scholarly journals Modelling the effects of row configuration on sorghum yield reliability in north-eastern Australia

2005 ◽  
Vol 56 (1) ◽  
pp. 11 ◽  
Author(s):  
Jeremy Whish ◽  
Giles Butler ◽  
Michael Castor ◽  
Shayne Cawthray ◽  
Ian Broad ◽  
...  

In recent years, many sorghum producers in the more marginal (<600 mm annual rainfall) cropping areas of Queensland and northern New South Wales have used skip row configurations in an attempt to improve yield reliability and reduce sorghum production risk. This paper describes modifications made to the APSIM sorghum module to account for the difference in water usage and light interception between alternative crop planting configurations, and then demonstrates how this new model can be used to quantify the long-term benefits of skip sorghum production. Detailed measurements of light interception and water extraction from sorghum crops grown in solid, single and double skip row configurations were collected from on-farm experiments in southern Qld and northern NSW. These measurements underpinned changes to the APSIM-Sorghum model so that it accounted for the elliptical water uptake pattern below the crop row and the reduced total light interception associated with skip row configurations. Long-term simulation runs using long-term weather files for locations near the experimental sites were used to determine the value of skip row sorghum production as a means of maintaining yield reliability. These simulations showed a trade-off between long-term average production (profitability) and annual yield reliability (risk of failure this year). Over the long term, the production of sorghum in a solid configuration produced a higher average yield compared with sorghum produced in a skip configuration. This difference in average yield is a result of the solid configuration having a higher yield potential compared with the skip configurations. Skip configurations limit the yield potential as a safeguard against crop failure. To achieve the higher average yield in the solid configuration the producer suffers some total failures. Skip configurations reduce the chance of total failure by capping the yield potential, which in turn reduces the long-term average yield. The decision on what row configuration to use should be made tactically and requires consideration of the starting soil water, the soil’s plant-available water capacity (PAWC), and the farm family’s current attitude to risk.

2016 ◽  
Vol 67 (9) ◽  
pp. 921 ◽  
Author(s):  
Michael Robertson ◽  
John Kirkegaard ◽  
Allan Peake ◽  
Zoe Creelman ◽  
Lindsay Bell ◽  
...  

The high-rainfall zone (HRZ) of southern Australia is the arable areas where annual rainfall is between 450 and 800 mm in Western Australia and between 500 and 900 mm in south-eastern Australia, resulting in a growing-season length of 7–10 months. In the last decade, there has been a growing recognition of the potential to increase crop production in the HRZ. We combined (1) a survey of 15 agricultural consultants, each of whom have ~40–50 farmer clients across the HRZ, (2) 28 farm records of crop yields and area for 2000–2010, (3) 86 wheat and 54 canola yield observations from well managed experiments, and (4) long-term simulated crop yields at 13 HRZ locations, to investigate recent trends in crop production, quantify the gap between potential and actual crop yields, and consider the factors thought to limit on-farm crop yields in the HRZ. We found in the past 10 years a trend towards more cropping, particularly in WA, an increased use of canola, and advances in the adaptation of germplasm to HRZ environments using winter and longer-season spring types. Consultants and the farm survey data confirmed that the rate of future expansion of cropping in the HRZ will slow, especially when compared with the rapid changes seen in the 1990s. In Victoria, New South Wales and South Australia the long-term water-limited potential yield in HRZ areas, as measured by experimental yields, consultant estimates and simulations for slow developing spring cultivars of wheat and canola was 5–6 and 2–3 t/ha for a decile 5 season. For Western Australia it was 4–5 and 2–3 t/ha, where yields were less responsive to good seasons than in the other states. The top performing farmers were achieving close to the water-limited potential yield. There are yield advantages of ~2 t/ha for ‘winter’ over ‘spring’ types of both wheat and canola, and there is scope for better adapted germplasm to further raise potential yield in the HRZ. Consultants stated that there is scope for large gains in yield and productivity by encouraging the below-average cropping farmers to adopt the practices and behaviours of the above-average farmers. The scope for improvement between the below- and above-average farmers was 1–3 t/ha for wheat and 0.5–1.5 t/ha for canola in a decile 5 season. They also stated that a lack of up-to-date infrastructure (e.g. farm grain storage) and services is constraining the industry’s ability to adopt new technology. Priorities for future research, development and extension among consultants included: overcoming yield constraints where growing-season rainfall exceeds 350 mm; adaptation of winter and long-season spring types of cereals and canola and management of inputs required to express their superior yield potential; and overcoming barriers to improved planning and timeliness for crop operations and adoption of technology.


Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 435 ◽  
Author(s):  
R. C. Dalal ◽  
K. Y. Chan

The Australian cereal belt stretches as an arc from north-eastern Australia to south-western Australia (24˚S–40˚S and 125˚E–147˚E), with mean annual temperatures from 14˚C (temperate) to 26˚C (subtropical), and with annual rainfall ranging from 250 mm to 1500 mm. The predominant soil types of the cereal belt include Chromosols, Kandosols, Sodosols, and Vertosols, with significant areas of Ferrosols, Kurosols, Podosols, and Dermosols, covering approximately 20 Mha of arable cropping and 21 Mha of ley pastures. Cultivation and cropping has led to a substantial loss of soil organic matter (SOM) from the Australian cereal belt; the long-term SOM loss often exceeds 60% from the top 0–0.1 m depth after 50 years of cereal cropping. Loss of labile components of SOM such as sand-size or particulate SOM, microbial biomass, and mineralisable nitrogen has been even higher, thus resulting in greater loss in soil productivity than that assessed from the loss of total SOM alone. Since SOM is heterogeneous in nature, the significance and functions of its various components are ambiguous. It is essential that the relationship between levels of total SOM or its identif iable components and the most affected soil properties be established and then quantif ied before the concentrations or amounts of SOM and/or its components can be used as a performance indicator. There is also a need for experimentally verifiable soil organic C pools in modelling the dynamics and management of SOM. Furthermore, the interaction of environmental pollutants added to soil, soil microbial biodiversity, and SOM is poorly understood and therefore requires further study. Biophysically appropriate and cost-effective management practices for cereal cropping lands are required for restoring and maintaining organic matter for sustainable agriculture and restoration of degraded lands. The additional benefit of SOM restoration will be an increase in the long-term greenhouse C sink, which has the potentialto reduce greenhouse emissions by about 50 Mt CO2 equivalents/year over a 20-year period, although current improved agricultural practices can only sequester an estimated 23% of the potential soil C sink.


2008 ◽  
Vol 59 (3) ◽  
pp. 247 ◽  
Author(s):  
David W. Lester ◽  
Colin J. Birch ◽  
Chris W. Dowling

Nitrogen (N) and phosphorus (P) are the 2 most limiting nutrients for grain production within the northern grains region of Australia. The response to fertiliser N and P inputs is influenced partly by the age of cultivation for cropping, following a land use change from native pasture. There are few studies that have assessed the effects of both N and P fertiliser inputs on grain yield and soil fertility in the long term on soils with contrasting ages of cultivation with fertility levels that are running down v. those already at the new equilibrium. Two long-term N × P experiments were established in the northern grains region: one in 1985 on an old (>40 years) cultivation soil on the Darling Downs, Qld; the second in 1996 on relatively new (10 years) cultivation on the north-west plains of NSW. Both experiments consisted of fertiliser N rates from nil to 120 kg N/ha.crop in factorial combination with fertiliser P from nil to 20 kg P/ha.crop. Opportunity cropping is practiced at both sites, with winter and summer cereals and legumes sown. On the old cultivation soil, fertiliser N responses were large and consistent for short-fallow crops, while long fallowing reduced the size and frequency of N response. Short-fallow sorghum in particular has responded up to the highest rate of fertiliser N (120 kg N/ha.crop). Average yield increase with fertiliser N compared with nil for 5 short-fallow sorghum crops was 1440, 2650, and 3010 kg/ha for the 40, 80, and 120 kg N/ha, respectively. Average agronomic efficiency of N for these crops was 36, 33, and 25 kg grain/kg fertiliser N applied. This contrasts with relatively new cultivation soil, where fertiliser N response was generally limited to the first 30 kg N/ha applied during periods of high cropping intensity. Response to P input was consistent for crop species, VAM sensitivity, and starting soil test P level. At both the old and new cultivation sites, generally all winter cereals responded to a 10 kg P/ha application, and more than half of long-fallow sorghum crops from both sites had increased grain yield with P application. At the old cultivation site, average yield gain for 10 kg P/ha.crop treatment was 480 kg/ha for all winter cereal sowings, and 180 kg/ha for long-fallow sorghum. Short-fallow sorghum did not show yield response to P treatment.


