Effect of phosphorus on three perennial Stylosanthes species in tropical Australia. II. Phosphorus and nitrogen within the plant and implications for grazing animals

1989 ◽  
Vol 40 (6) ◽  
pp. 1205 ◽  
Author(s):  
MA Gilbert ◽  
DG Edwards ◽  
KA Shaw ◽  
RK Jones
Keyword(s):  
Dry Season ◽  
Wet Season ◽  
Soil P ◽  
Plant Parts ◽  
Whole Plant ◽  
Nitrogen Concentrations ◽  
Tropical Australia ◽  
Whole Plants ◽  
Phosphorus Application ◽  
Green Stem

This paper describes the effect of phosphorus application on concentrations and distribution of phosphorus (P) and nitrogen (N) in three Stylosanthm specics (S. scabra cv. Scca, S. guiunensis cv. Schofield and S. viscosa CPI 34904) grown in the field on a soil of low acid-extractable (0.005 M H2SO4) P status (4 mg/kg). Over a two-year period (May 1978 to September 1979), regular measurements were made of P and N in whole plant shoots, leaves, stems, inflorescence, seed and litter.Phosphorus application increased P concentrations in all three legumes, but did not affect its pattern of seasonal change throughout the year. The P (and N) concentrations in most plant parts decreased through the wet season to reach minima in the late dry season. However, with seed there was little seasonal variation. In the second year, Seca was more efficient at taking up P and utilizing it for growth under low soil P conditions than Schofield. CPI 34904 was less efficient than Seca at taking up P, but also used P efficiently for growth. The efficient utilization of P in the leaves and stems of Seca and CPI 34904 meant that P levels were often below the level (0.12%) considered adequate for growth of grazing cattle. Dry season P concentrations in all legumes were inadequate. When P was applied, P concentrations in leaf and green stem of all species were higher than 0.12% during the wet season, but green stem of Seca and CPI 34904 fell below this level during the dry season.Applied P slightly increased N concentrations in leaves, green stems and whole plants of all species. Nitrogen concentrations were adequate (> 1.1% N) for maintenance of cattle weight at most times. Only in the late dry season did green stem of Seca contain insufficient N.Phosphorus application had little effect on the distribution of P and N within the plants. All species held a large percentage (20-50%) of these nutrients in green stems, but CPI 34904 was exceptional in directing up to 60% of the P and N to inflorescence and seed at the expense of leaf and stem.

Effect of species, plant part, and season of harvest on n-alkane concentrations in the cuticular wax of common rangeland grasses from southern Africa

2001 ◽  
Vol 52 (9) ◽  
pp. 875 ◽  
Author(s):  
D. G. Smith ◽  
R. W. Mayes ◽  
J. G. Raats
Keyword(s):  
Southern Africa ◽  
Diet Composition ◽  
Common Species ◽  
Flower Head ◽  
Grass Species ◽  
Wet Season ◽  
Reliable Technique ◽  
Plant Parts ◽  
Plant Samples ◽  
Whole Plant

The use of plant alkane concentrations to measure diet composition of herbivores has been shown to be a reliable technique in animals grazing temperate, sown pastures that contain a relatively small number of plant species. There is potential to develop this technique for use with free-range animals foraging upon species-rich rangeland. In order for the technique to be effective, the alkane concentration patterns (ACP) of the component species of the diet must be distinct from one another. Common species of grasses from southern Africa were analysed for their alkane concentrations in order to evaluate the use of the alkane technique for measuring diet composition under complex rangeland conditions. The alkane profiles were determined in different plant parts from 40 grass species gathered during the wet season and 23 gathered during the dry season. Statistical analysis, using ANOVA, showed that there were highly significant differences (P < 0.001) in the C 25, C 27 , C 29 C 31 , C 33 , and C 35 alkane concentrations between flower head and stem during both the dry and wet seasons. Similar statistical differences were apparent in the C 25 , C 27 , C 29 , and C 31 alkane concentrations of leaf and stem during both seasons; differences in C 33 and C 35 concentrations were significant but at a lower level (P < 0.01 and P < 0.05, respectively). Differences in C 25 , C 27 , and C 29 alkane concentrations between flower head and leaf were only significant (P < 0.001) during the wet season. Statistical differences (P < 0.001) between whole plant samples obtained in different seasons were due to changes in the proportion of flower head, leaf, and stem. Cluster analysis often showed less similarity between plant parts of the same species than between whole plant samples of different species. It was concluded that ACPs measured in the selected species were probably too similar and thus, plants could not be identified using the alkane technique. However, it was possible to use the alkane technique to determine the proportions of flower-head, leaf, and stem in the diet.

