along the altitudinal gradient except the higher values at low altitude, whereas soil P increased first and then decreased. Soil C:N increased with the increase in altitude, whereas C:P and N:P decreased first and then increased. Soil temperature and species richness were the main factors influencing soil nutrition and stoichiometric ratios. 3) Decoupling of soil C:N:P stoichiometry was observed in shady slope owing to changes in soil pH and temperature. 4) The rich contents of soil C and P were observed at two slopes along the altitudinal gradient, and high capacity of N supply existed at the topsoil in shady slope. These results suggested that slope aspect plays an important role in shaping the altitudinal pattern of soil C:N:P stoichiometry in mountainous forests.

scholarly journals Corn Growth and Yield on Suboptimal Upland Soil After Amended with Biochar and Low Levels of Fertilizer in West Kalimantan, Indonesia

2020 ◽  
Vol 2 (1) ◽  
pp. 94-102
Author(s):  
Sutarman Gafur ◽  
Saeri Sagiman ◽  
Tatang Abdurrahman
Keyword(s):  
Plant Growth ◽  
Soil Characteristics ◽  
Organic Content ◽  
Growth And Yield ◽  
Upland Soil ◽  
Soil C ◽  
West Kalimantan ◽  
Treatment Package ◽  
The Impact ◽  
Treatment Packages

Biochar is already well-known as a soil amendment material that has great potential to improve degraded soil properties. However, in order to maximize its role in improving important soil characteristics to support plant growth, it needs to be combined with other potential materials. In this study we are seeking a treatment package that is potentially useful and locally affordable.  This experiment is designed to study the effects of biochar and low input of NPK treatment packages on corn growth and yield in suboptimal upland soil of West Kalimantan, and to study the impact of these treatments on some important soil characteristics.  Four treatment levels were used: T0 (control), T1 (Biochar 5% (W/W), and NPK 300kg/ha), T2 (Biochar 5%, and NPK 600 kg/ha), T3 (Biochar 10% and NPK300 kg/ha, and T4 (Biochar 10% and NPK 600 kg/ha). Each treatment had four replications.  The results show that total plant dry weight increased from 151 g/plant (T1) to 237 g/plant (T4), while total corn production increased from 12.9 (T1) to 15.7 ton/ha (T4).  Furthermore, all treatment packages also significantly increased soil pH, C-organic content, CEC, and soil C/N ratios.  Moreover, the content of N, P, K, in the soil by the end of the experiment also increased on average 163, 1143, and 432%, respectively.  In short, all biochar based treatments significantly increased plant growth, yields, and some important soil charactersitics.  We highly recommend T3, with lower NPK levels than normally recommended, as a treatment package to be further field tested in suboptimal upland soil in West Kalimantan.

scholarly journals Effects of Grazing Exclusion on Biomass Growth and Species Diversity among Various Grassland Types of the Tibetan Plateau

2019 ◽  
Vol 11 (6) ◽  
pp. 1705 ◽  
Author(s):  
Suizi Wang ◽  
Jiangwen Fan ◽  
Yuzhe Li ◽  
Lin Huang
Keyword(s):  
Species Diversity ◽  
Plant Growth ◽  
Alpine Meadow ◽  
Management Strategies ◽  
Livestock Grazing ◽  
The Tibetan Plateau ◽  
Grazing Exclusion ◽  
Palatable Species ◽  
The Impact ◽  
Grassland Types

Livestock grazing is an important determinant of species diversity and plant growth. Overgrazing is identified as one of the most important disturbances resulting in grassland degradation. Although many restoration practices have been implemented, grazing exclusion is one of the most effective methods to restore degraded grasslands. We explored the impact of five years of grazing exclusion on plant growth and species diversity in four types of grasslands: temperate steppe (TS), swamp meadow (SM), alpine steppe (AS), and alpine meadow (AM). Our results showed that grazing exclusion increased plant height, coverage, biomass, and species diversity in all four grasslands. The aboveground biomass in AM (180.8%), TS (117.3%), and SW (105.9%) increased significantly more than AS (10.1%). Grazing exclusion in AM had the greatest effect on proportion of palatable species, and the increase in palatable species in AM was higher than that of the other grassland types significantly. Species diversity increased significantly within the enclosure in SM (23.9%) and AM (20.8%). Our results indicate that grazing exclusion is an effective management strategy to restore degraded grasslands and it works best in alpine meadow. This study contributes to the growing theoretical basis for grassland management strategies and has a significant effect on sustainable development for grassland resources and pastoral areas.

