Potential production of grass and clover monocultures in a mediterranean-type environment — an experimental approach

1974 ◽  
Vol 25 (6) ◽  
pp. 835 ◽  
Author(s):  
PS Cocks
Keyword(s):  
Dry Matter ◽  
Experimental Approach ◽  
Incident Light ◽  
Trifolium Subterraneum ◽  
Maximum Growth ◽  
Nutrient Deficiencies ◽  
Potential Production ◽  
Area Index ◽  
Before And After ◽  
Differential Ability

Monocultures of Lolium rigidum cv. Wimmera and Trifolium subterraneum cv. Woogenellup were established at four densities and mown at three contrasting heights over a 5 month period. Heavy applications of fertilizer were applied to eliminate nutrient deficiencies. Dry matter yields and leaf areas were measured before and after the 3-weekly defoliations, and shoot numbers before the defoliations. Growth rate was related to leaf area index (LAI) in all but one of the sampling periods. Maximum growth rates were proportional to light energy, and the average efficiency of conversion was 4.5% for the clover and 5.5% for the grass. Total herbage yields as high as 17.3 t ha-1 were obtained from the grass, and up to 16.4 t ha-1 from the clover. The results are discussed in relation to the differential ability of grass and clover to exploit the environment. The grass was leafier and had more shoots, but it is thought that clover intercepted more of the incident light at low LAI. The results indicate that potential yields would be reduced at the low LAI values associated with an efficiently utilized pasture.

Seed size as a factor in the growth of subterranean clover (Trifolium subterraneum L.) under spaced and sward conditions

1957 ◽  
Vol 8 (4) ◽  
pp. 335 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Seed Size ◽  
Seed Weight ◽  
Agricultural Research ◽  
Incident Light ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Area Index ◽  
Significant Difference

The significance of seed weight in the growth of subterranean clover (Trifolium subterraneum L) , of the Bacchus Marsh strain, has been assessed under both spaced plant and sward conditions at the Waite Agricultural Research Institute. Under conditions of spacing, plants of three widely separated seed size grades were grown a t a density of 1 per 25 sq. links. The dry weights of the plants were proportional to seed weight from the time of sowing (in May) till the end of October – over almost the entire growing period of the crop. Three sets of swards were grown a t a density of 25 plants per sq. link, each sward being planted with seed of one of the three sizes. Dry weight was proportional to seed weight in the early part of the season but when the swards reached a leaf area index of about 4 (i.e. when there were 4 sq. links of leaf surface on 1 sq. link of ground), a reduction in growth rate occurred. This critical leaf area index was reached first in "large seed" swards, followed later by "medium seed" and finally by "small seed" swards. Thus there was a period in which the swards were growing at different rates, and in which the dry weights came to parity, so that on the final sampling occasion (in December) there was no significant difference between the dry weights of the swards from the three seed sizes. It is concluded that a t a leaf area index of about 4, interception of incident light energy is complete.

The growth and development of a crop of bulrush millet (Pennisetum typhoides S. & H.)

1965 ◽  
Vol 65 (3) ◽  
pp. 341-349 ◽  
Author(s):  
J. E. Begg
Keyword(s):  
Growth Rate ◽  
Growth And Development ◽  
Dry Matter ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Internode Elongation ◽  
Area Index ◽  
Pennisetum Typhoides ◽  
General Flowering ◽  
Cutting Height

The growth and development of a crop of Bulrush millet (Pennisetum typhoides S. & H.) was evaluated by a series of ‘first’ harvests at weekly intervals during the growing season. A final harvest was taken at the end of the season to measure the regrowth.Tillers emerged from the second, until the 5th week after emergence where full light interception was recorded. Then a marked increase in dry-matter production, internode elongation and leaf area index occurred and a peak growth rate of 44 ± 4 g. of dry matter per square metre per day was recorded during the 9th week. General flowering occurred during the 13th week and at 16 weeks the crop yielded 21,735 kg. of dry matter per hectare.Regrowth yields were high following defoliations made at an early vegetative stage when the apical meristem was below the cutting height and then declined as internode elongation raised increasing numbers of apices above the cutting height. Extensive areas of the stand died when defoliated as it approached its period of maximum growth rate.

