Crop Sowing Research Articles

Shifting in Rainy Season Features in the Mekong Delta under the Background of Global Climate Change

Background: Shifting in the rainy season features (RSFs) have caused impishly cultivation activities around the world, especially under the impacts of enhancing climate change. In the Mekong Delta, rainfall is a crucial factor that determines crop sowing and harvesting dates. Methods: This study investigated the RSFs, including the rainy season onset date (RSOD), cessation date (RSCD) and length (LRS), in the Mekong Delta from 1995 to 2022. The study aimed to understand the spatial and temporal variability of the rainfall features and their implications across the Mekong Delta. The study utilized rainfall data at gauge stations across the Mekong Delta, covering a period of 30 years. The study employed descriptive statistical methods to analyze the RSFs, including RSOD, RSCD and LRS. Result: The results revealed the spatial and temporal variability of RSFs across the study area. The analysis of RSOD, RSCDand LRS revealed consistent patterns. However, the SD and CV values suggested moderate variability in these features, indicating the need for further investigation into the factors influencing these variations. The findings highlight the importance of considering RSFs for effective rain-fed resource management and planning in the Mekong Delta.

Justifying the Operation Parameters of a Robotic Cassette Loading Device of the Carousel Type for a Selection Seeder

Introduction. The development and implementation of automated and robotic machines and devices for performing works on selection and seed production of grain and other crops creates conditions for increasing productivity and reducing labor intensity of work and contributes to increasing the production volume of domestic crop seeds. For sowing crops at the 2nd stage of selection work, there are used cassette seeders, which have special loading devices for feeding cassettes with seeds divided into portions to autonomous seeding units, the number of which corresponds to the number of cells in the cassette. The robotic cassette loading device of selection seeders is designed for successive movement of cassettes with seeds to the seeding units and for feeding cassette blocks to the working area according to a specified program when performing the technological process of sowing on seed plots for breeding grain, leguminous and other crops. In this case, there must be ensured strict coordination of the robotic cassette loading device and seeder seeding units operation and for this it is necessary to justify the engineering parameters of the robotic cassette loading device taking into account its design.Aim of the Study. The study is aimed at analyzing the robotic cassette loading device operation in the interaction system between the seeder working parts during the technological process of sowing crops on selection breeding plots and justifying the parameters of the robotic cassette loading device of the carousel type for loading the selection seeder seeding units.Materials and Methods. To determine the parameters of the robotic cassette loading device, there were used physical and mathematical dependencies describing the operation of the robotic cassette loading device in various modes during selection sowing of grain and other crops at the second stage of work.Results. There were substantiated the parameters of the robotic cassette loading device of the carousel type for two operating modes: feeding cassettes in the working area to the discharge outlets of the work table and feeding a block of cassettes into the working area. There were calculated parameters of the manipulator mechanisms. For the actuator moving the cassettes, the minimum force is 7.2 N, the rod length is 700 mm, the rod speed is 60 mm/s, and for the electric motor rotating the robotic cassette loading device moving platform, the rotation frequency of the output shaft is 10 r/pm, the minimum required power on the output shaft of the moving platform drive is 55.7 W.Discussion and Conclusion. There were determined the engineering parameters of the robotic cassette loading device of the carousel type for loading the seeding units of a selection seeder at the 2nd stage of selection work. The calculation of the cassette feed speed of 0.033 m/s during the main sowing operation was carried out for the initial parameters: the seeder operating speed of 3.0 km/h, the plot length of 1 m and the length of the inter-tier path 0.5 m. For the cassette block feed mode, there was calculated the angular velocity of rotation of the moving platform (1.05 radians per second), at which the cassette block feed will take 1 second.

