Increased responsiveness of short oat cultivars to early sowing, nitrogen fertilizer and seed rate

1989 ◽  
Vol 40 (4) ◽  
pp. 729 ◽  
Author(s):  
WK Anderson ◽  
R McLean

Oat cultivars of tall (West), intermediate (Mortlock) and dwarf height (Echidna) were compared for their response to sowing time, nitrogen fertilizer and seed rate. Experiments were carried out in the 500-800 mm average annual rainfall zone in Western Australia at nine sites. Cultivars were compared in experiments involving different times (3) of sowing, levels (5) of applied nitrogen and rates (5) of seed and in another experiment including all combinations of two levels of sowing time, nitrogen and seed. The optimum sowing times for the three cultivars were similar, but the yield advantage for Echidna over West was 0.63 t ha-1 for late May sowing but only 0.25 t ha-1 for sowing in late July. Yield responses to applied nitrogen were dependent on soil nitrogen status, seasonal rainfall, sowing date, cultivar and seed-rate. On average, Echidna was more responsive (0.42 t ha-1) to the initial 30 kg ha-1 of nitrogen than Mortlock (0.23 t ha-1). The optimum seed rate (where an increase of 1 kg of seed increased yield by 10 kg ha-1) was 77, 67 and 61 kg ha-1 for Echidna, Mortlock and West corresponding to 225, 185 and 160 plants m-2. The largest yielding combination of cultivar, time of sowing, nitrogen and seed rates increased yields by from 1.32 to 3.23 t ha-1 (51-220%) compared to the control or low input treatment. Biomass at heading increased linearly to about 6.5 t ha-1 with rainfall up to 200 mm. Rainfall to heading in excess of 200 mm appeared to be inefficiently used for biomass production. Grain yields also increased linearly up to about 4 t ha-1 with increasing biomass at heading and up to 6 t ha-l with the correct choice of cultivar, time of sowing, nitrogen and seed rates.


1978 ◽  
Vol 90 (2) ◽  
pp. 341-343 ◽  
Author(s):  
G. S. Randhawa ◽  
T. S. Sahota ◽  
D. S. Bains ◽  
V. P. Mahajan

SummaryAn experiment to study the effect of sowing time (21 October, 5 November, 20 November, 5 December and 20 December), seed rate (5, 7·5 and 10 kg/ha) and application of nitrogen fertilizer (0, 20, 40 and 60 kg N/ha) was conducted at the Punjab Agricultural University, Ludhiana, on a loamy sand soil during the winter seasons of 1974–5 and 1975–6. The delay in sowing from 21 October to 20 December produced shorter plants with fewer spikes. The crop sown on 21 October using 7·5 or 10 kg seed/ha and supplied with 20 or 40 kg N/ha gave better yield than those of later sowings.



1974 ◽  
Vol 14 (67) ◽  
pp. 241 ◽  
Author(s):  
AC Taylor ◽  
RR Storrier ◽  
AR Gilmour

A four year study of the relations between wheat yields and various edaphic, cultural and climatic factors in the wheat belt of southern New South Wales indicated that seasonal rainfall was the major source of yield variation. A regression equation involving pre-sowing (January to April) and growing season (May to September) rain, soil nitrate nitrogen concentration (0-30 cm), average annual rainfall, sowing time and weed density proved to be the most useful function for predicting yield (R2 = 0.613). Equations relating expected grain yields to soil nitrate nitrogen concentrations were derived for a combination of average annual rainfall and pre-sowing and growing season rainfall conditions. These show that, under optimum rainfall conditions, soil nitrate levels would restrict yields on most farms, wherever nitrate concentrations in the surface 30 cm fell below 20 p.p.m.



Author(s):  
M.B. O'Connor ◽  
P.E.H. Gregg

On twenty-four sites throughout the country the effect of time and rate of applied nitrogen on "out-of-season" pasture production was studied over two seasons (1969-70 and 1970-71). Responses to spring-applied nitrogen wem more reliable than to autumn-applied. Spring responses varied from slight (2-7 kg DM/kg N) in the Waik& o, Bay of Plenty and parts of Canterbury to very good (10-20 kg DM/kg N) in Taranati, Dannevirke, southern Wairarapa, northern South Island, Westland and parts of Southland. When yield responses are considered as a substitute for hay, or other supplementary feedstuffs, payable results occur above about 7 kg DM/kg N. Factors such as time of application, soil type, pasture composition and amount of nitrogen in the soil affected the response to applied nitrogen.