Effect of cultivar, sowing time, and density on the growth of subterranean clover in winter

1997 ◽  
Vol 48 (7) ◽  
pp. 977 ◽  
Author(s):  
Y. J. Ru ◽  
J. A. Fortune ◽  
W. D. Bellotti
Keyword(s):  
Dry Matter ◽  
Plant Density ◽  
Subterranean Clover ◽  
Leaf Size ◽  
Trifolium Subterraneum ◽  
Early Spring ◽  
Dry Matter Yield ◽  
Sowing Time ◽  
Area Index ◽  
Sward Height

In winter and early spring in Mediterranean environments, animal production is often limited by the low herbage availability associated with low growth rates and short swards, which result in low intake. In the present study, 26 subterranean clover (Trifolium subterraneum) cultivars were evaluated for herbage availability early in the season. There were large variations in dry matter yield (0·3-0·7 g/plant), sward height (2·9-9·3 cm), and leaf area index (1·0-5·1) among cultivars after 70 days of growth, indicating a possibility for selection of cultivars based on these parameters. Increasing plant density from 460 to 4600 plants/m2 increased dry matter yield from 88·5 to 362·8 g/m2 and sward height from 2·6 to 8·3 cm at Day 60. Early sowing increased dry matter yield, sward height, petiole length, leaf number, and leaf size by 13, 6, 32, 10, and 23%, respectively, after 70 days of growth. These results indicate that new pastures should be established early if soil moisture is adequate, and that the time of the season break has an important influence on early growth of pastures and, consequently, on the budgeting of feed in farming practice.

Studies of phosphorus and potassium deficiencies in Trifolium subterraneum based on electrical measurements

1982 ◽  
Vol 60 (5) ◽  
pp. 634-644 ◽  
Author(s):  
Charles G. Greenham ◽  
Peter J. Randall ◽  
Warren J. Müller
Keyword(s):  
Low Frequency ◽  
Trifolium Subterraneum ◽  
Nutrient Status ◽  
Maximum Growth ◽  
Nutrient Deficiencies ◽  
Electrical Measurements ◽  
P Deficiency ◽  
Phosphate Treatment ◽  
Phosphorus And Potassium ◽  
Two Parameters

Electrical measurements were used to indicate changes in plant tissue due to alterations in nutrient status. An experiment with Trifolium subterraneum L., grown in soil at five rates of applied P, showed that inadequate P produced high values for (1) resistance to low frequency current (RLM) and (2) radius of the impedance locus (r). With increasing P the values of these two parameters fell, reaching a minimum at the P level giving maximum growth. Increasing the P supply above the optimum had no further effect.A study of K-deficient and of P-deficient plants showed the feasibility of diagnosing either deficiency or of discriminating between the two deficiencies, from changes in certain impedance parameters of the petiole tissue following correction of the deficiencies. Changes in membrane phase angle were consistent with K deficiency delaying and P deficiency hastening aging of the plasma membrane. RLF of both petioles and leaflets was increased by P deficiency, and the value for attached but not detached petioles from P-deficient plants was reduced by treatment with phosphate. RLF values for attached P-deficient leaflets decreased in response to phosphate treatment during leaf development but no longer responded (within 6 days of treatment) after a certain stage of maturity.Changes in RLF and r resulting from the correction of P deficiency show that some factor in addition to increase in tissue K is involved, most likely the plasmodesmata. The differences between RLF changes due to correction of nutrient deficiencies and those due to injury are noted.

A Model of the Effect of Interspecies Competition for Light on Dry-Matter Production

1984 ◽  
Vol 11 (4) ◽  
pp. 277 ◽  
Author(s):  
GM Rimmington
Keyword(s):  
Dry Matter ◽  
Incident Light ◽  
Light Energy ◽  
Dry Matter Production ◽  
Interspecies Competition ◽  
Area Index ◽  
Unit Leaf ◽  
Matter Production ◽  
Absorption Of Light ◽  
Competition For Light

A model of the effect of interspecies competition for light on the daily dry-matter production of competing species is developed. It describes the absorption of light by the component species, accounting for their different optical properties. Absorption equations are formulated from the principle of conservation of light energy within a unit-leaf-area-index of canopy, and the integral of absorbed light energy is then used to calculate the rate of dry-matter production of each component species. This model proved useful for the analysis of data from experiments in which New Zealand white clover (Trifolium repens L.) and perennial ryegrass (Lolium perenne L.) were grown in mixtures. Application of the model enabled the proportion of incident light energy absorbed by each component to be estimated and unambiguous differentiation between the amount of light energy absorbed and the efficiency of use of the absorbed light energy.