Influence of planting patterns and integrated weed management practices on weed biomass, growth and yield of Spring maize

Weed infestation is a serious problem in corn production that impacts global production and with increasing food demand worldwide, certain manipulation is required in agronomic practices to improve corn production. This experiment was conducted on the Research farm of the Department of Agronomy, Lovely Professional University, Phagwara to evaluate the impact of planting patterns and integrated weed control treatments on maize crops during the Spring season of 2023 and 2024. The experiment was laid out in Split Plot Design with 3 planting methods in main plots viz., M1 - Flat sowing with single row, M2 - Flat sowing with paired row and M3 - Ridge sowing and 5 weed control treatments in subplots viz., T1 - atrazine + pendimethalin (0.75 + 0.75 kg/ha), pre-emergence followed by straw mulching, T2 - pendimethalin (0.60 kg ha-1), pre-emergence + intercropping cowpea f. b. earthing up (EU) and straw mulching (SM), T3 - intercropping dhaincha f. b. earthing up and straw mulching, T4 - 2 hand weedings (4 and 6 WAS) and T5 - unweeded (control) with 4 replications. The results indicated that sowing of maize crops on ridges produced significantly better crop growth and yield with significantly lesser weed biomass than paired row sowing. Among the weed control treatments, the intercropping treatments, followed by earthing up and straw mulching, were effective in weed control and produced significantly higher growth and yield than other weed control treatments. It can be concluded that planting maize on ridges with intercropping followed by earthing up and straw mulching produced the best results, which can be adopted by the farmers to sustainably improve the yield and earn better profits as the methods involved are environment friendly and do not require any additional investment.

Seed-transmission of turnip mosaic virus demonstrated unequivocally in a Brassica species.

Turnip mosaic virus (TuMV) causes important diseases in Brassicaceae crops worldwide. In 2023, Brassica rapa ssp. perviridis cv. Tendergreen seedlings with virus-like symptoms were found growing within an insect-proof glasshouse. The affected seed lot (A), three others of Tendergreen, and five belonging to other B. rapa subspecies, B. juncea or Wasabia japonica were sown in trays within Controlled Environment Rooms (CER's) from which other plants were absent. TuMV was detected in 10% of seed lot A seedlings but none from other seed lots. Next, seed lot A (experiment 1) or seed from Tendergreen mother plants infected with B. napus TuMV resistance breaking strain isolate 12.1 (experiment 2) were sown in trays. In each experiment, these trays were subdivided into two batches, one being placed inside transparent plastic boxes, each batch then being placed in different CER's. TuMV was detected in 10% and 9% of seedlings inside or outside the boxes (experiment 1), or 1% of seedlings from both situations (experiment 2). Since virus contamination by aphid vectors or contact was excluded, TuMV seed transmission was demonstrated unequivocally. A complete TuMV genome obtained from an infected seedling (isolate BRSB1, accession PQ160044) was compared with 44 other genomic sequences from TuMV phylogroup World-B. It belonged to the same subclade as Australian resistance breaking strain isolates 12.1 and 12.5 (99.9% nucleotide identities) and 10 New Zealand sequences (99.2-99.5% nucleotide identities). Our findings have important implications concerning sowing crops with TuMV-infected seed and spreading readily seed-borne or resistance breaking TuMV strains nationally or internationally.

Efficacy of weed control and selectivity in soybean in the application of preemergent herbicides and their carryover in sorghum and maize

Further studies are necessary to evaluate not only the effectiveness of preemergent herbicides for weed control and selectivity in soybeans but also the potential carryover damage to crops planted in succession, such as sorghum and maize. This study aimed to assess the efficacy of preemergent herbicides in controlling Euphorbia heterophylla L. and Digitaria insularis L., as well as their selectivity in soybeans (Glycine max L.) and the residual effects on crops sown in succession, including maize (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench). Two field experiments were conducted with soybean, both in a randomized block design, consisting of the following treatments: sulfentrazone + diuron, flumioxazin + imazethapyr, diclosulam, sulfentrazone, s-metolachlor and flumioxazin, in addition to weeded controls and without weeding, with four replicates. Subsequently, the sowing of maize and sorghum was performed. Visual evaluations of weed control were performed at 14, 21, 28, 35 and 42 days after application of the treatments (DAA) and of phytotoxicity in soybean, sorghum and maize at 14, 21, 28, 35 and 42 days after planting emergence (DAE), and at the end, yield estimate. It was found that the sulfentrazone, sulfentrazone + diuron and imazethapyr + flumioxazin treatments were effective in controlling D. insularis and E. heterophylla up to 42 DAA. For sorghum and maize, no significant injury levels were observed for any treatment, with the exception of sulfentrazone alone, which provided significant reductions in productivity.