Evaluation of management options for increasing the productivity of tropical savanna pastures. 3. Trees

1989 ◽  
Vol 29 (5) ◽  
pp. 631 ◽  
Author(s):  
WH Winter ◽  
JJ Mott ◽  
RW McLean
Keyword(s):  
Dry Season ◽  
Perennial Grasses ◽  
Fertility Level ◽  
Wet Season ◽  
Management Options ◽  
Themeda Triandra ◽  
Weight Losses ◽  
Nitrogen Concentrations ◽  
The Mean ◽  
Stocking Rates

The effect of killing trees upon the production and quality of native perennial grasses, Themeda triandra, Chrysopogon fallax, Sehima nervosum, and Sorghum plumosum, and oversown legumes from the genus Stylosanthes, was studied over 4 years at Katherine, in the semi-arid tropics of northwestern Australia. The pastures were either unfertilised or received low inputs of superphosphate, and for each fertility level were grazed at 3 stocking rates. At no time were legume yields affected by killing the trees but, in the first 3 years, the amount of grass was approximately twice as much when the trees were killed. During this period the mean grass yields declined 4-5 fold from about 2.2 t/ha. By the fourth year the advantage from tree killing upon grass yield was apparent only at the lowest stocking rates at each fertility level. Nitrogen concentrations of the grasses and legumes, with the exception of S. hamata, were increased 7 and 10% respectively above the mean annual values of 0.89 and 1.75% where the trees were killed, while the phosphorus and sulfur concentrations were not affected. Tree killing had no effect upon wet season liveweight gains during the last 2 years of the experiment. However, there were some benefits during the dry season when weight losses were lower for most treatments during the early dry season (June-September) and also lower for the lowest stocking rate treatment without fertiliser during the late dry season (October-November).

scholarly journals Nitrous oxide and methane in two tropical estuaries in a peat-dominated region of northwestern Borneo

2016 ◽  
Vol 13 (8) ◽  
pp. 2415-2428 ◽  
Author(s):  
Denise Müller ◽  
Hermann W. Bange ◽  
Thorsten Warneke ◽  
Tim Rixen ◽  
Moritz Müller ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Inorganic Nitrogen ◽  
Monsoon Season ◽  
Peat Soil ◽  
Dry Season ◽  
N2o Emissions ◽  
Wet Season ◽  
Tropical Estuaries ◽  
Ch4 Emissions ◽  
Nitrogen Concentrations

Abstract. Estuaries are sources of nitrous oxide (N2O) and methane (CH4) to the atmosphere. However, our present knowledge of N2O and CH4 emissions from estuaries in the tropics is very limited because data are scarce. In this study, we present first measurements of dissolved N2O and CH4 from two estuaries in a peat-dominated region of northwestern Borneo. Two campaigns (during the dry season in June 2013 and during the wet season in March 2014) were conducted in the estuaries of the Lupar and Saribas rivers. Median N2O concentrations ranged between 7.2 and 12.3 nmol L−1 and were higher in the marine end-member (13.0 ± 7.0 nmol L−1). CH4 concentrations were low in the coastal ocean (3.6 ± 0.2 nmol L−1) and higher in the estuaries (medians between 10.6 and 64.0 nmol L−1). The respiration of abundant organic matter and presumably anthropogenic input caused slight eutrophication, which did not lead to hypoxia or enhanced N2O concentrations, however. Generally, N2O concentrations were not related to dissolved inorganic nitrogen concentrations. Thus, the use of an emission factor for the calculation of N2O emissions from the inorganic nitrogen load leads to an overestimation of the flux from the Lupar and Saribas estuaries. N2O was negatively correlated with salinity during the dry season, which suggests a riverine source. In contrast, N2O concentrations during the wet season were not correlated with salinity but locally enhanced within the estuaries, implying that there were additional estuarine sources during the wet (i.e., monsoon) season. Estuarine CH4 distributions were not driven by freshwater input but rather by tidal variations. Both N2O and CH4 concentrations were more variable during the wet season. We infer that the wet season dominates the variability of the N2O and CH4 concentrations and subsequent emissions from tropical estuaries. Thus, we speculate that any changes in the Southeast Asian monsoon system will lead to changes in the N2O and CH4 emissions from these systems. We also suggest that the ongoing cultivation of peat soil in Borneo is likely to increase N2O emissions from these estuaries, while the effect on CH4 remains uncertain.