1990 ◽  
Vol 30 (5) ◽  
pp. 607 ◽  
Author(s):  
WK Anderson ◽  
WR Smith

Average commercial wheat yields in the southern, high rainfall area of Western Australia have seldom exceeded 1.5 t/ha and wheat is not widely grown. However, the average annual rainfall and length of growing season (>400 mm and >6 months) are conducive to much larger yields. Thirteen factorial experiments with mid and long season cultivars (Aroona and Osprey), 2 levels of applied nitrogen (N) (40 and 80 kg N/ha), 2 seed rates (50 and 100 kg/ha) and with or without fungicide were conducted at 8 sites over 2 seasons. The experiment was done to investigate combinations of cultivar and agronomic practices suitable for increased wheat production in long season environments in Western Australia. Largest grain yields (>4 t/ha) were obtained where wheat followed a grass-free break crop, and the mid season cultivar was used with 80 kg N/ha and 100 kg/ha of seed. Increases due to cultivar and seed rate were more consistent than those due to N, and increases from application of fungicide were less consistent. It is suggested that the optimal wheat production 'package' will include sowing in May in rotation with a grass-free break crop, seed rate of about 100 kg/ha and, when all other factors are optimal, N rates of over 40 kg/ha. The greatest yield increases were associated with the sites where wheat followed a grass-free crop. Increases due to other factors were relatively smaller. Hectolitre weight and percentage of small grain (<2 mm) often reached levels that would have entailed downgrading in commercial deliveries. However, in the most productive crops where root and leaf diseases were minimal, these quality parameters were seldom deficient and grain protein contents exceeded 10% at yields of up to 4 t/ha.



Author(s):  
B.K. Cameron

THE PROPERTY to be discussed is a mixed sheep and cropping unit, situated ei ht a miles east of Ashburton and midway between the Ra aia and the Ashburton rivers. Average annual rainfall is 27 in., evenly spread, but there is very high summer evaporation and therefore frequent droughts. On average, the soil is below wilting point for 40 to 50 days each summer. Winters are cold with the soil temperature being below 48°F for about four months each year. The soil is a Lismore stony silt loam averaging 9 in. in depth over gravel.



1968 ◽  
Vol 70 (3) ◽  
pp. 405-410 ◽  
Author(s):  
I. T. Jones ◽  
J. D. Hayes

SUMMARYThe effects of low and high seed rates on height, culm and panicle morphology of four oat cultivars grown in field trials in two growing seasons were investigated. Significant differences were detected between cultivars in the number of extended culm internodes, panicle whorls initiated, total height, length of panicle and individual internodes. Differences in seed rate had no effect on the number of culm internodes, but high seed rate significantly reduced the whorl number in the panicle, total plant height, length of panicle and the three upper internodes. The fourth internode remained unaffected, but the lowermost internode showed a relative length increase at high seed rate. The interaction of cultivar x seed rate was significant for total height, and for the length of the central internodes, but the length of the panicle was similarly affected in all cultivars.Panicle conformation was markedly affected by seed rate; high population density caused a reduction in number of grain-bearing whorls, and reduced the number of spikelets and total grain weight per whorl, and 1000 grain weight particularly in the lowermost whorls. The percentage of husk in the grain was increased slightly at high seed rate. The effect of seed rate on culm and panicle morphology is discussed in relation to the development of stiffer-strawed oats.



2001 ◽  
Vol 172 (5) ◽  
pp. 523-531 ◽  
Author(s):  
Jean-Louis Rajot

Abstract To assess the mass budget of aeolian sediments transported by wind (erosion vs. deposition) at the scale of village land units (25 kmX25 km), measurements were carried out during 3 years (from 1996 to 1998) in a cultivated field and in a fallow area simultaneously. These were located in the Sahelian zone of Niger with an average annual rainfall of 560 mm. The vertical upward fluxes of particles &lt;20 mu m exported from the study area were estimated from the horizontal sediment fluxes measured using BSNE sand catchers. This mass of exported dust was compared with the vertical downward fluxes of particles of the same size range (&lt;20 mu m) measured using passive CAPYR collectors. Values of deposition recorded in the field and in the fallow were similar. In the field, wind erosion reached its maximum in May and June when the vegetation cover was minimal. In the fallow area, wind erosion was always very low in comparison with the field. It occurred during the strongest storms when the grass cover was minimal. Nevertheless, the net balance between deposition and erosion was highly positive in the fallow areas. These results have been extrapolated at the scale of the village land units based on the current land use. At this scale, the balance was positive for the arable land, indicating a net deposition of aeolian sediments of +0.36 t ha (super -1) yr (super -1) . However, the complete disappearance of fallow land would result in a balanced budget for the arable land.



