No-till Maize Research Articles

Experimental and Numerical Analysis of Straw Motion under the Action of an Anti-Blocking Mechanism for a No-Till Maize Planter

To address the low clearance rate issue of the anti-blocking mechanism for maize no-till planters in the Huang-Huai-Hai Plain of China, experiments and simulations were conducted to analyze the individual and collective movements of straw under the action of the round roller-claw anti-blocking mechanism. A tracer-based measurement method for straw displacement was applied firstly. Experimental results showed that the straw forward displacement could be characterized by the average horizontal displacements of longitudinal and lateral tracers, while the straw side displacement could be characterized by the lateral displacement of the longitudinal tracer. The straw forward displacement was 58.95% greater than the side displacement. Forward, side, and total displacements of straw increased as the mechanism’s forward speed increased from 3 km/h to 7 km/h, with corresponding rates of increase at 233.98%, 43.20%, and 162.47%, respectively. Furthermore, a model of straw–soil–mechanism interaction was constructed in EDEM 2022 software. The relative error between experimental and simulated straw clearance rates was 11.20%, confirming the applicability of the simulation model for studying straw–soil–mechanism interaction. Based on the simulation model, three straw tracers of different lengths were selected to study the motion behavior of straw. It was inferred that despite differences in straw length, the movement behaviors of the three straw tracers under the influence of the anti-blocking mechanism were similar. Additionally, longer straws exhibited greater displacements in all directions. This paper serves as a reference for studying straw motion behavior influenced by anti-blocking mechanisms.

The Effect of Furrow Opener and Disc Coulter Configurations on Seeding Performance under Different Residue Cover Densities

The performance of the no-till seeder is one of the most important factors that affect the success of the no-tillage. Striking the right balance between furrow opener design and residue cover is essential for optimizing seeding conditions and ensuring sustainable agricultural practices that promote both soil conservation and high-yield crop production. This study investigates the impact of residue cover on no-tillage maize seeding after wheat harvest, focusing on plant spacing, seeding depth, mean emergence time, and percent emergence. Trials with hoe-type and double-disc-type furrow openers, accompanied by plain- or ripple-disc-type coulters, were conducted in Antalya, Turkey. The results indicate that residue cover had no significant effect on mean plant spacing, but a higher residue cover increased spacing variation. The seeding depth in hoe-type furrow opener trials remained consistent, while double-disc-type furrow openers showed lower depths with 80% and 90% residue covers. The percentage of plant emergence and mean emergence time decreased as the residue cover increased in double-disc-type furrow opener trials. At 90% residue cover, PE decreased to 60%. The impact of disc coulters on hoe-type furrow openers was limited, but they increased seeding depth and MET in double-disc-type furrow openers. These findings can help optimize residue management for improved efficiency in no-till farming systems.

Does no-till crop management mitigate gaseous emissions and reduce yield disparities: An empirical US-China evaluation

Global agricultural systems face one of the greatest sustainability challenges: meeting the growing demand for food without leaving a negative environmental footprint. United States (US) and China are the two largest economies and account for 39 % of total global greenhouse gases (GHG) emissions into the atmosphere. No-till is a promising land management option that allows agriculture to better adapt and mitigate climate change effects compared to traditional tillage. However, the efficacy of no-till for mitigating GHG is still debatable. In this meta-analysis, we comprehensively assess the impact of no-till (relative to traditional tillage) on GHG mitigation potential and crop productivity in different agroecological systems and management regimes in the US and China. Overall, no-till in China did not change crop yields, although soil CO2 (8 %) and N2O (12 %) emissions decreased significantly, while soil CH4 emissions increased by 12 %. In contrast to Chinese no-till, a significant improvement in crop yields (up to 12 %) was recorded on US cropland under no-till. Moreover, significant decreases in soil N2O (21 %) and CH4 (12 %) emissions were observed. Of the three cropping systems, only wheat showed significant reduction in CO2, N2O and CH4 emissions in the Chinese no-till system. In the case of US, no-till soybean-rice and maize cropping systems demonstrated significant emission reductions for N2O and CO2, respectively. Interestingly, yields of no-till maize in China and rice in US exceeded those of other no-till cereals. In China, no-till on medium-texture soils resulted in significant reductions in GHG emissions and higher crop yields compared to other soil types. In both countries, the relatively higher crop yields under irrigated versus non-irrigated no-till and the significant yield differences on fine textured soils under US no-till are likely due to the substantial N2O reductions. In summary, crop yield disparities from no-till between China and the US were related to the insignificant effects on controlling CH4 emissions and successfully mitigating N2O, respectively. This study comprehensively demonstrates how cropping system and pedoclimatic conditions influence the relative effectiveness of no-till in both countries.