2015 ◽  
Vol 47 (1) ◽  
pp. 171-184 ◽  
Author(s):  
Charles Onyutha

Variability analyses for the rainfall over the Nile Basin have been confined mostly to sub-basins and the annual mean of the hydroclimatic variable based on observed short-term data from a few meteorological stations. In this paper, long-term country-wide rainfall over the period 1901–2011 was used to assess variability in the seasonal and annual rainfall volumes in all the River Nile countries in Africa. Temporal variability was determined through temporal aggregation of series rescaled nonparametrically in terms of the difference between the exceedance and non-exceedance counts of data points such that the long-term average (taken as the reference) was zero. The co-occurrence of the variability of rainfall with those of the large-scale ocean–atmosphere interactions was analyzed. Between 2000 and 2012, while the rainfall in the equatorial region was increasing, that for the countries in the northern part of the River Nile was below the reference. Generally, the variability in the rainfall of the countries in the equatorial (northern) part of the River Nile was found to be significantly linked to occurrences in the Indian and Atlantic (Pacific and Atlantic) Oceans. Significant linkages to Niño 4 regarding the variability of both the seasonal and annual rainfall of some countries were also evident.


2011 ◽  
Vol 48 (No. 4) ◽  
pp. 159-166
Author(s):  
M. Kopeć

The fertilising experiment was set up in 1968 on the mountain meadow (720 m a.s.l.) in Czarny Potok near Krynica (20&deg;8&rsquo; E, 49&deg;4&rsquo; N). The experiment was conducted on the acid Cambi soil and comprised objects fertilised with two nitrogen forms and two doses against the background of PK fertilisation, the untreated object, and plots with unilateral P and N fertilisation. The paper concerns 30 years of investigations (1968&ndash;1997) of the effect of different NPK fertilisation on the dynamic of yields and the meadow sward quality against a&nbsp;background of the same treatments. The dynamic of the botanical composition was presented as well as the dynamic of the grassland yield potential with systematic mineral fertilisation and liming. The application of nitrogen fertilisation with the rate of 90 N.ha<sup>&ndash;1</sup> + PK under mountain conditions and systematic liming of the meadow enables to maintain or increase production over the long period, to decrease the production risk and to prevent degradation of the environment and natural resources.


MAUSAM ◽  
2021 ◽  
Vol 65 (1) ◽  
pp. 67-72
Author(s):  
PRAGYAN KUMARI ◽  
RAJAN KUMAROJHA ◽  
AWADOOD WADOOD ◽  
RAMESH KUMAR

Daily rainfall data of 56 years (1956-2011) of Palamau district of Jharkhand have been considered to analyse the long term average and its temporal variability on weekly, monthly, seasonal and annual basis. The average annual rainfall at Palamau was 1138 mm with 34 per cent coefficient of variation indicating thereby that the rainfall was not much stable over the years. July was the highest rainfall recipient month (332 mm) followed by August (310 mm) during the monsoon period. Trend analysis on rainfall of past 56 years exhibited a decreasing pattern of 8.33 mm and 7.04 mm per year in annual and kharif season rainfall, respectively. Agricultural drought was most frequently observed in early (23-26 SMW) as well as late (37-40 SMW) stages of kharif crops. Meteorological droughts of different intensities, viz., mild, moderate and severe over the observed periods showed that station is prone to mild-moderate type of drought. Short duration, low water requiring but high value crops like maize, pulses, oilseeds and some vegetables can be opted for this region to minimize the production risk.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2354
Author(s):  
Viliam Bárek ◽  
Martina Kováčová ◽  
Vladimír Kišš ◽  
Oleg Paulen

