Effect of grazing intensity and cultivar on morphology, phenology, and nutritive value of subterranean clover. 1. Morphology and phenology of subterranean clover during the growing season

1999 ◽  
Vol 50 (7) ◽  
pp. 1191 ◽  
Author(s):  
Y. J. Ru ◽  
J. A. Fortune
Keyword(s):  
Flowering Time ◽  
Grazing Intensity ◽  
Subterranean Clover ◽  
Maturity Group ◽  
Early Maturity ◽  
Flowering Duration ◽  
Plant Parts ◽  
Heavy Grazing ◽  
Grazing Intensities ◽  
Late Maturity

The effect of grazing intensity and cultivar on plant morphology was examined with 26 cultivars of subterranean clover during the growing season. The cultivars were grown in 3 groups (early, mid, and late) according to their flowering time and grazed under 2 grazing intensities (heavy and light) at a 2-weekly interval. Heavy grazing delayed flowering time by only about 2 days for early and late maturity cultivars without influencing flowering duration. Late and mid maturity cultivars had more (P< 0.05) branches, petioles, and leaves with shorter branches under heavy grazing than under light grazing, whereas early maturity cultivars did not show any significant differences in the numbers of plant parts under the 2 grazing intensities. The effect of grazing intensity on the proportions of plant parts was small over all cultivars, indicated by a 2 percentage unit increase in the proportions of leaf in September, burr in October, and stem in November by heavy grazing. There was a large cultivar variation in flowering duration, and the numbers, lengths, and proportions of plant parts. The ranges of flowering duration were 24–66, 26–66, and 31–76 days and of branch length after cessation of flowering were 12–20, 6–14, and 5–14 cm for the early, mid, and late maturity groups, respectively. The late maturity group had more branches, leaves, petioles, and stems, and the early maturity group had less with the mid maturity group being intermediate. The variation in the proportions of plant parts among cultivars was not related to flowering time or flowering duration.

Effect of grazing intensity and cultivar on morphology, phenology, and nutritive value of subterranean clover II. Nutritive value during the growing season

2000 ◽  
Vol 51 (8) ◽  
pp. 1047 ◽  
Author(s):  
Y. J. Ru ◽  
J. A. Fortune
Keyword(s):  
Mineral Content ◽  
Nutritive Value ◽  
Grazing Intensity ◽  
Subterranean Clover ◽  
Growing Season ◽  
Maturity Group ◽  
Early Maturity ◽  
Pasture Quality ◽  
Heavy Grazing

With the decline in pasture quality in southern Australia, the development of management strategies to improve nutrient supply for grazing animals is essential and requires a clear understanding of the interaction between animals and plants. The impact of grazing intensity on the morphology of subterranean clover was previously examined. This paper reports the effect of grazing intensity on the nutritive value of subterranean clover, and the variation in quality of cultivars during the growing season. Grazing intensity influenced nutritive value and interacted with cultivar maturity. Heavy grazing depressed dry matter digestibility (DMD) by 5 percentage units in October for early maturity cultivars but increased DMD by 3 percentage units in September for mid maturity cultivars. The influence of grazing intensity on nitrogen content was small. Heavy grazing did not affect acid detergent fibre for the early maturity group, but depressed it for the mid maturity group throughout the season. Acid detergent lignin remained comparable for all cultivars during the season. Mineral content of subterranean clover showed variable response to grazing treatments. Nutritive value varied among cultivars within each maturity group. DMD ranged over 53–64%, 44–62%, and 45–53% for early, mid, and late maturity groups, respectively, at the end of the growing season. The cultivar rank in all nutritional parameters changed with the progress of the season. The large ranges in the decline rate of DMD within each maturity group during the last 8 weeks of growth gave an indication of the potential quality of the cultivars during late spring and early summer. Despite the variation in mineral content there were no cultivars in which the concentration of minerals was below the minimum requirements of sheep. These results indicate that there is a potential for the selection of high quality cultivars within a breeding program, and that indicative targets of grazing intensity need to be further developed with a focus on pasture quality.

