Annual Crops Research Articles

Perennial crops shape the soil microbial community and increase the soil carbon in the upper soil layer

Soil biodiversity is threatened by intensive agriculture that relies on annual grain crop production, thus leading to a decline in soil functions and ecosystem services. Perennial grain crops have a positive impact on the soil microbial community, but the responsive microbial groups and the magnitude of their response remain uncertain. To elucidate this, we analysed soil microbial biomass and community composition, bacterial growth and soil total carbon in five crops: organic perennial intermediate wheatgrass (IWG, Thinopyrum intermedium, Kernza®), organic IWG-alfalfa intercrop, organic biennial grass-legume mixture, organic annual wheat or rye and conventional annual wheat. The analysis was carried out at three time points under two growing seasons at four different soil depths. Five years after establishment, IWG had greater amounts of soil total fungi and bacteria, and of arbuscular mycorrhizal (AM) fungi, saprotrophic fungi, gram-negative (G−) and gram-positive (G+) bacteria compared to annual wheat. Crop perenniality influenced the soil microbial community structure although precipitation, soil temperature and water content were the main drivers of the patterns of and temporal variations in the microbial community. Perennial crops, with reduced tillage and low nitrogen input management increased the proportions of fungi relative to bacteria, AM fungi to saprotrophic fungi, G− bacteria to G+ bacteria, and the growth rate of total bacteria. This resulted in a more active soil microbial community with higher microbial biomass than annual wheat and contributed to the increased soil total carbon storage in the 0–5 cm soil layer in a humid continental climate. The findings emphasize the importance of combining a no tillage strategy with long-term vegetation cover to increase soil quality.

Development and assessment of Nirgundi-Chakramardha biopesticide against Diamondback Moth on Cabbage

Introduction: The global population is rapidly approaching 9.7 billion by 2050, with Africa and Asia playing significant roles in this growth. This surge necessitates increased crop production, highlighting the importance of effective pest control to ensure food security. India, facing an annual crop loss of about 30% due to pests and diseases, emphasizes the urgency of maintaining ecological balance in natural ecosystems. The diamond back moth (Plutella xylostella L.) poses a substantial threat to cruciferous plants globally, causing severe yield losses of 50–80% in infested cabbage. Addressing this challenge is crucial for minimizing crop losses and securing successful harvests. Our study aimed to analyze the emergence and abundance of small, medium, and large-sized larvae before and after applying treatments. Materials and Methods: A study with five treatments, including Nirgundi-chakramardha biopesticide and a control (Cypermethrin), was conducted. Each treatment was replicated four times, and the entire experiment was set up using a randomized block design. Results: After chemical application, all treatments displayed significant differences. The biopesticide in our study produced notable results within trial groups. Notably, the control group exhibited excellent results compared to the other treatments. Conclusion: The Nirgundi-chakramardha Biopesticide exhibited insecticidal activity against Diamondback moth pests, specifically targeting medium-sized larvae. Although not statistically significant compared to the control group, its efficacy in pest control, especially during the larval stage, indicates its potential as a viable pest management option. Further research and optimization could improve its effectiveness in combating Diamondback moth infestations.

EXPLORING THE RELATIONSHIP BETWEEN RAINFALL AND CROP YIELD AND BEST PRACTICES ADOPTION USING PARTICIPATORY APPROACH.

Crop yield is a standard measurement for the amount of agricultural production. Sustainable agriculture demands an increase in crop yield. This study deals with rainfed agriculture; hence, precipitation becomes the driving factor for crop yield. Heat maps are used to examine the rainfall and crop yield correlations. ML is an essential tool in decision-making, and many ML algorithms are available for prediction. This study uses the ML algorithms to predict whether the crop yield will increase with increased rainfall. Logistic regression, Decision tree classifier, Random Forest classifier, and XGBoost classifier are the algorithms chosen for analysis. Altogether this region consists of forty crops but focuses on five predominant annual crops. Implementation-based results are the universal goal of every research which society needs. The chances of implementation are associated with two major components: the reliability of the results and society's willingness. Analysis of these components needs ground truthing and Participatory Rural Appraisal, respectively. Farmers and villagers filled out a questionnaire about the details required for this study. The survey was an active approach to collecting necessary information from the participants. The survey showed positive results among one hundred and fifty samples from six blocks. Finally, cashew nut, sugarcane, and turmeric showed good dependency on the precipitation, and around 88% of villagers are ready to implement the results derived from ML algorithms.

