Nitrogen response of pasture grasses on duplex soils formed from granite in southern Queensland

1975 ◽  
Vol 15 (75) ◽  
pp. 498 ◽  
Author(s):  
EF Henzell ◽  
DCI Peake ◽  
Mannetje L 't ◽  
GB Stirk

The response to fertilizer N of native pasture containing black spear grass (Heteropogon contortus) and of buffel grass (Cenchrus ciliaris cv. Biloela) was measured on granitic soils at the Narayen Research Station, in southern Queensland. Experiments were carried out in grazed and ungrazed areas. In 1968-69, which was as dry as any year on record for this district, neither pasture responded to N; in wetter years both did, the native pasture giving a lower yield than the sown buffel grass pasture. Grazed areas that received 168 kg N ha-1 year-1 as urea did not respond to further additions. Analysis of buffel grass yields over intervals of 8 to 16 weeks during the growing season indicated that 1. there was no growth or response to N unless the rainfall exceeded about 30 mm, 2. above 30 mm the response to near-optimum rates of N increased with rainfall, 3. buffel grass grown with such rates of N produced more than four times as much DM per unit rainfall as buffel grass without added N when 100 mm of rain fell. Examination of rainfall records suggested that there is a high probability of worthwhile responses to N on these soils at Narayen.Spear grass and other native grass plants were killed by high rates of N during the first, dry season. The results of a pot trial with Biloela buffel grass and a late flowering strain of spear grass showed that N increased drought damage in both grasses but spear grass was more susceptible than buffel grass.

1975 ◽  
Vol 15 (76) ◽  
pp. 645 ◽  
Author(s):  
DCI Peake ◽  
GD Stirk ◽  
EF Henzell

Leaf water potentials (�1) were measured on pasture plants at the Narayen Research Station in southern Queensland. The main findings were: 1. There were marked differences between species in the value of �1, measured during drought. Lucerne (Medicago sativa cv. Hunter River) and buffel grass (Cenchrus ciliaris cv. Biloela) usually showed a lower (i.e. more negative) �1 than Siratro (Macroptilium atropurpureum cv. Siratro), when they were grown together in a mixed pasture. Siratro seemed to possess a useful degree of drought avoidance. High drought resistance was observed in buffel grass; this was attributed to its tolerance of water stress. Green panic (Panicum maximum var. trichoglume cv. Petrie) was found to have as low a �1 as lucerne during drought when the two species were grown with Siratro in a mixed pasture. 2. The plants were under severe water stress before all the available water was removed from the deeper soil horizons. 3. �1 was lower in nitrogen-fertilized buffel grass or spear grass (Heteropogon contortus), than in the corresponding unfertilized controls. 4. The vapour-exchange and dye-marker densiometric methods gave different values for �1 in buffel grass, green panic and Siratro; the vapour exchange technique recorded lower, i.e, more negative figures than the other method when the plants were under severe water stress. The two methods gave similar values for lucerne. The relation between the values obtained for buffel grass by the two methods was affected by nitrogen fertilization. The reaction of sown pasture plants to drought at Narayen is discussed.


1992 ◽  
Vol 43 (2) ◽  
pp. 241 ◽  
Author(s):  
JJ Mott ◽  
MM Ludlow ◽  
JH Richards ◽  
AD Parsons

The close correlation between grazing-induced mortality and major climatic patterns in Australian savannas, led us to the hypothesis that moisture conditions during the dry, non-growing season could affect sensitivity to grazing in the subsequent growing season. Using three widespread savanna species (Themeda triandra, Heteropogon contortus and Panicum maximum), this hypothesis was tested experimentally and the mechanisms controlling this response examined and quantified. In T. triandra drought during the dry season led to major mortality in defoliated plants in the next growing season. This mortality was caused by a synchrony of tillering at the commencement of the wet season, leaving few buds for replacement once parent tillers were killed by defoliation. T. triandra was also the most sensitive species to defoliation. This sensitivity was due to the poor ability of the plant to maintain positive carbon gain after defoliation. Several factors contributed to this poor ability, including: low total photosynthetic rate, low specific leaf area, and a large proportion of sheath material with poor photosynthetic capacity remaining after cutting. Both H. contortus and P. maximum growing under irrigated and fertilized conditions did not display any effects of previous moisture treatments when defoliated during the next wet season and were much less sensitive to defoliation than T. triandra.


