Manure application to soil has declined globally due to increased availability of mineral fertilizers. However, mineral fertilizer overuse has caused serious consequences for soil quality and the environment. We analyzed the results of 20 long‐term field trials (22–32 years, start year [ranged from 1980 to 1990] to 2012) and combined this with a climate change model and soil organic carbon (SOC) model to quantify the importance of manure and mineral fertilizers for grain yield and SOC sequestration across croplands in China. During the past three decades mineral fertilizers have increased grain yield for 91–184% but had minor impact on SOC sequestration (4–16%). In contrast, manure applied with mineral fertilizer increased grain yield by only 6–19% but strongly raised the SOC content (9–39%) compared with mineral fertilizer. Modeling (to the year 2099) indicated that manure used in combination with mineral fertilizers will increase future C sequestration in soils across China by 2,086 Tg C and by 2,482 Tg C based on current net primary productivity with no climate change and on increased net primary productivity with climate change scenarios, respectively. This corresponds to an additional 43–58% increase in C sequestration compared to mineral fertilizers only. The manure efficiency for C sequestration in soil was about 9.6% of C input and decreased with increasing SOC content. To maintain the current SOC content (i.e., 2010), 11 t·ha−1·year−1 fresh manure or 4.8 t·ha−1·year−1 dry maize straw would be required. We conclude that the regular use of manure with mineral fertilizers is essential for the long‐term dual functions of soil for food production and SOC sequestration.
Biochar application is widely studied to mitigate the threats of soil degradation to food security and climate change. However, there are big variations in the effects of biochar application on crops, soils, and the atmosphere during crop production. This study provides a global dataset of biochar application effects on crop yield, soil properties, and greenhouse emissions. The dataset is extracted and integrated from 367 peer-reviewed studies with 891 independent field, laboratory, and incubation experiments across 37 countries. This dataset includes 21 variables before and after biochar application (including soil properties, crop yield, greenhouse gas emissions, etc.) of 2438 items, focusing on two main biochar application types: biochar application alone and combined with fertilizers. Background information on climate conditions, initial soil properties, management practices, and characteristics of biochar sources and production is also contained in the dataset. This dataset facilitates a comprehensive understanding of the impact of biochar application, supports the utilization of agricultural wastes for biochar production, and assists researchers in refining experimental protocols for further studies.