Break-crop benefits to wheat in Western Australia – insights from over three decades of research

2012 ◽  
Vol 63 (1) ◽  
pp. 1 ◽  
Author(s):  
Mark Seymour ◽  
John A. Kirkegaard ◽  
Mark B. Peoples ◽  
Peter F. White ◽  
Robert J. French

Broadleaf break crops improve cereal yield through disease and weed control, increased nitrogen (N) availability and other mechanisms. In the rainfed farming systems of Australia the magnitude of the yield benefit is highly variable, yet is a major driver for adoption of break crops which are often less profitable and more risky than cereals. Declining area of break crops throughout Australia has re-ignited interest in better understanding the circumstances in which break-crop benefits can be maximised from a farming systems perspective. We compiled and analysed a database of 167 crop sequence experiments conducted throughout Western Australia in the period 1974–2007 to evaluate the impact on wheat (Triticum aestivum L.) grain yield from the use of narrow-leafed lupin (Lupinus angustifolius L.), field pea (Pisum sativum L.), canola (Brassica napus L.) or oats (Avena sativa L.), or following a long fallow where no crop had been sown the previous year. Adjusted for the years in which each was represented the average yield benefit to wheat compared with wheat after wheat was 0.60, 0.45, 0.40, 0.35 and 0.30 t/ha following lupin, field pea, canola, oats or fallow, though direct comparisons between break crops could not be made as few experiments (3) included all species. For all break crops, the mean wheat yield increase was independent of the level of wheat yield, representing a step-change rather than a proportional improvement in yield. Analysis of the larger number and spread of lupin experiments revealed that break-crop benefits increased in higher rainfall areas, following higher yielding lupin crops (>1.5 t/ha), and that the break-crop benefit in terms of yield and water-use efficiency increased significantly after 1991. These observations were often related to the level and/or effectiveness of diseases or grass weed control in the break crop; however, increased contribution of fixed N was also likely with better legume crops. For both lupin and field pea, the magnitude of the break-crop response declined as rate of N fertiliser applied to subsequent wheat crop increased, although non-N related benefits (disease and weed control) tended to dominate wheat response to lupin after 1989. Significant break-crop benefits from lupins (+0.40 t/ha) persisted to a third wheat crop (n = 29) but effects were inconsistent beyond that point. The magnitude, persistence and reliability of the break-crop benefits revealed in this study provide a more accurate framework to assess their likely benefit within the farming system. Further information is required to define the key ‘trigger points’ for the major drivers of the response – water, N, weeds and disease – at which the benefits outweigh the higher risk of these crops and would influence the decision to include them within the system.

1996 ◽  
Vol 36 (2) ◽  
pp. 209 ◽  
Author(s):  
KHM Siddique ◽  
SP Loss ◽  
SP Herwig ◽  
JM Wilson

The growth, phenology, grain yield and neurotoxin (ODAP) content of Lathyrus sativus, L. cicera and L. ochrus were compared with a locally adapted field pea (Pisum sativum L.) to examine their potential as grain legumes in Western Australian farming systems. About 17 lines of each species were obtained from ICARDA, Syria, and grown at 3 agro-climatically different sites. In general, the 3 species were later flowering than field pea, especially L. cicera and L. ochrus; however, L. sativus was the last species to mature. The best Lathyrus lines produced biomass near flowering similar to field pea. At the most favourable site, grain yields were up to 1.6, 2.6 and 1.7 t/ha for L. sativus, L. cicera and L. ochrus respectively, compared with a field pea grain yield of 3.1 t/ha. There was considerable genotype and environmental variation in ODAP concentration in the seed. On average, the ODAP concentration of L. ochrus (6.58 mg/g) was about twice that of L. sativus, and L. cicera had the lowest ODAP concentration (1.31 mg/g). Given that Lathyrus spp. have not had the same breeding effort as field pea and other grain legumes in Australia, these results encourage further selection or breeding. In the shor-tseasoned, mediterranean-type environment of Western Australia, harvest indices and grain yields could be improved with early flowering. Low ODAP concentration should also be sought.


