Aboveground Dry Biomass Research Articles

Pilot Evaluation of Field Pea Accessions Under Water Deficit Conditions

Field pea, a key pulse crop for sustainable agriculture, faces significant production challenges due to drought, exacerbated by extreme climatic changes. This study evaluated 17 field pea plant introductions (PIs) and two commercial varieties under greenhouse conditions to assess their performance, determine the relationships between agronomic traits and grain yield (GY), and identify genotypes with stable yields under drought stress. Two water treatments were applied: 100% field capacity for well-watered (WW) and 60% field capacity for water deficit (WD) conditions, with drought stress imposed 21 days after planting. Significant genotypic variation was observed under both conditions. Water deficit significantly reduced GY, the number of pods per plant (NPP), plant height (PH), aboveground dry vegetative biomass (ADVB), and days to maturity (DTM) while increasing stomatal density on both adaxial (SD.ADX) and abaxial leaf surfaces (SD.ABX). Traits associated with GY in WW, such as NPP, PH, ADVB, and SD.ADX, showed stronger correlations under WD, with DTM being significantly associated with GY only in WD. Top-performing genotypes in both conditions exhibited higher pod numbers, increased aboveground dry vegetative biomass, late maturity, and lower adaxial stomatal density. Notably, PI 272215 was identified as a top performer under both conditions, with an 88% yield stability index. PI 180702 demonstrated comparable performance to PI 272215 but with no yield loss under the same conditions. These findings can be used for future field pea breeding programs aimed at developing drought-tolerant field pea varieties.

Impact of the Russian invasion on wheat biomass in Ukraine

Abstract Ukraine was the seventh-biggest worldwide producer of wheat in 2021 before the Russian invasion. The war caused a disruption of the global wheat market but the impact on the different levels of the production chain remains unclear. Here we leverage high resolution satellite imagery and crop modeling to analyze specifically the impact of the war on the evolution of the dry aboveground biomass in wheat fields. We compare the Kherson region, a battlefield occupied by the Russian army in 2022 with the Poltava region which was not invaded. We also compare the wheat biomass in both regions in 2022 with the two previous years before the war. We find that the wheat biomass sharply declined in the Kherson region in 2022 only. We interpret this result as a consequence of the abandonment of invaded land by farmers. The lack of agricultural management, in particular the lack of fertilization and irrigation could explain the reduced crop growth in summer, thereby contributing to shortages in the wheat production chain.

Estimation of aboveground biomass of Alfalfa using field robotics

Alfalfa is a high-yielding forage crop that is widely grown in the United States for grazing, hay and silage making. A proper maintenance of these grasslands is necessary to ensure optimum productivity and profits. The pre-harvest estimation of biomass yield helps in quantifying the profits and optimizing the forage allocation in advance. Most traditional methods of forage estimation are relatively laborious and time-consuming. Recent developments in contact and remote sensing technologies opened numerous paths for performing aboveground biomass estimation tasks with flexibility and easiness. This study focused on the development of crop height measurement systems for estimating the aboveground biomass yield of Alfalfa (Medicago sativa L.). Five different systems for measuring crop height were evaluated on their ability to estimate aboveground wet and dry biomass. The crop height measurement systems used in this study were Structure-from-Motion, Ultrasound Sensor and Ski, Inertial Measurement Unit and Ski, Inertial Measurement Units and Roller, and a Depth Camera. The results indicated that the system using the Inertial Measurement Unit sensor and ski (IMU-Ski) performed the best among ground-based methods (R2= 0.79; SeY= 3166 kg-wet/ha). The Structure-from-Motion (SfM) method using UAV also provided satisfactory results for biomass predictions (R2= 0.74; SeY= 2543 kg-wet/ha). The models based on IMU-Ski and UAV-based SfM methods were facilitated with vegetation coverage as an additional independent variable to evaluate their effect on biomass predictions. The results indicated that the vegetation coverage did not improve the predictions in any of these systems. Thus, the models based on only the crop height (IMU-Ski and UAV-SfM) were the recommended approaches for Alfalfa biomass estimations. The addition of data points for wide ranges of crop height and vegetation coverage is recommended for future studies to improve the results and ensure the adaptability of these systems in varying environmental conditions.