Hydro-thermal conditions and their impact on irradiance and hygro-thermal use efficiency of wheat in central Punjab

The experiments were conducted to develop indices to provide critical insights into crop phenology and yield responses of wheat to thermal and moisture conditions during rabi 2021-22 and 2022-23 at PAU, Ludhiana, Punjab. The wheat variety Unnat PBW was sown on three dates (D1: 27th October, D2: 17th November, D3: 8th December) under three irrigation regimes (I1: irrigations at CRI, Jointing, 50% Flowering, Soft dough stages, I2: irrigations at CRI, Flag leaf emergence, soft dough stage, I3: irrigations at Jointing, Soft dough stage). Results revealed that the crop sown on 27th October acquired maximum number of calendar days and various heat indices viz. growing degree days (GDD), solar thermal degree days (STDD) and hygrothermal units (HGTU) for attaining physiological maturity while 8th December sown crop resulted in lowest accumulation. However, late sown crop was observed to accumulate more STDD. Wheat sowing before 17th November resulted in higher grain yield and energy use efficiencies. Four irrigations at critical stages took highest GDD, STDD and HGTU for attaining maturity which was at par with two irrigations. Application of four irrigations resulted in significantly higher yield and energy use efficiencies. Similar performance of three irrigations was observed when irrigation was not skipped at anthesis stage.

Development of a machine for cultivation and sowing of grain crops

BACKGROUND: When designing sowing machines, requirements are imposed to ensure soil preparation and sowing of grain crops as part of the implementation of energy-saving technology, since their productivity largely depends on these types of work. Thus, increasing the efficiency of sowing machines is an urgent task. AIM: – the development of a seeder design that allows, with maximum simplification of the design compared with analogues, reducing metal consumption and increasing the manufacturability of the product, both in production and in operation, to ensure the best conditions for the growth of crops and a significant increase in yield. In one pass, the seeder sows the main crop, small-seeded crop (binary component) and introduces mineral fertilizers, and can also be used when putting waste and fallow lands into circulation. METHODS: Methods of system analysis, mathematical modeling, and experiment planning were used in the development of the drill design. Experimental studies were conducted in the field and laboratory conditions in accordance with existing methods, using modern electronic and mechanical devices. Experimental data processing was carried out in the environment of the MathCAD system, Microsoft Office Excel. RESULTS: In contrast to known analogues, the proposed technical solution of the seeder simplifies the design, reduces the weight and improves the manufacturability of the product - on a simple frame welded in one plane from pipes, but free enough for the passage of crop residues and soil particles, on one side are installed stands with tines for mounting discs, and on the other - for mounting the hopper. The plane of attachment of tines for disc mounting is as close as possible to the soil surface, which reduced the load on the frame and reduced its material intensity. The seed drill-cultivator developed by the authors allows to realise all operations related to soil cultivation and sowing of grain crops Translated with DeepL.com (free version). CONCLUSIONS: The design solutions for the cultivator planter obtained by the authors simplified the design of the planter compared to its analogues, reduced its metal consumption, and therefore its weight, which makes it possible to use tractors of a smaller class with lower fuel consumption. The adjustment of the angle of attack of the discs has also been simplified, and the additional installation of baking powder has reduced the clogging of the seeder with crop residues and soil lumps.