2001 ◽  
Vol 52 (2) ◽  
pp. 295 ◽  
Author(s):  
R. A. Latta ◽  
L. J. Blacklow ◽  
P. S. Cocks

Two field experiments in the Great Southern region of Western Australia compared the soil water content under lucerne (Medicago sativa) with subterranean clover (Trifolium subterranean) and annual medic (Medicago polymorpha) over a 2-year period. Lucerne depleted soil water (10–150 cm) between 40 and 100 mm at Borden and 20 and 60 mm at Pingrup compared with annual pasture. There was also less stored soil water after wheat (Triticum aestivum) and canola (Brassica napus) phases which followed the lucerne and annual pasture treatments, 30 and 48 mm after wheat, 49 and 29 mm after canola at Borden and Pingrup, respectively. Lucerne plant densities declined over 2 seasons from 35 to 25 plants/m2 (Borden) and from 56 to 42 plants/m2 (Pingrup), although it produced herbage quantities similar to or greater than clover/medic pastures. The lucerne pasture also had a reduced weed component. Wheat yield at Borden was higher after lucerne (4.7 t/ha) than after annual pasture (4.0 t/ha), whereas at Pingrup yields were similar (2 t/ha) but grain protein was higher (13.7% compared with 12.6%) . There was no yield response to applied nitrogen after lucerne or annual pasture at either site, but it increased grain protein at both sites. There was no pasture treatment effect on canola yield or oil content at Borden (2 t/ha, 46% oil). However, at Pingrup yield was higher (1.5 t/ha compared to 1.3 t/ha) and oil content was similar (41%) following lucerne–wheat. The results show that lucerne provides an opportunity to develop farming systems with greater water-use in the wheatbelt of Western Australia, and that at least 2 crops can be grown after 3 years of lucerne before soil water returns to the level found after annual pasture.


2000 ◽  
Vol 80 (2) ◽  
pp. 441-449 ◽  
Author(s):  
J. R. Moyer ◽  
R. E. Blackshaw ◽  
E. G. Smith ◽  
S. M. McGinn

Cropping systems in western Canada that include summer fallow can leave the soil exposed to erosion and require frequent weed control treatments. Cover crops have been used for soil conservation and to suppress weed growth. Experiments were conducted under rain-fed conditions at Lethbridge, Alberta to determine the effect of short-term fall rye (Secale cereale L.), winter wheat (Triticum aestivum L.) and annual rye cover crops in the fallow year on weed growth and subsequent wheat yield. Under favorable weather conditions fall rye was as effective as post-harvest plus early spring tillage or herbicides in spring weed control. Winter wheat and fall rye residues, after growth was terminated in June, reduced weed biomass in September by 50% compared to no cover crop in 1993 but had little effect on weeds in 1995. Fall-seeded cover crops reduced the density of dandelion (Taraxacum officinale Weber in Wiggers) and Canada thistle [Cirsium arvense (L.) Scop.] but increased the density of downy brome (Bromus tectorum L.), wild buckwheat (Polygonum convolvulus L.), and thyme-leaved spurge (Euphorbia serpyllifolia Pers.) in the following fall or spring. Wheat yields after fall rye and no cover crop were similar but yields after spring-seeded annual rye were less than after no cover crop. Spring-seeded annual rye did not adequately compete with weeds. Cover crops, unlike the no cover crop treatment, always left sufficient plant residue to protect the soil from erosion until the following wheat crop was seeded. Key words: Allelopathies, fall rye, nitrogen, soil conservation, soil moisture, weed control, spring rye, winter wheat


2001 ◽  
Vol 41 (3) ◽  
pp. 327 ◽  
Author(s):  
M. B. Peoples ◽  
J. A. Baldock

Experimental estimates of amounts of foliage nitrogen (N) fixed in Australian pastures range from 2 to 284 kg N/ha.year for annual and perennial legumes growing in temperate and tropical environments. Differences in the amounts of N2 fixed relate primarily to the legume content and net productivity of pastures. On average, close to 20–25 kg of shoot N are fixed for every tonne of legume herbage dry matter produced across a wide range of environments. Strategies likely to improve the potential for N2 fixation include: (i) rhizobial inoculation at time of first sowing a new legume species; (ii) amelioration of nutritional problems (applications of superphosphate or lime); (iii) manipulation of pasture composition (herbicide applications to remove grasses in annual pastures in the year prior to cropping); and (iv) including lucerne to offset the year-to-year variability in N2 fixation inputs from annual legumes. However, pasture response to such management treatments and the subsequent availability of soil mineral N may be modified by livestock effects on nutrient cycling, pasture productivity and botanical composition. Conclusions about the relative size of the contributions of fixed N to the N economies of Australian farming systems depend on whether or not estimates of fixed N are included for nodulated roots. Thus residual net inputs of fixed N after each year of a legume-based pasture are generally rated sufficient to balance the N removed by at least 1 subsequent wheat crop provided estimates of below-ground N are included in calculations. Pasture type influences the duration of subsequent rotational benefits and while residual effects on mineral N are commonly exhausted within 2 years after an annual legume-based pasture phase, N carry-over following lucerne generally lasts considerably longer.


