Windbreak research in a South Australian cropping system

2002 ◽  
Vol 42 (6) ◽  
pp. 781 ◽  
Author(s):  
I. K. Nuberg ◽  
S. J. Mylius ◽  
J. M. Edwards ◽  
C. Davey

This paper presents the results of 3 years (1994–96) work on the effect of shelter created by a 9 m high Aleppo pine (Pinus halepensis) windbreak in the Mediterranean environment of South Australia on the productivity of wheat, canola, faba beans and oats. Elements of the classic windbreak signature could be detected in the yield responses of 6 of 8 crop years. For example, in the dry year of 1994, yields in the sheltered zone (3–6 H) were 44, 49 and 81% greater than in the exposed zone (18–24 H) for wheat, faba beans and canola, respectively. In 1995, a wet year, only faba beans showed a response (18% increase). In 1996, oats showed an apparent 25% yield increase in the sheltered zone compared with the unsheltered zone. However, these yield differences were not due to shelter alone. For example, covariate analysis of 1995 wheat and bean yield data with soil texture indicated that yield variation across the paddock could be explained by variation in depth to calcareous clay loam. Cumulative water use of wheat was greater in the 3–12 H zone in 1994 (dry year) but less in 1995 (wet year); however, these differences are likely to be also due to soil variation in the 2 plots used. Nevertheless, the windbreak effectively altered the microclimate. Cumulative temperature was measured at 4 distances on the leeward side of the windbreak and used to predict the time taken for wheat to reach anthesis at each location. The correlation between normalised values of observed and predicted times to anthesis was found for 3 wheat crops with different times of sowing in 1995 (r2 = 0.62). It was concluded that (i) shelter will affect the physiology of crops grown in this environment, (ii)�the shelter effect on enhancing crop yield is relatively subtle compared with other sources of yield variation and (iii)�the evidence for a water-saving mechanism in enhancing crop yield is inconclusive.

1981 ◽  
Vol 21 (112) ◽  
pp. 516 ◽  
Author(s):  
AD Rovira ◽  
PG Brisbane ◽  
A Simon ◽  
DG Whitehead ◽  
RL Correll

Significant yield responses of up to 0.9 t/ha were obtained with the nematicides aldicarb and dibromochloropropane in seven of eleven field trials with the wheat variety, Condor. Both nematicides reduced the numbers of white cysts of Heterodera avenae on the roots of wheat. With aldicarb the increase in wheat yields varied directly as the decrease in white cysts: dibromochloropropane gave similar increases in yield as aldicarb with a greater reduction in cyst numbers. There was no yield increase with either nematicide when cereal cyst nematode was not present. An analysis of covariance indicated that over all the sites 64% of the increase in yield due to aldicarb could be explained in terms of cysts of cereal cyst nematode.


2008 ◽  
Vol 59 (10) ◽  
pp. 950 ◽  
Author(s):  
M. R. Bennell ◽  
A. P. Verbyla

Integrating belts of woody perennials into Australian farms is proposed as a method of enhancing crop productivity through shelter benefits while addressing natural resource management issues including groundwater recharge. This paper presents yield data from cereal and pulse crops collected from windbreak sites through the eastern agricultural districts of South Australia, using a harvester equipped with a yield monitor. The crop response followed the expected pattern of a competition zone of reduced yield of 1–4 tree heights (H) adjacent to the windbreak followed by a shelter benefit zone of unchanged or improved yield extending out to a maximum of 20H. The yield response in the sheltered benefit zone is +3.7% for all cereals (2.2H–9.7H) and is +14.0% for all pulse crops (1.7H–10.4H). Wheat and barley have similar results, with gains in the shelter benefit zones of 4.1% and 2.1%, respectively, with windbreak competition effects resulting in net yields of 3.0% for wheat and –1.1% for barley in the sheltered zones. Faba bean (Vicia faba) shows a strong consistent response to wind shelter, with a yield increase of 19.6% in the shelter benefit zone (1.5H–19.6H) and net gain of 19.1% in the sheltered zone (crop edge at 1.0H and extending to 19.6H). The response of cereals to sheltered effects varied across the years of the survey, with net positive results in 1997 (7.4%) and 1999 (7.5%) and close to zero in 1998 and 2000. A theoretical prediction of potential crop yield based on climate for the years of the survey showed that 1997 and 1999 had lower yield potential than 2000 and 1998. This suggests that the climatic conditions occurring during the growing season also influence crop shelter responses. Where cereals are the predominant crop the net yield returns from windbreaks would be small, even if root pruning could be successfully undertaken.


1970 ◽  
Vol 18 (2) ◽  
pp. 125-131
Author(s):  
L. Sibma

Statistical treatment of yield data from potatoes, sugar-beet, peas, wheat, barley, flax and maize grown in short- and long-term experiments where water and mineral supplies were optimum showed that variations in yields, especially those of potatoes, were positively correlated with the total global radiation received during the growing period. Partial correlation coefficients showed that the length of the growing period and the annual yield increase might explain much of the yield variation.-G.M.H. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2021 ◽  
Vol 13 (4) ◽  
pp. 2362
Author(s):  
Thomas M. Koutsos ◽  
Georgios C. Menexes ◽  
Andreas P. Mamolos

Agricultural fields have natural within-field soil variations that can be extensive, are usually contiguous, and are not always traceable. As a result, in many cases, site-specific attention is required to adjust inputs and optimize crop performance. Researchers, such as agronomists, agricultural engineers, or economists and other scientists, have shown increased interest in performing yield monitor data analysis to improve farmers’ decision-making concerning the better management of the agronomic inputs in the fields, while following a much more sustainable approach. In this case, spatial analysis of crop yield data with the form of spatial autocorrelation analysis can be used as a practical sustainable approach to locate statistically significant low-production areas. The resulted insights can be used as prescription maps on the tractors to reduce overall inputs and farming costs. This aim of this work is to present the benefits of conducting spatial analysis of yield crop data as a sustainable approach. Current work proves that the implementation of this process is costless, easy to perform and provides a better understanding of the current agronomic needs for better decision-making within a short time, adopting a sustainable approach.