Influence of moisture supply during the growing period on productivity and fodder value of soybean

Abstract The paper presents the results of research on comparative study of seed yield formation and aboveground biomass yield of soybean in years with different moisture availability, under the conditions of the Central region of the Non-Chernozem zone of Russia. It has been found that the maximum accumulation of both raw and dry aboveground biomass, crude protein and fodder units in soybean agrocenosis is observed at the stage of full seed (R6). The average values for maximum yields in the experiment were the following: of aboveground raw biomass – 24.8 t/ha, aboveground dry biomass – 6.82 t/ha, protein yield in aboveground dry biomass – 1 278 kg/ha, yield in fodder units – 3.68 t/ha, the contribution of leaves to the yield of aboveground dry biomass being 23.0%, leaves accumulated 20.0% of protein where its content being 20.9%; the contribution of stems to the yield of aboveground dry biomass was 36.0%, stems provided 11.0% of protein accumulated where its content being 5.8%; the contribution of beans reached 41.0%, beans ensured 69.0% of crude protein where its content being 30.1%. Increased moisture availability contributed to a significant growth of the yield of aboveground raw biomass – 1.09-1.19-fold, aboveground dry biomass – 1.08-1.15-fold, protein yield in aboveground dry biomass – 1.10-1.21-fold, yield in fodder units in aboveground dry biomass – 1.07-1.14-fold. On average in the experiment seed yield reached 2.54 t/ha, yield of protein accumulated in seeds was 1 008 kg/ha, of fodder units – 3.40 t/ha. Increased level of available moisture contributed to increase in seed yield – by 1.14-1.21 times, collection of crude protein per unit area – by 1.19-1.31 times, yield of fodder units – by 1.13-1.21 times. It was found that the yield of aboveground biomass harvested at the stage of full seed (R6) significantly exceeded the seed yield: in terms of dry matter yield – by 2.69 times, protein yield – by 1.27 times, fodder units yield – by 1.08 times.

Microclimatic effects of tree shelters on the early establishment and resilience of seeded acorns vs. outplanted seedlings

Little is known about the effects of tree shelters on the early response of oak seedlings produced by acorn seeding. In this paper, we explore the effects on holm oak (Quercus ilex L. subsp. ballota (Desf.) Samp.) seedlings of the microenvironment created by the tree shelters and the restoration method (seeding vs. outplanting) in terms of emergence, survival, growth, and resilience after harvesting. For this purpose, seedling height [H], root collar diameter [RCD], number of leaves, and aerial biomass were monitored. We made two sowings of acorns in February 2017 and February 2018, together with a seedling outplanting in February 2018 in a common garden site in semiarid SE Spain. In total, 600 acorns were randomly sowed and 300 nursery-grown seedlings were outplanted and studied until 2022. Mother tree and initial acorn mass were also monitored as additional variables in the analyses. Tree shelters consisted of closed plastic Tubes, Mixed tubes, Cork shelters, Tiles, and a Control with no shelter. Emergence rate was positively influenced by the Tube shelter (86%) as compared to the Control (64%), and especially by the initial acorn mass. By contrast, mother tree or year of sowing seemed to have no effect. The survival rate for the emerged acorns (88%) was statistically similar to that of outplanted seedlings (91%), and was unaffected by mother tree, tree shelter, or acorn mass. In terms of growth, the slenderness ratio (H:RCD) was considerably higher in seedlings from directly seeded acorns than for those that were outplanted. With the exception of Tile, all the shelters showed a higher slenderness ratio than the Control, especially the Tube shelter, which also showed a lower number of leaves and a lower aboveground dry biomass than the Control, Cork, and Tile shelters. Virtually no interactions were observed between the mother tree and the tree shelter. At harvesting, all the growth-related parameters were still strongly dependent on the acorn mass and the initial seedling features recorded after the first growing season. Resprouting rate and growth were also highly dependent on the acorn mass and the plant features at the beginning of the experiment and at harvesting. In summary, we did not find evidence to support tree shelters to improve the microclimate of holm oak seedlings both seeded or outplanted. Direct acorn seeding can be as successful as outplanting of nursery-grown seedlings. Selection of heavy acorns from mothers with a high germination and emergence rate is highly advisable.

