Agronomic efficiency
Effects of Biogas Digestate on Winter Wheat Yield, Nitrogen Balance, and Nitrous Oxide Emissions under Organic Farming Conditions
Biogas digestate is increasingly used in organic farming to improve soil fertility and crop yields, but it can also cause environmentally relevant N₂O emissions. A four-year field study in southern Germany (2019–2022) tested how digestate affects winter wheat yield, nitrogen efficiency, and N₂O-N emissions. Digestate application strongly increased yields, though long-term fertilized plots performed better than newly treated ones. The highest N₂O emissions occurred in long-term fertilized plots, but surprisingly high emissions also appeared in winter in unfertilized plots. Overall, the study shows that N₂O emissions are influenced not only by fertilization but also by tillage, post-harvest practices, previous crops, and weather conditions.
Effects-of-Biogas-Digestate-on-Winter-Wheat-Yield-Nitrogean-Balance-and-Nitrous-Oxide-Emiss.pdfDigestate as Fertilizer
Agriculture is one of the fundamental economic sectors of any country. The variety of goods provided by agriculture ranges from food and animal feed to products for the industry and in recent years also increasingly for electricity, heat, and fuels based on energy crops.
However, modern agriculture should always focus on the responsible use of natural resources. Agriculture is thus facing the challenge of operating as efficiently, sustainably, and in a manner that is as environmentally friendly as possible. Agriculture must become more efficient in the coming years because agricultural land will have to feed more and more people, especially in view of global population development.
Responsible use of fertilizers plays a decisive role here in maintaining the production of agricultural productsm at a consistently high level. Global consumption of the most important fertilizers on the world market, potassium, nitrogen, and phosphate, has risen steadily over recent years. However, like any other raw material, themnatural sources of these fertilizers are finite. Experts predict a supply problem in the future, especially with regard to phosphorus reserves.
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Digestate_as_Fertilizer.pdf
Effects of anaerobic digestion on digestate nutrient availability and crop growth: A review
Anaerobic digestion (AD) changes the composition of the original feedstock, altering factors such as ammonium levels, pH, and the carbon-to-nitrogen ratio, which influence how plants access nutrients after field application. Although AD increases ammonium-nitrogen in slurries, it does not automatically lead to better nitrogen uptake or greater fertilizer savings. When crop residues or cover crops are digested, farms gain more mobile organic fertilizers, allowing more precise nitrogen application when and where crops need it. AD of dairy manure may reduce immediately available phosphorus and micronutrients, though this does not seem to limit short-term crop uptake—yet more research is still required to fully understand these effects.
Engineering-in-Life-Sciences-2012-Moller-Effects-of-anaerobic-digestion-on-digestate-nutrient-availability-and-crop.pdfThe Effectiveness of Digestate Use for Fertilization in an Agricultural Cropping System
This study evaluated the performance of animal-based digestates (from pig, chicken, and cow manure) as sustainable fertilizer alternatives to synthetic nitrogen over three consecutive years. Digestate applications enhanced soil phosphorus and potassium levels and led to higher grain yields, particularly in the third year. Nitrogen use efficiency remained moderate but showed a strong positive relationship with yield. Although grain and straw quality responses varied, no adverse effects were observed. Overall, the findings highlight the promising short- to mid-term potential of digestates under favorable climatic conditions.
The-Effectiveness-of-Digestate-Use-for-Fertilization-in-an-Agricultural-Cropping-System.pdf