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Catalogue: Ground Cover
In terms of in-crop rainfall, recent seasons in many grain-growing areas have been little better than those experienced during the Millennium Drought... After a promising start, there was little follow-up rain in many districts the majority of growers still reported a satisfactory result... Growers who have been progressively improving their soil-moisture management, and becoming more comfortable with programs such as Yield Profit , had enough confidence even to top-dress with urea despite the lack of rain...
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Catalogue: GRDC Publications
Best Practice Guidelines Cotton Farming Systems.. Growers may achieve maximum profitability by applying additional spring-irrigations... The nitrogen requirement of an 8 t/ha wheat crop is approximately 275 kg N/ha studies in 2008 showed that many long-fallow paddocks that lodged had well in excess of this amount of nitrogen available (see Figure 9 (a))...
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Catalogue: GRDC Updates
Making best use of soil moisture.. John Passioura, CSIRO Plant Industry, Canberra ACT Take-home messages Prospects for getting crops that yield well during a drought in the sense of greatly exceeding the benchmark of 20 kg/ha/mm are very remote When diagnosing causes of low WUE it helps to dissect WUE into two components: the above-ground biomass/ha per mm of seasonal water supply, and the harvest index - the proportion of the biomass that is in the grain... The benchmark has three components embedded in it, namely: ?X the evaporative loss of available water from the soil ?X the ratio between the water used by the crop (transpiration) and the crop's above-ground biomass (called the transpiration efficiency) and ?X the proportion of the biomass that is converted into grain (the Harvest Index)...
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Catalogue: GRDC Updates
Table 1 shows that when planting between October and the 1 st of January, there is an 80% chance of receiving at least 107-126 mm of in-crop rainfall this calculation does not consider the impact of rainfall timing on crop demand... I have used 100 mm as an average loss figure for a summer crop in this region... Figure 4 supports the back of the envelope calculation suggesting the 180mm of starting water is the minimum required to achieve a 3t yield 6 to 8 years in 10...
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Catalogue: GRDC Updates
But I don't think it is that clear cut - most farmers in Australia would be pretty happy if they could achieve a 5t wheat crop, but if you belonged to the 10t club in Europe, and you only got enough rain for a 5t crop, you would claim you had suffered a pretty bad drought... The definition of drought is going to change dependent on your specific environment... By combining different parents of known good performance under drought, and then yield testing in the target environment we have been able to select varieties such as Gladius that perform exceptionally well under most drought conditions encountered by growers...
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Catalogue: GRDC Media
Staying green to avoid drought: How stay-green sorghum helps northern growers.. Stay green sorghum confers many advantages such as drought tolerance and resistance to water stress and lodging, while also boosting yields... During the conditions, the plants prioritise grain filling with the available water, leading to senescence in the leaves, weakening of the stem and lodging...
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Catalogue: Ground Cover
Sorghum is one of the most efficient crops for water usage, but tough northern-region summers and frequent dry spells restrict average yields to less than three tonnes per hectare... Thirty years ago, breeders discovered a variety of sorghum that remained green and produced good yield after dry summers, unlike the other sorghum plants that dried out and delivered low yields... The GRDC-funded research aims to produce, under experimental conditions, improved stay-green hybrids for northern region growers with yield increases of up to 30 per cent in drought conditions compared with normal varieties...
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Catalogue: GRDC Media
Staying green to avoid drought: How stay-green sorghum helps northern growers.. Stay green sorghum confers many advantages such as drought tolerance and resistance to water stress and lodging, while also boosting yields... During the conditions, the plants prioritise grain filling with the available water, leading to senescence in the leaves, weakening of the stem and lodging...
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Catalogue: Ground Cover
The distinction between continuous but insufficient supply of water from deep soil layers typical of the northern region, and a small-event dominated regime in the southern region is relevant for managing and identifying plant traits conducive to improved growth under limited water supply.. Rainfall has three key features: amount, seasonality and event size... Analysis of rainfall patterns between Horsham in Victoria and Emerald in central Queensland, using long-term rainfall records (1913-2003) and simulations, shows rainfall seasonality in eastern Australia can be the difference between starting the season with a wet or dry profile...
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Catalogue: GRDC Updates
Graph two is for a heavy clay Black Vertosol from Spring Ridge; results show the plant available water capacity (PAWC) is 272mm... Rooting depth should be determined through perusal of physical and chemical data and the physical observation of roots and water extraction through soil coring and/or electronic monitoring... Simulation of water storage using the >100 year climate record shows that a short fallow from wheat (assuming a dry soil profile at harvest in November of the previous year) results in a 50% chance of at least 110mm (range of 0-300mm) of water being available for an April planting at Spring Ridge and 80mm (range of 0-180mm) at Nyngan (Figure 8)...
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