Recycling agricultural, municipal and industrial pollutant wastes into fertilizers for a sustainable healthy food production

Assessing psychological factors on farmers' intention to apply organic manure: an application of extended theory of planned behavior

Different from the previous studies on social and economic impacts, this study focused on the assessment of psychological factors on farmers' application of organic manure. We explored the psychological evaluation based on the extended theory of planned behavior (TPB), which consists of attitude (AT), perceived behavior control (PBC), subjective norm, moral norm (MN), environmental risk perception (ERP), and perceived policy effectiveness (PPE). Further, we explored the moderating effects of PPE. We studied 235 tea growers in China to verify the model and analyzed the psychological factors in their decisions regarding organic manure application. The results showed that by incorporating psychological factors, such as MN, ERP, and PPE, the extended TPB's ability to explain farmers' intention to apply organic manure increased by 6%. The results also confirmed that psychological factors (ERP, PPE, AT, PBC, and MN) positively influenced farmers' inclination to use organic manure. Finally, PPE was found to have a negative mediating effect on attitude and intention. Given the influence of these psychological factors (PBC, ERP, and PPE), we discovered that increasing the policy publicity, raising the policy subsidy, and promoting the popularization of sustainable agriculture and environmental awareness, are essential to encourage farmers' utilization of organic manure.

Innovative bio-waste-based multilayer hydrogel fertilizers as a new solution for precision agriculture

The aim of the research work was to present a multilayer hydrogel capsule with controlled nutrient release properties as an innovative fertilizer designed for sustainable agriculture. Preparation of the capsules included the following steps: sorption of micronutrients (Cu, Mn, Zn) on eggshells (1) and their immobilization in sodium alginate, with the crosslinking agent being the NPK solution (2). The capsules were coated with an additional layer of a mixture of biopolymers (0.79% alginate, 0.24% carboxymethylcellulose and 8.07% starch)by means of dipping and spraying techniques. The biocomposites were characterized by limited (<10% within 100 h for the structures encapsulated by the dipping method) release of fertilizer ions (except for small K⁺ ions). The hydrogel fertilizer formulations were analyzed for physicochemical properties such as macro- and micronutrient content, surface morphology analysis, coating structure evaluation, mechanical properties, swelling and drying kinetics. High nutrient bioavailability was confirmed in vitro (extraction in water and neutral ammonium citrate). Germination and pot tests have revealed that the application of multicomponent hydrogel fertilizers increases the length of cucumber roots by 20%, compared to the commercial product.

Phytochemicals from Red Onion, Grown with Eco-Sustainable Fertilizers, Protect Mammalian Cells from Oxidative Stress, Increasing Their Viability

Red onion, a species of great economic importance rich in phytochemicals (bioactive compounds) known for its medicinal properties, was fertilized with sulphur-bentonite enriched with orange residue or olive pomace, with the aim of producing onion enriched in health beneficial compounds. There is a worldwide great demand of minimally processed food or food ingredients with functional properties because of a new awareness of how important healthy functional nutrition is in life. Phytochemicals have the capacity to regulate most of the metabolic processes resulting in health benefits. Red onion bioactive compound quantity and quality can vary according to cultivation practices. The main aims of the current research were to determine the chemical characteristics of the crude extracts from red onion bulbs differently fertilized and to evaluate their biological activity in normal and oxidative stress conditions. The lyophilized onion bulbs have been tested in vitro on two cellular models, i.e., the H9c2 rat cardiomyoblast cell line and primary human dermal fibroblasts, in terms of viability and oxygen radical homeostasis. The results evidenced different phytochemical compositions and antioxidant activities of the extracts obtained from red onions differently fertilized. Sulphur-bentonite fertilizers containing orange waste and olive pomace positively affected the red onion quality with respect to the red onion control, evidencing that sulphur-bentonite-organic fertilization was able to stimulate plant a secondary metabolism inducing the production of phytochemicals with healthy functions. A positive effect of the extracts from red onions treated with fertilizers—in particular, with those containing orange waste, such as the reduction of oxidative stress and induction of cell viability of H9c2 and human fibroblasts—was observed, showing a concentration- and time-dependent profile. The results evidenced that the positive effects were related to the phenols and, in particular, to chlorogenic and p-coumaric acids and to the flavonol kaempferol, which were more present in red onion treated with low orange residue than in the other treated ones.

Industrial Waste Pretreatment Approach for 3D Printing of Sustainable Building Materials

The large volume of industrial by-products and wastes from the construction, timber and paper industries has become a serious challenge worldwide. Recycling these industrial wastes as functional materials in the construction industry is an efficient approach for sustainable development. This study presents a pretreatment approach for recycling construction and demolition waste (CDW) and industrial side-streams (such as green liquor sludge, fiber waste, flotation sand and fly ash) in order to produce a geopolymer for the 3D printing of construction materials. A treatment approach was developed for screening the residues from CDW with a maximum size of 16 mm and for a combined line treatment for industrial side streams. The treatment processes utilized suitable and economical separation techniques for the recycling of waste materials. The crushing of the screened residues resulted in a homogeneous material size that facilitates the separation of mixed wastes and simplifies the classification of materials. The combined plant enabled the cost-effective treatment of various industrial wastes in a single process unit. The results show that the economic and environmental impact of the chosen techniques, in terms of their energy consumption, is highly dependent on the treatment line, separation technique and quantity of the individual waste that is processed. These recycled industrial wastes can be used as sustainable materials for the production of geopolymer concrete, contributing to the sustainability of the construction industry.

A quick review of advantages and limitations of biological fertilizers in wheat cultivation

Achieving adequate, healthy and nutritious food is emphasized as one of the basic rights of individuals in society in all the world countries. In this regard, the agricultural sector is committed to approach the necessary capability in establishing food security and self-reliance on basic products. Soil is very important as a basic source and bed of production, so that food safety mainly depends on soil security and to enlighten thoughts. Due to climate changes, lack of organic matters, and soil conditions, soil fertility management and nutrition of wheat plant are important. To this aim, knowing information about the soils and providing required nutrients could help to approach desired levels of wheat production in quantity and quality. Instead of chemical fertilizers, biological fertilizers have been seen useful for approaching the purposes. However, lack of enough information besides negative sights of view by the farmers are those the most important limiting factors. Therefore, investigating various aspects of biological fertilizers is very important for reaching a point of optimum usage of biological fertilizers for sustainable agricultural systems especially for the wheat production.

The Influence Paths of Agricultural Mechanization on Green Agricultural Development

For sustainable agricultural development, increasing efforts are put on promoting agricultural mechanization and green agricultural development all over the world. Based on the panel data of Chinese provincial agriculture from 2002 to 2018, the System Generalized Method of Moments model and mediation model are constructed to explore the paths of agricultural mechanization affecting green agricultural development. The results show that agricultural mechanization can not only promote the green agricultural development directly but also indirectly by transferring the agricultural labor force and increasing fertilizer input. However, because of the surge of pesticide demand, agricultural mechanization also leads to serious pollution indirectly. With the development of large-scale agricultural machinery, the direct promotion of agricultural machinery on green agricultural development will be more significant. However, it will be less efficient to substitute more agricultural labor force with machinery power. The problem of pesticide abuse will also become more serious. Therefore, it is important for green agricultural development to encourage human capital investment in agricultural mechanization. In addition, more attention should be paid to improving the input efficiency of fertilizers and pesticides so that agriculture will be sustainable in production and the ecological environment.