scholarly journals Grazing and Cultivated Grasslands Cause Different Spatial Redistributions of Soil Particles

2019 ◽  
Vol 16 (15) ◽  
pp. 2639 ◽  
Author(s):  
Jinsheng Li ◽  
Jianying Shang ◽  
Ding Huang ◽  
Shiming Tang ◽  
Tianci Zhao ◽  
...  
Keyword(s):  
Soil Layer ◽  
Soil Health ◽  
Grazing Intensity ◽  
Health Condition ◽  
Soil Particle ◽  
Particle Sizes ◽  
Soil Layers ◽  
Soil Particles ◽  
Heavy Grazing ◽  
Grazing Intensities

The distribution of soil particle sizes is closely related to soil health condition. In this study, grasslands under different grazing intensities and different cultivation ages grasslands were selected to evaluate the dynamics of soil particle size redistribution in different soil layers. When the grazing intensity increased, the percentage of 2000~150-μm soil particles in the 0–10-cm soil layer decreased; 150~53-μm soil particles remained relatively stable among the grazing intensities—approximately 28.52%~35.39%. However, the percentage of less than 53-μm soil particles increased. In cultivated grasslands, the larger sizes (>53 μm) of soil particles increased and the smaller sizes (<53 μm) decreased significantly (p < 0.05) in the 0–10 cm-soil layer with increasing cultivation ages. The increase in small soil particles (<53 μm) in topsoil associated with grazing intensity increased the potential risk of further degradation by wind erosion. The increase in big soil particles (>53 μm) in topsoil associated with cultivation ages decreased the soil capacity of holding water and nutrient. Therefore, to maintain the sustainability of grassland uses, grazing grasslands need to avoid heavy grazing, and cultivated grasslands need to change current cultivation practices.

Factors affecting the productivity of irrigated annual pastures. 2. Defoliation by dairy cows

1986 ◽  
Vol 26 (3) ◽  
pp. 305 ◽  
Author(s):  
CR Stockdale
Keyword(s):  
Grazing Intensity ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Total Production ◽  
Pasture Production ◽  
Factors Affecting ◽  
Grazing Intensities ◽  
Seed Reserves ◽  
Clover Seed

The influence of grazing intensity on the productivity of an irrigated annual pasture was studied for 3 years in northern Victoria. Lax-, medium- and hard-grazing intensities were described by post-grazing pasture heights of 7.2, 5.2 and 3.0 cm, respectively. Also, one instance of variable grazing frequency occurred, in winter of year 1. Hard-grazed plots produced 1 3 and 17% less herbage in years 1 and 2, respectively, than did lax- and medium-grazed plots, which produced similar amounts of herbage. When the interval between grazings was extended, the variation in productivity was reversed; lax grazing resulted in 9% less total production than heavier grazing. In years 1 and 2, there was little effect of grazing treatment on botanical composition until spring, at which time there was a marked reduction in the amount of subterranean clover (Trifolium subterraneum) in the hard-grazed plots, with a concomitant increase in grass content. There were no significant effects of grazing intensity on the amounts of weeds in either year. However, in year 3, weeds were important contributors to pasture production early in the season. This, together with reduced clover seed reserves and increased incidence of disease in subterranean clover with hard grazing, suggests that the long-term regenerating ability of an annual pasture may be impaired if severely grazed at regular intervals.

scholarly journals High-density linkage map reveals QTL for Type-I seed coat cracking in RIL population of soybean [Glycine max (L.) Merr.]