Effect of grazing intensity and number of grazings on herbage production and seed yields of Trifolium subterraneum, Medicago murex, and Ornithopus compressus

1994 ◽  
Vol 34 (2) ◽  
pp. 181 ◽  
Author(s):  
DJ Conlan ◽  
BS Dear ◽  
NE Coombes
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Grazing Intensity ◽  
Trifolium Subterraneum ◽  
Grazing Pressure ◽  
Early Spring ◽  
Pasture Legumes ◽  
Heavy Grazing ◽  
Ornithopus Compressus ◽  
The Impact

The impact of grazing intensity and number of grazings was assessed on the growth and seed production of 5 annual pasture legumes [Trifoliunz subterraneum var. subterraneum cv. Karridale, var. brachycalycinum cv. Clare, var. yanninicum cv. Trikkala; Medicago murex (murex medic) cv. Zodiac; Ornithopus compressus L. (yellow serradella) cv. Avila]. There were 7 grazing treatments: an ungrazed control; and 2 grazing intensities (light and heavy), each for 3 periods of grazing (winter, winter-early spring, winter-late spring). Tethered sheep in small experimental plots were used to provide controlled herbage removal across all cultivars through winter and winter-spring grazing. This grazing system resulted in significantly different levels of herbage being present in the light and heavy grazing treatments following each grazing period. Grazing had variable effects on seed production: <35% increase for Trikkala, and no significant effect for Karridale. Both cultivars continued growth and seed production late in the season after grazing pressure was removed on 8 November. Seed yield of Clare was reduced by 46-49% by heavy grazing treatments. Seed yield of murex medic was not significantly affected by grazing, while that of serradella was reduced by 30-55% by grazing late in the season. The seed yield responses show that cultivar and species responses to grazing may be highly variable. Under favourable spring conditions, Trikkala, Karridale, and murex medic can be grazed heavily until late in the season without adversely affecting seed yield, whilst Clare and Avila cannot.

scholarly journals Efficiency of Spathiphyllum spp. as a plant-microbial fuel cell

2021 ◽  
Vol 27 (2) ◽  
pp. 173-182
Author(s):  
Kei Jung Kwon ◽  
Bong Ju Park
Keyword(s):  
Soil Moisture ◽  
Fuel Cell ◽  
Plant Growth ◽  
Microbial Fuel Cell ◽  
Dry Weight ◽  
Volumetric Soil Moisture ◽  
Plant Soil ◽  
Significant Difference ◽  
Plant Microbial Fuel Cell ◽  
Plant Plant

Abstract The purpose of this study was to investigate the utility of an ornamental plant, Spathiphyllum spp., as a plant-microbial fuel cell (Plant MFC) to produce voltage and current. This study also evaluated the effect of the Plant MFC on water use efficiency and plant growth. The experiment used four experimental groups: used MFC without plant (Soil MFC), used MFC with plant (Plant MFC), unused MFC without plant (Soil Pot), and unused MFC with plant (Plant Pot). Plant MFC generated higher voltage and current levels than Soil MFC. The average voltage of Plant MFC and Soil MFC was 0.475 V and 0.375 V, respectively, and the average current was 0.110 mA and 0.030 mA, respectively. Plant MFC using Spathiphyllum spp. produced a constant voltage output, with a deviation of 0.027 V during the four-month indoor experiment. The difference between the maximum and minimum voltage during the day was as small as 0.015 V, which supports the utility of Plant MFC as a stable power source. Volumetric soil moisture content, chlorophyll fluorescence (Fv/Fm), photosynthesis rate, leaf area, fresh weight, and dry weight of Plant MFC and Plant Pot were measured. There was no significant difference in any values, and volumetric soil moisture and plant growth were not affected by the utilization of Plant MFC. Thus, a Plant-MFC using Spathiphyllum spp. can play the same ornamental role as conventional plants and at the same time be used as a sustainable bioelectricity source.

scholarly journals Does Altitude Effect on Species Composition and Diversity on Himalayan Rangeland?

2017 ◽  
Vol 1 ◽  
pp. 26-30
Author(s):  
Dilkumar Limbu ◽  
Madan Koirala ◽  
Zhanhuan Shang
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Altitudinal Gradient ◽  
Diversity Index ◽  
Grazing Intensity ◽  
Floristic Composition ◽  
Diversity Indices ◽  
Altitude Effect ◽  
Wiener Diversity Index ◽  
The Impact

Himalayan rangelands have diverse floristic composition and important ecological services. The floristic diversity and composition play an important role in grassland ecosystem regulation. It is different in altitudinal gradient due to grazing intensity, climatic condition and topography. To reveal the vegetation composition values, this work was conducted on August and September 2011 in Tinjure-Milke mountain ridge, Guphapokhari, Nepal. In the present study we have described the impact of altitude on the species richness, species diversity and dispersion behavior of different plants (grasses) in Himalayan rangeland. The values of community indices were observed to be: RD (0.09 to 49.57), RF (3.57 to 14.71), RA (0.23 to 47.59), IVI (3.89 to 111.87), Shannan-Wiener diversity index (1.09 to 2.23) and species diversity evenness (0.12 to 0.19) at the study area, MilkeJaljale, eastern Nepal. Similarly, Species richness (R) value of 8.87 to 11.86 and Simpson dominant index value of 0.12 to 0.42 were observed. All diversity indices were reversed to altitudinal gradient higher the altitudes lower the values. Species richness of all plants showed a unimodal relationship with altitude. Similarly, negative correlation of density and species richness with altitude and slope was recorded.