Effect of intensity of defoliation on regrowth of pasture

1956 ◽  
Vol 7 (5) ◽  
pp. 377 ◽  
Author(s):  
RW Brougham
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Unit Area ◽  
Incident Light ◽  
Ground Surface ◽  
Maximum Level ◽  
Maximum Growth ◽  
Light Interception ◽  
Maximum Efficiency ◽  
Rate Of Increase

A pasture association comprising short-rotation ryegrass, red clover, and white clover was subjected to three different intensities of defoliation by cutting down to 1, 3, and 5 in. At 4-day intervals over a period of 32 days, measurements were taken of herbage dry matter yield, the leaf area per unit area of ground, and the percentage of light penetrating to a level 1 in. above the ground surface. Where pasture was defoliated to 1 in., light interception was almost complete (95 per cent. or over) approximately 24 days after cutting, whereas pastures defoliated to 3 in. and 5 in. intercepted almost all the incident light 16 and 4 days after cutting respectively. At these stages of growth the leaf area was approximately 5 sq. ft per sq. ft of ground and the herbage yield approximately 1450 lb dry matter per acre, regardless of treatment. The rate of pasture growth increased until complete light interception was approached, and thereafter an almost constant maximum rate was sustained. Leaf efficiency (the rate of increase of herbage dry weight per unit area of leaf) was greatly influenced by intensity of defoliation. Efficiency was initially lower following severe defoliation than following less severe treatment. It increased rapidly to a maximum and thereafter declined gradually. Maximum efficiency in the 3 in. and 5 in. cutting treatments was attained when maximum growth rate was first reached. For pasture defoliated to 1 in., it reached a maximum level during the phase of accelerating growth.

Competition between plants of different initial seed sizes in swards of subterranean clover (Trifolium subterraneum L.) with particular reference to leaf area and the light microclimate

1958 ◽  
Vol 9 (3) ◽  
pp. 299 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area ◽  
Incident Light ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Light Energy ◽  
Light Extinction ◽  
Unexpected Finding ◽  
Sampling Occasion ◽  
Area Index ◽  
Initial Seed

A study was made of the development and fate of individual plants growing from contrasting seed sizes in swards of subterranean clover (var. Bacchus Marsh). Three sets of swards were grown in boxes, from large, small, and mixed (large and small) seeds respectively, all sown at the same number of plants per unit area; the swards were harvested on five occasions. Leaf area in each 2 cm layer of the sward was determined separately and measurements of the light intensity reaching each layer were obtained at each harvest. Counts of the plants on each occasion revealed a steady drop of about 30 per cent. over the whole period; in the "mixed" swards, only plants from small seed sizes died, the number of large-seeded plants remaining unchanged. The data of leaf area and numbers in each layer showed that leaf area is concentrated in a relatively shallow band at the top of the sward, the area attained by individual leaves increasing with height in the sward and with time. Leaves are not retained in the canopy at heights below that at which light extinction occurs. An unexpected finding was that, as the sward developed, the leaf area index (the ratio of leaf area to ground covered) required for the absorption of all incident light energy increases, and it is suggested that this is due to changes in leaf morphology. The importance of the position at which leaves of individual plants are held in the canopy is stressed; although at the first sampling occasion, the small-seeded plants had 25 per cent. of the leaf area of the mixed sward, they were so located as to absorb only 10 per cent. of the incident light energy; at the last sampling occasion, the values were 10 and 2 per cent. respectively. It is concluded that the disappearance of the small-seeded plants from the mixed swards was due to shading from the large-seeded plants.

scholarly journals The nitrogen topdressing mode of indica-japonica and indica hybrid rice are different after side-deep fertilization with machine transplanting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaodan Wang ◽  
Yaliang Wang ◽  
Yuping Zhang ◽  
Jing Xiang ◽  
Yikai Zhang ◽  
...  
Keyword(s):  
Single Dose ◽  
Controlled Release ◽  
Nitrogen Uptake ◽  
Dry Matter ◽  
Hybrid Rice ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Quick Release ◽  
Significant Difference ◽  
Spikelets Per Panicle