Liquid bio-slurry enhances the productivity of N-fertilized maize under field conditions in Ethiopia

Enhancing maize production and productivity is critical for ensuring small-scale farmers' food security. Yet, declining soil fertility poses a substantial challenge to cereal production, including maize, in developing countries. Farmers are currently finding liquid bio-slurry to be a valuable organic amendment because it improves maize productivity and food security by altering the physicochemical properties of the soil. However, extensive research on liquid bio-slurry as an organic amendment in Ethiopia is still limited. Hence, a field experiment was conducted at two sites to identify the optimal combination of inorganic nitrogen (N) and liquid bio-slurry to improve maize productivity. The trial involved the application of two mineral N fertilizers and five different rates of liquid bio-slurry in a randomized complete block design with three replications. The results revealed that the main effects of mineral N and liquid bio-slurry were significant (p< 0.05) on most of the parameters examined. The interaction between mineral N x liquid bio-slurry had a significant (p< 0.05) effect on plant height, ear length, number of rows ear-1, number of kernels ear-1, above-ground dry biomass yield, hundred-grain weight, grain yield, and straw yield. The highest grain yield (8,220 kg ha-1) was achieved by combining 46 kg N ha-1 with 18 t liquid bio-slurry ha-1. Therefore, 46 kg N ha-1 with 18 t liquid bio-slurry ha-1 is highly recommended for increasing maize yield in the study sites and other areas with similar agroecological zones.

DETERMINING THE ASSOCIATIONS BETWEEN CROP PHENOLOGY, GROWTH, YIELD, AND YIELD-RELATED PARAMETERS OF MALT BARLEY (HORDEUM VULGARE)

The study was conducted at two locations, namely Holeta and Kulumsa Agricultural research centers of Ethiopia, for 2 consecutive years from 2019 to 2021 main cropping seasons. The objective of the experiment was to determine the association between crop phenology, growth, yield, and yield-related parameters. One variety of newly harvested pre-basic seed class of malt barley variety, namely IBON 174/03, was used for the experiment. Total number of treatment combinations was eighteen. The treatments were laid out in a randomized complete block design in two factorial arrangements with three replications. The factors are five deterioration/aging days 0 (control/un-aged), 2, 4, 6, 8, and 10 days and three seeding rates (75, 100, and 125 kg/ha). Before artificial deterioration, the seed moisture content for all treatments was 12.5%. Seeds were subjected to artificial deterioration treatments and placed in an incubator at 42°C for 0 (control), 2, 4, 6, 8, and 10 days at approximately 100% relative humidity. The result revealed that above-ground dry biomass (AGDBM) and grain yield (GYLD) per hectare were significantly affected both by deterioration days and seed rate. As deterioration day increased the mean value for AGDBM and GYLD per hectare was significantly reduced and as the seeding rate increased from 75 to 125 kg/ha AGDBM and GYLD per hectare increased by 30.53% and 21.01%, respectively. The main effect of deterioration days showed a significant difference (p<0.05) for spike length (SL) as deterioration days increased from 2 to 10 days SL was reduced by 7.7–22.62% as compared to un-aged treatment but, the percentage reduction for barley seed deteriorated for 6 and 10 days recorded similar value which is 22.62% as compared to un-aged treatment. Seed per spike and thousand kernels weight were influenced by the main effect of seed rate but, not by deterioration days. As the seeding rate increased from 75 to 125 kg/ha, number of seeds per spike reduced by 4.75% whereas, seeds sown at a low seeding rate (75 kg/ha) recorded a higher thousand kernel weight (TKW) as compared to the seed sown at higher seed rate 100 and 125 kg/ha. Interaction effect of deterioration days and seed rate were only significant for TKW and it was non-significant for the rest of the evaluated crop phenology, growth, yield, and yield-related parameters. This study was only a field experiment result based on further conclusions on how aging can affect the genetic potential such as germination and viability; laboratory inclusive test will be required.

