Crop Grain Research Articles

Efficient and Accurate Calibration of Discrete Element Method Parameters for Black Beans

Discrete element parameters of the black bean (BLB) are key to developing high-performance BLB machineries (e.g., seeders and shellers), which are still lacking in previous literature. In this study, the effects of the radius and lifting speed of cylinder-in-cylinder lifting method (CLM) simulations were investigated to efficiently and accurately obtain the repose angle. Discrete element method (DEM) parameters of the BLB were determined by combining the Plackett–Burman Design test, the steepest ascent design test, and the central composite design test. The results show that the measurement moment (i.e., 12 s) of repose angles should be determined when kinetic energy reaches the minimal threshold (1 × 10−6 J) to efficiently and accurately obtain repose angles; too early or too late a measurement can result in inaccurate repose angles or excessive computation time of the computer, respectively. The lifting speed and cylinder radius affected the lateral displacements of BLBs and came at the cost of higher computation time and memory usage. A lifting speed of 0.015 m s−1 and a radius of 40 mm of the cylinder were determined in CLM simulations. The static friction coefficient and rolling friction coefficient between BLBs significantly affected the repose angles. A static friction coefficient of 0.202 and rolling friction coefficient of 0.0104 between BLBs were obtained based on the optimization results. A low relative error (0.74%) and insignificant difference (p > 0.05) between the simulated and measured repose angles were found. The suggested method can be potentially used to calibrate the DEM parameters of BLBs with good accuracy. The results from this study can provide implications for investigating interactions of BLBs and various BLB processing machines and for the efficient and accurate determination of DEM parameters of crop grains.

A New Proposal for Soybean Plant Stand: Variation Based on the Law of the Minimum.

The hypothesis of this study is that it is possible to determine the plant stand in the soybean (Glycine max L. Merril) crop based on the spatial variability of management units, which are limiting factors in maximizing crop yield. Our objectives were as follows: (I) to evaluate the relationship between soil physical and chemical attributes to establish potential management units for variable-rate seeding; (II) to propose a method for varying plant stands based on the law of minimum soil nutrients; an (III) to relate the interaction between different plant stands on soybean grain yield, taking into account the interaction between the spatial variability of the mapped attributes. Field experiments were carried out on two plots over two agricultural years. The areas were seeded by randomly varying the soybean stand across strips in the first year. The most limiting soil nutrient was established and used, together with the soil CEC, to determine management units (MUs), which were also used to seed soybeans in VRT (Variable Rate Technology) in the same plots in the second year. MUs with the lowest restriction for maximizing yield were sown in the second year with the lowest plant stand. Data were processed using multivariate statistics. Our findings reveal that it is possible to establish MUs for seeding soybeans with different stands following the spatial variability of limiting soil nutrients according to the law of the minimum and thus increase the crop grain yield. Spatial variability of potassium (K) in the plot, identified as limiting, affected the spatial variability of grain yield. Decreasing plant stands in MUs with the lowest limitation level increases yield. However, increasing the stand in MUs with a higher limitation level can lead to increased intraspecific competition, affecting yield as well as increasing input costs.

Co‐inoculation with Rhizobium, Azospirillum, and microalgae increases common bean yield and profitability

AbstractWidely used as inoculants in agriculture, nitrogen‐fixing bacteria can be associated with other plant growth‐promoting microorganisms (PGPMs) to increase crop grain yield. This study aimed to evaluate whether co‐inoculation with Rhizobium tropici and Azospirillum brasilense associated with microalgae or cyanobacteria enhances common bean (Phaseolus vulgaris) grain yield and its economic gains in contrasting sandy and clayey soils. Water‐soluble protein content and indole‐3‐acetic acid (IAA) production of two cyanobacteria (Anabaena cylindrica and Calotrix brevissima) and six Chlorophyta microalgae (Nannochloropsis oculata, Haematococcus pluvialis, Muriellopsis sphaerica, Chlorella protothecoides, Chlorella vulgaris, and Botryococcus braunii) were determined. Anabaena cylindrica and C. brevissima had the highest IAA production, 336.7 ± 44.7 and 94.1 ± 11.8 µg IAA mg−1 of protein, respectively. Two field experiments were carried out to evaluate the triple inoculation of these Chlorophyta microalgae and cyanobacteria associated with R. tropici plus A. brasilense on the agronomic efficiency and profitability of common bean. Co‐inoculation of C. vulgaris plus R. tropici and A. brasilense in common bean had grain yield of 1277.5 kg ha−1 in clayey soil and 2960.3 kg ha−1 in sandy soil, increasing by 219.7 and 656.0 kg ha−1, respectively, in relation to double inoculation of R. tropici + A. brasilense. In the sandy soil, common bean with triple co‐inoculation had the highest profit ($956 ha−1), which was 25.6% higher than the N fertilized plants. Co‐inoculation with PGPMs generated the highest economic gains, and in addition, it is an eco‐friendly agronomic practice for sustainable food production.