AbstractDetermination of the optimal fertilization method is crucial to maximize nitrogen use efficiency and yield of different rice cultivars. Side-deep fertilization with controlled-release nitrogen, in conjunction with machine transplanting and subsequent topdressing, was applied to Indica–japonica hybrid rice ‘Yongyou1540’ (YY1540) and indica hybrid rice ‘Tianyouhuazhan’ (TYHZ). Four nitrogen treatments were applied in 2018 and 2019: traditional nitrogen application with quick-release nitrogen (T1), single-dose deep fertilization at transplanting with 100% controlled-release nitrogen (T2), and deep fertilization of 70% controlled-release nitrogen and topdressing of 30% quick nitrogen at tillering (T3), or at panicle initiation (T4). Side-deep fertilization reduced the fertilizer application frequency without causing yield loss, T4 enhanced the yield of YY1540 by increasing the number of productive tillers and number of spikelets per panicle compared with T1, T2 and T3. The yield of TYHZ showed no significant difference among treatments. The T4 treatment decreased the number of tillers at the tilling peak stage and increased the percentage productive tillers and number of differentiated spikelets. Compared with the other treatments, T4 increased dry matter accumulation and leaf area index during panicle initiation and grain ripening, and contributed to enhanced nitrogen uptake and nitrogen utilization in YY1540. On average, nitrogen uptake and utilization in YY1540 were highest in T4, but no significant differences among treatments were observed in TYHZ. Dry matter accumulation and nitrogen uptake from panicle initiation to heading of YY1540 were correlated with number of spikelets per panicle, but no significant correlations were observed for TYHZ. Supplementary topdressing with quick-release nitrogen at the panicle initiation stage was required to increase yield of indica–japonica hybrid rice, whereas single-dose deep fertilization with controlled-release nitrogen is satisfactory for the indica hybrid cultivar.

scholarly journals Effect of Organic Manures on Growth, Rhizome Yield and Quality Attributes of Turmeric (Curcuma longa L.)

2012 ◽  
Vol 10 (1) ◽  
pp. 16-22 ◽  
Author(s):  
M. Z. U. Kamal ◽  
M. N. Yousuf
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Curcuma Longa ◽  
Dry Weight ◽  
Fresh Weight ◽  
Area Index ◽  
Yield Attributes ◽  
Organic Manures ◽  
Neem Cake ◽  
Yield And Quality

The investigation was carried out to evaluate the effect of different organic manures on turmeric with reference to vegetative growth, biomass production, rhizome yield and its attributes of turmeric (Curcuma longa L.). Turmeric showed better response to the application of organic manures. Plant with neem cake application had the taller plant (79.30 cm), maximum number of tillers per plant (5.40), leaf number (5.40), leaf area (44.09) leaf area index (0.429), fresh weight of halum ( 190.05g), fresh weight of root (49.13 g), fresh weight of rhizome per plant (256.21 g) and dry weight of halum (15.21g), dry weight of root (7.32 g), dry weight of rhizome per plant (40.35 g), total dry matter yield (6.85 t ha-1) than those received other types of manures. Moreover, yield attributes such as number of mother rhizomes per plant-1 (1.75), more number of primary rhizomes per plant-1 (5.19), secondary rhizomes per plant-1 (18.03) and tertiary rhizomes per plant (7.69) were also highly accelerated by neem cake application. Similarly, the same treatment expressed the best in terms of size of mother rhizome (7.69 cm), primary rhizome (21.86 cm) and secondary rhizomes (7.05 cm).All these parameters in cumulative contributed to  produce the highest estimated fresh rhizomes yield & cured rhizomes yield (29.48 t ha-1, 5.59 t ha-1 respectively). The highest curing percentage (20.28) was observed in T3 treatment having mustard cake@ 2.0 t/ha. Thus, organic manure like neem cake was best fitted natural fertilizer for turmeric cultivation.DOI: http://dx.doi.org/10.3329/agric.v10i1.11060The Agriculturists 2012; 10(1): 16-22

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