Game domestication for animal production in Kenya: the nutritional ecology of oryx, zebu cattle and sheep under free-range conditions

1985 ◽  
Vol 104 (2) ◽  
pp. 375-382 ◽  
Author(s):  
M. R. Stanley Price
Keyword(s):  
Rank Order ◽  
Feeding Habits ◽  
Nutritional Ecology ◽  
Dry Season ◽  
Selection Combining ◽  
Zebu Cattle ◽  
Wet Season ◽  
Interspecific Differences ◽  
Dry Conditions ◽  
Nitrogen Concentrations

SummaryObservations on oryx, sheep and cattle under natural grazing conditions in both a wet and a dry season are given and discussed.Dry faecal outputs by the sheep and oryx were less in the wet than in the dry season. Output by the cattle was greater than both, and showed little seasonal difference. Faecal nitrogen concentrations showed no interspecific overlap, in the rank order sheep > oryx > cattle. All were greater in the wet season, and the rank order maintained.Drinking water intakes were similar for oryx and sheep in both seasons. The cattle's water intake was greater in the wet season. Expressed as ml/kg W0·85/day, there were no overlaps in species' mean intakes, in the order cattle > sheep > oryx, in the ratio 100:57:24. In the dry season, the herd walked 16 km on non-drinking days, and a further 7 km on alternate days when receiving water. Under wetter conditions with more forage available, the herd walked only 11 km daily.Slight interspecific differences in the times spent walking, feeding, standing and lying were found over a 48 h period. In the wet season less time was spent walking and feeding, with corresponding increases in the other activities. The oryx were notable in that rumination occupied far less of their daytime activity than for the sheep or cattle although the total times spent ruminating were similar.The results are discussed in relation to differences in the species’ feeding habits and strategies of diet selection, combining the grazing results with observations from penned animals on a common diet. The intakes of water agree with the results from penned animals, confirming oryx's adaptation to hot, dry conditions. The advantages of a low water requirement, met by intermittent drinking, are discussed.The possible detrimental effects on productivity of a regime of day-grazing and night-penning under hot conditions are discussed. In the light of these, some advantages to oryx of scheduling its rumination to the night hours are suggested.

Does desiccation risk drive the distribution of juvenile cane toads (Bufo marinus) in tropical Australia?

2009 ◽  
Vol 25 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Travis Child ◽  
Benjamin L. Phillips ◽  
Richard Shine
Keyword(s):  
Field Experiments ◽  
Tidal Flow ◽  
Temporal Variations ◽  
Dry Season ◽  
Bufo Marinus ◽  
Primary Role ◽  
Wet Season ◽  
Juvenile Dispersal ◽  
Tropical Australia ◽  
Desiccation Risk

Abstract:Immediately after their transition from aquatic to terrestrial life, juveniles of many anuran species are restricted to the margins of natal ponds. Understanding the factors determining the duration of that pondside aggregation has direct management ramifications in the case of the invasive cane toad (Bufo marinus) in tropical Australia. Previous work suggests that dispersal confers biotic advantages (reduced risk of cannibalism, enhanced feeding opportunities) to juvenile toads, but desiccation risk constrains these small animals to the moist margins of the pond. If so, juvenile dispersal should be sensitive to fluctuating hydric conditions on a diel and seasonal cycle. We tested this prediction with field observations (monitoring of dispersal to and from the pond) and field experiments (manipulating hydric regimes). Our results support a dynamic model of juvenile distribution, with a primary role for temporal variations in desiccation risk as the primary factor driving dispersal. During the dry season, strong diel cycles in desiccation risk generate a ‘tidal’ flow of juveniles, dispersing out in the moist morning but retreating to the pond margins at midday. Dispersal rates were enhanced by artificial watering during the dry season, and by the onset of the wet season.