Влияние предпосевной обработки семян и агрохимикатов на урожайность озимой пшеницы

High yields cannot be achieved without the use of fertilizers, but how much they can pay off in modern economic realities and in drought conditions is unknown. In this regard, it is important to have new knowledge about effective systems of application of mineral fertilizers and agrochemicals in winter wheat cultivation in the zone of chestnut soils of the Lower Volga region. Therefore, the purpose of our research was to study the effect of growth stimulants in pre-sowing seed treatment and leaf fertilization with liquid fertilizers on the productivity of winter wheat in the Volgograd region. On average for 2021-2023 years, the minimum photosynthetic potential of winter wheat - 1288 thousand m2 day/ha was formed on plots without UAN 32 and growth regulators, and the highest - 2063 thousand m2 day/ha on plots with two fertilizers UAN 32 and growth regulator Emistim. Autumn fertilization with UAN 32 increased dry aboveground biomass of winter soft wheat in the variety Kamyshanka 6 at earing phase by 13%, two and three fertilizations by 26 and 27%, respectively. Growth regulator Polidon increased dry aboveground biomass of winter wheat at earing phase by 4%, Alfastim by 7%, Emistim by 12%. In the phase of milk ripeness dry biomass from growth regulator Polidon increased by 6%, Alfastim by 11%, Emistim by 14%. The lowest plant height of the variety Kamyshanka 6 was formed on the control - 0.89 m, the highest was on plots with two fertilizers and all variants on factor B and averaged 0.94 m, which is 0.05 m higher than the control. Spikelet length in the experiment was maximum in plots with two fertilizers and growth regulator Emistim. The minimum biological yield of winter wheat Kamyshanka 6 - 4.04 t/ha was obtained in the control variant, the maximum yield - 5.66 t/ha was observed in plots with two fertilizers UAN 32 and application of Emistim.

Mapping winter wheat crop traits dynamic change and growth performance for variable rate application using Sentinel-1 and Sentinel-2

Site specific crop management for variable rate application is extensively recognized as a method for distributing agricultural input unevenly across a field, tailored to the diverse requirement of different areas. From the previous study, this approach proven to reduce agricultural input expenses by 10 % without impacting yield and ensure environmental sustainability. This study presents a new approach to delineate management zones for precision agriculture using crop biophysical property variability assessment within winter wheat fields. A multivariate random forest framework was developed to estimate winter wheat’s biophysical properties within fields from surface reflectance and backscatters of Sentinel-1 and Sentinel-2. Combining Sentinel-1 and Sentinel-2 data resulted in more precise estimation of the green area index (R²=0.98), aboveground dry biomass (R²=0.90), plant height (R²=0.94), and leaf nitrogen content (R²=0.78). Sentinel-2 alone was particularly effective in estimating shoot density (R²=0.94). These estimates were then used to create management zones for precision agriculture, classified based on agronomic performance benchmarks. The fuzzy c-mean clustering algorithm helped generate homogeneous management zones, considering the biophysical variations within fields.The ultimate goal is to integrate these biophysical property maps and management zones into crop management workflows. This integration will assist farmers in recognizing field variability and understanding its causes. Moreover, the spatial distribution of these zones supports variable rate application, guiding farmers towards more efficient, profitable, and sustainable crop management practices.

Tolerance of Young Blackberries to a Selection of Preemergence Herbicides and Rates

Limited preemergence herbicides are registered for new blackberry (Rubus subgenus Rubus) plantings. This greenhouse experiment was designed to investigate the effects of a broad selection of preemergence herbicides at multiple rates on blackberry transplants. Screening was initiated Aug 2021 and repeated Mar 2022 in Fayetteville, AR, USA, in a greenhouse at the Milo J. Shult Agricultural Research and Extension Center. ‘Ouachita’ blackberry plugs were transplanted into utility pots that contained field soil and growth media treated with preemergence herbicides. After transplanting, plant height was measured from the substrate to the highest apical meristem of 25 representative plants. Initial blackberry plant heights were 13.5 and 9.2 cm in 2021 and 2022, respectively. Twenty-five treatments were evaluated, consisting of 12 preemergence herbicides at 1× and 2× field rates, and one untreated control. Herbicide treatments included diuron, flumioxazin, halosulfuron, indaziflam, mesotrione, napropamide, oryzalin, pendimethalin, rimsulfuron, S-metolachlor, simazine, and sulfentrazone applied to substrate in containers at their respective 1× or 2× field rates. Data were collected on plant height, blackberry injury ratings, internode length, leaf chlorophyll content, and destructive harvest, including leaf count, leaf dry biomass, and aboveground dry biomass. Specific leaf areas and leaf area-to-dry matter ratios were calculated. When observed, plant injury tended to increase from 7 days after treatment (DAT) until 42 DAT. Greater injury levels were observed in response to treatment with mesotrione at the 1× (78%) and 2× rates (90%), halosulfuron at the 1× rate (58%), halosulfuron at the 2× rate (68%), and diuron at the 2× rate (73%). Injury from diuron was rate dependent, with the 1× rate causing relatively low injury (19%). At both the 1× and 2× rates, flumioxazin, indaziflam, napropamide, S-metolachlor, and pendimethalin treatments exhibited similar responses to the untreated control.

