scholarly journals Influence of different systems of grazing, type of swards and fertilizing on underground phytomass of pastures

2011 ◽  
Vol 49 (No. 1) ◽  
pp. 18-23 ◽  
Author(s):  
S. Hejduk ◽  
F. Hrabě
Keyword(s):  
Surface Layer ◽  
Soil Layer ◽  
Dry Weight ◽  
Forage Yield ◽  
Total Weight ◽  
Mineral Fertilizers ◽  
Rotational Grazing ◽  
Continuous Grazing ◽  
Grazing System ◽  
Total Dry Weight

Problems concerning total dry weight and distribution of underground phytomass were studied in a pasture trial at Rapotin near &Scaron;umperk, the CzechRepublicin the period 1995&ndash;1999. The total weight of dry underground pasture phytomass (DUP) was 976 g/m<sup>2</sup> (5-year average) in a soil layer of 0&ndash;200 mm (both live and dead roots). The DUP was significantly increased by mineral fertilizers (90 kg N/ha, 30 kg P/ha a 90 kg K/ha). The weight of DUP was not significantly influenced by a grazing system, renewal or resowing of the original grassland. In unfertilized plots, DUP weight amounted to 989 g/m<sup>2</sup>, i.e. 92 g/m<sup>2</sup> (8.6%) less than in fertilized plots in the period 1996&ndash;1999. In the same period, under the grassland exploited by rotational grazing 1142 and under continuous grazing 1082 g/m<sup>2</sup> DUP were determined, i.e. by 60 g/m<sup>2</sup> (5.5%) less. The highest DUP weight in the period 1996&ndash;1999 was found in autumn 1997 (1222 g/m2) immediately before achieving the maximum forage yield in May 1998. In a layer of 0&ndash;20 mm, 54.6% of the total DUP was found. In this surface layer, significant increase in the DUP weight was found in fertilized plots. In 1999, some 88.5 and 90.2% of DUP were concentrated in unfertilized (903 g/m<sup>2</sup>) and fertilized (952 g/m<sup>2</sup>) plots, respectively in a layer of 0&ndash;100 mm.

The inter-relationships of grazing method and stocking rate in the efficiency of pasture utilization by dairy cattle

1963 ◽  
Vol 61 (2) ◽  
pp. 147-166 ◽  
Author(s):  
C. P. McMeekan ◽  
M. J. Walshe
Keyword(s):  
Dairy Cows ◽  
Large Scale ◽  
Age Distribution ◽  
Grazing Management ◽  
Vanishing Point ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Continuous Grazing ◽  
Grazing System ◽  
Stocking Rates

1. A large-scale grazing management study comparing rotational grazing and continuous grazing with dairy cows at two stocking rates over four complete production seasons is described.2. The four treatments were: (i) controlled grazing, light stocking rate; (ii) controlled grazing, heavy stocking rate; (iii) uncontrolled grazing, light stocking rate; (iv) uncontrolled grazing, heavy stocking rate.Each treatment involved 40 cows for a first 2-year phase and 42 cows for the following 2 years. Each herd had a normal age distribution pattern and seven 2-year-old first lactation heifers (17% of total herd) were introduced each year to maintain this pattern.3. Stocking rate was the more important factor affecting the efficiency of pasture utilization as measured by per acre output of milk and butterfat. In general, high stocking was associated with higher outputs per acre despite lower yields per animal.4. Grazing method was of less importance. In general, controlled rotational grazing was superior to uncontrolled continuous grazing, both per animal and per acre, but the average influence even of these extremes of management was only half that of stocking rate.5. Significant interactions between stocking rate and grazing method existed. Under continuous grazing a point was reached where production per acre declined to the vanishing point with increased stocking rate due to excessive depression of per cow yield: this point was not reached under rotational grazing at the same high stocking levels.6. The results suggest that optimum stocking rate under rotational grazing occurs at a level some 5–10% higher than under continuous grazing. A depression of 10–12% in per cow yield, compared with more lenient grazing, corresponds with optimum stocking level irrespective of the grazing system. This estimate is suggested as a guide line in applying the principles involved.

