Alternative fertilization practices lead to improvements in yield-scaled global warming potential in almond orchards

This study investigates the impact of alternative fertilization practices on the yield-scaled global warming potential (YS-GWP) in almond orchards. Almond production is a contributor to greenhouse gas emissions, primarily due to nitrogen-based mineral fertilizers. This research aims to identify strategies that reduce the environmental footprint of almond cultivation while maintaining yield. Field experiments were conducted in an almond orchard using three alternative fertigation practices: Advance Grower Practice (AGP), Pump and Fertilize (P&F), and High Frequency Low Concentration (HFLC). AGP is the current practice used by producers to meet annual N demand for almond tree growth; P&F is a reduction in applied N rate in response to measured N concentrations in the groundwater so that the added N and groundwater N reach the same total N applied; HFLC is a practice of applying smaller N rates per individual event. HFLC uses a greater number of fertigation events to reach similar total annual N load as other treatments. Cumulative N2O and CH4 emissions were used to determine GWP by converting the emissions to carbon dioxide equivalents (CO2eq) within a 100-year horizon. Nitrous oxide emissions were multiplied by a radiative forcing potential CO2eq of 298 and CH4 by 25 (UNFCCC, 2007). The results revealed that both P&F and HFLC reduced the YS-GWP compared to AGP. HFLC demonstrated 52–78% decrease in GWP per unit of almond yield compared to AGP, while P&F showed 48–58% decrease over AGP. These reductions were attributed to the reduced nitrous oxide emissions associated with P&F and HFLC. Further, P&F and HFLC tended to have higher N use efficiency than AGP. We demonstrate that adopting alternative fertilization practices can effectively mitigate the environmental footprint of almond orchards while maintaining crop yields. These practices offer viable options for almond growers to reduce greenhouse gas emissions, enhance sustainability, and contribute to climate change mitigation.

Climate change impacts on insect pests for high value specialty crops in California

California is a global leader in production and supply of walnuts and almonds, and the state is the largest producer of peaches in the U.S. These crops have an important contribution to the California's agricultural economy. Damages to these crops from lepidopteran pests, mainly from Codling moth (Cydia pomonella) (family: Tortricidae), Peach twig borer (Anarsia lineatella) (family: Gelechiidae) and Oriental fruit moth (Grapholita molesta) (family: Tortricidae), are still high, despite the improvement in pest management activities. Given that temperature increase can directly impact the rate of growth and development of these pests, it is important to understand to what extent dynamics of these pests will change in future in California. The objective of this study was to quantify changes in the biofix, lifecycle length, and number of generations for these pests for the entire Central Valley of California. Using a well-established growing-degree days (GDD) model calibrated and validated using observations from orchards of California, and climate change projections from the Coupled Model Intercomparison Project phases 5 and 6 (CMIP5 and CMIP6) General Circulation Models, we found that biofix dates of these pests are expected to shift earlier by up to 28 days, and length of generations is expected to be shortened by up to 19 days, and up to 1.4 extra generations of these pests can be added by the end of the century depending on the scenario. Results from this work would enable industries to prioritize development of practices that are more effective in the long run, such as developing better cultural and biological pest solutions and insect tolerant varieties. Growers and researchers can take proactive actions to minimize future risks associated with these damaging pests. This work can be scalable to other pests and regions to understand regional dynamics of damaging agricultural pests under climate change.

Production of high protein yeast using enzymatically liquefied almond hulls

Animal feed ingredients, especially those abundant in high quality protein, are the most expensive component of livestock production. Sustainable alternative feedstocks may be sourced from abundant, low value agricultural byproducts. California almond production generates nearly 3 Mtons of biomass per year with about 50% in the form of hulls. Almond hulls are a low-value byproduct currently used primarily for animal feed for dairy cattle. However, the protein and essential amino acid content are low, at ~30% d.b.. The purpose of this study was to improve the protein content and quality using yeast. To achieve this, the almond hulls were liquefied to liberate soluble and structural sugars. A multi-phase screening approach was used to identify yeasts that can consume a large proportion of the sugars in almond hulls while accumulating high concentrations of amino acids essential for livestock feed. Compositional analysis showed that almond hulls are rich in polygalacturonic acid (pectin) and soluble sucrose. A pectinase-assisted process was optimized to liquefy and release soluble sugars from almond hulls. The resulting almond hull slurry containing solubilized sugars was subsequently used to grow high-protein yeasts that could consume nutrients in almond hulls while accumulating high concentrations of high-quality protein rich in essential amino acids needed for livestock feed, yielding a process that would produce 72 mg protein/g almond hull. Further work is needed to achieve conversion of galacturonic acid to yeast cell biomass.