Development of site-specific allometric equation and predicting aboveground biomass of natural and plantation forests of Oxytenathera abyssinica (A. Rich.) Munro, Northwestern Ethiopia

Bamboo is an ideal plant for commercial production due to its rapid growth rate, high biomass production, low cost of production and environmental friendliness. Although Ethiopia has the highest bamboo cover in Africa, allometric equations for estimating its biomass are scarce. Most allometric models developed to date have been largely concerned with trees and shrubs. The objective of this study was to generate species- and site-specific allometric models that could be used to estimate the total aboveground dry biomass and culm dry biomass of lowland bamboo in northwest Ethiopia. Three power form-based allometric models were created using diameter at breast height (DBH) and culm height (H) as independent variables. One hundred and eight Oxytenathera abyssinica culms were used to predict the total aboveground biomass and culm biomass. Model one (M1) was the best model to predict the culm and total aboveground biomass of the species, regardless of forest type. The allometric models may provide useful information about aboveground biomass and culm biomass estimation methods to forestry professionals, bamboo producers and other stakeholders, and could help in the calculation of the country’s contribution to global carbon sequestration and trade.

Impact of Soil Moisture Depletion on Various Yield Components and Water Usage to Trigger Pods in Chickpea (Cicer arietinum L.) Desi Genotypes

ABSTRACTChickpeas are well adapted to rainfed conditions, but a lack of moisture during the reproductive phase can result in lower pod setting and ultimately reduced grain yield. The exact reasons for this reduction are not fully understood, partly because of the lack of information on soil moisture content (SMC) and water use during podding. This study aimed to address this knowledge gap by quantifying the impact of gradual drought on various yield components of desi‐type genotypes using the fraction of transpirable soil water (FTSW) method. Two water treatments were applied at the start of anthesis: well‐watered (WW) and drought‐stressed (DS). The WW was maintained at 24% SMC, whereas the DS was dried to 3% SMC. The results showed that DS caused early podding (3.3 days less), with reductions in plant height (11.4 cm), leaf area (1249.5 cm2), flowers (18.6), pods (27.4), seeds (37.0), grain yield (0.2 g), aboveground dry biomass (11.4 g) and harvest index (0.2 g), while increasing flower abortion (14.6) and seed biomass (1.5 g). However, diverse genotypic responses were observed to treatments, as well as water usage, FTSW and SMC that triggered pods which ranged from 1.12 to 1.89 L, 0.05 to 0.43 and 4.0% to 12.2%, respectively. A positive association between days taken and the amount of water used to terminate pods indicated that quicker‐triggering genotypes, such as Rupali and Genesis 836, consumed less water to develop pods than Flipper, ICCV_06109 and PBA Slasher did. Conversely, the negative association between the amount of water used and the number of pods triggered, seeds and grain yield explained the superior performance of Rupali and Genesis 836. These genotypes extracted less water (FTSW = 0.36 and 0.43; SMC = 10.3% and 12.2%, respectively) to develop pods and maintained favourable photosynthesis at lower transpiration rates for longer periods, allowing them to use residual moisture more efficiently. Our research offers crucial insights that can be beneficial to breeders and physiologists, paving the way for future studies aimed at developing drought‐tolerant genotypes.

Changes in Some Photosynthesis Indicators Under Different Donor-Acceptor Relations of Wheat Under the Influence of Drought

The results of studies of changes in some parameters of photosynthesis - the formation of leaf surface and the area of ​​other assimilating organs, the accumulation of dry above-ground biomass, chlorophyll content in the ontogenesis of wheat genotypes at different donor-acceptor relationships are presented. In the studied varieties, the dynamics of leaf surface area and the amount of increase in dry biomass during ontogenesis depend not only on the developmental phase and genotypic characteristics of the plants, but also on the state of donor-acceptor relationships in the whole plant system, as well as on the influence of drought. In all studied varieties, when half the ear was removed under both conditions, an increase in the area and dry biomass of stems and leaves was observed. With a decrease in the attracting ability of the ear, it needs significantly less leaf photosynthesis products and the remainder of the assimilates is spent on increasing the area of ​​the leaves themselves. At the same time, changes in donor-acceptor relationships affect the chlorophyll content in leaves. In all cases, the removal of leaves of the 7th tier leads to an increase in the chlorophyll content in the leaves of the 8th tier and vice versa. When half of the ear is removed, the chlorophyll content of both leaves of the 7th and 8th tiers decreases significantly.