ЭФФЕКТИВНОСТЬ СИДЕРАТОВ В ЗЕМЛЕДЕЛИИ НЕЧЕРНОЗЕМЬЯ

The results of research on the effectiveness of mineral fertilizers are presented. It was found that the highest content of nitrogen, phosphorus and potassium was in winter rye plants grown using slanted and full siderates. The minimum content of nutrients was in winter rye plants grown using an occupied pair. The maximum grain yield was obtained by cultivating winter rye using pure steam with the use of mowing siderate and sideral steam. On a non-fertilized background, it amounted to 3.27 t/ha and 3.25 t/ha, respectively, and on a fertilized background, 4.12 t/ha and 4.08 t/ha. The grain from these variants had the maximum crude protein content. In terms of the effectiveness of the effect on the yield and grain quality of winter rye, the mown siderate was not inferior to the full sideral fertilizer. The study of the use of siderates in the sowing form showed that during the autumn period, peas and mustard accumulated the largest biomass, and rapeseed accumulated the least. The largest amount of nitrogen 33 kg/ha was accumulated in the biomass of peas, and phosphorus 6 kg/ha and potassium 36 kg/ha by the biomass of white mustard. The least amount of nutrients accumulated in the biomass of rapeseed. Sowing of sideral crops had a positive effect on the formation of yields and improving the quality of winter rye grain. The yield of winter rye grown without sowing siderates and without fertilizing was 2.32 t/ha. The increase in the variant with seeded vetch was 0.47 t/ha, with seeded mustard - 0.37 t/ha and with seeded peas - 0.40 t/ha. The sowing of spring rapeseed did not lead to a significant increase in the yield of winter rye. Nitrogen fertilization of winter rye during the spring tillering phase provided an increase in grain yield by 0.62 t/ha. Against the background of top dressing, the sowing of vetch provided an increase in grain yield of 0.48 t/ha, white mustard – 0.39 t /ha, seeded peas – 0.32 t/ha. There was no reliable increase from the sowing of spring rapeseed.

Expert System for Sowing Agricultural Crops Using Artificial Intelligence

The possibilities and scope of application of artificial intelligence methods in the agro-industrial complex are considered. Positive trends in the application of intelligent systems in various areas of the agro-industrial complex are highlighted, as well as the factors that slow down the rate of implementation of intelligent technologies in agriculture. The prototype of an expert system for providing recommendations on the organization of sowing of agricultural crops depending on the type of soil is developed.

Sowing Environments and Yield of Maize (Zea mays L.) Cultivars under Changing Climate Conditions of North Western Himalayan Region

Sowing dates, as one of the primary agronomic practices have significant influence over yield of maize especially during the times of climate change. Therefore, the present field investigation was conducted during the Kharif cropping seasons of 2013 and 2014 to evaluate different sowing dates for their influence over maize (Zea mays L.) yield. The field experiment was conducted in a randomized block design with factorial arrangement consisting of four dates of sowing and three maize cultivars. The study results revealed that sowing of crop by 10th June can have taller plants (261.5 and 265.2 cm for 2013 and 2014, respectively), significantly better yield contributing characters of maize such as number of cobs per plant (1.1 and 1.1 for 2013 and 2014, respectively), number of grains per cob (258.7 and 268.3 for 2013 and 2014, respectively) and test weight (268.5 and 271.6 grams for 2013 and 2014, respectively). Similarly, the significantly higher maize grain (57.3 and 60.1 quintal/hectare for 2013 and 2014, respectively) and stover yield (108.8 and 109.2 quintal/hectare for 2013 and 2014, respectively) was recorded with sowing of maize crop by 10th June. Among the maize cultivars, HQPM-1 resulted in substantially higher maize grain (53.9 and 56.5 quintal/hectare for 2013 and 2014, respectively) and stover yield (102.9 and 104.1 quintal/hectare for 2013 and 2014, respectively). Based on the present field investigation, it can be concluded that sowing of maize by 10th June and maize cultivar HQPM-1 can be recommended for better yield levels under the given conditions of North-western Himalayas.

Automated control complex of agrotechnology in precision farming

The paper presents a project of an automated complex for managing agricultural technology. The complex consists of two inseparable components, a control unit and an executive robotic technological machine. The control unit implements the modern theory of controlling a complex dynamic system, which is an agricultural field with sowing crops. The main distinctive feature of the proposed management theory is that the object of management is an agrocenoses, which includes sowing crops and weeds. This feature is transferred to the executive technological machine, through which the simultaneous application of mineral fertilizers and herbicide treatment is carried out. At the same time, the formation of optimal technological operations is carried out on the basis of Earth remote sensing data. Based on these data, the parameters of the state of the agrocenoses are assessed, and the resulting estimates are system-wide feedback through which agricultural technology is managed. The presented complex is of interest to specialists developing individual components of modern precision farming systems.