Enhancing Iron and Zinc Uptake in Spring Wheat Through Commercial Arbuscular Mycorrhizal Fungi Inoculation under Different Soil Phosphorus Addition Levels

Improving the concentrations and bioavailability of micronutrients, especially iron (Fe) and zinc (Zn), in crop grains is important to alleviate their deficiencies in humans. Inoculating crops with arbuscular mycorrhizal fungi (AMF) can potentially enhance soil nutrient supply and crop yield, but the effectiveness is influenced by soil factors, particularly soil phosphorus (P) availability. A greenhouse pot experiment was conducted to evaluate the effect of a commercial AMF product on spring wheat (Triticum aestivum L.) yield and grain concentrations of Zn and Fe under different soil P addition levels (0, 5 and 20 mg P kg-1 dry soil). Results showed that AMF inoculation significantly increased root colonization rate of wheat across all P addition levels. Wheat growth, as evidenced by dry weights of shoot and grain, was significantly enhanced by AMF and high P addition treatments. AMF inoculation did not affect grain Zn concentration, but significantly increased grain Fe concentration compared to the un-inoculated control. As expected, P addition resulted in a significant reduction in grain concentrations of Fe and Zn, primarily due to a growth dilution effect. An integrated analysis using the radar plot concludes that AMF inoculation is most effective in increasing crop yield and grain micronutrient concentrations when soil P levels are low. Importantly, while adequate P supply is crucial for maintaining crop productivity, it may decrease grain micronutrient availability without complementary strategies.

Relay strip intercropping of soybeans and maize achieves high net ecosystem economic benefits by boosting land output and alleviating greenhouse gas emissions.

Cereal-legume intercropping provides a solution for achieving global food security, but the mechanism of greenhouse gas emissions and net ecosystem economic benefits of maize-soybean relay intercropping are poorly understood. Hence, we conducted a two-factor experiment to investigate the effects of cropping systems, containing maize-soybean relay intercropping (IMS), monoculture maize (M) and monoculture soybean (S), as well as three nitrogen levels at 0 (N0), 180 (N1), 240 (N2) kg N ha-1 on crop grain yield, greenhouse gas emissions, soil carbon stock and net ecosystem economic benefit (NEEB). The average grain yield of IMS (7.7 t ha-1) increased by 28.5% and 242.4% compared with M (6.0 t ha-1) and S (2.2 t ha-1). The land equivalent ratio (LER) of IMS was 2.0, which was mainly contributed by maize (partial LER: 1.2) rather than soybean (partial LER: 0.8). Although the total grain yield of IMS remarkably enhanced by 43.6% and 45.5% in N1 and N2 contrast in N0, the LER was 37.5% and 38.6% lower in N1 and N2 than in N0. The net global warming potential (GWP) of maize and soybean was 11.6% and 1.8% lower in IMS than in the corresponding monoculture, which resulted from a decline in GWP and enhanced soil organic carbon stock rate. Moreover, NEEB was 133.5% higher in IMS (14 032.0 Chinese yuan per year) than in M, mainly resulting from an increase in total economic gains and a decline in GWP cost. A more robust response in yield gain rather than total costs to N inputs of IMS led to 46.8% and 48.3% higher NEEB in N1 and N2 than in N0. Maize-soybean relay intercropping with 180 kg N ha-1 application can obtain yield advantages without raising environmental costs, which provides an approach to achieving sustainable agricultural production. © 2024 Society of Chemical Industry.