Euphytica ◽  
2020 ◽  
Vol 216 (10) ◽  
Author(s):  
Beom Kyu Kang ◽  
Jeong Hyun Seo ◽  
Hyun Jo ◽  
Krishnanand P. Kulkarni ◽  
Man Soo Choi ◽  
...  
Keyword(s):  
Seed Coat ◽  
Recombinant Inbred Lines ◽  
High Density ◽  
Type I ◽  
Maturity Group ◽  
Early Maturity ◽  
Glycine Max L ◽  
Late Maturity ◽  
High Density Linkage Map

Abstract Seed coat cracking (SCC), particularly the Type-I irregular cracking, is critical in determining the quality of appearance and commercial value of soybean seeds. The objective of this study was to identify the quantitative trait loci (QTLs) for SCC with high-density genetic map. One hundred sixty-seven recombinant inbred lines (RILs) developed from a cross between Uram (SCC-resistant) and Chamol (SCC-susceptible) were evaluated for SCC over 2 years (2016–2017). The QTL analysis identified 12 QTLs located on chromosomes 2 (D1b), 6 (C2), 8 (A2), 9 (K), 10 (O), 12 (H), 19 (L), and 20 (I). Out of the 12 QTLs, qSC2-1, qSC9, SC10-1, qSC10-2, and qSC12 were novel QTLs and the other seven QTLs (qSC2-2, qSC2-3, qSC6, qSC8, qSC19-1, qSC19-2, and qSC20) were found to co-localize with the previously identified QTLs. The mean SCC of the RILs of early maturity group was significantly higher than that of the late maturity group, suggesting an association between SCC and maturity loci. In addition, although 10 QTLs were distantly located from the maturity loci (E1, E3, E4, E7, and E10), qSC10-1 and qSC10-2 co-localized with the maturity loci E2. The results obtained in this study provide useful genetic information on SCC which could be used in the SCC breeding programs.

scholarly journals Genotypic Variation of Different Maturity Groups of Maize (Zea mays L.) for Seed Physiological Quality

2020 ◽  
pp. 139-149
Author(s):  
O. Bankole ◽  
A. Oluwaranti ◽  
S. A. Ajayi ◽  
F. E. Awosanmi
Keyword(s):  
Crop Production ◽  
Seed Quality ◽  
Genotypic Variation ◽  
Accelerated Ageing ◽  
Maturity Group ◽  
Early Maturity ◽  
Maize Genotypes ◽  
Maize Varieties ◽  
Late Maturity ◽  
Maturity Groups

Maize genotypes of different maturity groups with good seed quality had been developed, but there is little or no information on how the seed quality of the maize genotypes are affected by their maturity groups. Therefore, the objectives of this study were to evaluate maize varieties of different maturity groups for seed quality and determine genotypic variations that exist within the different maturity groups of maize for seed quality. Laboratory experiments were conducted in the Seed Science Laboratory of the Department of Crop Production and Protection, Obafemi Awolowo University, Ile-Ife, Nigeria. Seeds of sixteen maize genotypes of different maturity groups were subjected to imbibition, germination, accelerated ageing, conductivity and seedling vigor tests. The late maturity group (TZLCOMP.4DTF2,TZLCOMP. 1C6/DT.SYN-1-W, WHITEDTSTR/TZLCOMP.1-W, OBASUPER1) gave the best viability, speed of germination and days to complete germination while the extra early maturity group (2009TZEE-ORISTRQPM, 2000SYNEE-WSTR,2013TZEE-WDTSTR, TZEE-WPOPDTC2STRC5F2) had the least performance. The early (2014TZE –YDTSTR, 2013DTESTR–WSYN, EVDT-2000STRC0, 2009DTEWSTRSYN) and extra-early maturity groups had the longest root length and highest root number respectively. However, the different maturity groups of maize evaluated imbibed water at the same rate. TZEE-WPOP DT STR C5 F2, 2013 DTE STR – W SYN, AFLATOXIN R-SYN2, TZL COMP.1 C6/DT. SYN-1-W among extra early, early, intermediate and late maturity groups respectively performed best for viability and vigor tests.

scholarly journals Differences in the photosynthetic and physiological responses of Leymus chinensis to different levels of grazing intensity