Assessment of sowing environment for wheat cultivars and evaluation of growing degree days for phenological stages in the Northwest Himalayan region of Himachal Pradesh

BackgroundThe date of sowing is a non-monetary input factor that plays a crucial role in field crop management. Based on the sowing time, management practices of crop production affect crop growth, development, and yield. Under varied environmental conditions, this factor may be useful in addressing low yields and combating/escaping stresses either due to diseases or due to any unfavourable environment.ResultsA field experiment was conducted during the rabi season of 2017–18 and 2018–19 to study the accumulated growing degree days (GDD) and performance of six wheat cultivars (HS 562, HD 2967, HD 3086, HI 1544, MACS 6222 and WR 544) under four sowing dates (5th November, 25th November, 15th December and 5th January). The study revealed that 5th November is the best date for sowing resulting in higher pooled grain yield of 4.85 Mg ha−1 and 3.94 Mg ha−1 at Bajaura and Malan, respectively. Significant reductions in the grain yield and yield attributes were observed when the date of sowing was set beyond 5th November. Among the cultivars tested, HS 562 gave a significantly higher pooled grain yield of 4.46 and 3.75 Mg ha−1 at Bajaura and Malan, respectively. Pooled data on physiological maturity revealed that variety HS 562 took the highest calendar days (168 days) and GDD (1573.42 °C days) to attain physiological maturity at Bajaura while at Malan HI 1544 and HD 3086 took the highest calendar days (156 and 155 days, respectively) and GDD (2055.41 and 2051.81 °C days, respectively) to attain their physiological maturity.ConclusionFrom the study, it can be concluded that the early date of sowing provides the crop with ample duration to accumulate growing degree days resulting in a higher accumulation of photosynthates resulting in significantly higher yield attributes and grain yield. Therefore, 5th November is recommended as the best time for sowing of wheat crop whereas the sowing must not be delayed beyond 25th November. HS 562 was superior among the cultivars and is recommended for Malan and Bajaura regions for attaining higher yield.

Effect of Sowing Time on Infestation of Sucking Pests in Okra

Okra is highly susceptible to sucking pests like leafhopper, whitefly, and red spider mite, leading to significant yield losses. While farmers rely on insecticides for pest control, excessive use poses risk to the environment. To explore alternatives, a study was conducted at CCS Haryana Agricultural University, Hisar, during kharif 2023 to assess the effect of sowing time on sucking pests infestation in okra. For this, okra was sown on different times i.e., in the 3rd week of May, 1st and 3rd week of June, and 1st and 3rd week of July. The population of leafhopper, whitefly and red spider mite was recorded weekly, starting from the appearance of the pest. The study revealed that leafhopper population in crop sown in the 1st and 3rd week of July was on a par, however, significantly lower than that in other crops. Okra sown in the 1st week of July resulted in significantly lower population of whitefly than rest of the sowing times having population on a par with each other. Mite infestation was significantly lower in crop sown in the 3rd week of July compared to the others. Based on these findings, July appears to be the most suitable time for sowing okra to minimize sucking pests’ infestation.

Weather based Yield Prediction of Pigeonpea Crop with the Resource Use Efficiency under Varied Sowing Windows

Background: Sowing of crops at the optimal time is a non-cash input, which maximizes yield by effectively utilizing available resources. Choosing the best sowing time is crucial for exploiting a crop’s fullest potential in a specific environment with good agronomic management. Methods: A long term experiment (2004-2020) was conducted at research farm under AICRP on Agro meteorology field unit, University of Agricultural Sciences, GKVK, Bengaluru from 2004-2020 to find out the different sowing windows on the performance and resource use efficiencies in pigeonpea. Result: Long term (2004-2020) pooled data analysis reveals that, among the different sowing windows, early sown pigeonpea produced higher seed yield with effective utilization of the resources compared to the normal and late sown crops.

Irrigation During Flowering Is Critical for Enhancing Productivity and Economics of Late-Sown Indian Mustard Compared to other Management in the Arid Regions of Western India