Application of Lanthanum at the Heading Stage Effectively Suppresses Cadmium Accumulation in Wheat Grains by Downregulating the Expression of TaZIP7 to Increase Cadmium Retention in Nodes.

Reducing cadmium (Cd) accumulation in wheat is an effective way to decrease the potential threats of Cd to human health. The application of lanthanum (La) in agricultural fields is eliciting extensive attention due to its beneficial effects on improving yields and inhibiting Cd accumulation in edible parts of crops. However, the potential mechanism of La-restricted Cd accumulation in crop grains is not entirely understood. Here, we investigated the effects of La and Cd accumulation in wheat grains by implementing application at the shooting and heading stages. Some associated mechanisms were explored. Results showed that La application at the shooting and heading stages considerably promoted the thousand-grain weight. La application at the shooting and heading stages increased Cd accumulation in the first node beneath the panicle (N1) but reduced Cd levels in the other tissues. La application at the heading stage exerted greater effects on Cd storage in N1 while reducing Cd concentrations in the other tissues compared with La application at the shooting stage. La addition substantially decreased the translocation of Cd from the lower nodes to the upper internodes, but increased Cd translocation from the lower internodes to the upper nodes. The expression of TaZIP7 in N1 was downregulated by La treatment. These results suggest that the effective reduction in Cd in wheat grains by La application at the heading stage is probably a consequence of the successful promotion of Cd storage in nodes by downregulating the expression of TaZIP7 during the grain-filling stage, thereby hindering the redirection Cd from nodes to grains.

VINNYTSIA REGION: STATUS AND TRENDS OF PRODUCTION, PROCESSING AND STORAGE OF GRAIN

The article is devoted to the study of the state of production, processing and storage of grain in the Vinnytsia region. The objectives of the research were to monitor the collected areas and gross harvests of the main crops in 2011-2021, establish the trends of their changes, analyze the capacities of transport and technological equipment and granaries of the region. The analysis was conducted on the basis of data from the State Statistics Service of Ukraine for 2011-2021. The analysis of harvested areas and gross harvests of grain of the main crops at agricultural enterprises of the region in 2011–2021 showed their tendency to increase. During this period, harvested areas increased by 1.42 times, and annual volumes of gross grain harvests had a wave-like growth pattern. Linear trend equations are proposed for forecasting harvested areas and gross grain harvests, which are characterized by coefficients of determination R2 of 0.79 and 0.65, respectively. The largest gross harvests were given by corn, wheat and sunflower, and smaller – by barley, soybeans and rapeseed. In 2018-2021, the gross harvest of these crops was within the following limits (thousand tons): corn 2015-2620, wheat 1200-1691, and sunflower 755-1001. 66 enterprises receive grain from vehicles, and 65 forward it. The average capacity of receiving grain is 3032.41 t/day, and forwarding 1183.61 t/day. There are 21 railway transport enterprises hiring, and 55 enterprises offering leave. The average capacity of receiving devices from the railway is 949.52 t/day, and the output capacity is 1448.69 t/day. 111 grain dryers from 11 producing countries are installed at the considered 53 enterprises of the region. Of them, 18.9% of enterprises have dryers of Ukrainian production only, 20.8% of enterprises have both domestic and foreign ones, but the majority of enterprises have dryers of foreign production only, which are 1.85 times more than the number of Ukrainian made dryers. It was established that 82 separators are used for grain cleaning at 37 elevators, most of which (63%) are domestically produced, which outnumber imported ones by 1.73 times. The total capacity of simultaneous storage of grain in 67 elevators of agricultural enterprises is 3554.35 thousand tons, of which 2449.41 thousand tons have harvesting elevators and 1104.94 thousand tons – production elevators. Their simultaneous storage capacity is less than the forecast values of gross grain harvests in 2022 – 6354.2 thousand tons, which requires the expansion of the elevator network of the Vinnytsia region.

