Plasma Treated Cattle Slurry Moderately Increases Cereal Yields

Abstract

Plasma treatment offers an approach to enhance the nitrogen (N) content of livestock slurry and biogas digestate, thereby increasing the efficacy of organic fertilizers. This innovative method is used to produce nitrogen-enriched organic fertilizer (NEO) containing a double concentration of plant-available N. Over three years, we conducted a comprehensive study in 14 spring wheat and barley field trials in Norway. The primary objective was to assess and compare the cereal grain yield achieved by applying NEO to other conventional fertilizers. The NEO utilized in our research was derived from the unit developed by the Norwegian company N2 Applied. The results indicated that 120 kg N ha−1 in NEO yielded in the same range of cereal grains as 95 kg N ha−1 in mineral fertilizer. Moreover, the combination of untreated slurry and 55 kg N ha−1 in mineral fertilizer Opti-NS yielded the same as 120 kg N ha−1 in NEO. Surprisingly a combination of 12 kg N ha−1 in mineral fertilizer at sowing day and 108 kg N ha−1 in NEO at the three-leaf stage led to a higher yield in spring wheat than 120 kg N ha−1 NEO spread at sowing day in two out of three experimental years. Moreover, applying NEO directly to plants has shown no visible signs of harm. Lastly, filtering the slurry resulted in higher cereal grain yields than the untreated slurry. In conclusion, despite possessing the same N content, utilizing NEO yielded a 15–20% lower cereal grain yield than mineral fertilizer. Nonetheless, 20–30% more yield than the native amount of cattle slurry it derived. However, we have observed an unexplained loss of approximately 17% of the nitrogen in NEO, which does not translate into increased grain yield or nitrogen productivity.

Cropping Systems and Agronomic Management Practices of Field Crops

“…In the second article, 17-year-old integrated nutrient management under a maize-wheat cropping system was studied by Dhaliwal et al [12] for the buildup of organic carbon, microbial communities, and soil nutrient status. Nevertheless, this Special Issue dealt with technical aspects of fertilization, such as the subsurface application of mineral fertilizers to decrease the accumulation of nutrients in the top soil layers under no-tillage systems [13], the application of compost by microdosing to double the fertilized area and improve sorghum (Sorghum bicolor [L.] Moench) productivity in Southern Mali [14], or the use of plasma-treated cattle slurry to produce nitrogen-enriched organic fertilizers [15].…”

Nitrous oxide and methane fluxes from plasma-treated pig slurry applied to winter wheat

“…This process lowers the pH of the slurry and reduces the potential for NH 3 emissions (Nyang'au et al 2024). An increase in the N content of the plasma-treated slurry means the product has the potential to replace synthetic inorganic fertiliser and has been shown to increase yields compared to untreated slurry (Mousavi et al 2022;Cottis et al 2023), as well as reducing both CH 4 and NH 3 emissions during storage (Graves et al 2018). Whether the beneficial gains of increasing the amount of inorganic N available for immediate plant uptake are counterbalanced by other N losses upon application to the soil, such as N 2 O to the atmosphere, however, are unknown.…”

“…The overarching consensus is that soils amended with organic fertiliser have higher N 2 O and CH 4 emissions than those amended with inorganic fertiliser (Thangarajan et al 2013;Walling and Vaneeckhaute 2020;He et al 2023). The effects of using plasma-treated slurry as an organic fertiliser on soil N 2 O and CH 4 emissions is relatively unknown, however, and most of the existing research on plasmatreated organic waste has focused on the effects of plasma-treated cattle slurry on crop yield, soil biota and NH 3 emissions (Mousavi et al 2022;Cottis et al 2023). If plasma-treated pig slurry is to become a potential solution to reduce non-CO 2 GHG emissions, it will be necessary to explore the extent to which it can achieve this relative to non-treated pig slurry and inorganic fertiliser.…”