scholarly journals Whole-Plant and Seed Bioassays for Resistance Confirmation

Weed Science ◽  
2015 ◽  
Vol 63 (SP1) ◽  
pp. 152-165 ◽  
Author(s):  
Nilda R. Burgos
Keyword(s):  
Best Management Practices ◽  
Crop Production ◽  
Management Practices ◽  
List Type ◽  
Plant Parts ◽  
Resistance Evolution ◽  
Whole Plant ◽  
Weedy Species ◽  
Whole Plants ◽  
Sites Of Action

Much of agriculture-related research today involves weed resistance to herbicides. Resistance evolution is perhaps the strongest driver for the quest for new herbicide targets, novel weed intervention technologies, and the promotion of best management practices for sustainable crop production (Burgos et al., 2006; Norsworthy et al. 2012; Vencill et al. 2012). To date, 222 weedy species collectively have evolved resistance to 150 herbicides representing 21 sites of action (Heap 2014). For decades, scientists have developed numerous protocols for resistance confirmation using seeds, different plant parts, or whole plants. These have been reviewed by Beckie et al. (2000) and Burgos et al. (2013). We draw from these and other sources to present general guidelines for resistance confirmation that students and new researchers can use in planning their experiments. The most immediate questions that stakeholders seek to answer with resistance bioassays include:1.Is the population resistant?2.What is the level of resistance?3.What alternative herbicides can be used?

scholarly journals Root System Morphology of Ipê-Roxo Tree Grown in Soil Subjected to Phosphorus Application in Subtropical Climate Region

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1563
Author(s):  
Carolina Fogliarini Parcianello ◽  
Álvaro Luís Pasquetti Berghetti ◽  
Maristela Machado Araujo ◽  
Gabriel Alberto Sans ◽  
Vanessa Marques Soares ◽  
...  
Keyword(s):  
Root System ◽  
Control Plant ◽  
Root Diameter ◽  
Subtropical Climate ◽  
P Availability ◽  
Soil P ◽  
Climate Region ◽  
Whole Plant ◽  
Phosphorus Application ◽  
The Impact

Phosphorus (P) availability in subtropical soils does not often meet the nutritional demand of native tree species such as the ipê-roxo tree (Handroanthus heptaphyllus); therefore, it is necessary to supply P at planting. However, the impact of P on root system growth remains unknown. The aim of the current study was to investigate the effect of P application on root morphology of H. heptaphyllus plants over a 36-month period in a subtropical climate region. During the experiment, the plants subjected to fertilization with 40 kg P ha−1 were compared to untreated control. Plant roots were scanned through minirhizotron system 18 and 36 months after transplant (MAT), and generated images were used to determine total root length, mean root diameter and total root volume. Plant height and leaf P concentrations were also evaluated. Phosphorus application enhanced root and whole plant growth with a more evident effect at 36 MAT, when soil P availability decreased. The results give important information on the cultivation of H. heptaphyllus plants in soils presenting low P availability.

Study of Vidanga on Krimi Roga w.s.r. to Round Worms

2017 ◽  
Vol 2 (04) ◽  
Author(s):  
Abhilasha . ◽  
Vijay Shankar Dubey
Keyword(s):  
Public Health Problem ◽  
Intestinal Wall ◽  
Major Public Health Problem ◽  
Embelia Ribes ◽  
Worm Infestation ◽  
Whole Plant ◽  
The Face ◽  
Whole Plants ◽  
Recurrent Nature ◽  
Weak Resistance

Krimi have been considered a major public health problem through out the world (WHO, 1967 Wandan, 1983 McLaren, 1984). In our country this problem is equally significant. It effects the children more frequently than adult (CCRAS 1987). Krimi hamper growth and development of a person, create malnutritional condition and decrease immunity thus the effective solution of this problem is necessary. Of all the herbs used in treating worm infestation, Vidanga is the best. So, Vidanga was selected for the present study. Whole plant of Embelia ribes Linn. were used as materials, as whole plants are used as medicine. Acharya Charaka describe Krimiroga in Vimanasthana. In most of patients, who are suffering from worm infestation have an Vivarnata (discolouration) on the face. “Vivarnata” had been described by Acharya Charaka under the Lakshana of Purishaja Krimi and it has been also described in Rasavaha Srotodusti Lakshana. Krimis robe the digestive nutritive assets through the intestinal wall, which we are making with high effort. So the deficiency of Rasa Dhatu create. According to Dhatu Poshana Nyaya if the Rasa Dhatu is not sufficient then other Dhatu can’t form properly and ultimate weak resistance and poor immunity develops and it is one cause of recurrent nature of disease. Prakriti Vighata and Nidana Parivarjana eradicate Krimiroga from the base.