A Synthesis Analysis of the Relationship between Main and Ratoon Crop Grain Yields in Ratoon Rice

Ratoon rice represents a viable means to enhance rice production efficiency in terms of both area and time. Nonetheless, the development of specific varieties tailored for ratoon rice has been hindered by the complexity of trait considerations required during breeding/screening processes. A pivotal step towards advancing ratoon rice breeding programs involves reducing the dimensionality of selection traits. In this study, we performed a comprehensive analysis exploring whether the yield of the main crop could serve as a predictor for ratoon crop yield, thereby simplifying the selection process. Our findings revealed significant variability in the rice yields of both main and ratoon crops, with the ratoon crop yield averaging 51% of the main crop. Importantly, the correlation between grain yields of the main and ratoon crops did not deviate from the identity line, substantiating the feasibility of predicting ratoon crop yield based on the main crop yield. The number of panicles in the ratoon crops was found to be closely linked to that of the main crop; however, the size values of the panicles in the ratoon crops exhibited less of a dependency on the main crop’s panicle size. Additionally, a general decrease in grain weight was observed in the ratoon crops compared to the main crop. In summary, this study elucidates a pathway for the simplification of selection traits, thereby enhancing the efficiency of breeding high-yielding ratoon rice varieties, with the ultimate aim of fostering the sustainable development of ratoon rice.

Content and Distribution of Radionuclides in the Profile of Light Gray Forest Soil and Agrocenosis Plants

The results of long-term radiation monitoring of light gray forest soil and cultivated plants of the reference area are presented. Correlation analysis has determined the relationship between the distribution of artificial and natural radionuclides in the soil profile with its agrochemical properties. The distribution of radionuclides in the soil profile is determined by the intensity of the podzolic process. The profile shows the eluvial-illuvial differentiation of radionuclides, when an increase in their accumulation occurred in the illuvial horizon. According to the density of contamination of the surface soil layer with cesium-137 and strontium-90, a satisfactory level of the environmental situation was determined, according to which the soil of the site is classified as uncontaminated. Rows of cultivated plants with an increasing ability to accumulate caesium-137 and strontium-90 from the soil have been constructed. The grain of all grain crops accumulated less cesium-137 and strontium-90 compared to straw. All grown plant products of all types of crops fully met veterinary and hygienic standards for the content of caesium-137 and strontium-90 in feed (green mass, straw and feed grain) and food grains. The coefficients of accumulation and transfer of caesium-137 and strontium-90 from soil to plants were calculated.

Predicting Cd accumulation in crops and identifying nonlinear effects of multiple environmental factors based on machine learning models

The traditional prediction of the Cd content in grains (Cdg) of crops primarily relies on the multiple linear regression models based on soil Cd content (Cds) and pH, neglecting inter-factorial interactions and nonlinear causal links between external environmental factors and Cdg. In this study, a comprehensive index system of multi-type environmental factors including soil properties, geology, climate, and anthropogenic activity was constructed. The machine learning models of the tree-based ensemble, support vector regression, artificial neural network for predicting Cdg of rice and wheat based on the environmental factor indexes significantly improved the accuracy than the traditional models of linear regression based on soil properties. Among them, the tree-based ensemble models of XGboost and random forest exhibited highest accuracies for predicting Cdg of rice and wheat, with R2 in the test dataset of 0.349 and 0.546, respectively. This study found that soil properties, including Cds, pH, and clay, have greater impacts on Cdg of rice and wheat, with combined contribution rates accounting for 65.2 % and 29.7 % respectively. Since wheat sampling areas are located in central and northern China, they are more constrained by precipitation and temperature than rice sampling areas in the south. Geologic and climate factors have a greater impact on Cdg of wheat, with a combined contribution rate of 49.9 %, which is higher than the corresponding rate of 20.9 % in rice. Furthermore, the Cdg of rice and wheat did not exhibit an absolute linear relationship with Cds, and excessively high Cds can reduce the bioconcentration factor of Cd accumulation in crops. Meanwhile, other environmental factors such as temperature, precipitation, elevation have marginal effects on the increase of Cdg of crops. This study provides a novel framework to optimize traditional soil plant transfer models, as well as offer a step towards realizing high precision prediction of Cd content in crops.