ABSTRACT Global warming delays the harvest of kharif crops, which delay the subsequent sowing of Indian mustard, especially in northwestern India and also causes dry winters that exacerbate challenges for the timely sowing of rabi-crops. To check this, a field experiment was conducted during the Rabi-seasons of 2018–19 and 2019–20 to assess the influence of sowing dates, irrigation, and fertilizer levels under late-sown conditions. A split-plot design was used with two sowing dates, two irrigation levels and four fertilizer levels (87.5%, 100%, 112.5% and 125% RDF; Recommended-fertilizers-dose). Crop sown in the 4th week of November significantly reduced seed (46.79 and 38.77%) and stover yield (43.72 and 41.62%) as compared to the 2nd week of November sowing during 2018–19 and 2019–20, respectively. Uptake of NPK by seed and stover was higher with the 2nd week of November sowing. The 2nd week of November sowing resulted in significant increase in water productivity by 63.72% and Benefit cost ratio (B:C) by 75.45% over the 4th week of November sowing. Irrigation at flowering stage increased the seed yield, water productivity and B:C by 11.94%, 1.72% and 9.17%, respectively, as compared to No post-sown irrigation. The biological yield of the Indian mustard increased with every increase in fertilizer doses but the response was significant up to 112.5% RDF (90 kg N, 33.75 kg P2O5 and 22.5 kg K2O ha−1). Application of 112.5% RDF increased the seed, stover yield, water productivity and B:C by 16.17%, 9.29%, 15.66% and 11.27%, respectively, over 87.5% RDF.

Nitrogen fertilization and sowing date as wheat climate change adaptation tools under Mediterranean conditions

In the current situation, climate change has substantially disturbed precipitation occurrence in the Mediterranean region, by increasing its variability and decreasing the total annual amount, which both negatively affect rainfed crop productivity. We hypothesize that a simple cost-effective method for enhancing crop adaptation to new climate conditions would consist of modifying the crop sowing date. Traditional nitrogen (N) fertilization rates could also be adjusted to the current situation given the interdependent water/N relation in plant nutrition. Based on this hypothesis, during a 4-year field experiment with bread wheat (Triticum aestivum L., var. Pistolo), the effects of three sowing dates (October, November, February) and three N fertilization rates (54 kg N ha−1, 27 kg N ha−1, 0 kg N ha−1) on crop development, yield, grain quality, soil N content and N use efficiency were analyzed. The results showed that water scarcity was the predominant limiting factor, because it outweighed N deficiency with half-fertilized crops being as productive as fully fertilized treatments. Nevertheless, sowing date was the most influential factor, with up to a 30 % yield increase noted for the November-sown wheat compared to that sown in October, while delaying wheat sowing to February decreased crop yields. Grain protein content remained the same between the November- and October-sown crops, but increased in the February one crops. Optical sensor measurements showed that an optimal assessment of the current water/N nutritional status of crops can be achieved with these tools.

Exploring the nexus of grain production and climate variability under nitrogen and hydrothermal regimes using CERES-wheat model

Field experiment was conducted at Punjab Agricultural University, Bathinda from 2017-18 to 2019-20 to evaluate the growth and yield of wheat under varying sowing dates (Nov. 15, Nov. 30 & Dec 15), irrigation regimes (IW: CP = 0.6, 0.8, & 1.0), and nitrogen levels 80% RDN, RDN & 120% RDN). Timely sowing (15 November) resulted in significantly highest grain yield (5090 kg ha-1) and delay in sowing caused reduction in yield by 2.83 % and 9.91 % in crop sown on 30 November and 15 December respectively. Yield and yield attributes were found to increase with increase in irrigation and nitrogen levels. The highest yield was achieved with 15 November sowing, IW: CPE ratio 1.0 and 120% RDN. The sensitivity of the validated CERES-wheat model to increase in temperature by 0.7, 1.2, 1.5 0C and CO2 concentration by 435, 460, 500 ppm, as projected for years 2030, 2040 and 2050 respectively, revealed reduction in the wheat yield. The combination of 15 November sown crop, irrigation at IW:CPE ratio 1.0, and recommended dose of nitrogen showed resilience against increasing CO2 concentration and temperature rise.