scholarly journals Effects of long-term cattle market conditions on continuous season-long and rotational grazing system revenues

2020 ◽  
Vol 42 (3) ◽  
pp. 227
Author(s):  
J. L. Windh ◽  
J. P. Ritten ◽  
J. D. Derner ◽  
S. Paisley ◽  
B. Lee
Keyword(s):  
Rotational Grazing ◽  
Market Conditions ◽  
Net Returns ◽  
Continuous Grazing ◽  
Grazing System ◽  
Grazing Systems ◽  
Time Of Year ◽  
One Year ◽  
Cattle Market

In this study we evaluated the combination of long-term market conditions and the price slide in the cattle market on revenues associated with continuous and rotational grazing systems. A price slide is a market phenomenon in which lighter cattle sell at a higher price per unit of liveweight compared with their heavier counterparts. We used actual herd average starting and ending weights in this market analysis, and analysed the outcome using five years’ data from a continuous and rotational comparative grazing study. Despite consistently lower weight gains with rotational grazing, differences in gross revenues per steer between grazing treatments ranged from US$43.46 to minus $5.72 across the study years. We observed annual differences in the net returns across years between the two grazing systems; net returns were greater for steers in the continuous grazing treatment in three of the five years, one year with net returns that did not differ between systems, and one year in which net returns were lower with continuous grazing. These variable results showcase the complexity in having both differences in end of grazing season weight classes between the grazing systems and the differential effects of price slide among weight classes. Therefore, we argue that it may be a better management strategy for land managers to determine the optimal ending weights and the time of year to market livestock to meet the goals of an operation, rather than trying to determine which grazing system is ‘best’.

Performance After Planting of Four Types of Container-grown Lodgepole Pine Seedlings

1973 ◽  
Vol 3 (2) ◽  
pp. 185-195 ◽  
Author(s):  
F. Endean ◽  
D. Hocking
Keyword(s):  
Lodgepole Pine ◽  
Dry Weight ◽  
Total Weight ◽  
Stem Length ◽  
Controlled Environment ◽  
Root Weight ◽  
Pine Seedlings ◽  
Total Dry Weight ◽  
Shoot Weight ◽  
Environment Experiment

Four types of container-grown lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) seedlings differing in age and rearing regime were transplanted into a controlled laboratory environment and into the field. After 12 weeks, seedlings were excavated and stem length and dry weight of shoot and roots were measured, these and derived parameters were compared with values obtained at the time of planting. Survival was uniformly high, the largest seedlings prior to planting performed best under all conditions. In the controlled environment experiment, initial shoot weight, total weight, and ratio of shoot weight/shoot length were significantly correlated with final root weight, an important factor in initial establishment; in addition shoot and total weight increment were significantly and positively correlated with initial shoot/root ratio. In the field no overall significant correlations were obtained. Shoot/root ratio decreased slightly in the controlled environment and significantly in the field after outplanting. Results suggest that the largest plant which can be grown and planted economically shows largest increment and achieves largest final total dry weight and root dry weight in the first growing season after outplanting. The need for a physiological rather than morphological grading of seedlings is stressed.

Synthesis of system outcomes for a grazing-management experiment in temperate native pastures

2017 ◽  
Vol 57 (9) ◽  
pp. 1869 ◽  
Author(s):  
W. B. Badgery ◽  
D. L. Michalk
Keyword(s):  
Field Experiments ◽  
Grazing Management ◽  
System Level ◽  
Advisory Group ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Experimental Modelling ◽  
Continuous Grazing ◽  
Grazing System ◽  
The Impact