Forage boost or grain blues? Legume choices shape Kernza intermediate wheatgrass dual-purpose crop performance

Context or problemKernza intermediate wheatgrass is a new perennial grain crop with the potential to produce high nutritive value forage when intercropped with legumes. Understanding the potential benefits of intercropping systems requires considering the interaction between different legume species intercropped, intermediate wheatgrass row spacing, and environments encompassing spatial and temporal variation. Objective or research questionWe aimed to evaluate the effect of these factors on the biomass allocation to harvestable (grain, intermediate wheatgrass forage, legume forage) and non-harvestable (weed biomass) outputs. MethodsIn four environments, given by the combination of two sites (Wisconsin, USA) and two establishment years, we sowed intermediate wheatgrass in two row spacings in eight cropping systems: three intermediate wheatgrass monocultures [control without N fertilization, intermediate wheatgrass fertilized with 45 or 90 kg N ha−1 as urea], and four intermediate wheatgrass-legume intercrops (intermediate wheatgrass with alfalfa, Berseem clover, Kura clover, or red clover). We evaluate grain yields, intermediate wheatgrass and legume forage, and weed biomass over three consecutive years. ResultsOur results suggest that intercropping legumes does not affect Kernza grain yield in the first grain production year, which is the year with the highest yield potential. In subsequent production years, grain yields were lower in red clover intercrops than in intermediate wheatgrass monoculture control or fertilized, depending on the environment. Among the legumes tested in our study, red clover and alfalfa were suitable for increasing total biomass production in most of the environments and red clover reduced weed biomass compared to intermediate wheatgrass monocultures. ConclusionsOur results encourage intercropping legumes with intermediate wheatgrass because of the increase in forage yield and quality. These benefits can compensate for lower Kernza grain yields commonly observed in the second and third production years. Implications or significanceOur study provides valuable insights into the intermediate wheatgrass potential as a dual-use crop for grain and forage production. Improving our understanding of the factors that influence grain yield and forage production such as post-harvest management, multiple forage harvests or grazing, may optimize the productivity and sustainability of these cropping systems.

Using VIS-NIR hyperspectral imaging and deep learning for non-destructive high-throughput quantification and visualization of nutrients in wheat grains

High-throughput and low-cost quantification of the nutrient content in crop grains is crucial for food processing and nutritional research. However, traditional methods are time-consuming and destructive. A high-throughput and low-cost method of quantification of wheat nutrients with VIS-NIR (400-1700 nm) hyperspectral imaging is proposed in this study. Stepwise linear regression (SLR) was used to predict hundreds of nutrients accurately (R2 > 0.6); results improved when the hyperspectral data was processed with the first derivative. Knockout materials were also used to verify their practical application value. Various nutrients' characteristic wavelengths were mainly concentrated in the visible regions of 400–500 nm and 900–1000 nm. Finally, we proposed an improved pix2pix conditional generative network model to visualize the nutrients distribution and showed better results compared with the original. This research highlights the potential of hyperspectral technology in high-throughput and non-destructive determination and visualization of grain nutrients with deep learning.

Transport characteristics of heavy metals in the soil-atmosphere-wheat system in farming areas and development of multiple linear regression predictive model

Heavy metal accumulation in agricultural products has become a major concern. Previous studies have focused on the transport of heavy metals from the soil and their accumulation in crops. However, recent studies revealed that wheat leaves, ears, and awns can also transport and accumulate heavy metals. Wheat grains can be influenced by two sources of heavy metals: soil contamination and atmospheric deposition. To comprehend the transport characteristics of heavy metals in soil, atmospheric deposition, and wheat, 37 samples each for wheat rhizosphere soil, wheat roots, stems, leaves, and grains were collected. Fifteen samples of atmospheric dry deposition and atmospheric wet deposition were collected from Linshu County (northern area), China. Based on the test data, the characteristics of heavy metals and their distribution in the study area were analyzed. Migration patterns of heavy metals in crops from different sources were investigated using Pearson correlation and redundancy analysis. Finally, a predictive model for heavy metals in wheat grains was developed using multiple linear regression analysis. Significant disparities in the distribution of heavy metals existed among wheat roots, stems, leaves, and grains. The coefficient of variation of heavy metals in atmospheric deposition was relatively high, indicating discernible spatial patterns influenced by human activities. Notably, a positive correlation was observed between the concentration of heavy metals in wheat grains and atmospheric deposition of Hg, Cd, and Pb. Conversely, Zn and Ni levels in wheat grains were significantly negatively associated with soil Zn, Ni, pH, and OM content. The contribution of heavy metal elements from different sources varied in their impact on the grain's heavy metal content. Specifically, atmospheric deposition was the primary source of Hg and Pb in wheat grains, while Cd, Ni, Cu, and Zn were predominantly derived from soil. Using a multiple linear regression model, we could accurately predict Hg, Pb, Cd, Ni, Zn, and As concentrations in crop grains. This model can facilitate quantitative evaluation of ecological risk of heavy metals accumulation in crops in the study area.