Selenium Nanoparticles Boost the Drought Stress Response of Soybean by Enhancing Pigment Accumulation, Oxidative Stress Management and Ultrastructural Integrity

Drought is a persistent and devastating obstacle to crop production, affecting both humanity and livestock. The application of selenium (Se) effectively mitigates various types of abiotic stresses and enhances crop yield under unfavorable conditions. However, our understanding of how nano-Se (nSe) alleviates drought stress (DS) in soybeans is still limited. To address this gap, our study focused on assessing the effectiveness of foliar nSe application during the reproductive stage of soybeans. Three concentrations of nSe were applied to plants grown in pots filled with clay loam soil, simulating DS conditions. Our findings reveal that nSe spraying significantly promoted the accumulation of above-ground dry biomass and enhanced relative water content (RWC) and photosynthetic pigment over alone-DS treatment. Furthermore, nSe application boosted the activity and contents of protective enzymes and osmolytes, resulting in a dose-dependent reduction in electrolyte leakage (EL), reactive oxygen species (ROS) accumulation, and malondialdehyde (MDA) content. Additionally, nSe improved stomatal characteristics and mesophyll cell ultrastructure, further mitigating the adverse effects of drought stress. These findings suggest the potential of nSe as an effective strategy to enhance soybean tolerance and potentially improve crop yields under drought conditions.

Estimation of greenhouse gas emission due to open burning of rice straw using Sentinel data

In recent decades, Vietnam has gradually become a critical global rice producer. During that production process, residual straw becomes an environmental pollutant due to open burning, raising greenhouse gas emissions. This study combines the optical images of the Sentinel-2 satellite and the radar images of the Sentinel-1 satellite to estimate the dry biomass of rice and to determine gas emissions due to rice straw burning over the fields in Quoc Oai district, Hanoi city for urban environmental management purposes. Sentinel-2 images have been classified into the land covers, thereby identifying the areas of ​​rice cultivation and the areas of ​​burned straw. Meanwhile, the Sentinel-1 radar image has been used to calculate the dry biomass of rice due to its ability to penetrate clouds, an obstacle to optical images in tropical regions. Furthermore, a field trip during harvesting season allows us to measure aboveground dry biomass. Then, the analysis shows a high correlation between the backscatter V.V. and V.H. of the radar image and the in-situ dry biomass (R=0.923 and R2=0.852), with a relatively low average error (RMSE = 6.58 kg/100 m2). By linear regression method, the study found the total rice dry biomass of 28728.5 tons, which was obtained after the Summer rice crop 2020 for the whole Quoc Oai district, of which 2037.91 tons of rice straw have been burned, releasing a large amount of greenhouse gas emission with 2398.6 tons of CO2, 189.5 tons of CO, 18.8673 tons of PM10 dust, 17.2087 tons of PM2.5 dust and some other gases. The identical procedure has also been applied to the western region of Hanoi city center to estimate the amount of gas emissions. This study has proven the effectiveness of an approach and contributed to supporting urban managers in proposing appropriate policies to monitor and protect the environment.

Effect of Quizalofop-p-ethyl + Bentazone and Pendimethalin Herbicides on Weeds, Yield Components, and Yield of Mung Bean (Vigna radiata (L.) Wilczek) in Guragie Zone, South Central Ethiopia