Estimation of radiological health risks due to 226Ra, 232Th, and 40K in foods consumed in Iraqi Kurdistan Region

ABSTRACT This study investigates the activity concentration of natural radionuclides in a diverse range of food samples in the Koya district markets food baskets, including both domestic and imported products. The samples cover annual crops (e.g. coffee, tea, kidney beans), tree nuts (e.g. almonds, pistachios), and other items (e.g. beef, fish, milk) by using a high-purity germanium (HPGe) detector. This research addresses a notable gap by providing baseline data on radionuclide concentrations and assessing potential health risks. Average activity concentrations for ²²⁶Ra, ²³²Th, and ⁴⁰K were 0.943, 0.367, and 191.8 Bq kg−1, respectively. Radium equivalent activity values ranged from 2.88–58.48 Bq kg−1, all below the safety limit. The average excess lifetime cancer risk (ELCR) was 0.154 mSv a−1, indicating safety for most samples, though coffee and tea showed higher levels. This study provides new data crucial for future research and regulatory monitoring, underscoring the need for further investigation into geological impacts on radionuclide levels.

The Cycles agroecosystem model: Fundamentals, testing, and applications

Models of the soil–plant-atmosphere continuum are repositories of knowledge and gears in analytical and decision support tools applied to agroecosystems. In this paper, we present the Cycles agroecosystem model theory along with test cases and applications. Cycles combines innovations for simulating soil hydrology and biogeochemistry, including carbon and nitrogen saturation theory, with a modular software architecture. These elements enable simulating monoculture or polyculture crop sequences and associated management practices, containerizing for applications that require high-performance computing, and data assimilation at runtime. A comparison of simulated and measured daily evapotranspiration (ET) obtained with the eddy covariance method for maize (Zea mays L.) and shrub willow (Salix spp.) shows that Cycles represents well meteorological and vegetation controls of ET (root mean square error or RMSE = 0.75 mm d-1). Cycles accurately simulated differences of 150 mm in growing season ET between these two plant communities. Comparisons of modeled versus measured soil water content under soybean (Glycine max [L.] Merr.) in southeastern Pennsylvania for six soil layers at 0.1-m increments show accurate representation of water depletion and recharge (RMSE of 0.027–0.011 m3 m−3). Simulations of growth and nitrogen uptake of wheat (Triticum aestivum L.) in eastern Washington also highlight the model’s skill simulating processes that affect water and nutrient fluxes simultaneously. To highlight Cycles’ suitability for incorporation in high performance computing applications, we present a coupling of Cycles with an autonomous crop sequence builder (Cycles-A) in the Chesapeake Bay watershed. This system automatically identified areas for double cropping and selected the optimum combination of annual crops across the watershed. The Cycles model innovations and agroecosystem framing continue advancing the premise of making models not only dynamic knowledge repositories but useful tools for research and landscape management.

Can repellent crops reduce the abundance of the common vole (Microtus arvalis) as a way to reduce crop damage?

The common vole is one of the most damaging rodents in agriculture. A number of methods are used to suppress its numbers and limit damage. One option is growing crops that are not suitable for voles; this might limit their numbers and distribution. Through long-term monitoring of common voles throughout the Czech Republic, their abundance in eleven crop types (annual, biennial and perennial crops) was evaluated through active burrow counts. Reference crops were selected from perennials and biennials and annual crops were selected as potential repellents. The perennial crops were clover with alfalfa, which serve as the primary habitat for voles. These crops are where voles are found in their highest densities, and from which they spread to the surrounding crops during periods of high abundance. The biennial winter rape was selected because it provides favourable conditions for voles to overwinter and multiply rapidly in the spring. Compared to perennial crops and winter rape, significantly lower numbers of voles were found in onions, poppy seeds and maize. Additionally, fewer voles were also found in mustard compared to perennial crops. Onion and poppy were the only crops to show a significantly lower abundance of voles in comparison to wheat. The annual crops tested are unattractive to voles and due to the cultivation practices used, they do not even have enough weeds as food. As profitable crops they can be cultivated over sufficiently large areas to potentially prevent the spread of voles to surrounding crops, especially during outbreak years.