Increasing the intensity of grazing management from continuous grazing or set-stocking to intensive rotational grazing has been proposed as a way of improving the profitability and environmental outcomes for native pasture-based grazing systems in the high-rainfall zone (HRZ) of southern Australia. The present paper synthesised the results and outcomes of eight papers covering different aspects of a grazing-system study investigating the intensity of grazing management at Panuara (33°27ʹS, 148°56ʹE), 25 km south-west of Orange, New South Wales. The systems analysis covered soils and soil water, pastures, animal production, profitability and business risk by using a combination of field experiments and biophysical modelling. The experimental approach, engagement with stakeholders and the potential impact of the research outcomes are discussed; as are the future directions for grazing system research. Increasing the intensity of grazing management from a 1- to a 20-paddock system resulted in a 21% higher pasture growth, 22% higher stocking rate and 20% higher lamb production per hectare. However, modelling demonstrated that seasonal variability had a greater impact on profitability than did the management system, and whole-farm profitability of the 20-paddock system was lower than that of the 1- and 4-paddock systems due to higher infrastructure costs. Pasture stability was associated with a high perennial grass content (>70%), and a stocking rate of 4.2 ewes/ha for continuous grazing or 5.3 ewes/ha for intensive rotational grazing limited the potential for degradation events. Advantages were identified in fencing and managing production zones, with different production potential within a farm, to improve utilisation across the landscape and efficiency of fertiliser use. The farming-system approach successfully integrated field research with pre- and post-experimental modelling, and with strategic input from an advisory group containing farmers, researchers and advisors, to develop a full understanding of the impact, at a system level, of increasing the intensity of grazing management in the HRZ.

Photoperiod Effects on the Reproductive Biology of Purple Nutsedge(Cyperus rotundus)

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 539-542 ◽  
Author(s):  
R. D. Williams
Keyword(s):  
Reproductive Biology ◽  
Dry Weight ◽  
Cyperus Rotundus ◽  
Total Weight ◽  
Purple Nutsedge ◽  
Flowering Response ◽  
Total Dry Weight

The effects of 8-, 12-, and 16-h photoperiods on the growth and reproductive biology of purple nutsedge(Cyperus rotundusL.) were investigated over a 3-month period. Plants under the 8-h photoperiod produced the least total, shoot, root, rhizome, and tuber dry weight. Flowering occurred only at the 12-h photoperiod; thus, purple nutsedge is intermediate in flowering response to daylength. Although the total dry weight varied with photoperiod, the relative amount of dry weight (as percent of total weight) partitioned to shoots, roots, rhizomes, and tubers was constant.

Rotational grazing increases purple prairie clover frequency in the rangeland plant communities under semi-arid environment

2022 ◽  
Author(s):  
Tianqi Zhao ◽  
Alan D. Iwaasa
Keyword(s):  
Plant Communities ◽  
Environmental Changes ◽  
Arid Environment ◽  
Rotational Grazing ◽  
Continuous Grazing ◽  
Grazing System ◽  
Two Factors ◽  
Grazing Systems ◽  
Perennial Legume ◽  
Increasing Precipitation

Purple prairie clover (PPC, Dalea purpurea Vent.) is a grazing tolerant perennial legume with good nutritional quality and is widely distributed across North America. Deferred rotational grazing (DR) and continuous grazing (CG) are the most widespread grazing systems on North American grasslands. We conducted a 10-year grazing study to assess the effects of environmental factors and grazing on the frequency of PPC in plant communities. The results showed that the frequency of PPC decreased and then increased with increasing precipitation under CG (P<0.05), while there was no significant change under DR (P>0.05). Meanwhile, PPC frequency increased with temperature under DR (P<0.05), but did not change under CG (P>0.05). Both grazing systems and the number of grazing years had a significant effect on PPC frequency (P<0.05), and there is no interaction between those two factors (P>0.05). We found that from 2011 to 2020, the growth rate of PPC population is 18.24% and 11.69% per year under DR and CG grazing, respectively. Moreover, after 10 years of grazing, the PPC increase in DR was 22.86% higher than that of CG. Thus, selecting the DR grazing system can increase PPC and is an effective practice for coping with environmental changes.

scholarly journals Tibetan sheep grazing modifies rodent density and their interactions effect on GHG emissions of alpine meadow