2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Rafia Mumtaz ◽  
Shahbaz Baig ◽  
Iram Fatima

Land management for crop production is an essential human activity that supports life on Earth. The main challenge to be faced by the agriculture sector in coming years is to feed the rapidly growing population while maintaining the key resources such as soil fertility, efficient land use, and water. Climate change is also a critical factor that impacts agricultural production. Among others, a major effect of climate change is the potential alterations in the growth cycle of crops which would likely lead to a decline in the agricultural output. Due to the increasing demand for proper agricultural management, this study explores the effects of meteorological variation on wheat yield in Chakwal and Faisalabad districts of Punjab, Pakistan and used normalised difference vegetation index (NDVI) as a predictor for yield estimates. For NDVI data (2001-14), the NDVI product of Moderate Resolution Imaging spectrometer (MODIS) 16-day composites data has been used. The crop area mapping has been realised by classifying the satellite data into different land use/land covers using iterative self-organising (ISO) data clustering. The land cover for the wheat crop was mapped using a crop calendar. The relation of crop yield with NDVI and the impact of meteorological parameters on wheat growth and its yield has been analysed at various development stages. A strong correlation of rainfall and temperature was found with NDVI data, which determined NDVI as a strong predictor of yield estimation. The wheat yield estimates were obtained by linearly regressing the reported crop yield against the time series of MODIS NDVI profiles. The wheat NDVI profiles have shown a parabolic pattern across the growing season, therefore parabolic least square fit (LSF) has been applied prior to linear regression. The coefficients of determination (<em>R</em><sup>2</sup>) between the reported and estimated yield was found to be 0.88 and 0.73, respectively, for Chakwal and Faisalabad. This indicates that the method is capable of providing yield estimates with competitive accuracies prior to crop harvest, which can significantly aid the policy guidance and contributes to better and timely decisions.


2015 ◽  
Vol 66 (6) ◽  
pp. 580 ◽  
Author(s):  
R. J. French ◽  
R. S. Malik ◽  
M. Seymour

Western Australian grain production is dominated by wheat, but growing wheat continually in unbroken sequences leads to increasing problems with soil nutrient depletion, root and leaf disease build-up, high weed burdens, and possibly other less well-defined production constraints. These can adversely affect both production and grain quality. Including breaks in the crop sequence in the form of break crops, pasture, or fallow can reduce these problems, but these breaks can be expensive to implement, in terms of both direct cost and forgone revenue. It is therefore critical to predict the response of subsequent wheat crops to a break in order to choose crop sequences rationally. We conducted a 4-year experiment at Wongan Hills, Western Australia, evaluating how wheat productivity in a wheat-based cropping sequence is affected by including wheat, barley, lupins, triazine-tolerant and Roundup Ready® canola, oaten hay, volunteer pasture, serradella pasture, and chemical fallow. Wheat yield responded positively to fallow, lupins, oaten hay, volunteer pastures and serradella but not to barley or canola when compared with continuous wheat. Responses depended on seasonal conditions; in a dry year, a very large response occurred after fallow but not after lupin or serradella, whereas in a wetter year, there were large responses after these crops. Fallowing, cutting hay, crop-topping lupins, and spray-topping volunteer and serradella pasture all reduced seedset of annual ryegrass dramatically, and reduced weed competition was a major contributor to the observed break crop responses. Nitrogen fixation by lupins and serradella and water storage by fallow in a dry year were also important, but soilborne diseases did not contribute to wheat yield responses. Some yield responses persisted for at least 3 years, and the contribution of effects of weed competition to yield responses increased over this time. These results emphasise the importance of understanding which productivity constraints are present in a cropping system at a given time when deciding whether a break is necessary and which is the most appropriate break. The results also emphasise the importance of managing the wheat crop after a break to maximise the response and its longevity.


Author(s):  
Maria Angeles Fernández-Zamudio ◽  
Maria Dolores De-Miguel ◽  
Pedro Caballero

Olive, vine and almond in rainfed farming systems are the most traditional crops in the large inland extensions of the Spanish Mediterranean. Their economic contributions enable farming activities to be maintained meaning that the villages remain inhabited. In the rainfed-farms in the Mediterranean regions it is possible to find only a certain proportion of the farms with some type of irrigation system. Given the water scarcity, the aim of this work is to determine the impact that an irrigationwater pricing policy would have on these regions, as outlined in the European Water Framework Directive. After analysing the direct effect water price would have on the net margin in these crops, demand functions have been obtained, applying the Multiattribute Utility Theory. The calculations, with reference to a farm that is representative of these regions, have been applied to two model scenarios, each with a different level of mechanization. Results show the impact on economic, social and environmental aspects of the pricing policy under the current water allotment. The work is completed by analysing the different contexts of irrigation-water availability on the farm. The study leads to the conclusion that increasing mechanization may be the most straightforward strategy to ensure the survival of these farms in the short to medium term if the current trend of increasing irrigation-water prices is consolidated. 


Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 548
Author(s):  
Cyrine Rezgui ◽  
Wassila Riah-Anglet ◽  
Marie Benoit ◽  
Pierre Yves Bernard ◽  
Karine Laval ◽  
...  

Due to legume-based systems improving several aspects of soil fertility, the diversification of agrosystems using legumes in crop succession is gaining increasing interest. The benefits of legumes aroused the interest of farmers in the association of the Economic and Environmental Interest Group (EEIG), who introduced the idea of using the winter pea instead of rapeseed in their crop succession. The aim of this study is to evaluate the effects of the winter pea compared to those of rapeseed, as a head crop of the rotation, on soil microbial communities, enzyme activities, nitrogen (N) balance and yields. The field experiment involved two farmer plots that were selected within the EEIG. In each plot, two crop successions, including winter pea–wheat and rapeseed–wheat with fertilized and unfertilized strips, were examined for two years. Three times a year, under the wheat crop, composite soil samples were collected at depths of 0–20 cm, for microbial abundance and enzyme activity analyses, and twice a year at a depth of 0–60 cm, for the measuring of the mineral N. The results showed that the rapeseed–wheat succession maintained or enhanced soil bacterial and fungal biomasses and their enzyme activities. The winter pea–wheat succession enriched the soil’s mineral N content more consistently than the rapeseed–wheat succession. The mineral N enhancement’s effect was maintained under the wheat crop. Overall, the impact of the winter pea was positive on the soil’s N dynamics, but wheat yields were equivalent regardless of the previous crop (winter pea or rapeseed with and without fertilization). In the Normandy region, as rapeseed requires a large amount of N fertilizer and pesticide to maintain the yield and quality of crop products, it is suitable to favor the introduction of the winter pea as the head crop of the rotation, which indirectly allows for a reduction in the costs of input production and use, the working time of farmers and environmental pollution.


1970 ◽  
Vol 34 (1) ◽  
pp. 97-104 ◽  
Author(s):  
M Robiul Alam ◽  
M Akkas Ali ◽  
MSH Molla ◽  
MA Momin ◽  
MA Mannan

Balanced fertilization with optimum potassium management may lead to maximize wheat yield. The experiment was carried out at the Farming Systems Research and Development (FSRD site, Pushpapara, Pabna during the rabi seasons of 2003-04 and 2004-05 to ascertain the effect of potassium application on wheat. Five different levels of potassium (K) were tested on wheat crop. Yield contributing characters and yield exerted significant variation due to application of different levels of K and the best performance of the crop parameters was recorded when 36 kg K/ha was applied. Remarkable increase in grain, straw and total biomass yield was recorded in the same treatment. Regarding the grain quality of wheat, the highest protein content was recorded from 36 kg K/ha, which was 6.86% and 4.98% higher over omission of K (control) and recommended dose (100% estimated K). The highest net benefit was obtained from 36 kg K/ha, which was 40.52% higher over omission of K (control). Key Words: Potassium; yield; protein content; wheat. DOI: 10.3329/bjar.v34i1.5759Bangladesh J. Agril. Res. 34(1) : 97-104, March 2009


Author(s):  
Shahbaz Khan ◽  
Atif Rasool ◽  
Sohail Irshad ◽  
Muhammad Bilal Hafeez ◽  
Madad Ali ◽  
...  

Abstract Wheat is the main crop in the world ranks after rice and the largest grain source of Pakistan. Among several reasons for diminishing wheat yield in Pakistan, water stress throughout the growing season decreases crop production because of the short life span. Two years (2015–16 and 2016–17) field experiments were conducted to assess the impact of various water regimes (full irrigation, irrigation at 45, 60, and 75 mm potential soil moisture deficit (PSMD)) on the growth and yield of wheat. Maximum crop growth rate was recorded by application of irrigation at 45 mm PSMD. Application of irrigation at 45 mm PSMD ensured maximum radiation use efficiency regarding total dry matter production and grain yield. The maximum number of productive tillers, spike length, and grain yield were recorded under 45 mm PSDM treatment. The present results show that the effect of water is more pronounced regarding the growth and productivity of wheat. Application of irrigation at 45 mm PSMD ensures higher economical yield.


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