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Highlights: [•] Long-term field experiment studying the effect of repeated farm compost amendment. [•] Chemical, biological and physical properties were integrated into a soil quality index. [•] Farm compost increased soil quality and crop yields. [•] Causal relationship between soil quality and crop production. [•] SOC was pointed out as the most important indicator influencing crop production. [Copyright &y& Elsevier]

• Maize root penetration was greater following white mustard below 30 cm depth. • Maize root distribution was restricted at out-row positions under strip tillage. • Strip tillage could sufficiently loosen top soil for maize production. • Maize biomass was marginally higher under strip tillage with white mustard combination. Soil compaction is a serious threat to agricultural production because of an expanding agricultural mechanization. Conservation tillage and use of pioneer plants can be an environmentally solution to alleviate the adverse effects of soil compaction. Root penetration into compacted soil of two winter cover crops with different rooting patterns, i.e. tap-rooted white mustard (Sinapis alba L.), and fibrous-rooted winter rye (Secale cereal L.), and of maize (Zea mays L.) in the consecutive growing season was assessed. Additionally, the effects of two spring tillage methods were evaluated, i.e. strip tillage and intensive tillage (by mouldboard ploughing). Winter rye showed significantly higher root penetration than white mustard in the top 15 cm, while an opposite trend was observed at 20–45 cm depth. After one season, maize root penetration was significantly greater following white mustard than winter rye at 30–40 cm depth. Strip tillage, like intensive tillage, could sufficiently loosen soil for adequate maize growth even though maize root distribution was restricted to tilled rows in contrast with intensive tillage. In conclusion, white mustard already showed positive short-term effects on maize growth, whereas strip tillage did not negatively affect it. Combining both is a viable option to reduce the negative impact of soil compaction on maize growth. [ABSTRACT FROM AUTHOR]

To evaluate the agronomic value of animal manure, we quantified the effects of pedo-climatic, crop and management factors on crop productivity, N use efficiency, and soil organic matter, described with simple indicators that compare manures with mineral fertilizers. We selected 80 European long-term field experiments that used bovine farmyard manure or bovine liquid slurry, alone (FYM and SLU) or combined with mineral fertilizers (FYMm and SLUm), and compared them to mineral fertilizer only reference treatments. We collected 5570 measurements from 107 papers. FYM produced slightly lower crop yields (−9.5%) when used alone and higher (+11.3%) yields when used in combination with N fertilizer (FYMm), compared to those obtained using mineral fertilizers only. Conditions promoting manure-N mineralization (lighter soil texture, warmer temperature, longer growing season, and shallower incorporation depth) significantly increased the effect of FYM/FYMm on crop yield and yield N. The production efficiency of FYM (yield:N applied ratio) was slightly lower than that of mineral fertilizers (-1.6%). The apparent N recoveries of FYM and FYMm were 59.3% and 78.7%, respectively, of mineral fertilizers. Manured soils had significantly higher C (+32.9% on average for FYM and FYMm) and N (+21.5%) concentrations. Compared to mineral fertilizers, yield was reduced by 9.1% with SLU, but not with SLUm. Influencing factors were similar to those of FYM/FYMm. Efficiency indicators indicated SLU (but not SLUm) was less effective than mineral fertilizers. Slurry significantly increased SOC (on average for SLU and SLUm by +17.4%) and soil N (+15.7%) concentrations. In conclusion, compared to mineral N fertilizers, bovine farmyard manure and slurry were slightly less effective on the crop, but determined marked increases to SOC and soil N, and thus, to long-term soil fertility maintenance. [ABSTRACT FROM AUTHOR]

Policy can influence the long-term agricultural resource productivity by stimulating/discouraging farmers to apply certain land use practices (LUP), as LUPs may affect the soil organic carbon (SOC) stock, hence influencing crop productivity. We introduce six policy strategies, each characterized by its own mix of LUPs, for the Flemish agricultural sector. Three strategies reveal the impact of the Common Agricultural Policy (CAP) in the past, while others reflect the potential of the CAP and the application of compost. We use the life cycle impact assessment indicators 'SOC change' and 'biomass productivity loss', which account for the impact of LUPs on SOC and yield, to assess the effects on long-term productivity. To avoid burden shifting, also the resource footprint is calculated. Several farm management systems (FMS) are distinguished, each characterized by a specific combination of farm type, agricultural region, rotation system and manure type. The results highlight that policies such as the CAP significantly contribute to a better SOC stock and (to a lesser extent) productivity. Furthermore, applying extra compost seems to be promising: it can result in an increasing resource productivity and reduced resource footprint. It is important to consider the resource footprint as only for one strategy the resource consumption outweighs the benefit (i.e. reduction in N fertilizer) in the short or medium term, while also being beneficial in terms of resource productivity. As the results differ per FMS, a differentiated approach is advisable when specific LUPs are stimulated in the context of sustainable farming. • Policy affects the choices farmers make regarding land use practices (LUP). • LUPs affect soil organic carbon (SOC) stock and productivity. • Policy strategies characterized by a certain mix of LUPs are introduced. • Long-term productivity and resource footprint of policy strategies are compared. • Cover crop cultivation and compost use are beneficial in terms of SOC and yield. [ABSTRACT FROM AUTHOR]