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Soil bulk density (ρb) is an important indicator of soil quality, productivity, compaction and porosity. Despite its importance, ρb is often omitted from global datasets due to the costs of making many direct ρb measurements and the difficulty of direct measurement on rocky, sandy, very dry, or very wet soils. Pedotransfer functions (PTFs) are deployed to address these limitations. Using readily available soil properties, PTFs employ estimator equations to fit existing datasets to estimate properties like ρb. However, PTF performance often declines when applied to soils outside those in the training dataset. Potentially, recalibrating existing PTFs using new observations would leverage the power of large datasets used in the original PTF derivation, while updating information based on new soil observations. Here, we evaluate such a recalibration approach for ρb estimation, benchmarking its performance against two alternatives: the original, uncalibrated PTFs, and novel, local PTFs derived solely from new soil observations. Using a ρb dataset of N = 360 total observations obtained in West Azerbaijan, Iran, we varied the local dataset size (with N = 15, 30, 60, and 360) and recalibrated four existing PTFs with these data. Local PTFs were generated based on stepwise multiple linear regression for the same datasets. The same PTFs (original, recalibrated, and local) were also applied to the study area, and the resulting ρb estimates were compared with the global SoilGrids dataset. Recalibration of PTFs reduced errors relative to the original uncalibrated PTFs; for instance, the NSE increased from −22.07 to 0.30 (uncalibrated) to 0.20–0.41 (recalibrated), and RMSE decreased from 0.12 to 0.60 Mg m−3 (uncalibrated) to 0.10–0.13 Mg m−3 (recalibrated). The recalibrated PTFs performance was comparable to or better than local PTFs applied to the same data. Recalibration of existing PTFs with local/regional uses provides a viable alternative to the use of global datasets or the development of local PTFs in data‐scarce regions. Highlights: Existing global PTFs were calibrated and tested using a small dataset for local utilisation.Several new local PTFs were also developed using the same datasets.Recalibration of existing global PTFs is comparable to or more accurate than developing new PTFs. [ABSTRACT FROM AUTHOR]

Under the fifth strategic development plan of Iran, the government is necessitated to trigger the agro-ecological initiatives like conservation agriculture (CA) by stimulating farmers to become involved in the schemes as efficiently as possible, along the lines of global policies to enhance environmentally-friendly development. This study, as being the case, calls for the knowledge gap of motivation-intention-behavior, investigating the association of diverse motivations of 382 farmers in Tabriz, East Azerbaijan, with the soil conservation behavior (SCB), also inclusive of the contribution of CA features, including relative advantage, compatibility, complexity, observability, and testability, as the farmers were stratified to low and high SCB. The theoretical framework consists of the theory of planned behavior (TPB) and motivational model (MM), the former is commonly used and the latter has the potential to be given much attention, conceptualized by well-being, identity, hedonistic, and idealistic concepts. The study provides evidence that 70.42% of farmers adhere to and carry out SCB at a low rate; whereas, 29.58% of the rest has a high adoption rate. The results also illustrate that attitude towards CA contributes to influencing SCB, as well as the significant and positive impact of PBC on behavioral intention and SCB. While well-being motivation has a negative impact on attitude towards CA, behavioral intention, and SCB, identity and hedonistic motivations have a significant and positive impact on attitude and SCB that are mediated by behavioral intention. The paper concludes that (1) the agricultural extension needs to change farmers' attitudes by making farmers aware of the relative advantage, compatibility, and testability of CA, (2) farmers should receive technical, financial, and educational support to increase their volitional control on CA, (3) it is strongly suggested addressing the primary obstacles to SCB, which are facilitated by delivering the subsidized agricultural inputs (e.g., fertilizer, fuel, and livelihoods) to farmers with well-being motivations, (4) the agricultural extension is also recommended recognizing farmers with identity and hedonistic incentives, they are as a reference group and are imitated by non-adopter or slowly adopter farmers. • Study addresses the intake of conservation agriculture. • Attitude towards conservation agriculture affects soil conservation behavior. • Behavioral control affects behavioral intention and soil conservation behavior. • Well-being motivations affect attitude towards conservation agriculture negatively. • Identity and hedonistic motivations affect intention and soil conservation behavior. [ABSTRACT FROM AUTHOR]