scholarly journals The seasonal changes of the gut microbiome of the population living in traditional lifestyles are represented by characteristic species-level and functional-level SNP enrichment patterns

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xue Zhu ◽  
Jiyue Qin ◽  
Chongyang Tan ◽  
Kang Ning
Keyword(s):  
Gut Microbiome ◽  
Seasonal Changes ◽  
Dry Season ◽  
Urban Setting ◽  
Snp Analysis ◽  
Wet Season ◽  
Human Gut ◽  
Human Gut Microbiome ◽  
Genome Level ◽  
Prevalent Species

Abstract Background Most studies investigating human gut microbiome dynamics are conducted on humans living in an urban setting. However, few studies have researched the gut microbiome of the populations living traditional lifestyles. These understudied populations are arguably better subjects in answering human-gut microbiome evolution because of their lower exposure to antibiotics and higher dependence on natural resources. Hadza hunter-gatherers in Tanzania have exhibited high biodiversity and seasonal patterns in their gut microbiome composition at the family level, where some taxa disappear in one season and reappear later. Such seasonal changes have been profiled, but the nucleotide changes remain unexplored at the genome level. Thus, it is still elusive how microbial communities change with seasonal changes at the genome level. Results In this study, we performed a strain-level single nucleotide polymorphism (SNP) analysis on 40 Hadza fecal metagenome samples spanning three seasons. With more SNP presented in the wet season, eight prevalent species have significant SNP enrichment with the increasing number of SNP calling by VarScan2, among which only three species have relatively high abundances. Eighty-three genes have the most SNP distributions between the wet season and dry season. Many of these genes are derived from Ruminococcus obeum, and mainly participated in metabolic pathways including carbon metabolism, pyruvate metabolism, and glycolysis. Conclusions Eight prevalent species have significant SNP enrichments with the increasing number of SNP, among which only Eubacterium biforme, Eubacterium hallii and Ruminococcus obeum have relatively high species abundances. Many genes in the microbiomes also presented characteristic SNP distributions between the wet season and the dry season. This implies that the seasonal changes might indirectly impact the mutation patterns for specific species and functions for the gut microbiome of the population that lives in traditional lifestyles through changing the diet in wet and dry seasons, indicating the role of these variants in these species’ adaptation to the changing environment and diets.

scholarly journals Seasonal Climate Impacts on Vocal Activity in Two Neotropical Nonpasserines

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 319
Author(s):  
Cristian Pérez-Granados ◽  
Karl-L. Schuchmann
Keyword(s):  
Air Temperature ◽  
Daily Rainfall ◽  
Climatic Conditions ◽  
Dry Season ◽  
Climate Impacts ◽  
Calling Behavior ◽  
Wet Season ◽  
Focal Species ◽  
Calling Activity ◽  
Vocal Activity

Climatic conditions represent one of the main constraints that influence avian calling behavior. Here, we monitored the daily calling activity of the Undulated Tinamou (Crypturellus undulatus) and the Chaco Chachalaca (Ortalis canicollis) during the dry and wet seasons in the Brazilian Pantanal. We aimed to assess the effects of climate predictors on the vocal activity of these focal species and evaluate whether these effects may vary among seasons. Air temperature was positively associated with the daily calling activity of both species during the dry season. However, the vocal activity of both species was unrelated to air temperature during the wet season, when higher temperatures occur. Daily rainfall was positively related to the daily calling activity of both species during the dry season, when rainfall events are scarce and seem to act as a trigger for breeding phenology of the focal species. Nonetheless, air temperature was negatively associated with the daily calling activity of the Undulated Tinamou during the wet season, when rainfall was abundant. This study improves our understanding of the vocal behavior of tropical birds and their relationships with climate, but further research is needed to elucidate the mechanisms behind the associations found in our study.

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