Understanding biorefining efficiency--the case of agrifood waste

Determinants of carbon and nitrogen sequestration in multistrata agroforestry

Agroforestry has the potential to sequester carbon (C) and nitrogen (N), thereby counteracting climate change and soil degradation. However, the lack of empirical quantitative evidence on determinants of C and N stocks hampers the management of these stocks. The aim of this study was to identify the key determinants of the C and N stocks in multistrata agroforestry. We sampled 81 plots with broad variation in 12 hypothetical determinants of C and N stocks aboveground and in two soil layers, located in three Ethiopian regions with varied multistrata agroforestry traditions and characteristics. Above-ground stocks were assessed using an allometric equation, and soil stocks were assessed with the fixed-depth method. The hypothetical determinants, i.e., the duration of agroforestry practice, the tree density, the proportion of plants with a high basal diameter, legumes and native species, the species diversity, the main crops, soil texture and pH, and altitude, were tested using linear mixed models. The duration of agroforestry, tree density, and proportion of plants with a high basal diameter (>25 cm) explained half of the variation in the soil C stock, which represented nearly three quarters or more of the total C stock. Duration and tree density explained most of the soil N stock, although legumes also influenced soil N. A high proportion of large legume trees reduced C/N, whereas a high proportion of large non-legume trees increased C/N. The aboveground C stock was explained by species diversity or the proportion of stems with a basal diameter >10 cm, depending on the main crop. There is a high potential to manage C and N stocks and their persistence, as well as soil productivity, by managing the duration of agroforestry, the density of large trees, the proportion of legumes, and the main crops in multistrata agroforestry.

Cellulose Recovery from Agri-Food Residues by Effective Cavitational Treatments

Residual biomass from agri-food production chain and forestry are available in huge amounts for further valorisation processes. Delignification is usually the crucial step in the production of biofuels by fermentation as well as in the conversion of cellulose into high added-value compounds. High-intensity ultrasound (US) and hydrodynamic cavitation (HC) have been widely exploited as effective pretreatment techniques for biomass conversion and in particular for cellulose recovery. Due to their peculiar mechanisms, cavitational treatments promote an effective lignocellulosic matrix dismantling with delignification at low temperature (35–50 °C). Cavitation also promotes cellulose decrystallization due to a partial depolymerization. The aim of this review is to highlight recent advances in US and HC-assisted delignification and further cellulose recovery and valorisation.

How Much Is the Eco-Efficiency of Agricultural Production in West China? Evidence from the Village Level Data

This study evaluates the eco-efficiency of agriculture in Pupiao Town, in the Yunnan province of China, through micro-level research. The term "eco-efficiency" refers to the efficiency with which ecological resources are used to meet human needs. Interviews and field research were conducted to collect the data of the 23 villages from 2016 to 2018. The Data Envelopment Analysis model (DEA) was used for data analysis. The results were as follows: (1) The eco-efficiency scores of Pupiao Town had considerable spatial heterogeneity, exhibiting a general trend of higher in the middle and lower in the east and west, which suggested eco-efficiency may be correlated with topography and transportation. (2) The value of eco-efficiency for the entire town had considerable areas for improvement and showed a slow-growth trend. (3) Fertilizers, pesticides, agricultural diesel, agricultural carbon emission, and non-point source pollution had a significant impact on eco-efficiency, followed by agricultural labor and arable land. (4) Agricultural chemicals were primary determinants affecting eco-efficiency. Most of the factors had a stronger effect on the eastern and western regions. The study suggests that transportation should be improved to promote the conveyance of market information and the application of more efficient and productive farm methods. The most important way is to improve effective utilization and to reduce the amount of agricultural chemicals. In addition, it is necessary to offer technical training and help to support farmers in upgrading their farm operations.