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Min Liu ◽  
Jirui Gong ◽  
Bo Yang ◽  
Yong Ding ◽  
Zihe Zhang ◽  
...  
Keyword(s):  
Electron Transport ◽  
Photosynthetic Capacity ◽  
Photosynthetic Apparatus ◽  
Chloroplast Ultrastructure ◽  
Grazing Intensity ◽  
Photosynthetic Electron Transport ◽  
Thermal Dissipation ◽  
Leymus Chinensis ◽  
Heavy Grazing ◽  
Grazing Intensities

Abstract Background Grazing is an important land use in northern China. In general, different grazing intensities had a different impact on the morphological and physiological traits of plants, and especially their photosynthetic capacity. We investigated the responses of Leymus chinensis to light, medium, and heavy grazing intensities in comparison with a grazing exclusion control. Results With light grazing, L. chinensis showed decreased photosynthetic capacity. The low chlorophyll and carotenoid contents constrained light energy transformation and dissipation, and Rubisco activity was also low, restricting the carboxylation efficiency. In addition, the damaged photosynthetic apparatus accumulated reactive oxygen species (ROS). With medium grazing, more energy was used for thermal dissipation, with high carotene content and high non-photochemical quenching, whereas photosynthetic electron transport was lowest. Significantly decreased photosynthesis decreased leaf C contents. Plants decreased the risk caused by ROS through increased energy dissipation. With high grazing intensity, plants changed their strategy to improve survival through photosynthetic compensation. More energy was allocated to photosynthetic electron transport. Though heavy grazing damaged the chloroplast ultrastructure, adjustment of internal mechanisms increased compensatory photosynthesis, and an increased tiller number facilitated regrowth after grazing. Conclusions Overall, the plants adopted different strategies by adjusting their metabolism and growth in response to their changing environment.

Effect of cultivar and grazing intensity in spring on shear and compression energies of dry mature subterranean clover (Trifolium subterraneum L.)

1997 ◽  
Vol 48 (8) ◽  
pp. 1199 ◽  
Author(s):  
Y. J. Ru ◽  
J. A. Fortune
Keyword(s):  
Flowering Time ◽  
Large Range ◽  
Grazing Intensity ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Plant Materials ◽  
Leaf Petiole ◽  
Dry Matter Digestibility ◽  
Highly Correlated ◽  
Shear Energy

Twenty-six cultivars of subterranean clover were divided into 3 maturity groups according to the flowering time and sown in 2 blocks with 4 replicates. The plots were grazed under 2 intensities (hard and lax) during the growing season. The proportions of leaf, petiole, stem, and burr before senescence, dry matter digestibility (DMD), herbage availability, and seed yield in summer were measured. The energies required to shear and compress the resultant dry mature plant materials were determined using an Instron material testing instrument. The results showed a large range for shear (11·3-18·2 kJ/m2) and compression energies (2·8-4·6 kJ/kg DM) among the 26 cultivars. Grazing intensity in spring did not affect shear energy (P > 0·05) but increased the compression energy of dry mature subterranean clover by 0·2 units (P < 0·05). The energy required to shear or compress plant materials was highly correlated with herbage availability, flowering time, proportions of leaf and petiole in the sward, and fibre content of the plant materials, with the relationships being modified by grazing intensity in spring. Compression energy was related to DMD of plants (r = -0·7) and shear energy did not account for a significant amount of variation in DMD.

Runoff and sediment yield from snowmelt and rainfall as influenced by forage type and grazing intensity

1998 ◽  
Vol 78 (4) ◽  
pp. 699-706 ◽  
Author(s):  
S. I. Gill ◽  
M. A. Naeth ◽  
D. S. Chanasyk ◽  
V. S. Baron
Keyword(s):  
Sediment Yield ◽  
Environmental Sustainability ◽  
Grazing Intensity ◽  
Annual Runoff ◽  
Rainfall Simulation ◽  
Sediment Yields ◽  
Natural Rainfall ◽  
Grazing Intensities ◽  
Grazing Systems ◽  
Runoff And Sediment Yield