Characterising the Genomic Landscape of Differentiation Between Annual and Perennial Rye.

Annuality and perenniality represent two different life-history strategies in plants, and an analysis of genomic differentiation between closely related species of different life histories bears the potential to identify the underlying targets of selection. Additionally, understanding the interactions between patterns of recombination and signatures of natural selection is a central aim in evolutionary biology, because patterns of recombination shape the evolution of genomes by affecting the efficacy of selection. Here, our aim was to characterise the landscape of genomic differentiation between weedy annual rye (Secale cereale L.) and wild perennial rye (Secale strictum C. Presl), and explore the extent to which signatures of selection are influenced by recombination rate variation. We used population-level sequence data of annual and perennial rye to analyse population structure and their demographic history. Based on our analyses, annual and perennial rye diverged approximately 26,500 years ago (ya) from an ancestral population size of ~85,000 individuals. We analysed patterns of genetic diversity and genetic differentiation, and found highly differentiated regions located in low-recombination regions, indicative of linked selection. Although all highly differentiated regions, as revealed by F ST-outlier scans, were located in low-recombining regions, not all chromosomes showed this tendency. We therefore performed a gene ontology enrichment analysis, which showed that highly differentiated regions comprise genes involved in photosynthesis. This enrichment was confirmed when F ST outlier scans were performed separately in low- and intermediate-recombining regions, but not in high-recombining regions, suggesting that local recombination rate variation in rye affects outlier scans. Cultivated rye is an annual crop, but the introduction of perenniality may be advantageous in regions with poor soil quality or under low-input farming. Although the resolution of our analysis is limited to a broad-scale, knowledge about the evolutionary divergence between annual and perennial rye might support breeding efforts towards perennial rye cultivation.

Exploring the rhizosphere of perennial wheat: potential for plant growth promotion and biocontrol applications

Perennial grains, which remain productive for multiple years, rather than growing for only one season before harvest, have deep, dense root systems that can support a richness of beneficial microorganisms, which are mostly underexplored. In this work we isolated forty-three bacterial strains associated with the rhizosphere of the OK72 perennial wheat line, developed from a cross between winter common wheat and Thinopyrum ponticum. Identified using 16S rDNA sequencing, these bacteria were assessed for plant growth-promoting traits such as indole-3-acetic acid, siderophores and ACC-deaminase acid production, biofilm formation, and the ability to solubilize phosphate and proteins. Twenty-five strains exhibiting in vitro significant plant growth promoting traits, belong to wheat keystone genera Pseudomonas, Microbacterium, Variovorax, Pedobacter, Dyadobacter, Plantibacter, and Flavobacterium. Seven strains, including Aeromicrobium and Okibacterium genera, were able to promote root growth in a commercial annual wheat cultivar while strains from Pseudomonas genus inhibited the growth of Aspergillus flavus and Fusarium species, using direct antagonism assays. The same strains produced a high amount of 1-undecanol a volatile organic compound, which may aid in suppressing fungal growth. The study highlights the potential of these bacteria to form new commercial consortia, enhancing the health and productivity of annual wheat crops within sustainable agricultural practices.

