Effect of nitrogen and cobalt application on herbage and seed yields of serradella and subterranean clover

1985 ◽  
Vol 25 (3) ◽  
pp. 588 ◽  
Author(s):  
MDA Bolland

The response of serradella and subterranean clover to soil applications of cobalt in the absence and presence of regular applications of nitrogen fertilizer was measured in a field experiment on a nitrogen-deficient soil near Esperance, Western Australia. In an ancillary experiment, also sited near Esperance on a nitrogen-deficient soil, the responses of three serradella species and two cultivars of subterranean clover to regular applications of nitrogen were measured. Yields of herbage and seed were used to measure the response to the fertilizer treatments. Neither serradella, nor subterranean clover responded to cobalt application. However, in winter, herbage yields of serradella were markedly improved by regular applications of fertilizer nitrogen. Yield increases were three- to eight-fold, depending on the species. However, by springtime, there was no herbage response of serradella to fertilizer nitrogen. Seed yields of serradella and yields of subterranean clover at any harvest were unaffected by regular applications of nitrogen. It is concluded that low winter temperatures limit the rate of symbiotic nitrogen fixation for serradella which in turn limits dry matter production.

1988 ◽  
Vol 28 (6) ◽  
pp. 765 ◽  
Author(s):  
MDA Bolland ◽  
MJ Baker

Seed of 2 cultivars of wheat (Triticum aestivum) and 1 burr medic (Medicago polymorpha) with increasing phosphorus (P) concentrations (wheat 1.4-3.7 g P/kg dry matter, medic 3.3-7.9 g P/kg dry matter) were collected from field experiments with variable levels of applied superphosphate (wheat 0- 577 kg P/ha, medic 0-364 kg P/ha) in south-western Australia. These seeds were used in further experiments to examine the effect of seed P concentration on the subsequent dry matter (DM) production of seedlings and plants in 3 glasshouse pot experiments and 1 field experiment. Seed of the same size (wheat, 35 mg/seed; medic, 3.6 mg/seed) but with increasing P concentration produced substantially higher DM yields in the absence or presence of freshly applied superphosphate P up to 28-35 days after sowing in the pot experiments and 67 days after sowing in the field experiment.


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.


1991 ◽  
Vol 31 (6) ◽  
pp. 777
Author(s):  
MDA Bolland

The effect of superphosphate applications (0, 25, 50, 75, 100 and 125 kg P/ha to the soil surface) on the dry matter (DM) herbage production of dense swards of subterranean clover (Trifolium subterraneum cv. Junee) and yellow serradella (Ornithopus compressus cv. Tauro) was measured in a field experiment on deep, sandy soil in south-western Australia. The swards were defoliated with a reel mower at weekly intervals from 88 to 158 days after sowing, to a height of 2 cm for the first 9 cuts, 4 cm for the tenth cut and 5 cm for the eleventh cut. Yellow serradella was more productive than subterranean clover. Consequently, for the relationship between yield and the level of phosphorus (P) applied, yellow serradella supported larger maximum yields and required less P than subterranean clover, to produce the same DM herbage yield. Maximum yields of yellow serradella were 12-40% larger. To produce 70% of the maximum yield for yellow serradella at each harvest, yellow serradella required about 50% less P than subterranean clover. However, when yields were expressed as a percentage of the maximum yield measured for each species at each harvest, the relationship between yield and the level of P applied was similar for both species, and they had similar P requirements.


1980 ◽  
Vol 60 (1) ◽  
pp. 209-212 ◽  
Author(s):  
H. ANTOUN ◽  
L. M. BORDELEAU ◽  
D. PRÉVOST ◽  
R. A. LACHANCE

Specific activities of the assimilatory and "regulatory" types of nitrate reductase were studied in 41 strains of Rhizobium meliloti having different symbiotic nitrogen fixation activities. Both nitrate reductase enzymes were present in very effective and ineffective strains and no significant correlation was found between the specific activities of the two enzymes and the dry matter yields of alfalfa obtained with the 41 strains. Measurements of the specific activities of the two nitrate reductase enzymes in the vegetative bacteria cannot be used as a rapid physiological test for the selection of very effective strains of R. meliloti.