Changes in the distribution of annual rainfall totals, together with the increase in temperature over the last 40 years, are causing more frequent periods of drought, and plants are more often exposed to water stress. The aim of this study was to monitor the effect of different water regimes (irrigated and non-irrigated) of individuals of walnut tree (Juglans regia L.) in a private orchard located in the West of Slovakia. Our research was focused on dendrometric and sap flow measurements in the period from 28 March to 2 June 2019. The results showed differences in the sap flow of walnut trees during the budbreak period: when trees were irrigated, sap flow in the diurnal cycle was around 130 g·h−1 (20.48%), higher than in the non-irrigated treatment. Dendrometric differences between the irrigated and non-irrigated treatments were not significant. The sap flow data in the flowering period of the irrigated variant were slightly higher at 150 g·h−1 (35.62%) than non-irrigated. Dendrometric differences were more significant when the difference between the variants was more than 1.5 mm. Continuation of this research and analysis of the data obtained in the coming years will allow us to evaluate the effects of the environment on fruit trees in the long term.


1987 ◽  
Vol 23 (3) ◽  
pp. 349-356
Author(s):  
M. J. Jones

SUMMARYRegional population recommendations for sorghum production in Botswana were calculated by applying long-term meteorological records to an experimentally developed model linking sorghum yield to plant population and rainfall. The basic recommendation at any place was taken to be that population maximizing local long-term yield means while keeping the risk of crop failure to one year in ten or less. Values ranged from 25 000 to nearly 70 000 plants ha−1, according to rainfall amount and reliability. The modifications of these basic recommendations necessary to allow for differences in standards of husbandry and for sorghum variety are discussed.


2003 ◽  
Vol 43 (10) ◽  
pp. 1211 ◽  
Author(s):  
S. G. Clark ◽  
E. A. Austen ◽  
T. Prance ◽  
P. D. Ball

Climate variability is a major constraint to farming in south-eastern Australia and one that is out of the farmers' control. However, a better understanding of long-term climate variability would be beneficial for on-farm management decisions. A series of long-term simulations were undertaken with the GrassGro decision support tool to determine the effect of climate variability on pasture and animal production at 6 locations in south-eastern Australia. The simulations ran from 89 to 119 years using daily weather records from each location. All simulations were for spring-lambing flocks of medium sized Merino ewes stocked at above-average district stocking rates, grazing well-fertilised, perennial grass–subterranean clover pastures. Annual rainfall total and, in particular, the distribution of rainfall during the year, were found to be more important than other weather variables in determining the amount of pasture grown in a year. The timing of the season opening rains (autumn break) was most important. The localities varied in their responses to climate variability, particularly in the timing of the autumn break; the pasture growth response to winter rainfall; and the relationship between rainfall and animal production.


2021 ◽  
Vol 23 (4) ◽  
pp. 367-374
Author(s):  
CAI CHENG-ZHI ◽  
LIAO CONG-JIAN ◽  
XIAO DAN ◽  
ZENG XIAO-SHAN ◽  
ZUO JIN

The crop yield potential of world soybean from 2019 to 2028 has been projected using ARIMA model based on the yields from 1961 to 2018. Both annual global mean temperature and the yields of world soybean have been projected to rise during the ensuing decade 2019-2028. Projected average yields of world soybean varies from 2841 to 3276 kg ha-1 while 4324 to 4807 kg ha-1 in the case of top (national) yields of world soybean. Annual global mean temperatures may vary from 15.0 to 15.3oC and likely to exert positive impact on average yield (R squared = 0.80) while negative on top yield (R squared = 0.40) of world soybean. It may be concluded that for world soybean yields in 2019 to 2028, the opportunities for improving production should be dependent on both high and low-yielding countries as the yield remained between 30 and 70 per cent of potential limit i.e. in middle place around the turn-point of S-shaped curve in long-term trend partly affected by global warming.


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