Combining management and breeding advances to improve field pea (Pisum sativum L.) grain yields under changing climatic conditions in south-eastern Australia

The grain yield of field pea (Pisum sativum L.) between 1959-60 and 1991-92 was examined in selected Hundreds in important peagrowing regions of South Australia. Over the 33 years, the rates of increase in grain yield have been substantial, ranging from 20 to 48 kg/ha.year. The rate of increase in the State average for the same period was 22 kg/ha. year. The largest rates of increase have occurred mainly in the Hundreds in the higher rainfall areas. Yields have increased irregularly. During the 1960s grain yields rose relatively slowly, but from the mid 1970s to the mid 1980s, large increases occurred. Since then, yields have increased relatively little or, in some Hundreds, declined. With one exception, grain yield was positively and significantly correlated with seasonal (April-October) rainfall in each Hundred, but there were few significant correlations with rainfall in individual months. Yield was often correlated with winter and autumn rainfall but not with spring rainfall. The efficiencies of seasonal water use in the Hundreds ranged from 2.7 to 4.8 kg/ha.mm; these were lower than the maximum values recorded for other winter grain legumes, suggesting that water use efficiencies can improve substantially.

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Climatic conditions for seedling recruitment within perennial grass swards in south-eastern Australia

Crop and Pasture Science ◽

10.1071/cp12162 ◽

2012 ◽

Vol 63 (4) ◽

pp. 389 ◽

Cited By ~ 2

Author(s):

R. Thapa ◽

D. R. Kemp ◽

M. L. Mitchell

Keyword(s):

Soil Moisture ◽

New South ◽

Perennial Grass ◽

New South Wales ◽

Climatic Conditions ◽

South Eastern ◽

South Wales ◽

Eastern Australia ◽

Moisture Conditions ◽

South Eastern Australia

Recruitment of new perennial grass plants within existing grassland ecosystems is determined by seed availability, suitable microsites, nutrients and climatic conditions, water and temperatures. This paper reports on the development of criteria to predict recruitment events using modelled soil moisture conditions associated with recruitment of species in five field experiments at Orange (Phalaris aquatica), Trunkey Creek (Austrodanthonia spp.), and Wellington (Bothriochloa macra) in central New South Wales, Australia, and the frequency of those conditions during the past 30 years. Recruitment events were recorded when a rainfall event (median 68 mm across the three sites) kept the surface volumetric soil moisture (0–50 mm) above the permanent wilting point for at least 15 continuous days, allowing for, at most, two ‘dry days’ in between. A key finding from our study is that rainfall events creating favourable soil moisture conditions for seedling emergence typically occurred in the second half of February, sometimes extending to early March. Previously it was thought that recruitment would more likely occur through autumn, winter, and spring when rainfall in southern Australia is more reliable. The 30 years’ data (1975–2004) showed that the P. aquatica site had a median of 20 continuous moist days each year in February–March, whereas, there were 16 and 10 days for the Austrodanthonia and B. macra sites, respectively. The probabilities of exceeding seven or 15 continuous days of moist surface soil were 98% and 78% at the P. aquatica site, 91% and 49% at the Austrodanthonia site, and 73% and 30% at the B. macra site, and indicated that some recruitment is possible in most years. These analyses were extended to several sites across New South Wales, Victoria, and Tasmania to estimate the frequency with which recruitment could occur within natural swards. Across these sites, the probabilities of exceeding seven continuous days of soil moisture were >55% and of exceeding 15 continuous days were lower, which showed that suitable climatic conditions exist during late summer–early autumn across south-eastern Australia for a recruitment event to occur. Future research may show that the criteria developed in this paper could have wider regional application.

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Persistence and productivity of perennial ryegrass in sheep pastures in south-western Victoria: a review

Australian Journal of Experimental Agriculture ◽

10.1071/ea00049 ◽

2001 ◽

Vol 41 (1) ◽

pp. 117 ◽

Cited By ~ 33

Author(s):

R. A. Waller ◽

P. W. G. Sale

Keyword(s):