Effect of Reduced Nitrogen Fertilization on the Chemical and Biological Traits of Soils under Maize Crops

The European Commission’s “Farm to Folk” strategy recommends reducing fertilizers by at least 20% by 2030. In this context, the aim of this study was to verify whether a 20 and 40% reduction of nitrogen (N) fertilization rate will be sufficient to maintain soil chemical features, fertility, and yields in monoculture maize cultivation in the no-tillage (NT) system versus the traditional plowing (PL) system. We also examined which tillage system (PL, NT) allows the reduction of fertilization while maintaining good yields of the tested soils. Two fields (10 ha each) were established for PL and NT maize cultivation, and soils (0–20 cm) were sampled twice per year—before maize sowing and after maize harvesting. A broad range of chemical and biological parameters were monitored (i.e., pH, forms of nitrogen, phosphorus and carbon, content of selected macronutrients and humic substances, and respiration activity). It was concluded that the 20% reduction in N fertilization (after 4 years of use) did not have an adverse effect on the soil’s chemical and biological features, which mainly depended on the season of the year. The maize yield seemed to be higher in the PL system, which was mostly the result of the tillage system rather than the N dose. The study will be continued in the next vegetation season to further verify our findings, especially with regard to the maize tillage system and yields.

Development and Performance Evaluation of a Pressure-Adjustable Waterjet Stubble-Cutting Device with Thickness Detection for No-Till Sowing

No-till maize (Zea mays L.) sowing is often affected by stubble. The high-pressure waterjet at a constant rate is powerless to precision applications of stubble cutting and causes water waste. In this study, a pressure-adjustable stubble-cutting device with a stubble-thickness detection device was designed. Through experiments, the quantitative analysis of the moisture content and electrical conductivity (EC) of the field soil and stubble during the spring sowing period was conducted, and the effect of soil moisture content (SMC), soil compaction (SC) and machine forward speed (V) on the stubble-thickness detection error (STDE) was explored. On this basis, the optimal parameters of the device were analyzed and evaluated, and a verification experiment was applied. The results showed that STDE decreased with the increase of SMC and SC and increased with the increase of V. The response time of the pressure adjustment system is 0.12 s. The stubble-cutting device with thickness detection for two-level pressure regulation reduced the water consumption (WC) by 13.22% under the condition that the stubble-cutting rate (SCR) remained unchanged. The WC increased with the increase of waterjet pressure (P) and decreased with the increase of V. The SCR increased first and then decreased with the increase of cutting angle (α). The response surface optimization analysis showed that when P was 26 MPa, α 90.45° and V was 3.36 km/h, the performance was optimal with a 3.03% STDE, a 95.49% stubble SCR and a 49.98 L/ha WC. The measured value of the field verification experiment had a 4.11% relative error existing in STDE, a 4.06% relative error existing in the SCR and a 1.81% relative error existing in WC compared with the predicted value of the regression model. In contrast to the constant rate waterjet cutting device, the application of this device can save WC by 13.22%. This study can provide a reference for the application of waterjet technology and conductivity detection technology in the agricultural field.