Nano-enabled strategies to promote safe crop production in heavy metal(loid)-contaminated soil

Nanobiotechnology is a potentially safe and sustainable strategy for both agricultural production and soil remediation, yet the potential of nanomaterials (NMs) application to remediate heavy metal(loid)-contaminated soils is still unclear. A meta-analysis with approximately 6000 observations was conducted to quantify the effects of NMs on safe crop production in soils contaminated with heavy metal(loid) (HM), and a machine learning approach was used to identify the major contributing features. Applying NMs can elevate the crop shoot (18.2 %, 15.4–21.2 %) and grain biomass (30.7 %, 26.9–34.9 %), and decrease the shoot and grain HM concentration by 31.8 % (28.9–34.5 %) and 46.8 % (43.7–49.8 %), respectively. Iron-NMs showed a greater potential to inhibit crop HM uptake compared to other types of NMs. Our result further demonstrates that NMs application substantially reduces the potential health risk of HM in crop grains by human health risk assessment. The NMs-induced reduction in HM accumulation was associated with decreasing HM bioavailability, as well as increased soil pH and organic matter. A random forest model demonstrates that soil pH and total HM concentration are the two significant features affecting shoot HM accumulation. This analysis of the literature highlights the significant potential of NMs application in promoting safe agricultural production in HM-contaminated agricultural lands.

Relay-cropping enhances the availability of low iLUC risk lignocellulosic feedstock for advanced biofuels

The relay-cropping (R) of a winter cereal and a high biomass yielding legume for advanced biofuel production can enlarge the legume growing season, thus increase its biomass yield and synchronize nitrogen (N2)-fixation capacity to uptake. The aim of the present study was to evaluate the biomass and food yield of two sunn hemp (Crotalaria juncea L.; cv. Ecofix) – wheat (Triticum aestivum L.; cv. Bologna) relay-cropping systems compared to double-cropping, in order to explore the impact on grain and biomass yield of the variable crops overlapping periods. The evaluated relay-cropping systems foreseen an early November wheat sowing into no till bare soil with: i) sunn hemp harvested at full flowering (beginning of November, R1) and ii) sunn hemp harvested at the end of flowering (end of November, R2). In the control (C) double-cropping, sunn hemp was harvested at the beginning of flowering (end of September). Quantitative and qualitative parameters were evaluated for each system across two growing seasons (2019–20 and 2021–22). Sunn hemp biomass and wheat straw residues were determined. The grain qualitative parameters determined for wheat were: grain volume weight (VW), crude protein, wet gluten, starch and Zeleny index (ZI). The R1 and R2 sunn hemp-wheat relay-cropping biomass yield (12.5 Mg d.m. ha−1 y−1) was similar to C (11.3 Mg d.m. ha−1 y−1). In 2019–20, environmental conditions were more favorable, thus, yields were higher than in 2021–22 by 72 %. Wheat grain yields in 2021–22 were higher in R1 (2.9 Mg d.m. ha−1) than C (2.0 Mg d.m. ha−1), with R2 showing intermediate values. In 2019–20, however, the grain quality was higher in R1 than in C for crude protein (+11 %), wet gluten (+15 %), and ZI (+26 %) eventually due to an increased N2-fixation by sunn hemp that reached full flowering. The local availability of low iLUC risk lignocellulosic feedstock for advanced biofuel could be increased through crop intensification with relay-cropping, showing the potential to provide additional biomass and enhance food quality thus complying with the additionality measures set out by the Delegated Regulation of REDIII.