1980 ◽  
Vol 7 (2) ◽  
pp. 207 ◽  
Author(s):  
JR Wilson ◽  
MM Ludlow ◽  
MJ Fisher ◽  
E Schulze

Three tropical grasses, green panic (Panicum maximum var, trichoglume), spear grass (Heteropogon contortus) and buffel grass (Cenchrus ciliaris) and the tropical legume siratro (Macroptilium atropurpureum), were grown in plots in a semi-arid field environment. The water relations characteristics of leaves from plants subjected to a soil drying cycle were compared with those of unstressed leaves from plants in irrigated plots. Minimum water potentials attained in the stressed leaves were c. -44, - 38, - 33 and - 13 bar for the four species, respectively. The grass leaves adjusted osmotically to water stress, apparently through accumulation of solutes, so that there was a decrease in osmotic potential at full turgor (Ψπ100) of 5.5, 3.9 and 7.1 bar, and in water potential at zero turgor (Ψ0) of 8.6, 6.5 and 8.6 bar for green panic, spear grass and buffel respectively. Water stress appeared to increase slightly the proportion of bound water (B) and the bulk modulus of elasticity (ε) of the grass leaves, but it did not alter the relative water content at zero turgor (RWC0) or the ratio of turgid water content to dry weight of the tissue. The Ψπ100 and Ψ0 of stressed siratro leaves decreased by 2.5-4 bar and 3-5 bar respectively when subjected to soil drying cycles. These changes could be explained by the marked decrease in the ratio of turgid water content to dry weight of the leaf tissue rather than by accumulation of solutes. The values of RWC0 and ε for siratro leaves were not altered by stress but, in contrast to the grasses, B was apparently decreased although the data exhibited high variability. Adjustments in Ψπ100 and Ψ0 of stressed leaves of buffel grass and siratro were largely lost within 10 days of rewatering.


2020 ◽  
Vol 29 (2) ◽  
Author(s):  
Oiva Niemeläinen ◽  
Antti Hannukkala ◽  
Lauri Jauhiainen ◽  
Kaija Hakala ◽  
Markku Niskanen ◽  
...  

The official variety trials at Rovaniemi, Finland (66.58°N, 26.01°E) in 1980–2017 show a substantial increase in dry matter yields (DMY) of timothy (Phleum pratense), meadow fescue (Festuca pratensis) and tall fescue (Festuca arundinacea), coinciding with a 156 °Cd increase in the average growing season Tsum and a 461 °Cd decrease in the average winter frost sum for the same period. The annual DMY of timothy was 3128, 4668, 8385 and 9352 kg ha-1 in the periods (P) 1980–1989 (P1), 1990–1999 (P2), 2000–2009 (P3), and 2010–2017 (P4). The first cut yielded 1792, 2166, 4008 and 4473, and the second cut 1337, 2503, 4378 and 4879 kg ha-1, respectively. Yields of meadow fescue followed a similar pattern. The first cut was about ten days and the second cut about one week earlier on P4 than on P1. Shorter snow cover period, milder winters, higher live ground cover of timothy in spring, and higher temperature sum during the growing season were most likely responsible for the yield increase. The results indicate a strong impact of climate change on DMY of perennial forage crops in the north.


