Potentials of improved manure management on resource use efficiency and emissions at a global scale

The consumption of milk and meat is expected to increase by 30% within the next two decades as a result of the increasing global population and the increasing share of animal protein in human diets. The production of this type of protein is associated with the production of manures, as only 10-50% of the nitrogen (N) and phosphorus (P) ingested by livestock is retained in products such as milk and meat, implying that 50-90% is excreted in the form of manure (i.e. urine and faeces).

This manure needs to be managed in order to minimize negative effects on the environment. Manure management pertains to all possible interventions along the chain starting with collection and storage and ending with land application, and their interacting effects on utilization.

Livestock plays an increasing role in food production with manure as a by-product. At present the utilization of this manure is far from perfect to the detriment of the environment. However, a better re-use of manures can reduce harmful emissions of N and P to water bodies and of N and GHG’s to the atmosphere. It will concomitantly reduce the demand for finite resources such as land, rock P and the fossil fuel needed to produce N fertilizers. Poor utilization of manures stems from inadequate collection, storage, treatment and transport systems, from the suboptimal composition, timing and methods of manure application, and from the allocation of manures to competitive non-agricultural destinations, including disposal. The latter is aggravated by the common spatial separation between animal feed production and livestock production.

Imperfections vary strongly per region, per country and per continent. To initiate the right actions in the right places, it is key to identify the character and extent of these imperfections. Such a region-specific picture is as yet not available, due to the lack of comprehensive and quantitative information and tools to interpret it. This project will a) develop a novel method of combining data on manure management from different sources, aimed at b) the production of an improved global map of the current management of manure and its ultimate use as fertilizer, c) identify region-specific shortcomings and required actions to improve the use of manures as fertilizer, and d) assess the potential agronomic and environmental impacts of these actions. The project will be executed in cooperation with another WUR-IPOP project on innovative data collection methods, the Ministry of Economic Affairs, Agriculture and Innovation, the Food and Agriculture Organization and possibly the universities of Hue (Vietnam) and Egerton (Kenya).


The priority of the present project is data collection and the development of an instrument to analyse these data and visualize the results of actual situations and alternatives, rather than the production of region specific action programmes, let alone a plan to implement these action programmes.

We expect to encounter (scale related) information gaps, and intend to keep a formal log of this missing information and actively disseminate this log in support of both parallel and future research projects. One of the minor outputs of this project hence is: ‘On-the-go’ log of information that is missing or missing at the required resolution, to be disseminated across related institutions via email, resulting, if possible, in a better quality of input data as the project proceeds and helpful directions for follow-up projects.

The envisaged major outputs of the projects are:

  • Publication(s) (paper(s) in refereed journal) on data collection and extrapolation methods to map the current manure management
  • Publication (paper in refereed journal) on region-specific mitigation options and their impact on the  agronomic performance and the environmental fate of the nutrients in manure both per unit area and per unit product
  • A set of global, digitalized maps visualizing both the current and potentially attainable impact of manure management.