A review of intercropping systems in Western Canada

AbstractIntercropping is gaining interest from Western Canadian producers who are looking for information on how to incorporate intercrops into their production systems. This review summarizes agronomic research on intercropping from the last 40 years in Western Canada and discusses the potential challenges of integrating intercropping into existing crop rotations while identifying challenges and possible solutions. Reviewed literature indicates that several intercrop combinations have been tested in small plots involving up to four crops simultaneously grown, with over 60% comprising pulse–oilseed combinations followed by pulse–cereal combinations at ∼30%. The land equivalent ratio (LER) for pulse–oilseed and pulse–cereal averaged 1.11 and 1.13, respectively. Key agronomic factors that influenced LER in different intercrop combinations have been summarized, and the relationship of N and seeding rate with crop grain LER and partial land equivalent ratio has been assessed. While the relationship between N rate and LER was unclear in pulse–oilseed combinations such as pea (Pisum sativum L.)–canola (Brassica napus L.), LER decreased linearly with increasing N rate (p < 0.004) in pea–barley (Hordeum vulgare L.) intercrop. We highlighted that incorporating intercrops into current rotations will decrease crop rotation lengths with possible implications for disease management. There are many logistical challenges to intercropping but new technology may help producers to adapt.

The accumulation of cadmium and lead in wheat grains is primarily determined by the soil-reducible cadmium level during wheat tillering

The significant increase in cadmium (Cd) and lead (Pb) pollution in agricultural soil has greatly heightened environmental contamination issues and the risk of human diseases. However, the mechanisms underlying the transformation of Cd and Pb in soil as well as the influencing factors during their accumulation in crop grains remain unclear. Based on the analysis of the distribution trend of Cd and Pb in soil during the growth and development stages of wheat (tillering, filling, and maturity) in alkaline heavy metal-polluted farmland in northern China, this study investigated the response mechanism of soil heavy metal form transformation to soil physicochemical properties, and elucidated the main determining periods and influencing factors for Cd and Pb enrichment in wheat grains. The results showed that an increase in CEC and SOM levels, along with a decrease in pH level, contributed to enhancing the bioavailability of Cd in the soil. This effect was particularly evident during the tillering stage and grain filling stage of wheat. Nevertheless, the effects of soil physicochemical properties on bioavailable Pb was opposite to that on bioavailable Cd. The enrichment of Cd and Pb in grain was significantly influenced by soil pH (r = −0.786, p < 0.01), SOM (r = 0.807, p < 0.01), K (r = −0.730, p < 0.01), AK (r = 0.474, p = 0.019), and AP (r = −0.487, p = 0.016). The reducible form of Cd in soil during the wheat tillering stage was identified as the primary factor contributing to the accumulation of Cd and Pb in wheat grains, with a significant contribution rate of 84.5%. This study provides a greater scientific evidence for the management and risk control of heavy metal pollution in alkaline farmland.

Identifying limiting nutrient(s) for better bread wheat and tef productivity in acidic soils of north‐west Amhara, Ethiopia

AbstractFood crop productivity is still low because of the decline of soil fertility in Ethiopia, particularly in north‐western Amhara. Fine‐tuning the source and rate of nutrients is required to solve soil fertility problems along landscape positions. Therefore, this study was initiated to investigate the need to apply selected nutrients to tef and wheat in acidic soils. This nutrient omission study was conducted in 74 farmers’ fields of Gozamen and Machakel districts. The omitted nutrients were sulfur (S), zinc (Zn), and boron (B). Potassium (K) was added, consisting of N, P, K, S, Zn, and B (All+K). Nitrogen plus phosphorus (NP) and no fertilizer treatments were used as positive and negative controls, respectively. Furthermore, 50% and 150% of the All+K treatments were also included. The finding revealed that the application of different nutrient types at variable rates had a significant role in the grain and biomass yield of both test crops in the acidic soils. No tef yield and the lowest yield of bread wheat were obtained from the no fertilizer application treatment. The application of All+K had no significant yield advantage compared to NP fertilizer alone. This implies that N and P are the most yield‐limiting nutrients to produce tef and bread wheat, whereas KSZnB nutrients are not yield limiting. Therefore, refining the rates of N and P in acidic soils is needed for the economical use of fertilizers. Finally, applying blended fertilizers without empirical evidence is not recommended for smallholder farmers in the study area.