scholarly journals Methane Emission from Sheep Respiration and Sheepfolds During the Grazing Season in a Desert Grassland

2015 ◽  
Vol 9 (1) ◽  
pp. 23-28
Author(s):  
Xiajie Zhai ◽  
Tingting Lu ◽  
Shiming Tang ◽  
Xiaojuan Liu ◽  
Xiuzhi Ma ◽  
...  
Keyword(s):  
Inner Mongolia ◽  
Weight Basis ◽  
Desert Grassland ◽  
Grazing Season ◽  
Heavy Grazing ◽  
Significant Difference ◽  
Grazing Intensities ◽  
Greenhouse Gas Budget ◽  
Grazing Ecosystem ◽  
Grazing Livestock

Methane (CH4) emissions from ruminants should be accounted for the natural grazed rangeland ecosystems when devising greenhouse gas budget inventory, in particular, their contribution to global warming. In this study, CH4 emission from sheep respiration at different grazing intensities (light grazing, 0.75 sheep/ha, LG; moderate grazing, 1.50 sheep/ha, MG; and heavy grazing, 2.25 sheep/ha, HG) and in sheepfolds were evaluated in a desert grassland of Inner Mongolia. Results indicated that daily CH4 emission from sheep was not significantly different between treatments. When CH4 emission was expressed emission per 100g daily, there was a significant difference of LG vs HG and MG vs HG, with the values of 15.64g, 20.00g and 28.63g for LG, MG and HG, respectively, during the grazing season. There was no significant difference among CH4 fluxes in sheepfolds (mean 39.0 ug m-1 h-1). Considering CH4 emissions from the grazing ecosystem, net CH4 emissions from LG, MG and HG plots were -18.33, -1.91 and 21.19 g/ha/day, respectively. The digestibility of forage had a positive correlation with CH emission expressed on daily and metabolic body weight basis. It is concluded that MG will improve the balance between CH emission from grassland and grazing livestock in the desert grasslands of Inner Mongolia.

The impact of heavy grazing on burrow choice in the pygmy bluetongue lizard, Tiliqua adelaidensis

2011 ◽  
Vol 38 (4) ◽  
pp. 299 ◽  
Author(s):  
Melissa Pettigrew ◽  
C. Michael Bull
Keyword(s):  
Native Species ◽  
Negative Impact ◽  
South Australia ◽  
Grazing Intensity ◽  
Grazing Pressure ◽  
Natural Ecosystems ◽  
Native Grasslands ◽  
Heavy Grazing ◽  
Microhabitat Structure ◽  
The Impact

Context Grazing pressure has directly altered and indirectly influenced natural ecosystems worldwide, and has affected and displaced many native species. The endangered pygmy bluetongue lizard Tiliqua adelaidensis is endemic to the mid-north of South Australia. It inhabits remnant native grasslands where it is reliant on the presence of natural spider burrows constructed by lycosid and mygalomorph spiders as refuge sites. These lizards spend the majority of the day associated with their burrow either in the burrow itself or basking at its entrance. The remnant native grasslands of South Australia have endured 200 years of agricultural changes and the introduction of domestic stock has meant that grazing pressure has substantially increased. The vegetation around a burrow is considered to be important in providing shelter for the lizard. However, too much vegetation may reduce basking opportunities and visibility of prey. Stock grazing has been maintained on the majority of sites that contain pygmy bluetongue populations and it is presumed that the lizards can tolerate some form of grazing. However, the level of grazing intensity directly influences the vegetation structure that surrounds the lizard burrows. Aims We aimed to investigate the consequences of severe grazing pressure on the choice of burrows by lizards, and on their burrow related behaviour. Methods We simulated heavy grazing pressure by manually removing aboveground vegetation in the field in replicated quadrats that contained artificial burrows, and by providing bare substrate in half of experimental enclosures in the laboratory. Key results In the field, lizards only occupied the artificial burrows in control quadrats, where vegetation had been left intact. In the laboratory, lizards that occupied both burrows basked for longer at the burrow entrance where vegetation was present. Conclusions Heavy grazing management that results in the majority of vegetation being removed could have a negative impact on pygmy bluetongue lizard recruitment and sustainability. Implications Grazing regimes should be carefully monitored to consider the needs of species that rely heavily on microhabitat structure for their persistence. For the endangered pygmy bluetongue lizard, heavy grazing should be avoided to promote amounts of vegetation suitable to sustain viable populations.

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