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yingxin Wang ◽  
Hang Yuan ◽  
Xinglu Zhang ◽  
Yi Sun ◽  
Shenghua Chang ◽  
...  
Keyword(s):  
Population Density ◽  
Ghg Emissions ◽  
Warm Season ◽  
Cold Season ◽  
Grazing Management ◽  
Rotational Grazing ◽  
Rodent Population ◽  
Continuous Grazing ◽  
Grazing System ◽  
Tibetan Sheep

AbstractDigging and mound-building by rodents lead to considerable disturbances in the topsoil and may affect plant composition, soil properties. However, little is known about the effects of these activities on GHG emissions, especially under different grazing management. This paper aimed to measure changes in CO2 and CH4 efflux with varying grazing management during the warm and cold seasons and to relate CO2 and CH4 efflux to pika burrow density and zokor mound density with different grazing management. Results of this study showed that CO2 efflux was significantly affected by the grazing season, whereas CH4 efflux was significantly affected by the grazing system. There were significant relationships between GHG efflux and rodent population density which were regulated by grazing management. CO2 efflux increased linearly with rodent density under seasonal continuous grazing in warm season. CO2 and CH4 efflux and rodent population density showed a significant quadratic convex relationship under rotational grazing at 24 SM/ha in warm and cold seasons and rotational grazing at 48 SM/ha in cold season. Under rotational grazing at light stocking rate (24 SM/ha), appropriate populations of rodents were beneficial for decreasing GHG emissions. This results also used to help drive a best-practices model for grazing practices of local herders.

scholarly journals Doses de fósforo e potássio no desenvolvimento da cultura de Crambe abyssinica

2016 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Lucia Helena Garófalo Chaves ◽  
Ramara Sena Souza
Keyword(s):  
Dry Weight ◽  
Mineral Fertilizers ◽  
Maturity Stage ◽  
Crambe Abyssinica ◽  
Fertilizer Use ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Phosphorus And Potassium ◽  
Total Dry Weight ◽  
Number Of Branches

<p>A cultura do crambe (<em>Crambe abyssinica</em>) é uma alternativa para produção de biodisel recebendo este enfoque por sua rusticidade, precocidade, alto teor de óleo e adaptabilidade. Os nutrientes minerais possuem funções essenciais e específicas no metabolismo das plantas. A aplicação de fertilizantes minerais é feita para repor sua perda, pois a cada ciclo as plantas extraem nutrientes dos solos. O manejo adequado do uso de fertilizantes no cultivo do crambe é pouco conhecido, não havendo recomendações específicas para a adubação. Portanto, objetivou-se estudar os efeitos da adubação mineral relativa aos elementos fósforo e potássio, no crescimento e na produção do crambe. O experimento foi instalado em casa de vegetação, com delineamento inteiramente casualizado em esquema fatorial 4 x 4 + 1, com três repetições, totalizando 51 unidades experimentais. As doses de fósforo e potássio utilizadas foram 50; 75; 100 e 125 kg ha<sup>-1</sup>. Aos 60 dias após o semeio (DAS) foram analisadas altura das plantas, diâmetro caulinar e número de ramificações. As plantas foram colhidas em fase de maturação aos 90 DAS, quando foram avaliadas a massa seca total das plantas, número de grãos por planta e massa de mil grãos. O crescimento e a produção do crambe, nestas condições, foram pouco influenciados pela aplicação de fósforo e potássio, provavelmente, porque a cultura foi prejudicada pela falta de adubação nitrogenada.</p><p align="center"><strong><em>Phosphorus and potassium doses in the development of </em></strong><strong><em>Crambe abyssinica</em></strong><strong><em>  culture</em></strong></p><p><strong>Abstract</strong><strong>: </strong>Mineral nutrients have essential and specific roles in plant metabolism. The application of mineral fertilizers is made to replenish its loss, for every cycle of the plant extract soil nutrients. The crambe culture is an alternative for the production of biodiesel getting this approach for its rusticity, precocity, high oil content and adaptability. Proper management of fertilizer use in crambe cultivation is little known and no specific recommendations for fertilizer. Therefore, the objective of this research was to study the effects of mineral fertilizers on the elements phosphorus and potassium on growth and production of crambe. The experiment was installed in a greenhouse, with a completely randomized design in a factorial 4 x 4 + 1, with three repetitions, totaling 51 experimental units. Phosphorus and potassium levels the used were 50; 75; 100 and 125 kg ha<sup>-1</sup>. The use of these elements caused no significant effect on the growth and production of crambe. Sixty days after sowing<strong> </strong>(DAS) plant height, stem diameter and number of branches were analyzed. Plants were harvested at maturity stage at 90 DAS, when the total dry weight of plants, number of grains per plant and thousand grain weights were evaluated. The growth and production of crambe, these conditions were little influenced by the application of phosphorus and potassium, probably because culture was hampered by a lack of nitrogen fertilization.</p>