Currently, there is interest in Western Canada in extending the grazing season using perennial and annual forages. Of greatest concern is the environmental sustainability of these grazing systems, with emphasis on their ability to withstand erosion. A study to examine the runoff and sediment yields of annual and perennial forages in central Alberta was initiated in 1994. Runoff and sediment yield were quantified under snowmelt and rainfall events for two seasons. Rainfall simulation was used to further examine runoff under growing season conditions. Four forage treatments (two annuals: triticale and a barley/triticale mixture and two perennials: smooth bromegrass and meadow bromegrass) and three grazing intensities (light, medium and heavy) were studied, each replicated four times. Total annual runoff was dominated by snowmelt. Generally runoff volumes, sediment yields, sediment ratios and runoff coefficients were all low. Bare ground increased with increasing grazing intensity and was significantly greater in annuals than perennials for all grazing intensities. Litter biomass decreased with increasing grazing intensity and was generally similar in all species for both years at heavy and medium grazing intensities. Results from the rainfall simulation corroborated those under natural rainfall conditions and generally indicated the sustainability of these grazing systems at this site. Key words: Forages, soil erosion, sustainability, rainfall simulation

Distribution and variability in development of the genus Trigonella in Asia Minor and its possible use in Australian environments

1981 ◽  
Vol 32 (5) ◽  
pp. 793 ◽  
Author(s):  
GM Halloran ◽  
AL Pennell
Keyword(s):  
Flowering Time ◽  
Subterranean Clover ◽  
Asia Minor ◽  
Vernalization Response ◽  
Developmental Patterns ◽  
Late Flowering ◽  
Commercial Cultivars ◽  
Wide Variability ◽  
Upper Level ◽  
Autumn Sowing

A number of Trigonella species were examined for their possible use in Australian environments. There was a wide variability in flowering time in Trigonella. Under an outdoor autumn sowing the range in flowering time was comparable with that found within early- to late-flowering Australian commercial cultivars of subterranean clover. The upper level of vernalization response was much lower in Trigonella than in subterranean clover. Good prospects exist within Trigonella for selecting genotypes with close adaptation (in terms of appropriate developmental patterns) to a range of Australian environments, a range at least as wide as that now occupied by subterranean clover and annual medic.

scholarly journals Transcriptome-wide gene expression plasticity in Stipa grandis in response to grazing intensity differences

2020 ◽  
Author(s):  
Zhenhua Dang ◽  
Yuanyuan Jia ◽  
Yunyun Tian ◽  
Jiabin Li ◽  
Yanan Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Grazing Intensity ◽  
Glycolate Oxidase ◽  
Bisphosphate Carboxylase ◽  
Grazing Intensities

Organisms have evolved effective and distinct adaptive strategies to survive. Stipa grandis is one of the widespread dominant species on the typical steppe of the Inner Mongolian Plateau, and is regarded as a suitable species for studying the effects of grazing in this region. Although phenotypic (morphological and physiological) variations in S. grandis in response to long-term grazing have been identified, the molecular mechanisms underlying adaptations and plastic responses remain largely unknown. Accordingly, we performed a transcriptomic analysis to investigate changes in gene expression of S. grandis under four different grazing intensities. A total of 2,357 differentially expressed genes (DEGs) were identified among the tested grazing intensities, suggesting long-term grazing resulted in gene expression plasticity that affected diverse biological processes and metabolic pathways in S. grandis. DEGs were identified that indicated modulation of Calvin–Benson cycle and photorespiration metabolic pathways. The key gene´expression profiles encoding various proteins (e.g., Ribulose-1,5-bisphosphate carboxylase/oxygenase, fructose-1,6-bisphosphate aldolase, glycolate oxidase etc.) involved in these pathways suggest that they may synergistically respond to grazing to increase the resilience and stress tolerance of S. grandis. Our findings provide scientific clues for improving grassland use and protection, and identify important questions to address in future transcriptome studies.

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