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Forage brassicas are currently widely used in temperate–humid livestock systems; however, they offer potential to diversify crop rotation and forage options in the drier, mixed crop–livestock zone of Australia. A literature review highlighted that in these hotter and more arid environments, forage brassicas are more likely to fit as autumn-sown forage crop where they offer an energy-rich, highly digestible feed source that could be used during periods of low production and nutritive value of other forage sources. However, brassicas can also accumulate several anti-nutritional compounds that require gradual introduction to livestock diets, thereby reducing potential health risks and optimising animal performance. Preliminary experimental and commercial evaluations in subtropical Australia found high production of some forage brassica genotypes (>5 t DM/ha with growth rates of 50–60 kg DM/ha.day), comparable or superior to widely used forage cereal or forage legume options. Several forage brassicas showed moderate to high resistance to the root-lesion nematode, Pratylenchus thornei , and hence are likely to provide break-crop benefits compared with susceptible species (e.g. wheat). Together, this evidence suggests that forage brassicas have significant potential for wider use in crop–livestock farming systems in Australia. However, research is needed to identify genotypic adaptation and to match different forage brassica genotypes to production environments or system niches, especially some of the new genotypes that are now available. There is also a need to develop regionally-relevant recommendations of agronomic and grazing management that optimise forage and animal production, and mitigate potential animal health risks. Forage brassicas are widely used to provide high-quality forage in temperate, high-rainfall livestock systems but are rarely used in crop–livestock systems in drier regions. We find that forage brassicas have several attributes suited to wider use in crop rotations, and preliminary experiments demonstrate favourable productivity compared with other forage options. This work demonstrates the wider potential and research needs for forage brassicas to be used throughout Australia's mixed crop–livestock systems. [ABSTRACT FROM AUTHOR]

Understanding the quantity and timing of labour to fulfill the goals of different cropping systems or crop rotations is critical, but poorly quantified and understood in many agricultural systems, including the grain-growing regions of eastern Australia. Yet, labour supply and demands are important considerations for farmers and can significantly influence their agronomic management and decisions to adopt modified crop rotation systems. Here, we investigated the extent to which crop rotation systems, that differed in their intensity (i.e. the proportion of time when crops were growing), and diversity (i.e. the range of crops grown) influence labour requirements and labour productivity. We used the Agricultural Production Systems sIMulator (APSIM) to simulate a set of different crop rotations and combined the output with farmer survey data and expert knowledge derived from farm advisers to compute the labour inputs for key crop operations (i.e. sowing, spraying, harvesting). This information was used to calculate the labour required and the timing of this demand for each cropping system. We showed that as the cropping intensity increases the labour demand also increases, and vice versa. However, only small differences in labour demands were identified between systems with differing crop diversity (i.e. range of crops grown). Thus, when it comes to labour demands, crop diversity is less critical than cropping intensity. Labour demand was highly seasonal, with peaks around the intense operations of sowing and harvesting. These peak demands constrained the area that could be managed by a unit of labour, particularly as the cropping intensity increased. Further, this analysis highlights that the most profitable systems may not necessarily be the most efficient in terms of labour productivity (i.e. return per unit of labour). This analysis shows that when labour is limiting, labour demands and especially peak periods may contribute to a farmer's choice of cropping systems, adding to other critical factors like risk aversion and profit maximisation. The analysis contributes to the literature on the role of labour in the context of influencing the implementation and adoption of what are seemingly more productive or profitable farming systems. In particular, the results demonstrate how labour as a critical farm resource (i.e. its quantity, seasonality and timing, and productivity) can influence the design of crop rotations. [Display omitted] • Many cropping systems in Australia are being modified by altering their intensities and crop diversity, but their labour demands are unknown. • Crop rotations with distinct intensity and diversity are simulated in APSIM to estimate their labour demands, seasonality, and economic returns. • Altering cropping intensity had stronger influence on labour demands and returns than changing the crop diversity in the rotation. • Labour demands between rotations is not substantial to influence a farmers decision on adopting alternative or modified cropping sequences. • Findings contribute to the growing discussion on the role of labour for the design and potential feasibility of innovative cropping systems. [ABSTRACT FROM AUTHOR]

Pulses have emerged as important rotation crops in Australia. Some are in demand in agricultural production systems due to their high potential market value, because of their roles as grain or forage crops, their nitrogen fixation capability, and because they provide a disease break or improve soil health. While several pulse crops have been identified for winter-season cropping, there are few adapted legumes apart from mungbean that are appropriate for dryland summer cropping. Currently, short-duration crops of mungbean are commonly used, but yields are highly variable and susceptible to drought. Here, we propose that cowpea has the potential to become an alternative rotation crop in dryland summer cropping zones, providing a competitive and profitable alternative pulse crop option where its drought tolerance could enable better performance under inconsistent in-crop rainfall. We demonstrate that cowpea has nutritional properties and putative uses that could prove valuable in emerging plant-based protein and aquaculture markets. [ABSTRACT FROM AUTHOR]