Tillage and mulching influence weed community dynamics and crop productivity of Sesbania alley–based food–fodder systems in rainfed agro-ecosystems

Context or problemCrop yield in rain-fed agro-ecosystems is limited by low soil moisture availability and weeds. Objective or research questionThis study aimed to answer the questions- 1. Do tillage practices, mulching and Sesbania alley-based food-fodder cropping system affect weed dynamics under rainfed agro-ecosystem? and 2. Is the productivity of a Sesbania alley-based rainfed food-fodder system affected by tillage practice, mulching or crop sequence? MethodsA four-year field experiment was conducted with Sesbania alley-based food-fodder systems (sorghum – chickpea; sorghum – barley; sorghum – mustard), and three tillage practices (conventional tillage; minimum tillage during rainy season - zero tillage during winter season; conventional tillage during rainy season - zero tillage during winter season) with and without mulch. ResultsDuring the study period, conservation agricultural techniques resulted in a shift in weed flora in all Sesbania alley-based cropping systems. Grass, broadleaf, and total weed densities declined by 8–9%, 35–38%, and 11–13%, respectively, across diverse cropping systems from 2014 to 15; however, sedge population increased (13–29% increase) during the same period. Mulching practices considerably reduced sedge density compared to the without-mulch treatment in all the tillage combinations. The lowest total weed biomass was recorded for minimum tillage during the rainy season and zero tillage + mulching treatment (17 g m–2) during the winter season. Weed species abundance and dominance were greater in 2014, while the diversity and evenness of weed species were higher in 2016, which indicates a weed shift. Sesbania hedgerow + (sorghum-mustard) with conventional tillage during the rainy season and zero tillage during the winter season without mulching had the highest weed diversity index and evenness than that of other treatment combinations. The Sesbania dry matter (DM) yield was significantly higher by 13% and 11% in minimum tillage during the rainy season and zero tillage during the winter season with mulching compared to conventional tillage without mulch in 2015–16 and 2016–17, respectively. However, tillage and mulching had a significant effect on the grain and straw yields of winter crops. All the tillage practices with Sesbania mulching recorded higher grain and straw yields for winter crops compared to the un-mulched treatments. ConclusionsThe innovative Sesbania alley-based rainfed food-fodder system, along with reduced tillage and mulching, improved productivity and altered weed dynamics. Implications or significanceThe knowledge gathered on weed dynamics may aid in determining weed management tactics under conservation agricultural practices. Double cropping is possible without compromising fodder needs by employing suitable tillage and mulching procedures, as well as Sesbania alley-based cropping systems.

The Preparation and Contact Drying Performance of Encapsulated Microspherical Composite Sorbents Based on Fly Ash Cenospheres.

Sorption technologies are essential for various industries because they provide product quality and process efficiency. New encapsulated microspherical composite sorbents have been developed for resource-saving contact drying of thermolabile materials, particularly grain and seeds of crops. Magnesium sulfate, known for its high water capacity, fast sorption kinetics, and easy regeneration, was used as an active moisture sorption component. To localize the active component, porous carriers with an accessible internal volume and a perforated glass-crystalline shell were used. These carriers were created by acid etching of cenospheres with different structures isolated from fly ash. The amount of magnesium sulfate included in the internal volume of the microspherical carrier was 38 wt % for cenospheres with ring structures and 26 wt % for cenospheres with network structures. Studies of the moisture sorption properties of composite sorbents on wheat seeds have shown that after 4 h of contact drying the moisture content of wheat decreases from 22.5 to 14.9-15.5 wt %. Wheat seed germination after sorption drying was 95 ± 2%. The advantage of composite sorbents is the encapsulation of the desiccant in the inner volume of perforated cenospheres, which prevents its entrainment and contamination and provides easy separation and stable sorption capacity in several cycles.