A Quantifying Approach to Soil Salinity Based on a Radar Feature Space Model Using ALOS PALSAR-2 Data

In arid and semi-arid areas, timely and effective monitoring and mapping of salt-affected areas is essential to prevent land degradation and to achieve sustainable soil management. The main objective of this study is to make full use of synthetic aperture radar (SAR) polarization technology to improve soil salinity mapping in the Keriya Oasis, Xinjiang, China. In this study, 25 polarization features are extracted from ALOS PALSAR-2 images, of which four features are selected. In addition, three soil salinity inversion models, named the RSDI1, RSDI2, and RSDI3, are proposed. The analysis and comparison results of inversion accuracy show that the overall correlation values of the RSDI1, RSDI2, and RSDI3 models are 0.63, 0.61, and 0.62, respectively. This result indicates that the radar feature space models have the potential to extract information on soil salinization in the Keriya Oasis.

Appraising Agroecological Urbanism: A Vision for the Future of Sustainable Cities

By the mid-century, urban areas are expected to house two-thirds of the world’s population of approximately 10 billion people. The key challenge will be to provide food for all with fewer farmers in rural areas and limited options for expanding cultivated fields in urban areas, with sustainable soil management being a fundamental criterion for achieving sustainability goals. Understanding how nature works in a fast changing world and fostering nature-based agriculture (such as low-input farming) are crucial for sustaining food systems in the face of worsening urban heat island (UHI) effects and other climatic variables. The best fit for the context is transformative agroecology, which connects ecological networks, sustainable farming approaches, and social movements through change-oriented research and action. Even though agroecology has been practiced for over a century, its potential to address the socioeconomic impact of the food system remained largely unexplored until recently. Agroecological approaches, which involve effective interactions between researchers, policy makers, farmers, and consumers, can improve social cohesion and socioeconomic synergies while reducing the use of various agricultural inputs. This review presents a timeline of agroecology transformation from the past to the present and discusses the possibilities, prospects, and challenges of agroecological urbanism toward a resilient urban future.

Are Cover Crops Affecting the Quality and Sustainability of Fruit Production?

The study of the interaction between fruit trees and cover crops has been addressed in numerous works over the last 50 years or more, evidencing the need to evolve from a productive orchard to an orchard that plays different ecosystem roles in terms of environmental sustainability rather than just productivity. This review, through an analysis of the scientific literature since the 1950s, highlights the development of sustainable soil management models in fruit tree orchards, mostly considering the relationship with fruit quality traits and with the ecosystem services that result from the adoption of cover crops, aiming at identifying and formulating technical recommendations in perennial orchards. Cover crop management surely improves soil features and positively influences fruit quality in perennial woody species, but also helps to develop a better habitat for beneficial insects, thus influencing pollination. A large number of scientific approaches highlight the beneficial use of a mixture of seeds in order to enhance biodiversity, aiming at improving ecosystem services for a transition towards more sustainable systems based on agroecological management.

Have farmers had enough of experts?

The exponential rise of information available means we can now, in theory, access knowledge on almost any question we ask. However, as the amount of unverified information increases, so too does the challenge in deciding which information to trust. Farmers, when learning about agricultural innovations, have historically relied on in-person advice from traditional ‘experts’, such as agricultural advisers, to inform farm management. As more farmers go online for information, it is not clear whether they are now using digital information to corroborate in-person advice from traditional ‘experts’, or if they are foregoing ‘expert’ advice in preference for peer-generated information. To fill this knowledge gap, we sought to understand how farmers in two contrasting European countries (Hungary and the UK) learnt about sustainable soil innovations and who influenced them to innovate. Through interviews with 82 respondents, we found farmers in both countries regularly used online sources to access soil information; some were prompted to change their soil management by farmer social media ‘influencers’. However, online information and interactions were not usually the main factor influencing farmers to change their practices. Farmers placed most trust in other farmers to learn about new soil practices and were less trusting of traditional ‘experts’, particularly agricultural researchers from academic and government institutions, who they believed were not empathetic towards farmers’ needs. We suggest that some farmers may indeed have had enough of traditional ‘experts’, instead relying more on their own peer networks to learn and innovate. We discuss ways to improve trustworthy knowledge exchange between agricultural stakeholders to increase uptake of sustainable soil management practices, while acknowledging the value of peer influence and online interactions for innovation and trust building.

The Role of Woody Plant Functional Traits for Sustainable Soil Management in the Agroforestry System of Ethiopia

A woody plant functional trait that directly affects its fitness and environment is decisive to ensure the success of an Agroforestry practice. Hence, recognizing the woody plant functional traits is very important to boost and sustain the productivity of the system when different plants are sharing common resources, like in Agroforestry system. Therefore, the objective of this paper was to understand how woody plant functional traits contribute to sustainable soil management in Agroforestry system and to give the way forward in the case of Ethiopia. The contribution of woody plant species in improving soil fertility and controlling soil erosion is attributed by litter accumulation rate and the season, decomposability and nutrient content of the litter, root physical and chemical trait, and spread canopy structure functional trait. However, spread canopy structure functional trait is used in coffee based Agroforestry system, while with management in Parkland Agro forestry System. Woody species of Agroforestry system added a significant amount of soil TN, OC, Av.P, K, Na, Ca, and Mg nutrients to the soil. Woody plant species of Agroforestry system and their functional traits are very important to ensure sustainable soil management. Thus, further investigation of the woody plant functional traits especially the compatibility of trees with cops is needed to fully utilize the potential of woody species for sustainable soil management practice.

Guest editorial -- Policies and practices in action to address soil erosion

This special issue is the second published after the Global Symposium on Soil Erosion (GSER, 15-17 May 2019, Rome, Italy) and includes contributions dealing with the 2nd theme of the GSER: Policies and practices in action to address soil erosion. While there is a good scientific understanding of the physical measures that can be used to prevent or mitigate soil erosion, the main constraints to progress often relate to policy development and or implementation as well as socio-economic aspects that provide limitations to implementation of sustainable soil management (SSM) practices including those directed to control erosion. There are no right or wrong answers to which policy or approach is most effective. Some combination of approaches needs to be adopted that work in the particular political, cultural, and socio-economic environment under consideration. The papers included in this special issue provide examples, from the national to local level, that could be adapted, or used, to improve uptake and implementation of SSM practices to prevent or reduce soil erosion. Regardless of what policy or plan is developed there has to be effective interaction with the local farmers and land managers as they are key to implementing any actions that will make a practical difference on the ground. Effective policies cannot be developed or implemented without bringing the land managers “on board” and the needs and limitations of the local farmers must be thoroughly understood and considered in any policy or plan development.

Effects of Organic and Inorganic Fertilizers on the Growth of Senecio biafrae (WOROWO) OLIVE & HIERN

Soils have shown a negative balance in nutrient budget which poses a great threat to sustainable soil management for increase in growth and crop yield. This study thus investigated the effects of organic and inorganic fertilizers on the growth of Senecio biafrae (Oliv. &Hiern). Topsoil, organic (poultry manure) and inorganic fertilizers (NPK 15:15:15) were used. The fertilizers were weighed and applied to the soil at 5g, 10g, 15g each; control topsoil without application of fertilizers and were replicated five times. Growth parameters including height, number of leaves and stem diameter were taken weekly for the period of the experiment. Application ofpoultry manure and NPK fertilizer had significant effects on all the growth parameters considered. The application of poultry manure resulted into significant increase in the growth parameters towards the latter part of the study. This study has shown that organic manure has great potential for improving soil productivity and plant growth. Keywords: Senecio biafrae, investigate, organic, inorganic, plant yield