Cover Crop Systems Impact on Biomass Production, Carbon-to-Nitrogen Ratio, Forage Quality, and Soil Health in a Semi-arid Environment

Cover cropping is a soil restorative strategy that can save degraded soils and offer additional benefits relative to the traditional fallow-based practice in semi-arid cropping systems. This study aimed to (i) quantify the above (shoot)- and belowground (root) biomass production, nutritive value, and tissue carbon and nitrogen concentrations from different annual cool-season cover crop systems, and (ii) determine their effects on soil organic carbon, total nitrogen, soil respiration, and soil microbial population biomass in a semi-arid environment. Treatments used were monocultures of annual ryegrass (Lolium multiflorum Lam.), oat (Avena sativa L.), faba bean (Vicia faba L.), yellow sweetclover [Melilotus officinalis (L.) Lam], winter pea (Pisum sativum L.), two three-species mixtures (Mix 1: annual ryegrass + faba bean + yellow sweetclover and Mix 2: Oat + faba bean + winter pea), and a fallow laid out in a randomized complete block design with three replications. Averaged across years, Mix 2 produced greater shoot biomass (9714 kg DM ha-1; SE = 699) than all other cover crop systems except, the monoculture of oat (7970 kg DM ha-1; SE = 699). The plant tissue C/N ratio of the mixtures and monoculture legumes was mostly similar (range = 19.4 – 29.1). Overall, legumes produced superior relative feed value (RFV; 112 – 161) compared to grass monocultures and mixtures (RFV; 80 – 95). Soil gram-negative bacteria biomass was greatest under the yellow sweetclover monoculture. Based on the results of this study, the mixed cover crop systems (Mix 1 and Mix 2) offered a better chance of fulfilling the dual role of soil health improvement and feed quality for livestock in this semi-arid environment.

The “right‐to‐farm” in Lac Saint‐Pierre (Québec, Canada) floodplains: Are problem‐framing processes able to foster conservation conflict resolution?

AbstractUsing qualitative data, we investigate the impact of the problem‐framing process on stakeholder mobilization for fish habitat restoration and its influence on transforming agricultural practices in floodplains. Problem‐framing involves defining and delineating a problem to suggest practical and measurable solutions for addressing it. We are examining how the conservation conflict changes over time in Lac Saint‐Pierre (LSP), part of the St. Lawrence River Basin in Québec, Canada. Such conflicts arise when there are differing perspectives, interests, or actions regarding conservation goals and objectives. In recent decades, the LSP floodplain has undergone significant changes, particularly the conversion of perennial crops to intensive annual crops, which are deemed incompatible with the ecological needs of yellow perch. This species has experienced a notable decline in LSP since the 1990s, prompting Québec authorities to impose a moratorium on yellow perch fishing in 2012 to safeguard stocks. This moratorium has catalyzed efforts at the policy level to restore its habitat. However, it has also engendered tensions between agricultural activities and conservation endeavors aimed at restoring yellow perch habitat, constituting the conservation conflict under investigation. To investigate this issue, we adopt a post‐normal science approach characterized by reflexivity, inclusivity, and transparency in addressing epistemological and ontological uncertainties among LSP stakeholders. Our findings offer insights into stakeholders' perspectives on the problem‐framing process and its outcomes, highlighting both supportive actions enhancing the effectiveness of certain strategies among LSP stakeholders and barriers hindering their mobilization. These results underscore the importance of incorporating diverse stakeholder perspectives during the problem‐framing process to enhance the robustness of the science–policy interface.

TOMATO GROWING TECHNOLOGY AND BIOLOGICAL FEATURES OF THE CULTURE

Tomato is a heat-loving annual crop that belongs to the nightshade family. Seeds begin to germinate at temperatures no lower than 10–15 °C. At a soil temperature of 15 °C, 14–22 days pass from sowing to emergence, and if it is below 10 °C, the seeds do not germinate at all.