玉米免耕机播种单体防黏土改进设计与试验

When the seeding monomer of no-tillage maize planter operates in sticky and wet soil, soil bonding and blocking of soil-touching parts will occur to different degrees, leading to functional failure and affecting the quality of seeding operation. Aiming to improve the anti-adhesion property with minimum cost, a seeding monomer is modified to operate in sticky and wet soil with the support of TRIZ (Theory of Inventive Problem Solving). There are two major scheme adjustments, including self-cleaning seedbed collating device and split gauge wheel. The Su-field model of seedbed collating device is constructed, and the design scheme of smaller wavy coulter and dirt scraper is proposed on the basis of the standard-solution tool and water-film theory. And the parameters of the wave are determined on account of force analysis of soil particles and bionic earthworm. Based on the systemic-functional analysis of the seeding depth-limiting device and the force analysis of gauge wheel during operation, a split type of depth-gauge wheel with large lug hole is designed. As a result, the field trial demonstrates that the improved monomer could meet the operation requirements of clay soil with the water content of 15%-25%. Compared with the original model, the residual clay content is decreased (seedbed collating device 57.5%, gauge wheel seeding depth-limiting device 10%). This study can provide reference for the anti-adhesion design of soil-contacting parts of agricultural machinery.

Row spacing and phosphorus use efficiency in no-tillage maize

Reduced row spacing has shown to increase maize (Zea mays L.) nitrogen (N) use efficiency, but little is known about it effects on phosphorous (P) use efficiency (PUE). The objective of this study was to evaluate the PUE of maize under reduced row spacing and varying N regimes. No till maize was grown in Balcarce, Argentina, during two growing seasons using three rows spacing (35, 52, and 70 cm) and three N rates (0, 90, and 180 kg N ha−1). Shoot dry matter (DM), grain yield, and accumulated P content were determined. At V6 and R6 growth stages, the P use efficiency (PUE = g aboveground DM or grain yield per g P available) and it components P utilization efficiency (PUTE = g aboveground DM or grain yield per g P uptake), and P uptake efficiency (PUPE = g P uptake/g P available) were determined. N rate and narrower rows increased total DM, grain yield, and accumulated P content. Phosphorous concentration, PUTE, PUPE and PUE were not affected by row spacing or N rate. The present study showed that row spacing did not affect P use efficiency in no till maize when the soil P availability was adequate.

Effect of Different Rates and Time of Application of Phosphorus on Yield, Soil Fertility, Nutrient Uptake and Monetary Returns of No-till Maize (Zea mays L.) after Lowland Rice

Field experiment was conducted during dry seasons for 2 consecutive years at College of Agriculture, Rajendranagar, Hyderabad on no-till maize after lowland kharif rice on sandy clay loam soil. The experiment was laid out in randomized block design with factorial concept and replicated thrice. Treatments executed are three Phosphorus levels (30, 45 and 60 kg P2O5 ha-1) and three Phosphorus application times (at 10 days before harvest of rice, at the time of sowing of maize and at the time of first irrigation to maize). The results revealed that application of 60 kg P2O5 ha-1 recorded superior grain and stover yield, gross returns, net returns, benefit cost ratio and nutrient uptake (Nitrogen, Phosphorus and Potassium) at crop harvest over that of 45 and 30 kg P2O5 ha-1. But, application of 60 kg P2O5 ha-1 left behind the soil with lower amount of available Nitrogen and Potassium and higher Phosphorus status after harvest of the crop. Application of phosphorus at 10 days before harvest of rice and at the time of sowing of maize being on par resulted in better grain and stover yield of maize, gross returns, net returns, benefit cost ratio and nutrient uptake (Nitrogen, Phosphorus and Potassium) at crop harvest over its delayed application (at the time of first irrigation to maize). The application of Phosphorus at 10 days before harvest of rice or at the time of sowing of maize depleted greater amount of available Phosphorus from the soil than its application along with first irrigation.