Author(s):  
M. Bakhmat ◽  
◽  
I. Sendetskyi ◽  

The results of researches of influence of ways of application of growth regulator "Vermiyodis" and sowing norms on productivity of winter rape of Cheremosh and hybrid Mercedes are covered. The study was performed during 2017-2020 on sod-podzolic soils of the experimental field of the Carpathian State Agricultural Research Station of the Institute of Agriculture of the Carpathian region of NAAS Taking into account the yield, it was found that the pre-sowing treatment of winter rapeseed Cheremosh with growth regulator "Vermiyodis" at a dose of 5 l / ha on average for 2017-2020 at sowing rates of 0.6 million / ha of similar seeds, the yield was 3.60 t / ha or 0.26 t / ha more than control, for sowing rates 0.8 million / ha of similar seeds - 3.92 t / ha or 0.21 t / ha more than control, for sowing rates 1.0 million / ha of similar seeds - 3.46 t / ha or 0.23 t / ha more than control. With a single spraying of winter oilseed rape plants during the growing season with the growth regulator "Vermiyodis" at a dose of 4 l / ha at sowing rates of 0.6 million / ha of similar seeds, the yield was 3.62 t / ha or 0.28 t / ha more control, with at the sowing rate of 0.8 million / ha of similar seeds, the yield was 3.94 t / ha or 0.33 t / ha more than the control, at the sowing rate of 1.0 million / ha of similar seeds, the yield was 3.48 t / ha or 0.25 t / ha more than control. In the variants where pre-sowing treatment of rapeseed seeds of winter hybrid Mercedes with growth regulator "Vermiyodis" at a dose of 5 l / t and during the growing season was carried out a single spraying of plants with growth regulator "Vermiyodis" at a dose of 4 l / ha at seeding rates of 0.6 million / ha similar seeds yield was 3.73 t / ha or 0.39 t / ha more than control, at sowing rates of 0.8 million / ha of similar seeds - 4.07 t / ha or 0.46 t / ha more than control, at sowing rates of 1.0 million / ha of similar seeds - 3.62 t / ha or 0.39 t / ha more than control. Double spraying of rapeseed plants of the winter hybrid Mercedes during the growing season of plants with the growth regulator "Vermiyodis" at a dose of 4 l / ha at sowing rates of 0.6 million / ha of similar seeds, the yield was 3.82 t / ha or 0.48 t / ha more control, for sowing rates of 0.8 million / ha of similar seeds - 4.15 t / ha or 0.54 t / ha more than control, for sowing rates of 1.0 million / ha of similar seeds - 3.68 t / ha or 0.45 t / ha more than control. In the variants where pre-sowing treatment of Cheremosh winter rape seeds with Vermiyodis growth regulator was carried out at a dose of 5 l / t and during the growing season, plants were sprayed with Vermiyodis growth regulator at a dose of 4 l / ha at sowing rates of 0.6 million / ha of similar seeds. yield was 3.91 t / ha or 0.57 t / ha more than control, for sowing rates of 0.8 million / ha of similar seeds - 4.24 t / ha or 0.63 t / ha more than control, for norms sowing 1.0 million / ha of similar seeds - 3.77 t / ha or 0.50 t / ha more than control.


2016 ◽  
Vol 16 (2) ◽  
pp. 113 ◽  
Author(s):  
I Made J. Mejaya ◽  
Ayda Krisnawati ◽  
Heru Kuswantoro

