Water use and productivity in sub. clover and murex medic swards. I. Dry matter production

1993 ◽  
Vol 44 (1) ◽  
pp. 89 ◽  
Author(s):  
MJ Blumenthal ◽  
RL Ison

A field experiment was established at Forbes in central-west New South Wales to investigate the hypothesis that the pattern and efficiency of water use varies between genotypes of both (Trifolium subterraneum) and murex medic (Medicago murex), and that this would affect the success of these genotypes in this environment. To test this hypothesis the productivity of two lines of M. murex (CD26 and CD53) and four cultivars of T.subterraneum (Seaton Park and Woogenellup, and two recently released cultivars, Junee and Dalkeith) were compared. Genotypes were grown both with and without irrigation and soil water was monitored for the duration of the field experiment (1987-1989). Soil water use differed little between genotypes, but when differences did occur they were related to maturity grading of the genotype with the earlier maturing cv. Dalkeith using more water without irrigation, and the later maturing cv. Junee using more water with irrigation. There was no evidence of sub. clover dry matter yield declining with time; total yield over the three years exceeded 18 000 kg/ha for all cultivars. Murex medic dry matter yields were higher than sub. clover in the year of sowing; however, dry matter yield in swards was depressed in the year following sowing and weeds contributed more to total sward yield compared to sub. clover in the third year. Both hard and soft-seeded subclover cultivars proved to be equally successful in terms of dry matter production with different cultivars performing better in different seasons and under different irrigation treatments. Sub. clover cvv. Dalkeith and Junee were able to take greater advantage of available soil water early. in autumn than the other genotypes. It was concluded that water availability is not the only factor limiting sub. clover and murex medic dry matter yield in this environment.

1988 ◽  
Vol 15 (6) ◽  
pp. 815 ◽  
Author(s):  
GC Wright ◽  
KT Hubick ◽  
GD Farquhar

Variation in water-use efficiency (W, g of total dry matter produced/kg water used), and its correlation with cultivar isotope discrimination in leaves (Δ) was assessed in peanut plants grown in small canopies in the field. Plants were grown in separate minilysimeters that were both embedded in the ground and positioned above the crop. Differences among cultivars were found in W and � and the relationship between W and Δ was compared for plants grown in open and closed canopies. Genetic variability in W in plants grown in the field under non-limiting water conditions was demonstrated, with Tifton-8, of Virginia habit, having the highest W (3.71 g/kg) and Rangkasbitung, an Indonesian cultivar of Spanish habit, the lowest (2.46 g/ kg). Variability in W was due to variation in total dry matter production more than that of water use. A strong negative correlation was found between Δ and W, and also between Δ and total dry matter. The relationship between whole plant W, including roots, and Δ was stronger than that between shoot W, without roots and Δ. The improvement occurred because of variation among cultivars in the root to shoot ratio. This highlights the importance of taking account of root dry matter in studies concerning W. There were significant differences in W and Δ between plants in pots above-ground compared to pots in the ground, with above-ground plants having significantly lower values of both W and Δ. The ranking of W and Δ among cultivars was not affected by the contrast in environment, which suggests these parameters are under strong genetic control. Total above-ground dry matter yield at maturity was negatively correlated with Δ, while pod yield was not. It appears a negative association between harvest index and Δ may exist; however not all cultivars used in this and other studies follow this response. Both water-use efficiency, Wand total dry matter production are negatively correlated with Δ in leaves of peanut plants grown in small canopies in the field. Measurement of Δ may prove a useful trait for selecting cultivars with improved W and total dry matter yield under field conditions.


2016 ◽  
Vol 67 (1) ◽  
pp. 69 ◽  
Author(s):  
M. R. McCaskill ◽  
M. C. Raeside ◽  
S. G. Clark ◽  
C. MacDonald ◽  
B. Clark ◽  
...  

Pastures sown to lucerne (Medicago sativa L.) with a perennial non-legume could increase feed supply relative to traditional pastures based on subterranean clover (Trifolium subterraneum L.). Such mixtures might also be preferable to pure lucerne pastures, which are prone to weed invasion. Yield and water-use efficiency (harvested dry matter per unit evapotranspiration) of mixtures with lucerne or subterranean clover were compared a field experiment established under rainfed conditions at Hamilton, Victoria. Soil moisture and dry matter production were measured over 2 years. Treatments included chicory (Cichorium intybus L.), cocksfoot (Dactylis glomerata L.) and tall fescue (Festuca arundinacea Shreb.) with either lucerne or subterranean clover; pure lucerne; and phalaris (Phalaris aquatica L.) and perennial ryegrass (Lolium perenne L.) with only subterranean clover. In the second year, dry matter production from lucerne mixtures exceeded that of equivalent mixtures with subterranean clover in spring, summer and winter. In spring, the lucerne component continued producing for longer than the clover component through its use of deeper stored soil water, and in summer, lucerne continued to grow slowly after the grass component had entered a drought-induced dormancy. In winter, the contribution from the lucerne component complemented, rather than competed with, that from the non-legume component. Water-use efficiencies during winter–spring ranged from 4 kg ha–1 mm–1 for chicory–clover to 27 kg ha–1 mm–1 for a fescue–lucerne mixture, and during summer–autumn from nil for cocksfoot–clover to 13 kg ha–1 mm–1 for a fescue–lucerne mixture. This study demonstrates that lucerne-based mixtures can increase forage supply per unit water use relative to traditional pastures based on subterranean clover.