Perennial Ryegrass ◽

Seedling Recruitment ◽

Climatic Conditions ◽

Grazing Management ◽

Annual Rainfall ◽

Nitrogen And Phosphorus ◽

Dormant State ◽

South Eastern ◽

Eastern Australia ◽

South Eastern Australia

Loss of perennial ryegrass (Lolium perenne L.) from the pasture within several years of sowing is a common problem in the higher rainfall (550–750 mm annual rainfall), summer-dry regions of south-eastern Australia. This pasture grass came to Australia from northern Europe, where it mostly grows from spring to autumn under mild climatic conditions. In contrast, the summers are generally much drier and hotter in this region of south-eastern Australia. This ‘mismatch’ between genotype and environment may be the fundamental reason for the poor persistence. There is hope that the recently released cultivars, Fitzroy and Avalon, selected and developed from naturalised ryegrass pastures in south-eastern Australia for improved winter growth and persistence will improve the performance of perennial ryegrass in the region. Soon-to-be released cultivars, developed from Mediterranean germplasm, may also bridge the climatic gap between where perennial ryegrass originated and where it is grown in south-eastern Australia. Other factors that influence perennial ryegrass persistence and productivity can be managed to some extent by the landholder. Nutrient status of the soil is important since perennial ryegrass performance improves relative to many other pasture species with increasing nitrogen and phosphorus supply. It appears that high soil exchangeable aluminium levels are also reducing ryegrass performance in parts of the region. The use of lime may resolve problems with high aluminium levels. Weeds that compete with perennial ryegrass become prevalent where bare patches occur in the pasture; they have the opportunity to invade pastures at the opening rains each year. Maintaining some herbage cover over summer and autumn should reduce weed establishment. Diseases of ryegrass are best managed by using resistant cultivars. Insect pests may be best managed by understanding and monitoring their biology to ensure timely application of pesticides and by manipulating herbage mass to alter feed sources and habitat. Grazing management has potential to improve perennial ryegrass performance as frequency and intensity of defoliation affect dry matter production and have been linked to ryegrass persistence, particularly under moisture deficit and high temperature stress. There is some disagreement as to the merit of rotational stocking with sheep, since the results of grazing experiments vary markedly depending on the rotational strategy used, climate, timing of the opening rains, stock class and supplementary feeding policy. We conclude that flexibility of grazing management strategies is important. These strategies should be able to be varied during the year depending on climatic conditions, herbage mass, and plant physiology and stock requirements. Two grazing strategies that show potential are a short rest from grazing the pasture at the opening rains until the pasture has gained some leaf area, in years when the opening rains are late. The second strategy is to allow ryegrass to flower late in the season, preventing new vegetative growth, and perhaps allowing for tiller buds to be preserved in a dormant state over the summer. An extension of this strategy would be to delay grazing until after the ryegrass seed heads have matured and seed has shed from the inflorescences. This has the potential to increase ryegrass density in the following growing season from seedling recruitment. A number of research opportunities have been identified from this review for improving ryegrass persistence. One area would be to investigate the potential for using grazing management to allow late development of ryegrass seed heads to preserve tiller buds in a dormant state over the summer. Another option is to investigate the potential, and subsequently develop grazing procedures, to allow seed maturation and recruitment of ryegrass seedlings after the autumn rains.

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Slope Deposits in the Snowy Mountains, South-Eastern Australia

Quaternary Research ◽

10.1016/0033-5894(71)90043-3 ◽

1971 ◽

Vol 1 (2) ◽

pp. 228-235 ◽

Cited By ~ 19

Author(s):

A. B. Costin ◽

H. A. Polach

Keyword(s):

Climatic Conditions ◽

Slope Instability ◽

Cold Period ◽

Mean Annual Temperature ◽

South Eastern ◽

Eastern Australia ◽

Catchment Areas ◽

Slope Deposits ◽

Carbonized Wood ◽

South Eastern Australia

Slope deposits in the Snowy Mountains of south-eastern Australia have a wide distribution above 1000 m elevation on slopes between approximately 5° and 25° which are well stabilized by the existing forest vegetation. The present environment is not severe enough to initiate slope instability.The slope deposits consist of fines with gravel and angular stones showing preferred downslope orientation, overlying a generally smooth substrate of weathered bedrock. Pockets and lenses of relatively stone-free organomineral soil containing fragments of carbonized wood sometimes occur near the interface between the slope deposits and the weathered bedrock. Fragments of the carbonized wood carefully selected from three sites in different catchment areas several kilometers apart have similar radiometric ages of between 31,000 and 34,000 years.The properties of the slope deposits and the context of the site and climatic conditions in which they now occur point to an origin under periglacial conditions commencing 31,000–34,000 years ago, associated with deep seasonal freezing and thawing although not necessarily with permafrost. It is estimated that a substantially lower mean annual temperature, at least 8–10°C less than the present, would have been necessary to produce periglacial conditions down to 1000 m in the Snowy Mountains. On the evidence of similar slope deposits elsewhere in south-eastern Australia, this major cold period was evidently widespread.Climatic conditions prior to the onset of the cold period appear to have been generally similar to those of today, except perhaps for rather moister and cooler summers.

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Fertilisation phosphatée et potassique dans la culture du pois sec

Canadian Journal of Plant Science ◽

10.4141/cjps09152 ◽

2010 ◽

Vol 90 (5) ◽

pp. 629-636 ◽

Cited By ~ 1

Author(s):

J. Lafond ◽

D. Pageau

Keyword(s):

Pisum Sativum ◽

Soil Analysis ◽

Climatic Conditions ◽

Mineral Fertilizers ◽

Western Canada ◽

P Availability ◽

Grain Yields ◽

Soil P ◽

Pisum Sativum L ◽

Medium Level

In Quebec, the P recommendations for dry peas (Pisum sativum L.) are nearly three times higher than those in western Canada, while recommendations for K are at least 20% lower. The objective of this project was to re-evaluate the P and K needs of dry peas under the climatic conditions of the Saguenay-Lac-Saint-Jean region (Quebec, Canada) in soils with a range of soil P and K availabilities. The treatments consisted of four P rates (0, 20, 40, 80 and 160 kg P2O5 ha–1) and three K rates (0, 50 and 150 kg K2O ha–1). The trials were conducted at two sites over 3 yr. Site 1 was classified as low in P availability and site 2 as medium according to the soil analysis. Both sites had a medium level of soil K availability. Grain yields increased significantly, by 6%, with increasing fertilizer P (3246 to 3437 kg ha–1). Potassium fertilization had no significant effect on grain yields. Grain yields were also 37% higher in the highest soil P site. This low response of the crop to mineral fertilizers was attributed to the significant soil contribution to crop P and K needs. Soil tests have also indicated an enrichment of P and K with large inputs of mineral fertilizers. Thus, a rate of 30-35 kg P2O5 ha–1 for P poor soils would be sufficient to meet the crop needs. For soils with moderate levels of K (201-400 kg K ha–1), a rate of 50 kg K2O ha–1 would be sufficient to meet the crop needs and to maintain the soil fertility. Key words: Enrichment, efficiency, phosphorus, potassium, Pisum sativum L.

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