<p>Identification of Early Maturing and High Yielding Soybean Germplasm. Preference to early maturing soybeans is higher than the late ones, since early maturing soybean can improve planting index and able to escape from fail of harvest due to drought stress. To identify accessions of soybean germplasm which will be used as gene resources in developing of early maturing and high yielding varieties, a numbers of 203 soybean germplasm accessions were evaluated at Jambegede Research Station on dry season 2006. Observation primarily conducted on physiological maturity and flowering date. Beside, observation also conducted on plant height, number of branches, 100 seeds weight and seed yield. Result showed that accession of MLGG 0751 and MLGG 0753 identified having early maturity (70 days). The early maturing accessions had lower yield than the late maturing ones. There was no accession having both of early maturing and high yielding traits. Accessions of MLGG 0751 and MLGG 0753 can be used as gene resources in developing of early maturing varieties.</p><p> </p><p><strong>Abstrak</strong></p><p>Preferensi terhadap kedelai berumur genjah lebih tinggi daripada berumur dalam karena kedelai berumur genjah dapat meningkatkan indeks pertanaman dan dapat menghindari kegagalan panen akibat cekaman kekeringan. Untuk mengidentifikasi aksesi plasma nutfah yang akan digunakan sebagai sumber gen dalam perakitan varietas kedelai berumur genjah dan berdaya hasil tinggi, sebanyak 203 aksesi plasma nutfah kedelai dievaluasi di Kebun Percobaan Jambegede pada musim kemarau 2006. Pengamatan terutama dilakukan terhadap umur masak fisiologis dan umur berbunga. Pengamatan juga dilakukan terhadap tinggi tanaman, jumlah cabang, bobot 100 biji, dan hasil biji tanaman. Hasil penelitian menunjukkan bahwa aksesi MLGG 0751 dan MLGG 0753 teridentifikasi berumur genjah (70 hari). Aksesi berumur genjah memiliki hasil biji lebih rendah daripada aksesi berumur dalam. Tidak diperoleh aksesi kedelai berumur genjah yang sekaligus berdaya hasil tinggi. Aksesi MLGG 0751 dan MLGG 0753 dapat digunakan sebagai sumber gen dalam perakitan varietas kedelai berumur genjah.</p>


1978 ◽  
Vol 18 (95) ◽  
pp. 808 ◽  
Author(s):  
NH Shaw ◽  
MB Dale

The percentage frequency of all herbaceous species in a native pasture oversown with S. humilis (T.S.) was measured at the beginning and end of an eight-year grazing experiment. Treatments imposed were three levels of molybdenized superphosphate (nil; 125 kg ha-1 annually; 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) in factorial combination with four stocking rates and two sowing methods for T.S. (ground sowing into spaced cultivated strips or aerial sowing). Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beast ha-1. Treatments did not induce any major changes in the proportions of native species in the pasture. Heteropogon contortus remained dominant and its frequency increased in all treatments. Of the total of 113 species recorded, only 18 reached 10 per cent frequency in at least one paddock on one occasion. Several of these showed statistically significant changes in response to treatment, but their relative importance was not greatly changed. Examination of the results by principal co-ordinate and canonical analysis, showed that the first vectors of the two data sets were highly correlated, indicating that the major control on floristic composition was not changed by oversowing with T.S. or by the treatments imposed. Treatment effects dominated in the second and third vectors in the final year. The controlling vector was found to be highly correlated with soil calcium, potassium, total exchange capacity and organic carbon, but the basis for the correlations remains undetermined.


1957 ◽  
Vol 8 (4) ◽  
pp. 325 ◽  
Author(s):  
NH Shaw

The results are reported of a study of the effect of annual burning, in the absence of grazing, on the botanical composition of a native pasture in south-eastern Queensland. The main effect of burning was to give dominance of Heteropogon contortus (L.) Beauv. ex R. & S. This appeared to be due to three main causes: established plants were resistant to fire; fire favoured the germination of seed; and fire reduced the basal ground cover of other species. The effects on other species and on the proportion of bare ground are reported. The significance of the results in relation to the present distribution of H. contortus-dominant pastures is discussed.