Cascading use of macadamia nutshell for production of energy and adsorbents through biomass gasification

This research delves into the viability of implementing macadamia nutshell in a cascading utilization strategy through gasification. The investigation entails a comprehensive scrutiny of the physiochemical attributes of the feedstock, coupled with an in-depth exploration of the transformations in the properties of both gaseous and solid products stemming from gasification under conditions pertinent to industry applications. Remarkably, macadamia nutshell gasification consistently produced syngas with high CO and H2 levels, resulting in an average Lower Heating Value of 13.8 MJ m-3. The characterization of the obtained chars unveiled a porous structure replete with micro-mesopores, attributing to a carbon dioxide adsorption capacity of 223 mg g-1. Surface analysis discerned a diverse array of functional groups and a marked presence of potassium and calcium (up to 31.37 wt% and 4.12 wt%, respectively). These findings bolster the potential of macadamia nutshell for cascading gasification, offering both energy generation and the production of solid adsorbents. The amassed dataset contributes to the realization of waste-free energy production through biomass gasification, thus propelling the progress of sustainable energy technologies.

How to find alternative crops for climate-resilient regional food production

CONTEXT. Agricultural food production is both affected by and contributing to climate change. At the global scale, agri-food systems are responsible for one-third of total greenhouse gas emissions. With progressing climate change, the risks of crop failure increase. Thus, an urgent need is to reduce emissions from food systems while increasing their resilience to climate change. Enormous untapped potentials to achieve these dual goals lie in transforming agri-food systems towards more diverse, plant-based, and regional food production systems. OBJECTIVE. In this paper, we present an innovative approach for identifying climate-adapted alternative food crops that could (1) help to diversify existing cropping systems and thus increase their climate resilience and can be (2) nutritious elements of plant-based regional diets with reduced emissions. METHODS. The approach builds on the model ecocrop to select food crops that could benefit from regionally projected changes in climate. The model-based analysis is complemented with a literature review to examine the ecocrop results for their plausibility and provide a broader assessment of potentials for cultivation, utilization, and nutritional values of model-selected crops. RESULTS AND CONCLUSIONS. The approach is applied to Switzerland, where we identify eight alternative crops with the potential to increase climate resilience while contributing to healthy human diets of regional consumers with benefits for climate mitigation (almond, pecan, sesame, durum wheat, quinoa, lentil, lupine, and borage). The literature review indicated that the increasing demand for many of these crops suggests great potential for regional marketing of crop products. The results produced in this study provide an initial guide for researchers and innovative farmers interested in experimenting with alternative crops in Switzerland, thus promoting climate-smart food system transformation from the production side. SIGNIFICANCE. Using our unbiased bottom-up screening approach, we identified climate-adapted alternative crops that can provide essential nutrients, cover nutritional gaps in Switzerland, diversify existing production systems, and improve sustainability.

Construction of eco-friendly multifunctional cashew nut shell oil-based waterborne polyurethane network with UV resistance, corrosion resistance, mechanical strength, and transparency

Vegetable oil-based waterborne polyurethane possesses numerous advantages, including its sustainability, environmental friendliness, and economic benefits. Nevertheless, its application is constrained by inferior mechanical properties and a low glass transition temperature. Hereon, the renewable polyols of sorbitan monooleate/cytidine were incorporated into the anionic cashew nut shell oil-based WPU network through molecular structure design. Series of CNSL-based WPU with outstanding UV resistance, mechanical properties, corrosion resistance, and transparency were successfully synthesized. The effects of Ce/SP content on the performance of CNSL-based WPU dispersions and films were investigated. The results demonstrated a remarkable enhancement in the properties of the modified WPU films. Specifically, the tensile strength and Tg were increased from 9.7 MPa to 23.9 MPa and 1.1 °C to 45.8 °C, respectively, while maintaining a toughness of 26 MJ/m−3, which attained or even surpassed the current vegetable oil-based WPU systems. It was confirmed excellent UV resistance within the UVB and UVC spectrums. Furthermore, with the increase in Ce/SP content, the water contact angle of films increased slightly, enhancing its water resistance. The IE of WPU-Ce and WPU-SP films reached 97.93 % and 98.42 % respectively, indicating outstanding corrosion resistance. This work presented novel strategies for the advancement of high-performance bio-based WPU, which held promising potential in diverse areas including coatings, corrosion protection, inks, and wearable applications.