Genome-wide association analysis reveals novel candidate loci and a gene regulating tiller number in orchardgrass

Tillers are specialized lateral shoots arising from axillary buds at basal nodes, and are also an important agronomic trait that determines the aboveground biomass and grain yield of various gramineous crops. So far, few genes have been reported to control tiller formation and most have been in the annual crop rice (Oryza sativa). Orchardgrass (Dactylis glomerata) is an important perennial forage crop with great economic and ecological value, but its genes regulating tillering have remained largely unknown. In the present study, we used a natural population of 264 global orchardgrass germplasms to determine genes associated with quantitative variation in tiller number through genome-wide association study analysis. A total of 19 putative loci and 55 genes associated with tiller number were thus identified. Additionally, 26 putative differentially expressed genes with tiller number, including DgCYC-C1, were identified by RNA-seq and genome-wide association study analysis. DgCYC-C1 which is involved in cell division, was overexpressed, revealing that DgCYC-C1 positively regulates tiller number. These results provide some new candidate genes or loci for the improvement of tiller number in crops, which might advance new sustainable strategies to meet global crop production challenges.

Effect of alternating temperature regimes on seed germination of guar [Cyamopsis tetragonoloba (L.) Taub.

Guar [Cyamopsis tetragonoloba (L.) Taub.] 2n=14, is an annual crop that belongs to the Fabaceae family and has a spring–summer growth cycle. This species has been assuming increasing importance among agro-industrial crops due to the high galactomannan content of its seeds for which a multitude of food and non-food applications have been developed. Guar is a viable rotation crop for growers in Mediterranean areas and can result in diversification in crop production systems. The effects of four alternating day/night temperature regimens on C. tetragonoloba seed germination were tested: (T1) 23/15 °C, (T2) 21/13 °C, (T3) 19/ 11 °C, and (T4) 17/09 °C with a 16/08 h light/dark photoperiod, respectively. Seeds from two guar cultivars (RGC-0936 and RGC-1066) were used. Treatments consisted of four replicates of 50 seeds each, arranged in a split-plot design with temperatures as the main plot and cultivars as the subplot. The results showed that lower temperatures reduced guar seed germination. The highest germination percentages were obtained at the 21/13 °C and 23/15 °C temperature regimens, while a significant drop in germination percentage occurred for the 19/11 °C treatment, and the lowest germination percentages were observed at 17/09 °C. No statistically significant differences were found between the two cultivars studied for seed germination percentages. The interaction effects among the different alternative temperature regimes on seed germination and guar cultivars were not statistically significantly different. The values obtained at the 21/13 °C temperature treatment allow us to conclude that this regimen is the minimum acceptable combination of temperatures to program the sowing date.

Average daily gain in lambs grazing mixed annual forage species compared with single species and relationship to feed on offer

Context Annual forage crops provide high-quality fodder for livestock during typical autumn and winter feed-gaps in the south-east of Australia and benefits through rotations in cropping systems. While benefits from intercropping with cereals and pasture or mixing canola and peas have been studied in Australia, the potential animal-production benefits of grazing mixed annual species forage crops have not been examined. Aims To determine average daily gain (ADG) and rumen fluid parameters when sheep graze mixtures of annual fodder crops compared with a single species. Methods Ninety six Dorset × Border Leicester × Merino lambs (mean = 44.3 ± 0.55 kg) were allocated to one of the following four treatment groups (n = 24/treatment) on the basis of sex and liveweight; a single species brassica control (canola) (Br) or annual forage species mixes containing brassica (canola, turnip, radish) and cereal (wheat, cereal rye) (B + C), brassica and legume (vetch, arrowleaf clove) (B + L) or brassica, cereal and legume (B + C + L). Liveweight and rumen fluid parameters were assessed prior to grazing and again 21 and 35 days after the commencement of grazing. Key results Mean ADG from Day 0 to Day 21 was lower for female, but not male, lambs grazing the Br control (231 ± 23 g head−1 day−1) than for those grazing any forage mix (B + C = 292 ± 23 g head−1 day−1, B + L = 296 ± 23 g head−1 day−1, B + C + L = 310 ± 22 g head−1 day−1). Liveweight change over 35 days of grazing was not different between any forage mixtures. Rumen fluid pH was higher (P < 0.001) for sheep grazing forages containing cereals (B + C = 6.97 ± 0.06, B + C + L = 6.86 ± 0.06) than for those grazing brassica or legume (Br = 6.59 ± 0.06, B + L = 6.68 ± 0.06). Total volatile fatty acid concentration was lower and rumen pH was higher when sheep grazed B + C than when they grazed any other forage mix. Conclusions The higher ADG in females grazing mixtures than in those grazing the Br was related to higher dry matter on offer. Further research should determine whether the lower pH observed when sheep grazed brassica and legume than when grazing mixes containing cereals is associated with subacute rumen acidosis and reduced fibre degradation and forage energy utilisation. Implications Mixed forage species can provide higher DM on offer and ADG. Improved rumen efficiency could be related to improved growth.

