Elevated atmospheric CO₂ levels are said to increase productivity of future crops, but do we know whether this response is dependent on the form of nitrogen (N) available to plants? In wheat, we showed that a simultaneous supply of NO₃^– and NH₄⁺ is required to maximise harnessing of elevated atmospheric CO₂ compared with sole NO₃^–, NH₄⁺ or urea applications. Our findings can help to maximise crop productivity while sustaining nutritional quality of the produce (e.g. grain protein concentration) in future environments with higher atmospheric CO₂ concentrations.

Soil testing is used to guide fertiliser requirements for crops, but the calibration of soil tests with crop yield can be imprecise. We present evidence that some of the variation in the soil-test calibration is due to soil, environmental and management factors. Understanding this variation in soil test calibration enables recommendations to be made that are more relevant to the conditions faced by farmers, such as for late sowings in dry years.

We present DNA evidence that the two most common foliar fungal diseases, tan (yellow) spot and septoria nodorum blotch, co-occur in Western Australian wheat fields. Despite their co-occurrence, septoria nodorum blotch occurs only in association with tan spot in the co-infected leaves. We highlight the importance of considering tan spot and septoria nodorum blotch as a complex, and accounting for this complex may be central to successful disease-management efforts.

Changes to climatic systems have affected rainfall in the wheatbelt of Western Australia. In the drier eastern areas, rainfall data from 85 sites showed decrease of 28.0–49.9 mm in growing-season rainfall (April–October) since 2000. This suggests that a climate shift has occurred since 2000, much like a previous shift in 1976, which needs further investigation to assess properly future climate-change impacts on agriculture.

The yield of direct-seeded rice has been shown to decrease after straw amendment; however, the reasons for this yield decrease and measures that can be taken to alleviate it are currently unknown. The results suggest that continuous flooding along with straw incorporation mainly limits soil phosphorus availability, thereby affecting yield performance, and that alternate wetting and drying irrigation could be a promising strategy for the sustainable production of direct-seeded rice.

Sowing time is a critical management decision requiring matching the environment to crop characteristics and maturity. These trials with faba bean showed that early sowing can result in excessive biomass and poor harvest index and late sowing may result in moisture stress during flowering, whereas mid sowing dates were found to be optimal. The study showed the value of quick-maturing varieties and the fact that high biomass production may not maximise yield.

Genetic diversity assessment is an important step in the conservation and management of genetic resources. This study reveals high genetic potential of Algerian chickpea at both phenotypic and genotypic levels. Promising genotypes were identified as basic genetic material for future use in breeding for increased production and disease resistance.

Buckwheat can be a source of healthy food and feed, owing to the high content of rutin, a flavonoid with antioxidant, anti-inflammatory and anti-carcinogenic properties. Cultivation of buckwheat under Mediterranean photothermal and water conditions affects rutin synthesis and partitioning within the plant. The longer growing season in Mediterranean regions than in traditional cultivation areas enables adjustment of the sowing time and harvest stage to optimise rutin concentration or content in buckwheat forage and grain.

Chia is a revalorised, orphan grain crop rich in omega-3, and is important as a food and for prevention of cardiovascular afflictions. This study characterised the developmental responses of chia in order to establish management and breeding strategies in different environments. Results suggest that developmental responses are associated with yield subcomponents; application of this knowledge could lead to increases in yield.

The forage grass Paspalum dilatatum responds to submergence by using carbohydrate reserves while attempting to de-submerge its leaves; if the leaves cannot emerge and submergence time extends, plants do not survive. When submergence was provoked by defoliation, plants still attempted to de-submerge their leaves; however, a second defoliation event further depleted the carbohydrate reserves and plants died. Thus, P. dilatatum does not tolerate complete submergence conditions caused by either deep water or repeated defoliation, which is vital information in planning grassland management.