Recycling of Hazelnut Husk; from Bio-waste to Phyto-Assisted Synthesis of Silver Nanoparticles

In the present work, green synthesis is utilized in the synthesis of silver nanoparticles with hazelnut (Corylus Colurna) husk which is the outer leaf part of the hazelnut shell and is considered bio-waste. According to transmission electron microscopy and x-ray diffraction analysis, the morphology of the silver nanoparticles synthesized by 0.1 g/mL hazelnut husk extract is found to be spherical with an average diameter of 6.57 nm and possesses ultra-narrow size distribution. UV-visible spectrometry reveals the absorbance peak range between 450–475 nm which is in the range of surface plasmon resonance peak of silver nanoparticles with spherical morphology. Antibacterial properties of the synthesized silver nanoparticles were tested on E. coli and significant antimicrobial activity was found with up to 79 % areal inhibition efficiency. The research revealed that the hazelnut husk extract, a reducing agent used in syntheses with different mass concentrations of hazelnut husk extract, also affects the size of the nanoparticles, allowing for the possibility of controlling their size. The antibacterial properties of silver nanoparticles, synthesized in a spherical form of different sizes, correspondingly increased their effect on bacteria which is observed in the inhibition zone. The synthesis of silver nanoparticles, which can be used in many fields for agriculture, cosmetics, and medical purposes, using plant extract and minimal chemicals is crucial because it affects its toxicity. The synthesis of silver nanoparticles with hazelnut husk not only reduces the chemical waste and toxicity, but it is both easily accessible and helps the environment and sustainability by recycling a normally considered bio-waste by-product of high-value-added crop to a technologically valuable product silver. Moreover, synthesized silver nanoparticles could be an essential part of applications ranging from antibacterial surface treatments to drug delivery systems.

Contract farming and the adoption of sustainable farm practices: Empirical evidence from cashew farmers in Ghana

Contract farming has been shown to increase agricultural productivity and thus welfare of farmers in developing countries. However, studies that look at the potential environmental effects of contract farming remain quite scanty. This is however crucial, since contract farming may contribute to intensification in cultivation of the contracted crops, in terms of area and the intensity of inputs used. This study investigates the impact of participation in contract farming on sustainable farm practices, using a marginal treatment effects (MTEs) approach to account for potential selection bias and heterogeneity across households. The empirical results show significant heterogeneity in the effects of contract farming on the intensity of sustainable farm practice use. In particular, farmers with high propensity to participate in contract farming tend to have low probabilities of using sustainable farm practices. The findings of this study not only provide new insights into the heterogeneous effects of contract farming, but also entry points for further research to address the dual challenge of agriculture to produce sufficient food, while reducing the adverse impact on the environment.

Application of machine learning to predict of energy use efficiency and damage assessment of almond and walnut production

A study was conducted in Shahrekord city, Iran, focusing on improving the production of almond and walnut crops on rural agricultural lands. The gardeners selected for the study shared similar characteristics and production histories. One of the major challenges in producing these crops was the manual harvesting process, which required a significant amount of human labor in the region. To collect data, questionnaires and face-to-face interviews were conducted. The study used machine learning models, specifically artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) models, to predict energy use efficiency and environmental impacts in almond and walnut production. Among the models used, the ANFIS model with a three-level topology was found to be the most accurate in predicting output energy generation and environmental impacts in both almond and walnut production. The R2 values for the testing stage ranged from 0.969 to 0.996 for output energy generation and 0.994 to 0.997 for environmental impacts. The study demonstrated the effectiveness of using machine learning models like ANN and ANFIS in predicting energy use efficiency and environmental impacts in almond and walnut production, which can aid in planning and managing these crops more sustainably and efficiently in the future.

An Eco-Friendly Modification of a Walnut Shell Biosorbent for Increased Efficiency in Wastewater Treatment

Herein, we report the performance of some low-cost biosorbents developed by environment-friendly modification of walnut shells. Two types of biosorbents were prepared by ecological modification of walnut shell surfaces: (1) biosorbents obtained by hot water treatment (WSH2O) and (2) biosorbents produced by mercerization (WSNaOH). Different techniques were used to evaluate the morphological, elemental, and structural modification of the biosorbents, by comparison with raw materials. These characterization techniques involved scanning electron microscopy (SEM) coupled with energy-dispersive X-ray analysis, and Fourier-transform infrared spectroscopy (FTIR). The biosorbents were employed for the removal of methylene blue (MB) and crystal violet (CV) cationic dyes (as model organic pollutants) from aqueous solutions. The kinetic adsorption data mainly followed the pseudo-first-order model. The maximum adsorption capacities of the produced biosorbents ranged from 102 to 110 mg/g and were observed at 330 K. Equilibrium data for adsorption were fitted to Langmuir and Freundlich isotherm models. The calculated values of thermodynamic parameters suggested that the investigated adsorption processes were exergonic (ΔG < 0) and exothermic (ΔH < 0). In addition, a possible valorization of the cost-effective and eco-friendly spent biosorbents was tested by performing secondary adsorption of the anionic dyes.