1978 ◽  
Vol 18 (95) ◽  
pp. 788 ◽  
Author(s):  
NH Shaw

Changes in the yield, botanical composition and chemical composition of a native pasture (Heteropogon contortus dominant) oversown with S. humilis (T.S.) were measured in a grazing experiment from 1966 to 1973. The 24 treatments were factorial combinations of two sowing methods for T.S. (ground sowing into spaced cultivated strips, or aerial sowing), three levels of molybdenized superphosphate (F0 = nil ; F1 = 125 kg ha-1 annually; F2 = 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) and four stocking rates. Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beasts ha 1 T.S. establishment by ground sowing was much more reliable than from aerial sowing, giving twice the average percentage frequency, and this proportion was maintained over years. High fertilizer improved establishment and the best legume stands were in the high fertilizer high stocking rate treatments. Total presentation yield of pasture was increased by fertilizer and reduced by high stocking rates. Over the last two years the means for March, adjusted by regression to the overall average stocking rate of 0.98 beasts ha-1, were 31 20,4020 and 5370 kg ha-1 for F0, F1 and F2 respectively, but these yields were reduced by ca 25 per cent for an increase of 0.5 beasts ha-1. H. contortus remained dominant and its mean contribution to total yield increased from 48 per cent in 1969 to 67 per cent in 1973. This proportion was reduced by 12.8 per cent over the range from 0.55 to 1.65 beasts ha-1, but high fertilizer had the opposite effect so that differences between the extremes low stocked F0 and high stocked F2 were small. The DM percentage yield of T.S. was strongly increased by fertilizer, and, most importantly, also by high stocking rates in the presence of fertilizer. Values for F0 treatments remained below 10 per cent, but in the final year values for F1 and F2 at the highest stocking rates were 36 and 27 per cent, respectively. Despite these large changes in T.S., there was overall stability of botanical composition. Phosphorus and nitrogen concentrations in T.S. and H. contortus were increased by superphosphate but there was an overall decline in potassium concentration. Soil phosphorus levels were greatly increased


1997 ◽  
Vol 37 (7) ◽  
pp. 755 ◽  
Author(s):  
R. J. Jones

Summary. Pasture production and steer liveweight gain were compared on native pasture (Bothriochloa decipiens, Heteropogon contortus, Themeda triandra and Chrysopogon fallax) and on native pasture oversown with Indian couch or Indian bluegrass (Bothriochloa pertusa). This grass was not a planned introduction to the area but is spreading in Central and North Queensland and its value as a pasture species is questioned by graziers. There were 3 nominal stocking rates of 0.3, 0.6 and 0.9 steers/ha. Each paddock was stocked with 3 steers of stratified ages. The experiment was sown in March 1988 and terminated in June 1993. The experiment, sited 50 km south of Townsville in eucalypt woodland on a solodic-solodised-solonetz soil, was sown in March 1988 and terminated in June 1993. Increases in stocking rate resulted in a linear decline in both pasture yield (by 3–5 t/unit increase in stocking rate) and steer gains (by more than 100 kg/unit increase in stocking rate). Differences between pastures were apparent only at the medium and high stocking rates where, over time, Indian couch gave higher pasture yields and steer gains. Younger steers gained far more weight than older steers. Mean gains over 3 years were weaners 125 kg/year, yearlings 93 kg/year and 2-year-old steers 46 kg/year. Native pasture remained fairly stable botanically at the low stocking rate, but the tufted perennial grass species declined at both the medium and high stocking rates. Sowing Indian couch hastened the botanical changes due to stocking rate, and it became the dominant species at these higher stocking rates. At the low stocking rate, the contribution of Indian couch declined from initial values indicating that this is not an invasive species in the area at a low stocking rate. Contribution of Indian couch to pasture yield was linearly related to stocking rate. Nutritional quality of the Indian couch was similar to the other native perennial grasses though calcium concentration was higher. Increased steer gains were related to higher yield on Indian couch pastures at the higher stocking rates rather than to improved quality. Maximum liveweight gain/ha was achieved at about 0.6 steers/ha. Stocking at 0.9 steers/ha was not sustainable. Even at the low stocking rate, steers would need to spend about 2.8 years on the pastures after weaning to reach 500 kg liveweight. It was concluded that B. pertusa is a useful pasture grass in this environment giving steer gains equal to, or higher than, the gains from the native pasture which it replaced.


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