Landscape Dynamics and Environmental Fragility Zoning in Hinh River Basin: Insights for protecting natural ecosystems

The landscapes in the Hinh River Basin are crucial and highly sensitive to climate change for the coastal province of Phu Yen and the entire south-central coastal region of Vietnam, offering vital environmental services to its downstream areas. Hinh River Basin has a rich system of rivers and streams and abundant surface water resources. However, it remains one of the region's top localities at risk and a very vulnerable region. This study aims to evaluate the changes in landscape (LC) over 10 years (2010-2023) and predict LC over the next six years using machine-learning (ML) algorithms on Google Earth Engine. To achieve these study goals, we establish: (i) potential environmental fragility (PEF) levels based on: terrain slope; geological domains; river hierarchy; percentage of sand in soil; annual mean precipitations; and (ii) emergent environmental fragility (EEF) levels through the addition of LC parameter to model. The methodology includes integrating the Analytic Hierarchy Process (AHP) into a Geographic Information System (GIS). Results show that three LC types (water, annual industrial crop, forest) are related to extremely high EEF. The predictive model suggests that, by 2030, the forest and annual industrial crop LCs in the study area will increase by around 20%. The analysis results show that there has been an increase in the area of planted forests, which can confirm the futher effectiveness of agricultural, forestry, afforestation and forest protection programmes in the study area (Plan for the implementation of forestry development strategy for the period 2021-2030, with a vision to 2050, Phu Yen Province, No 126/KH-UBND 13/7/2021; and Decision on the approval of the project for planting 15 million trees in Phu Yen Province for the period 2021-2025, No 1646/QĐ-UBND 16/11/2021).

394 Cover crops for efficient grazing systems

Abstract Grazing of cool-season cover crops provides a sustainable solution for extending the grazing season while potentially reducing the environmental impact of conventional row-crop farming practices. The primary objective of this study was to evaluate how different mixtures of cover crops affect stocker performance when grazed. The study was conducted across 18 paddocks that were sown with grass [‘Coker’ oat (Avena sativa)], grass + legume [‘Dixie’ crimson clover (Trifolium incarnatum)], or grass + legume + brassica [‘Turnip’ brassica (Brassica rapa subsp.; rapa)] at the Wiregrass Research and Extension Center in Headland, AL. These paddocks were randomly assigned to either grazed or un-grazed conditions (n = 3). In this study, yearling beef steers with an average body weight (BW) of 266 ± 44 kg were grazed in paddocks using the put and take method to maintain a forage allowance of 1 kg dry matter per kilogram of BW. Forage samples were collected biweekly to analyze biomass, botanical composition, and forage nutritive value. Grazing occurred from January 17 to March 22, 2023 (65 d). Steer BW were recorded at the beginning and end of the grazing season to calculate average daily gain. The data were subjected to analysis as a two-way ANOVA using Glimmix in SAS 9.4 (SAS Institute, Cary, NC), harvest date was considered a repeated measure. No treatment × grazing interaction was observed on forage yield performance [average (AVG) forage yield kg DM/ha; P = 0.460]. In addition, no difference was observed among the different cover crop mixtures (AVG forage yield kg DM/ha; P = 0.670). Grazed paddocks had a greater crude protein when compared with ungrazed paddocks (Grazed vs. Ungrazed %; P = 0. 017). However, there was no effect of cover crop mixture on crude protein (CP) concentration (AVG CP %; P = 0.670 for treatment effect). These results indicate that cool-season annual cover crops can provide sufficient forage yield and quality to support sufficient animal gains, even during the relatively short grazing season. Incorporating cover crops not only improves agricultural sustainability but can also enhance the resilience and long-term health of the agroecosystem.