1976 ◽  
Vol 16 (82) ◽  
pp. 739 ◽  
Author(s):  
BJ Scott ◽  
H Brownlee

Dry matter production and seed yields of a range of annual legumes grown in ungrazed swards were measured between 1966 and 1971 on seven sites in the low rainfall wheatbelt of central western New South Wales. Jemalong and Hannaford barrel medics (Medicago truncatula) were the highest yielding medic cultivars tested. Jemalong medic was slightly superior to Hannaford in dry matter production but seed yields were equal. The short season subterranean clovers (Trifolium subterraneum), Dwalganup and Geraldton, yielded much less dry matter and seed than the medics in most experiments. Although the mid-season subterranean clovers, Woogenellup and Clare, persisted for the duration of our experiments, their production was not as consistent as that of the medics, and plant densities decreased. The rose clovers (T. hirtum), Sirint and Kondinin, the cupped clovers (T. cherleri), Beenong and Yamina, and Snail (M. scutellata) and Paragosa (M. rugosa) medics did not produce satisfactory swards.


1974 ◽  
Vol 14 (69) ◽  
pp. 507 ◽  
Author(s):  
MH Campbell

In a series of experiments on unploughed hill country near Turondale, New South Wales, the effects of rate and type of herbicide on establishment, survival and persistence of surface-sown Medicago sativa, Trifolium subterraneum, Dactylis glomerata and Phalaris tuberosa were ascertained. Measurements of plant density and dry matter production of the pasture under grazing were made for up to seven years after sowing. Establishment was achieved under various rainfall conditions from eleven sowings. Herbicide application proved essential for the establishment and survival of the perennial species. Survival of M. sativa seedlings through their first summer was greater on the 2,2-DPA treatments than on paraquat treatments. The addition of simazine to paraquat increased survival of M. sativa over that on the paraquat-alone treatment. No similar effect was observed when simazine was added to 2,2-DPA. Establishment and survival were not influenced by rates of 2,2-DPA between 4.1 and 12.4 kg a.e. ha-1. Plant density in established swards was increased by up to 1200 per cent by strategic grazing applied after the improved species had completed seeding. Lucerne dominated other species and in the final year of measurement produced 87 per cent of a mean dry matter production of 9719 kg ha-1.


2011 ◽  
Vol 37 (8) ◽  
pp. 1432-1440
Author(s):  
Cheng-Yan ZHENG ◽  
Shi-Ming CUI ◽  
Dong WANG ◽  
Zhen-Wen YU ◽  
Yong-Li ZHANG ◽  
...  

1962 ◽  
Vol 42 (1) ◽  
pp. 46-52 ◽  
Author(s):  
G. G. Smeltzer ◽  
W. M. Langille ◽  
K. S. MacLean

In a field experiment, conducted on four different soil types, trace elements cobalt, zinc, manganese, copper, sodium and molybdenum were applied by sprayer to a grass-legume sward in late September in both 1955 and 1956. Treatment differences were evaluated in terms of total dry matter production and by the chemical composition of the plant tissue. The elements applied were detectable in plant tissue, but herbage yields were not affected. Apparently the trace elements in these different soil types were in the range of sufficiency for maximum herbage production.


1985 ◽  
Vol 40 (2) ◽  
pp. 267-277 ◽  
Author(s):  
T. A. Stewart ◽  
I. I. McCullough

ABSTRACTSilage cut twice annually (June and August) from a tetraploid red clover/grass sward and three times annually (May, July and September) from a low nitrogen (N) and high N perennial ryegrass/white clover sward was fed in proportion to dry-matter yield from each cut, over a 10-week period, each winter for 3 years to castrated male cattle of initial live weight 401 kg in year 1 and 425 kg in years 2 and 3. The silages were supplemented with 0, 1, 2 and 3 kg concentrate per head daily.Total dry-matter yield from the red clover/grass sward was similar to that from the perennial ryegrass/white clover sward (high N grass) receiving 360 kg N per ha but the digestibility, particularly of first cut material was much lower. Dry-matter production of the low N grass/white clover sward was 0·73 of high N grass sward and produced silages of similar digestibility and fermentation.Dry-matter intakes by the cattle were higher on the legume-based silages in years when clover made a worthwhile contribution to total yield, but this did not significantly improve utilization or animal performance compared with high N grass silage. Mean daily carcass gain per head on red clover/grass silage was 0·41 kg which was significantly less than the 0·61 kg on white clover/grass silage and 0·59 on high N grass (P < 0·001). Carcass output from red clover/grass silage was 618 kg/ha and 629 kg/ha from white clover/grass, both of which were significantly less than the 863 kg/ha from the high N grass silage (P < 0·001). Dressing proportion was also significantly poorer in animals fed red clover/grass silage compared with the other silage types.


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