Parameter Optimization and Experiment of a Seed Furrow Cleaning Device for No-Till Maize Seeding

To avoid the issues of seeds lying atop straw, where the seeds cannot germinate, during no-till maize seeding, a seed furrow cleaning device is proposed. The device uses rotating spring teeth and a curved sliding shovel to clear the straw from the seed furrow to the outside. The critical components of the side throwing mechanism, rotary disc and spring teeth design are analyzed, and the value range of the installation inclination angle, rotating speed and bending angle of spring teeth are determined. The force on the straw at the moment of starting to touch and throw it is analyzed theoretically in the three installation directions of forward inclination, radial and backward inclination on the rotary disc, and the backward inclination of the spring teeth is determined. A simulation model of the seed furrow cleaning device is established by using the discrete element method simulation software; the forwarding speed, rotating speed, installation inclination angle, and bending angle of spring teeth are used as influencing factors to carry out single-factor experiments. The influence characteristics of different parameters on seed ditch cleaning effect are analyzed from the aspects of straw cleaning quantity and soil disturbance. A field validation experiment is carried out, and the results show that when rotating speed is 180 r/min, installation inclination angle of spring teeth is 40°, and bending angle is 30°, the straw cleaning rate is 82.26%. The research could provide references to develop the no-till seeder for maize seeding.

User-Driven: A Product Innovation Design Method for a Digital Twin Combined with Flow Function Analysis

Since the lack of a specific design method, guidance and user participation in the product innovation design of digital twins, a product innovation design process of a user requirement-driven digital twin combined with flow function analysis is proposed based on the constructed innovation design model of the PPE-PVE-VVE-VPE digital twin. First, to obtain the orientation of the product innovation design, the user requirement knowledge graph is generated on the basis of product functional decomposition to intuitively express the mapping relationship between user requirements and product functional components. Then, composition analysis of the prototype physical entity (PPE) is conducted in the physical domain; flow function analysis identifies the prototype virtual entity (PVE) defects in the virtual domain; the vision virtual entity (VVE) is solved via flow evolution path as well as evaluated and selected from the users’ perspective to display simulation and rehearsal analysis. Finally, the vision physical entity (VPE) is constructed through the interaction and mapping of the VVE in the physical world, and users are involved in the operation of the VPE. The feasibility and effectiveness of the proposed method are verified by rede-signing a no-tillage maize seeding monomer.

The Ability of Nitrification Inhibitors to Decrease Denitrification Rates in an Arable Soil

A nitrification inhibitor is an effective tool that can be used to reduce the loss of nitrogen (N) and improve crop yields. Most studies have focused on the changes in the soil N mineralization process that may influence the dynamics of soil inorganic N and the soil N cycle. However, the effects of the inhibitors on denitrification rates remain largely unclarified. Therefore, in this study, we monitored the dynamics in annual denitrification rates affected by nitrification inhibitors from a maize field for the first time. Treatments included inorganic fertilizer (NPK), cattle manure, a combination of NPK and DMPP (3,4-dimethylpyrazole phosphate), and a combination of manure and DMPP, applied to brown soils in a no-tillage maize field. The findings demonstrated that the denitrification rate and denitrifying enzyme activity (DEA) were highly variable and there were no significant decreases in all treatment groups after the addition of DMPP. Compared to the control soils, the ammonium (NH4+-N) concentration was significantly increased, while the nitrate (NO3−-N) level was significantly decreased in the DMPP-amended soils less than 30 days after treatment application, indicating that nitrification was partially inhibited. The formation of NO3−-N and the nitrification rates could be markedly reduced by DMPP, while NO3−-N availability did not affect the denitrification rates. Complete degradation of DMPP was observed in the soil on day 70 after DMPP addition, and its half-life was 10 days. Our study may ultimately help to clarify the characteristics of denitrification rates affected by nitrification inhibitors from different N fertilizer types applied to soils and explore the influencing factors of the dynamics in annual denitrification rates. However, more field studies evaluating the effectiveness of nitrification inhibitors in reducing denitrification under different sites and climate conditions, and the molecular mechanisms driving denitrification rate changes, need to be performed in the future.