Weeds significantly hinder mung bean production in Ethiopia. A field experiment conducted during the 2022 cropping season in Guragie Zone investigated the impact of pre- and post-emergence herbicides on weed control and mung bean (Vigna radiata (L.)) yield. The experiment utilized a randomized complete block design with three replicates and four treatments. The study revealed that the interaction between location and weed control methods significantly influenced weed density, dry weight, and control efficiency. Additionally, location and weed control methods significantly affected various mung bean growth parameters, including days to flowering and maturity, plant height, pod and seed numbers per plant, and grain yield. Meskan Wordea produced significantly higher pods per plant (14.4) and seeds per pod (9.73). Meanwhile, the weed-free check yielded the maximum number of pods per plant (20.38) and seeds per pod (11.68). Conversely, the weedy check exhibited the lowest values (7.17 pods and 6.43 seeds per pod). The weed-free check also achieved the highest grain yield (1412.9 kg ha−1), aboveground dry biomass (3309.2 kg ha−1), and harvest index (42.94%). Conversely, the weedy check yielded the lowest values. Financial analysis revealed that the combined application of Quizalofop-p-ethyl + Bentazone herbicide in Ezeha location resulted in the highest net profit (33602.3 ETB ha−1). Therefore, for optimal mung bean growth and yield in the study area, we recommend planting the Rasa variety with Quizalofop-p-ethyl + Bentazone herbicide in Ezeha location.

Rare‐earth element phytoextraction efficiency in southern Chinese mines under different clipping intensities using a co‐cropping system (Dicranopteris pedata and Pinus massoniana)

AbstractOur understanding of how varying clipping intensities affect the efficiency of phytoextraction remains limited, particularly with co‐cropping systems. This study focuses on assessing the effects of different clipping intensities on phytoextraction efficiency within co‐cropping systems dominated by the key species Dicranopteris pedata and Pinus massoniana in rare‐earth mines of southern China. Our results confirmed the following. Firstly, the compensation index, dry aboveground biomass, and rare‐earth elements (REE) accumulation of clipped D. pedata per unit area were highest under 100% clipping (p < 0.05). Meanwhile, the bioabsorption coefficient, bioconcentration factor, and translocation factor of P. massoniana were less than 1. Secondly, the soil catalase, sucrase, and α‐diversity indices of bacteria and fungi separately indicated no significant variation between the clipping treatments and control. The REE content in tree rings increased, and the total REE contents in thicker tree rings were higher than those in the thinner tree rings of P. massoniana from 1997 to 2016. Additionally, the soil erosion intensity diminished significantly in the growth area of P. massoniana from 1995 to 2019. Thirdly, both D. pedata and P. massoniana, when subjected to 100% clipping, could effectively remove excess REEs from the 0–20 cm soil layer within 18.57–61.19 years. In contrast, P. massoniana alone achieved a removal rate of excess REEs in the 20–60 cm layer, within 923.16–1899.62 years. Thus, D. pedata with 100% clipping can phytoextract the maximum amount of REEs. It is noted that P. massoniana cannot be used for REEs phytoextraction or phytostabilization. Co‐cropping with 100% clipping would have a less negative impact on growth and REEs extraction, and the co‐cropping system can phytoextract excess REEs from the surface soil within decades. However, it is not efficient for the phytoextraction of excess REEs from deep soil layers.

Comparison of the Effects of Different Organic Amendments on the Immobilization and Phytoavailability of Lead

Organic materials, such as straw, animal manure, and their processed product biochar, are known to exhibit agronomic effects and the ability to remediate heavy metal contamination. However, knowledge regarding the relative effects of different organic amendments in soils on heavy metal immobilization and phytoavailability remain limited. Consequently, the effects of maize straw (MS), chicken manure (CM), mushroom cultivation waste (MW), and sawdust biochar (SB) on the immobilization and phytoavailability of lead (Pb) in wheat plants were investigated in this study using pot experiments. The results showed that the artificial application of Pb reduced soil pH, while increasing the total organic carbon (TOC) and cation exchange capacity (CEC) to various extents. Furthermore, the Pb treatment increased the adsorption of Pb by wheat grains (0.83 mg∙kg−1), resulting in decreased above-ground dry biomass (43.16 g∙pot−1) during the maturity growth period when compared with the control check (CK) treatment. The MS + Pb and CM + Pb treatments increased the exchangeable Pb fractions in the soil, but had a limited effect on Pb accumulation in wheat grains compared with the Pb treatment. In contrast, the SB + Pb treatment effectively increased soil pH and TOC, while decreasing the fraction of exchangeable Pb forms and increasing the oxidizable and residual Pb fractions, compared with the Pb treatment. Moreover, the MW + Pb treatment also increased the soil pH and CEC, displaying the potential to increase soil TOC, in addition to substantially modifying the portioning of Pb from exchangeable forms to less bioavailable fractions. Both the MW and SB amendments significantly reduced Pb concentrations in wheat grains (0.49 and 0.70 mg∙kg−1,∙respectively), resulting in increased above-ground dry biomass (51.59 and 54.12 g∙pot−1, respectively). In summary, the application of organic amendments, especially MW, could be an effective measure for enhancing Pb immobilization in polluted soils, thereby reducing its uptake and translocation to crops.