1996 ◽  
Vol 36 (5) ◽  
pp. 555
Author(s):  
ID Black ◽  
CB Dyson ◽  
AR Fischle

In 11 experiments over 6 seasons the herbicide sethoxydim was applied to Machete, Spear and Blade wheat cultivars in the absence or near absence of weeds (10 sites) or where the weeds were controlled by selective herbicides (1 site), in the cropping area north of Adelaide, South Australia. The rates applied included 9-47 g a.i./ha at the 2-3 leaf growth stage and 9-74 g a.i./ha at early tillering. Except for the very long growing season of 1992, there was a highly significant positive linear correlation between the number of degree days in the growing season at each experimental site and relative mean yield increase of these sethoxydim treatments. Yield increases ranged from nil in growing seasons of about 1000 degree days to 32% in a growing season of 1480 degree days, with a median of 8% over the experiments.


Bragantia ◽  
2010 ◽  
Vol 69 (suppl) ◽  
pp. 9-18 ◽  
Author(s):  
Osvaldo Guedes Filho ◽  
Sidney Rosa Vieira ◽  
Marcio Koiti Chiba ◽  
Célia Regina Grego

It is known, for a long time, that crop yields are not uniform at the field. In some places, it is possible to distinguish sites with both low and high yields even within the same area. This work aimed to evaluate the spatial and temporal variability of some crop yields and to identify potential zones for site specific management in an area under no-tillage system for 23 years. Data were analyzed from a 3.42 ha long term experimental area at the Centro Experimental Central of the Instituto Agronômico, located in Campinas, Sao Paulo State, Brazil. The crop yield data evaluated included the following crops: soybean, maize, lablab and triticale, and all of them were cultivated since 1985 and sampled at a regular grid of 302 points. Data were normalized and analyzed using descriptive statistics and geostatistical tools in order to demonstrate and describe the structure of the spatial variability. All crop yields showed high variability. All of them also showed spatial dependence and were fitted to the spherical model, except for the yield of the maize in 1999 productivity which was fitted to the exponential model. The north part of the area presented repeated high values of productivity in some years. There was a positive cross correlation amongst the productivity values, especially for the maize crops.


2005 ◽  
Vol 32 (10) ◽  
pp. 945 ◽  
Author(s):  
Thomas R. Sinclair ◽  
Graeme L. Hammer ◽  
Erik J. van Oosterom

Limitations on maximum transpiration rates, which are commonly observed as midday stomatal closure, have been observed even under well-watered conditions. Such limitations may be caused by restricted hydraulic conductance in the plant or by limited supply of water to the plant from uptake by the roots. This behaviour would have the consequences of limiting photosynthetic rate, increasing transpiration efficiency, and conserving soil water. A key question is whether the conservation of water will be rewarded by sustained growth during seed fill and increased grain yield. This simulation analysis was undertaken to examine consequences on sorghum yield over several years when maximum transpiration rate was imposed in a model. Yields were simulated at four locations in the sorghum-growing area of Australia for 115 seasons at each location. Mean yield was increased slightly (5–7%) by setting maximum transpiration rate at 0.4 mm h–1. However, the yield increase was mainly in the dry, low-yielding years in which growers may be more economically vulnerable. In years with yield less than ∼450 g m–2, the maximum transpiration rate trait resulted in yield increases of 9–13%. At higher yield levels, decreased yields were simulated. The yield responses to restricted maximum transpiration rate were associated with an increase in efficiency of water use. This arose because transpiration was reduced at times of the day when atmospheric demand was greatest. Depending on the risk attitude of growers, incorporation of a maximum transpiration rate trait in sorghum cultivars could be desirable to increase yields in dry years and improve water use efficiency and crop yield stability.


2006 ◽  
Vol 21 (1) ◽  
pp. 68-73 ◽  
Author(s):  
Eric A. DeVuyst ◽  
Thomas Foissey ◽  
George O. Kegode

AbstractCurrent production practices in the Red River Valley of North Dakota and Minnesota involve use of extensive tillage and/or herbicides to control weeds. Given the erosion potential, environmental concerns associated with herbicides, and herbicide-resistant weeds, alternative cropping systems that mitigate these problems need to be assessed economically. Furthermore, the role that government commodity programs play in the adoption of more ecologically friendly cropping systems needs to be determined. We evaluated 8 years of yield data (1994–2001) from field plots near Fargo, North Dakota, to compare the economics of two alternative cropping systems, reduced-input (RI) and no-till (NT), to a conventional tillage (CT) cropping system. The RI system relies on a more diverse rotation of soybean (SB), spring wheat (SW), sweet clover (SC) and rye, and uses fewer herbicide and fertilizer inputs than CT or NT. Both NT and CT systems rotate SB and SW. We found that CT returns averaged over $47 ha−1more than NT during the study period. Because SC yield data were not available, the economic competitiveness of RI was calculated using break-even yields and returns for SC. Historical SC yields in Cass County, North Dakota were not statistically different from the break-even yields. However, when government program payments were considered, break-even returns for SC increased by about $15 and $18 ha−1and break-even yields by 0.44 and 0.52 MT ha−1for RI to compare with NT and CT, respectively. These results indicate that CT management offers greater economic return than either RI or NT and that government program payments impede adoption of more environmentally friendly cropping systems in the northern Great Plains.


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