1965 ◽  
Vol 5 (19) ◽  
pp. 417 ◽  
Author(s):  
FC Crofts

Nitrogen fertilizer applied as sulphate of ammonia at 23 to 92 pounds of nitrogen an acre in early spring made forage available for grazing six weeks earlier and returned 19 to 22 pounds of additional dry matter (with 14 to 19 per cent crude protein) for each pound of fertilizer nitrogen applied. However, the responses to nitrogen fertilizer became progressively less over the late spring and summer period and the responses in the autumn, when additional forage is urgently needed for winter reserves, were relatively small.


1992 ◽  
Vol 32 (1) ◽  
pp. 49 ◽  
Author(s):  
RR Young ◽  
KJ Morthorpe ◽  
PH Croft ◽  
H Nicol

The tolerance of 5 species of annual medics (Medicago spp.), Trifolium subterraneum cv. Nungarin, and hedge mustard (Sisymbrium orientale) to a range of post-emergence broadleaf herbicides was tested over 2 years. The least damaging to M. truncatula was 2,4-DB, which provided more consistent and effective control of hedge mustard than the other chemicals tested, including the less expensive tank mix of 2,4-DB + diuron. MCPA amine or sodium salt (300 g a.i./ha), bromoxynil (420 g a.i./ha), and tank mixes containing MCPA amine (150-175 g a.i./ha) severely damaged annual medics, particularly M. truncatula, with flowering delayed by up to 21 days, and dry matter and seed yields often significantly (P<0.05) reduced. Seed yields of most test plants indicated a degree of recovery from herbicide damage assessed visually after 10 days. Hedge mustard was not always as severely damaged by MCPA amine as was M. truncatula. Nungarin subterranean clover and M. aculeata SAD 2356 were more tolerant than the M. truncatula cultivars of MCPA amine, MCPA sodium salt, MCPA tank mixes, and bromoxynil, and less tolerant of 2,4-DB. Medicago littoralis, M. polymorpha and M. laciniata were severely damaged by bromoxynil but were more tolerant of MCPA than M. truncatula.


1985 ◽  
Vol 25 (4) ◽  
pp. 893 ◽  
Author(s):  
MDA Bolland

Most of the sandy soils near Esperance, W.A., were cleared of native vegetation and sown to subterranean clover in the 1950s and 1960s. Over the past 20-30 years, pH values of the topsoil (1:5, soil: water) have decreased from 6.5-7.0 to 5.0-5.5. The application of 2 t/ha of agricultural lime increased the soil pH (1:5, 0.01 CaCl2) from 5.5 to 5.8, from 4.9 to 5.6, and from 5.1 to 5.5 at three sites that had been sown to subterranean clover for 10, 20 and 40 years respectively. However, lime had no effect on either dry matter production or seed yield of subterranean clover. Additions of calcium in a further experiment also did not affect the seed yield of subterranean clover. Irrespective of the lime treatments, the addition of nutrients (phosphorus, potassium, sulfur, copper, zinc, molybdenum, cobalt, manganese and boron) significantly (P<0.05) improved dry herbage yields by a factor of 1.3, 1.7 and 1.4 at the 10-, 20- and 40-year-old sites. However, the addition of nutrients did not affect seed yields of subterranean clover. In other experiments, the omission of sulfur, potassium and, for the deepest sandy site, phosphorus reduced dry herbage yields by between 10-30%. The omission of molybdenum from treatments of the 20- and 40-year-old pasture reduced herbage yields by 21 and 16% respectively. However, omission of molybdenum in the experiment sited on the 10-year-old pasture did not affect yields. Thus, as the acidification of the sandplain soils continues, molybdenum may become deficient and may limit herbage yields of subterranean clover.


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