Food systems are essential for human food security and nutrition. They are also the source of roughly one third of global anthropogenic greenhouse gas emissions, making them a central topic for climate mitigation. Focusing on five crops that dominate global agriculture—wheat, maize, rice, soybean and barley––, the study analyzes how their allocation across food, feed, bioenergy and other industrial (non-food) uses affects land, carbon and water footprints. Together, these crops occupy more than half of the world’s arable land and form the backbone of food supply and bio-based economic activities. Drawing on FAOSTAT data and harmonized environmental footprint global datasets, the paper documents current crop-specific production and allocation patterns across different uses and their impacts on sustainability outcomes. It shows how these patterns differ across crops and demonstrates that environmental outcomes depend not only on how crops are produced but also on how they are allocated among competing uses. The analysis then explores four illustrative scenarios: closing yield gaps; reducing food loss and waste; shifting dietary patterns away from high animal-source consumption; and promoting second-generation biofuels. These scenarios allow the identification of significant leverage points for reducing land, carbon and water footprints. Overall, the study shows that crop allocation decisions are a critical yet often overlooked factor in food-system sustainability. By linking environmental footprints to crop uses, it offers a framework for identifying policy priorities and guiding transitions toward more resource-efficient and resilient food systems.
Tag: barley
A simple model of P uptake by crops as a possible basis for P fertilizer recommendations
In the Netherlands the Pw value, based on an extraction of soil P with water, is used as a basis for P-fertilizer recommendations for arable crops. Using a simple, mechanistic model of P transport in the soil the Pw value required for adequate P uptake by crops can be calculated on the basis of daily uptake requirements, root area index, P-adsorption isotherms and total amount of P taken up during a growing season. Calculated Pw values for adequate uptake are in the same range as the present recommendation scheme based on field experiments. Possible refinements of the model are discussed. For each soil the Pw value can be calculated that corresponds to the P concentrations in the soil solution according to standards set to reduce environmental pollution. Our model predicts that, unless the root area index of non-cereal crops is considerably improved, these standards cannot be met in the plough layer without affecting crop production levels. Calculations show that the present method of determining the Pw value yields a reasonable compromise between a measurement of intensity and capacity of P supply in the soil.
Risk assessment by sowing date for barley (Hordeum vulgare) in northern Ethiopia
Risks of dry and wet sowing methods of rainfed barley were evaluated in northern Ethiopia. The evaluation was based on yield simulation using a validated AquaCrop model. Risks of failure (false start) were assessed by taking biomass threshold levels (<0.1 t ha-1) from defined early, normal and late sowing by farmer's and depth criterion over long-term (21-41 years) climate observation. The study verified that false start increased over the study area in the order from southwest to southeast and northeast. The risk level due to false start by farmer's criterion ranged from 5 to 37%, 9 to 37%, and 9 to 19% for early, normal and late sowing, respectively, whereas the false start risk by depth criterion ranged from 14 to 29% for early; 14 to 24% for normal; and 5 to 23% for late sowing. The long-term simulated average yield across the stations ranged from 0.8 0.8 to 1.5 0.7 t ha-1 for early, 0.9 0.7 to 1.6 0.5 t ha-1 for normal and 0.8 0.7 to 1.7 0.6 t ha-1 for late sowing when farmer's criterion was applied whereas the corresponding average yield when depth criteria was applied ranged from 0.8 0.6 to 1.5 0.6 t ha-1 for early, 0.6 0.6 to 1.6 0.7 t ha-1 for normal and 0.4 0.4 to 1.7 0.4 t ha-1 for late sowing. The result suggested that risks of false start reduced and barley yield relatively improved when normal/late sowing was applied based on farmer's criterion or when early/normal sowing was applied based on depth criterion. In most of the cases, stations situated southwest of the catchment were characterized by early onset and late cessation (longer length of growing period) whereas stations situated towards the northeast, northwest and southeast are more characterized by normal or late onset and early or normal cessation (shorter growing period). In general, yield reduced from west to east mainly due to the effect of onset and cessation of rain. This study also showed that weed infestation was prevalent when early sowing was applied. Thus to minimize the risk of false start and to reduce cost of weeding, sowing should be scheduled after sufficient moisture is ensured during which especially grass weeds would emerge before sowing so that the emerged weeds could be plowed over.