Mechanical and Biological Soil Decompaction for No-Tillage Maize Production

Soil structural quality in areas under a no-tillage system is altered after successive crops, where compaction is a recurrent problem. The objective of this study was to evaluate the effect of different forms of soil decompaction on maize grain production. A randomized split-plot block design with four replications was used, in a 5 × 3 × 2 factorial arrangement, consisting of five forms of mechanical soil decompaction: ripping to a depth of 0.3 m, ripping to a depth of 0.5 m, subsoiling to a depth of 0.3 m, and subsoiling to a depth of 0.5 m, and no-tillage; three crop seasons: 2014/2015, 2015/2016, and 2016/2017; and two cover crops: sunn hemp and pearl millet. The soil resistance to root penetration (RP, 0.0–0.40 m), density (0.0–0.40 m), moisture (0.0–0.40 m), fresh (FB), and dry (DB) above-ground biomass of cover crops, and maize yield were evaluated. The subsoiling to a depth of 0.3 or 0.5 m results in higher production of sunn hemp biomass but has no effect on millet. Mechanical and biological soil decompaction improved maize grain yield throughout the seasons by at least 28% above the average yield in the study area region. The RP of up to 3.3 MPa did not negatively affect cover crop biomass production and maize grain. The association between the mechanical and biological decompaction method using cover crops provided greater resilience to the preparation carried out up to three years after the application of the treatments, resulting in greater corn grain productivity.

Low soil carbon saturation deficit limits the abundance of cbbL-carrying bacteria under long-term no-tillage maize cultivation in northern China

The responses of cbbL-carrying bacteria to different levels of soil carbon saturation deficits (SCSD) under tillage managements are largely unknown. We assessed the influence of SCSD on the abundance and diversity of cbbL-carrying bacteria under long-term no-tillage with residue retention (NT) and conventional tillage without residue retention (CT) cultivation systems in maize. We found SCSD was smaller under NT than under CT in the 0–15 cm soil layer. The abundance and the Shannon diversity of cbbL-carrying bacteria in the NT treatment were lower than in the CT treatment. Soil carbon saturation and cbbL gene abundance showed a significant positive correlation, but there was no correlation between soil carbon saturation and cbbL gene diversity. However, the long-term NT practice decreased cbbL-carrying bacteria diversity and altered the community structure of the cbbL-carrying bacteria. Our results indicated that low SCSD limited the abundance of cbbL-carrying bacteria, but there was no relationship between low SCSD and diversity of cbbL-carrying bacteria. We suggest that further studies of cbbL-carrying bacteria carbon sequestration rates and capacity should be based on the effect of management practices on cbbL-carrying bacteria abundance and diversity. Our study has important implications for the relationship between the biological and physicochemical mechanisms in CO2 fixation.

Cover crops maintain or improve agronomic performances of maize monoculture during the transition period from conventional to no-tillage

Maize monoculture systems often cause environmental impacts such as soil erosion, nitrate leaching and pesticide transfer. Conservation tillage and the use of cover crops appear to hold promise for limiting these impacts, but questions about their performance remain, particularly during the transition period after conventional soil tillage ceases. In this study, effects of no-tillage maize and fallow-period management with different cover crop species, either pure or in mixtures, were studied on the agronomic performance of maize and on soil N and water dynamics. The study combined field experiments over three years (2012–2014) and simulation modelling with the STICS model. The biomass of cover crops produced during the fallow period varied from 0.8 to 10.5 t dry matter ha−1 depending on the cover crop species and date of termination. Differences in soil water content were quantified among the treatments studied, with the lowest water content at the beginning of the maize growing season with late termination of a cover crop composed of pure faba bean or a vetch-oat mixture in 2014 (25–50% of plant-water available capacity). Maize grain yields ranged from 8.5 to 13.6 t dry matter ha−1, with the lowest yields in the bare soil treatment. Simulations with STICS were consistent with the observations and indicated a decrease in drainage of 8–38 mm year−1, depending on the year and cover crop. Introducing cover crops into maize systems is a powerful mechanism for maintaining production while improving environmental performances during the transition phase of soil properties in conservation tillage.