Aboveground Biomass Estimation and Time Series Analyses in Mongolian Grasslands Utilizing PlanetScope Imagery

Mongolia, situated in central Asia and bordered by Russia to the north and China to the south, experiences a semi-arid climate across most of its territory. Grasslands are pivotal in Mongolia’s agricultural sustainability and food security, facing rapid changes in the last two decades that underscore the ongoing need for innovative approaches to assess vegetation conditions. This study aims to evaluate grassland biomass measurement and prediction through the analysis of high-resolution satellite data. By conducting a time series assessment of grazing-induced changes in vegetation dynamics at the long-term monitoring sites of the Botanic Garden and Research Institute, Mongolian Academy of Sciences, we seek to refine our understanding. The investigation covers biomass estimation across various Mongolian grassland landscapes, encompassing desert, steppe, and mountain regions. Spanning the grassland growing season from May 2020 to October 2023, the research leveraged diverse ground data types, including surface reflectance measurements, geographic coordinates for satellite data correction, and aboveground dry biomass. These components were instrumental in developing a biomass estimation model reliant on establishing correlations between the satellite-derived Normalized Difference Vegetation Index and biomass. The predicted biomass facilitated the time series map analysis and dynamic analysis. The PlanetScope surface reflectance correlates strongly at 0.97 with field measurements, indicating robust relations. Biomass and the Normalized Difference Vegetation Index show correlations of 0.82 for dry grassland, 0.80 for mountain grassland, and 0.65 for desert grassland, with a combined correlation coefficient of 0.62, revealing distinct characteristics across these grasslands. Time series dynamic analysis reveals rising biomass differences between grazed and ungrazed areas, suggesting potential grassland degradation. Variations in the slope coefficient of biomass differences among grassland types indicate differing degradation patterns, emphasizing the need for effective grazing management practices to sustain and conserve Mongolian grasslands. This highlights the potential of remote sensing in monitoring and managing grassland ecosystems.

Impacts of one-time large amounts of leafy vegetable waste incorporated into dryland fields on soil fertility and forage maize production

A large amount of vegetable waste is often dumped into the environment, causing serious pollution in major market distribution areas. This paper explores the feasibility and optimization of incorporating vegetable waste into dryland fields to improve soil fertility and crop productivity. The experimental design included three quantities of fresh leafy vegetable waste (QVW) buried into the soil: 800, 1600, and 2400 t·ha−1 and three covering soil thicknesses (CST): 10, 20, and 30 cm. Zero QVW was the control NW. By planting forage maize for two consecutive years, the variations of soil parameters and aboveground dry biomass (ABM) of maize plants were observed. Compared with the NW, the incorporation led to a distinct decline in soil bulk density (BD) by 2.00–17.41%, an increase in soil moisture (SM), organic carbon (SOC), total nitrogen (TN), and microbial carbon (MBC) by 5.84% −29.72%, 5.93% −50.17%, 16.98% −245.71% and 19.66% −304.08%, respectively. Topsoil conductivity (EC) and soil inorganic nitrogen (IN) were 3.81–9.43 fold and 19.02–88.29 fold that of NW. BD was significantly negatively correlated with the QVW and CST. SM, SOC, TN, and IN increased significantly with the increase of QVW and CST. The topsoil EC was significantly positively correlated with QVW, and negatively correlated with CST. The sequestration rates of SOC and nitrogen were significantly positively correlated with CST. The ABM in the incorporating vegetable waste treatment was 1.59–2.74 fold that of NW. The ABM showed a parabolic relationship with QVW (R2 = 0.97 **), and a linear relationship with CST (R2 = 0.91 **). Conclusively, the optimal QVW was 1346 t·ha−1, and the corresponding CST was 30 cm. Excessive QVW can cause topsoil salinization and constrain crop growth. Increasing CST contributes to sequestrating more water and nutrients and mitigating secondary salinization of the soil.