Biomass yield, crude protein yield and nitrogen use efficiency over nine years in annual and perennial cropping systems

Emerging biorefinery technologies can lead to new applications and new markets for various types of crop biomass. This may allow significant changes in agricultural production from crop rotations dominated by annual grain and seed crops towards annual or perennial cropping systems composed with the aims of higher biomass yield and environmental sustainability. In this study, we investigated 7 annual and 7 perennial cropping systems on a sandy loam soil, with large differences in N fertilization. Yield of dry matter (DM) and crude protein (CP) was measured over nine growing seasons from 2013 to 2021. A conventional four-year cash crop rotation with cereals and winter oil seed rape served as a reference and achieved mean annual yields of DM and CP of 10.5 and 0.85 Mg ha−1 y−1, respectively, across the nine years. Continuous maize and triticale had significantly higher DM and CP yields, with 57 and 15 % increases in DM yield compared to the reference crop rotation, respectively. Optimized four-year crop rotations with various annual crops including triticale, maize, beet, hemp or faba bean and various intermediate crops achieved 51–84 % and 42–78 % higher yield of DM and CP, respectively. Perennial cropping systems with festulolium and tall fescue with three or four harvests per year achieved 63–65 % higher DM yield and 192–200 % higher CP yield (2.47–2.55 Mg ha−1 y−1) compared to the cash crop rotation. Perennial cropping systems with miscanthus and willow had high DM but low CP yield. As a measure of nitrogen use efficiency, partial factor productivity of DM yield (PFPDM) and CP yield (PFPCP) were calculated, and both varied significantly between cropping systems, with highest PFPDM for M. × giganteus and willow (114–192 kg DM kg N−1) and lowest for festulolium and tall fescue (38–40 kg DM kg N−1). PFPCP was highest for the optimized crop rotations (6.88–7.94 kg CP kg N−1) and lowest for miscanthus (2.94–4.98 kg CP kg N−1). Across 12 of the cropping systems, which included both protein crops and lignocellulosic crops, there was a non-linear DM yield response to N fertilization rate with PFPDM decreasing from 134.9 to 37.2 kg DM kg N−1 when increasing the N rate from 50 to 500 kg ha−1 y−1. On the other hand, there was a linear CP yield response and, therefore, a constant PFPCP of 5.94 kg CP kg−1 N across N fertilization rates. The results clearly indicate that cropping systems can be modified to achieve higher DM and CP yields but also that choice of cropping system and optimal N fertilization may need adjustment depending on the use of the harvested biomass, the possibilities for biorefining into various components and products as well as the economic value of the components.

Mild three-stage alkali-oxygen treatment preserving the native macromolecular structure of lignin for effective disassembling of tobacco stalk

Tobacco stalks, as one of the annual economic crops rich in biomacromolecules such as cellulose and hemicellulose, are more difficult to decompose into cellulose fibers due to their high degree of lignification compared to other ordinary straw feedstocks, resulting in their underutilization. In this study, we developed a mild three-stage alkali‑oxygen (AO) process to efficiently deconstruct the tobacco stalk cell walls. The process, involving alkaline dosages of 15 %, 10 %, and 3 % at each stage, effectively dissociated the cell walls and yielded cellulose fibers with high brightness (42.0 % ISO). The organics in the spent liquor, including lignin, hemicellulose, and small-molecular extracts, were isolated through acid/ethanol precipitation and organic solvent extraction. Lignin characterization by 2D HSQC NMR indicated that the majority of native β-aryl ether linkages were preserved after AO treatment, making it suitable for producing chemicals or biofuels via depolymerization. Additionally, the small-molecular extracts contained numerous depolymerized products from lignin and carbohydrates, as well as bioactive compounds derived from the tobacco stalk. Overall, this mild, efficient, and eco-friendly process offers a promising approach for the valorization of tobacco stalks and similar biomass resources.