Use of Indices Applied to Remote Sensing for Establishing Winter–Spring Cropping Areas in the Republic of Kazakhstan

Farmers in Kazakhstan face unreliable water resources. This includes water scarcity in the summer, high fluctuations in precipitation levels, and an increase in extreme weather events such as snow, rain, floods, and droughts. Wheat production is regulated and subsidized by the Kazakh government to strengthen food security. The proper monitoring of crop production is vital to government agencies, as well as insurance and banking structures. These organizations offer subsidies through different levels support. Some farmers already use farmland soil monitoring combined with adaptive combinations of different crops. These include winter–spring plowing crop programs. Winter wheat crops are generally more adaptive and may survive summer droughts. Kazakhstan is a large country with large plots of farmland, which are complicated to monitor. Therefore, it would be reasonable to adapt more efficient technologies and methodologies, such as remote sensing. This research work presents a method for identifying winter wheat crops in the foothills of South Kazakhstan by employing multi-temporal Sentinel-2 data. Here, the researchers adapted and applied a Plowed Land Index, derived from the Brightness Index. The methodology encompasses satellite data processing, the computation of Plowed Land Index values for the swift recognition of plowed fields and the demarcation of winter wheat crop sowing regions, along with a comparative analysis of the acquired data with ground surveys.

Unveiling the impact of winter cover crops and weedy fallow on the soil seedbank

Cover crops (CCs) are recognised as valuable for weed management, while fallow soil between cash crop seasons likely increases weed presence. Weeds may offer similar ecosystem services as CCs, although they pose a risk of seedbank buildup. This study evaluated the impact of two winter CC systems (3-year triticale cultivation, TRIT; and a 3-year succession of rye, clover, and mustard, RCM) compared to weedy fallow (WF) on weed seedbank size and composition in a 3-year ‘maize (Zea mays L.)–maize–soybean (Glycine max (L.) Merr)’ crop succession. After 3 years, seed density of spring/summer weeds reduced in all treatments, potentially stemming from herbicide use during cash crop seasons and tillage operations. Triticale had the lowest seedbank density (9,487 seeds m−²) and higher diversity (Shannon Index 6.9) compared to WF (28,543 seeds m-² and 4.1, respectively). Furthermore, stochastic analysis revealed a lower risk of enlarging weed seedbanks in TRIT compared to WF (for seed densities above 900 seeds m−2). Moreover, management practices (CCs, cash crop sowing, termination/harvest) synchronised with weed seed production and germination likely contributed to the decreasing seed density of species including Portulaca oleracea and Chenopodium album, which were reduced by 90 and 80 %, respectively, by the study’s end. Over three years, autumn/winter and indifferent weed seed densities increased 4.2 times more in WF and RCM (22,638 seeds m−²) than in TRIT. This may be due to the varying growth rates among CC species in RCM, whereas TRIT consistently established rapidly, potentially outcompeting weeds until termination. Fallow periods between cash crops may increase weed species linked to that season and future crop–weed interference in varied crop rotations. Introducing CCs can mitigate this effect, although the choice of CC species may influence the extent of the impact.

Integration of prognostic sowing and harvesting schemes to enhance crop dynamic growth simulation in Noah-MP-Crop model

Detailed sowing and harvesting (S&H) information is crucial for climate-coupled crop models to accurately simulate dynamic crop growth. The timing of intra-annual crop growth not only reflects adaptation to climate change but also significantly influences terrestrial biophysical and biochemical processes, as well as the local climate. However, accurately providing sowing and harvesting dates in crop models is challenging due to the limited availability of S&H observations worldwide. In this study, we integrated a prognostic S&H scheme into the Noah-MP-Crop model to eliminate the need for prescribed S&H dates and optimised key crop-related parameters to better reproduce dynamic maize and soybean growth in the U.S. Corn Belt. Results indicated that the bias in estimating site-level S&H dates was within one week. The prognostic S&H schemes, along with optimised crop-related parameters, effectively captured maize and soybean growth at the site scale, as evidenced by leaf area index (LAI) and gross primary production (GPP) simulations. The determination coefficient (R2) for GPP ranged from 0.88 to 0.91 for maize and from 0.70 to 0.82 for soybean at two flux stations. Moreover, the prognostic schemes exhibited better regional LAI and GPP simulations at the beginning and end of the growing season compared to those using state-level median S&H dates, with significant improvements in correlation coefficients ranging from 0 to 0.6, particularly in maize-dominated regions. However, the accuracy in reproducing latent heat flux and sensible heat flux was less satisfactory and showed little association with crop growth status. This work provides an alternative approach to obtaining crop sowing and harvesting information in the Noah-MP-Crop model and facilitates studies on interactions between dynamic crop growth and the climate system, particularly when coupled with the widely used Weather Research and Forecasting (WRF) model.