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Despite the notable decline in potato cultivation areas across Poland and Europe, potatoes remain a crucial crop with diverse applications. Achieving the ambitious emission targets set by the EU for agricultural production may be easier with the practice of deep placement of slow-release fertilizers, which may increase yields and reduce greenhouse gas emissions. To examine the effect of deep placement of slow-release fertilizers on potato tuber yields, plant nutrient uptake, nutrient use efficiency, and soil N2O-N emissions, a two-year field experiment was conducted on loamy sand soil classified as Alblic Podzol (Ochric) soil, under temperate climate conditions prevailing in central Poland. The experiment involved a three-field rotation (potatoes, wheat, and peas), with potatoes being cultivated after peas in both years of the study. The experiment compared the effects of applying slow-release fertilizer at soil depths of 10 and 20 cm (DP10 and DP20) to fertilization with single-nutrient fertilizers applied to the soil surface (TD). The experiment utilized increasing doses of nitrogen and phosphorus, denoted as D0 (control), D1, D2, and D3, along with a standard dose of potassium across all tested fertilizer application methods. The results of this study confirmed that deep placement of slow-release fertilizers had limited effects on potato tuber yields. Deep placement of slow-release fertilizer increased plant nitrogen uptake by 2.8–13.5% compared to topdressing. Consequently, there was an improvement in nitrogen use efficiency from 29.8–75.0% on sites with fertilizer topdressing to 38.7–89.8% on sites with slow-release fertilizer deep placement. Phosphorus uptake by plants on sites with slow-release fertilizer deep placement was approximately 9.3–13.0% higher than on sites with fertilizer topdressing. This led to an enhancement in phosphorus use efficiency from about 15.1–19.5% on fertilizer topdressing sites to 19.4–25.4% on slow-release fertilizer deep placement sites. The impact of fertilizer deep placement was found to be less pronounced compared to the effects observed with increased nitrogen and phosphorus doses. The most important factors affecting tuber yield and nutrient use in potatoes were rainfall levels during the growing season. Deep fertilization did contribute to reduce soil N2O emissions by about 14%. However, further research involving different fertilization methods is needed to comprehensively assess the effectiveness of this practice in reducing greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Extreme meteorological phenomena resulting from climate change caused by anthropogenic emissions of greenhouse gases (GHG) require the implementation of CO2 mitigation practices from various industries, including agriculture. Owing to varying soil, climatic, and agrotechnical characteristics, they may have different efficiencies in mitigating soil CO2 emissions. The aim of this study was to evaluate the impact of three mitigation practices (reduced tillage, deep fertilizer placement, and soil afforestation) on CO2 emissions from sandy soils in Central and Eastern Europe allowing the prediction of the mitigation effectiveness of these methods. The average soil CO2-C flux under a moldboard plow system ranged from 218.4 ± 108.4 to 263.7 ± 176.6 mg CO2-C m−2 h−1 and under a reduced tillage system ranged from 169.7 ± 118.7 to 163.6 ± 115.2 mg CO2-C m−2 h−1 in a year with normal meteorological conditions and under extreme drought conditions, respectively. In the dry growing season, similar amounts of CO2-C were released from the soil fertilized to the soil surface and after mineral fertilizers application at a depth of 10 cm and 20 cm (133.7 ± 155.8, 132.0 ± 147.5 and 131.0 ± 148.1 mg CO2-C m−2 h−1, respectively). Meanwhile, from the forest soil, the average CO2-C emission in the dry growing season was 123.3 ± 79 mg CO2-C m−2 h−1. The obtained results revealed that reduced tillage on sandy soil allowed for reduced CO2 emissions from the soil by 28.7–61.2% in normal and drought weather, respectively. Under drought conditions, deep fertilizer placement did not reduce CO2 emissions from sandy soil, and CO2 emissions from forest soils were even higher than from arable soils. [ABSTRACT FROM AUTHOR]