2017 ◽  
Vol 68 (8) ◽  
pp. 781
Author(s):  
R. A. Culvenor ◽  
M. R. Norton ◽  
J. De Faveri

Perennial grasses have production and environmental benefits in areas of southern Australia typified by the mixed farming zone of southern New South Wales (NSW). The perennial grass phalaris (Phalaris aquatica L.) is widely used in southern Australia; however, it would find more use in the mixed farming zone if its persistence in marginal rainfall areas (450–500 mm average annual rainfall) were improved. We evaluated a range of germplasm (n = 29) including wild accessions, lines bred from these, and existing cultivars for persistence and production at three sites in a summer-dry area of southern NSW with 430–460-mm average annual rainfall. Two sites were used over 4 years and the third site over 5 years. Summer dormancy, maturity time and seedling growth were also assessed. Analysis of genotype × environment interaction employing factor analytic models and accounting for spatial and temporal correlations indicated that changes in persistence occurred mainly over time rather than between sites. Ranking changes occurred in the dry establishment phase of the experiment and during a severe final summer drought, with few changes occurring in the intervening high-rainfall years. Lines that survived the establishment phase best had vigorous seedlings and earlier maturity, whereas those surviving the final summer best were earlier maturing and higher in summer dormancy with high winter-growth activity. Some later maturing lines within the higher summer dormancy group were less persistent. Some accessions from North Africa were the most persistent; also, populations bred from these and other more persistent accessions generally persisted and produced better than cultivars used presently. However, present cultivars were capable of high yield in the higher rainfall years. We suggest that persistence of higher summer dormancy cultivars over very dry years could be improved by selecting for earlier maturity time.



Author(s):  
Abdul Wali Ahmed Al-Khulaidi ◽  
Abdul Habib Al-Qadasi ◽  
Othman Saad Saeed Al-Hawshabi

The study area is located on the South western mountains of Republic of Yemen, It is characterized by arid and semi-arid climate with high temperatures and low average annual rainfall. The aims of this study are to explore the natural plant species of one of the Important Plant areas of Arabian Peninsula and to evaluate the chance to be a protected area. 61 sample sites covering the whole ecological zones haven been conducted. 135 plant species are found, in which 3 plant species were endemic, 7 near endemic, 29 regional endemic. The study revealed also three vegetation communities with 7 vegetation associations (vegetation types). Vegetation dominated by Ficus cordata, F. sycomorus, Salvadora persica Tamarix aphylla and Ziziphus spina-christi were found on main wadis. Vegetation communities dominated by Acacia asak, Anisotes trisulcus, Jatropha variegate and Zygocarpum yemenense were found on rocky slopes and stony plateau.



2013 ◽  
pp. 01
Author(s):  
João Batista Pereira Cabral ◽  
Valter Antonio Becegato ◽  
Francismário Ferreira dos Santos

The erosivity index (EI30) and its spatialization were determined for the contribution basins of the Cachoeira Dourada hydroelectric system reservoir, located between the states of Goiás and Minas Gerais and limited by coordinates 640000-760000 m W and 7910000-7975000 m N. Average monthly and annual rainfall data corresponding to eight localities and to a 30-year period were treated. It was observed that in this period the average annual rainfall was 1441 mm, the highest and lowest indexes having occurred respectively in January and July (7.5 mm). EI30 varied from 7100 to 8500 MJ mm (ha h)-1. The most representative period was October to March, corresponding to 7880.3 MJ mm (ha h)-1and 94% of the average annual EI30. The average rainfall variation coefficient for all stations was 82.73%. There is an irregular rainfall distribution in the region and consequently a non-uniform spatialization of the erosivity indexes within the influence area of the reservoir. The highest rainfall values coincide with the period of soil preparation and development of annual-cycle plants, mainly soybean and corn.



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