BIOASSAY OF PROLACTIN

1969 ◽  
Vol 60 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Charles S. Nicoll
Keyword(s):  
Epithelial Cells ◽  
Lipid Content ◽  
Dry Weight ◽  
Fat Content ◽  
Assay Sensitivity ◽  
Mucosal Epithelium ◽  
Wet Weight ◽  
Total Dry Weight

ABSTRACT The response of the pigeon crop-sac to systemically acting prolactin (injected subcutaneously) was evaluated by measuring the wet weight of the responsive lateral lobes of the organ and by determining the dry weight of a 4 cm diameter disc of mucosal epithelium taken from one hemicrop. Of several different injection schedules tested, administration of prolactin in four daily injections was found to yield optimal responses. When compared with a graded series of prolactin doses, measurement of the mucosal dry weight proved to be a better method of response quantification than determination of the crop-sac wet weight with respect to both assay sensitivity and precision. The submucosal tissue of the crop-sac was estimated to constitute about 64 % of the total dry weight of the unstimulated organ and it was found to be relatively unresponsive to prolactin stimulation in comparison with the mucosa. The lipid content of the mucosal epithelium was determined using unstimulated crop-sacs or tissues which showed varying degrees of prolactin-induced proliferation. The fat content of the mucosal epithelial cells increased only slightly more rapidly than the dry weight or the defatted dry weight of the mucosa. Suggestions are made for the further improvement of the systemic crop-sac assay for prolactin.

Prospects of spring wheat cultivation in the conditions of arid Volga region

2020 ◽  
pp. 28-33
Author(s):  
Valery Genadievich Popov ◽  
Andrey Vladimirovich Panfilov ◽  
Yuriy Vyacheslavovich Bondarenko ◽  
Konstantin Mikhailovich Doronin ◽  
Evgeny Nikolaevih Martynov ◽  
...  
Keyword(s):  
Spring Wheat ◽  
Soil Layer ◽  
Weather Conditions ◽  
Volga Region ◽  
Mineral Fertilizers ◽  
Climate Conditions ◽  
Wheat Cultivation ◽  
Forest Belts ◽  
Clear Differentiation ◽  
The Impact

The article analyzes the experience of the impact of the system of forest belts and mineral fertilizers on the yield of spring wheat, including on irrigated lands. Vegetation irrigation is designed to maintain the humidity of the active soil layer from germination to maturation at the lower level of the optimum-70-75%, and in the phases of tubulation-earing - flowering - 75-80% NV. However, due to the large differences in zones and microzones of soil and climate conditions and due to the weather conditions of individual years, wheat irrigation regimes require a clear differentiation. In the Volga region in the dry autumn rainfalls give the norm of 800-1000 m3/ha, and in saline soils – 1000-1300 and 3-4 vegetation irrigation at tillering, phases of booting, earing and grain formation the norm 600-650 m3/ha. the impact of the system of forest belts, mineral fertilizers on the yield of spring wheat is closely tied to the formation of microclimate at different distances from forest edges.

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