Integrated farming optimization ensures high-yield crop production with decreased nitrogen leaching and improved soil fertility: The findings from a 12-year experimental study

Context or problemSustainable farming practices, including precision fertilization, water-saving irrigation and recycling of organic materials, have been implemented worldwide in recent decades to achieve high crop yields and minimize nonpoint source pollution. However, the comprehensive impacts of these agricultural practices have seldom been systematically evaluated in field production. As agricultural intensification started in the 1980s, most previous studies focused on a single practice in the context of low land productivity. Objective or research questionThe objective of this research is to investigate and evaluate how holistic farming practices affect both crop production and environmental quality. MethodsWe reported findings from a 12-year experiment (2008–2020) in the highly intensive North China Plain (NCP) farming region, and conventional and optimized farming measures were compared. Three field treatments with annual double cropping (winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.)) were chosen in the study, i.e., control without nitrogen (N) application (CK), farmers’ conventional practices (CON), and optimized practices (OPT), were chosen for this study. ResultsCompared with the CON treatment, OPT reduced N fertilizer input by 41.4 % and irrigation water by 27.1 % but produced similar grain yields; OPT increased the N recovery efficiency (REN) and N utilization efficiency (NUT2E) by 90.4 % and 53.0 %, respectively; these values were much greater than the increases in REN (+56.1 %) and NUT2E (+25.5 %) when soil N change was not considered. Similarly, compared with those in the CON treatment, the soil N stock (0–60 cm) in the OPT treatment increased by 8.4 %, and the N loss via leaching, ammonia volatilization and N2O + NO + N2 decreased by 47.1 %, 11.4 % and 28.6 %, respectively. ConclusionsOur study revealed that the integration of optimized practices of organic material recycling, precision fertilization and water-saving irrigation substantially reduced N losses, mainly through decreased N leaching, but maintained fertilizer N in the root-zone soil layer, which is important for a sustainable and high-yield crop production. Implications or significancesThe dissemination of these optimized practices to other regions in China and beyond will be highly important for achieving the dual goals of food security and environmental protection.

Groundwater table prediction and seasonal variation influenced by short rotation willow plantation on marginal riparian lands of the Prairie potholes in Canada

Shallow groundwater consumption via phreatophytic transpiration and resulting vegetation-linked groundwater table (GWT) fluctuation is a typical soil hydrological process in wetland riparian areas. However, upland and riparian land use alterations may further influence the shallow GWT fluctuation, temporally and spatially. In this multi-year field study, we investigated whether introducing short rotation willow (SRW) positively or negatively affects the shallow GWT, soil water availability, and soil health on marginal riparian lands of the Prairie Pothole Region (PPR). We compared the impact of SRW on these parameters to two common land uses: annual crop (AC) and pasture (PA). Depth to GWT was monitored via data loggers from 28 wells in two semi-arid PPR sites. The GWT depth varied by land use practices only in site B (p < 0.001; PA > SRW = AC) but not significantly in site A (p = 0.325), and the patterns were inconsistent between sites. In GWT depth prediction, the performance of Artificial Neural Network (ANN) was better than Autoregressive Integrated Moving Average (ARIMA) models but was inconsistent alike with field observations. The GWT depth responded to seasonal precipitation and potential evapotranspiration (ET) patterns. The monthly GWT fluctuations peaked between June and August due to increased precipitation, while they were lower during May and September with reduced precipitation; however, these variations were not significant (p > 0.05). Higher precipitation and lower potential ET throughout the wet year (i.e., in 2014) significantly (p < 0.05) raised GWT (i.e., decreased depth to GWT) under all land uses, and vice versa. Our study indicated that planting SRW in marginal riparian land of the PPR would not negatively impact shallow GWT or soil water availability. Moreover, the SRW plantation could also help manage soil salinity without severely depleting the soil's nutrient pools or diminishing soil quality and health indicator parameters measured during the first rotation.