Combing public-private partnership and large-scale farming increased net ecosystem carbon budget and reduced carbon footprint of maize production

Limited adoption of advanced technologies and land fragmentation limit the sustainable intensification of agriculture in developing countries. Here, we explore and establish an integrated management strategy by combining the public-private partnership (PPP) and large-scale farming (LSF) for more profitable and sustainable no-tillage maize production. A case study was conducted in the North China Plain to determine the applicability and the key drivers underpinning PPP-LSF success. On average, maize under PPP-LSF yielded 10.4 Mg ha−1, which was 11.8% and 19.4% greater than that of LSF and smallholder farming (SHF), respectively. Compared with LSF and SHF, the PPP-LSF achieved the highest energy use efficiency and the lowest negative environmental externalities. The carbon footprint of PPP-LSF was 267 kg CO2-eq Mg−1, which was 32.7% and 38.2% lower than that of LSF and SHF, respectively. A new causal factor analysis developed in this study revealed that the mechanised application of controlled-release formula fertilisers, eliminating top-dressing, was the main factor for low carbon footprint in PPP-LSF. The mean net ecosystem carbon budget (NECB), sustainability index, and net ecosystem economic benefit of PPP-LSF were 22.5 Mg C ha−1, 17.1 and 2040 $ ha−1, respectively, which were increased by 15.3% and 23.9%, 55.5% and 69.3%, and 28.7% and 50.3% compared with LSF and SHF. Higher net primary productivity related soil carbon sequestration potential and lower field carbon emissions were the main drivers of high NCEB of PPP-LSF. This real-world commercial crop production-based example illustrates the value and potential of PPP-LSF in utilising modern innovative farming technologies and management strategies to accelerate agricultural productivity and resources conservation with reduced environmental footprints.

Leaf and canopy stomatal resistance, aerodynamic resistance, and evapotranspiration of irrigated continuous no‐till and disk‐till maize

AbstractThe impact of no‐till (NT) management as compared with conventional tillage practices (e.g., disk till [DT]) on plant stomatal behavior in relation to model estimation of crop evapotranspiration (ETc) and plant physiological functions has not been sufficiently evaluated. This research investigated the effects of NT and DT management on maize (Zea mays L.) physiological parameters and ETc losses. We also tested the methodology to estimate ETc using a one‐step Penman–Monteith (PM) model with measured variable resistance from scaled‐up leaf stomatal resistance (RL) to canopy resistance (RC) with Bowen Ratio Energy Balance System (BREBS)‐measured ETc. Photosynthetic photon flux density (PPFD) explained 76 and 79% of the variability in RL for NT and DT maize, respectively, which varied with growth stage. Disk‐till maize RL was 29, 5, 25, and 4% higher than NT maize RL during the vegetative, tasseling and silking, reproductive, and near‐physiological‐maturity stages, respectively. The seasonal average scaled‐up RC values for NT and DT maize were 102.4 and 128.6 s m–1, respectively. The PM‐estimated ETc correlated strongly with the BREBS‐measured ETc, with the PM model estimates being 8 and 6% within the BREBS measurements on an hourly and daily basis, respectively. To the best of our knowledge, this research is the first to develop the response curves (PPFD vs. RL) for maize for different growth stages under NT and DT. The analyses presented here can provide invaluable data and information for plant physiology research, crop modeling, determining crop response to different management, and environmental drivers.

水氮减量对地膜玉米免耕轮作小麦主要光合生理参数的影响

<p id="C3">The effect of no-tillage combined with water and nitrogen reduction of mulching maize on the stability and increase of wheat yield has been verified, but the research of the photosynthetic physiological mechanism of its formation is still relatively weak. From 2018 to 2020, the split zone design was adopted, and two farming methods of film-mulched corn no-tillage (NT) and traditional tillage (CT) was arranged with two irrigation levels of traditional irrigation (I₂, 2400 m ³ hm ^‒2) and traditional irrigation reduce 20% (I₁, 1920 m ³ hm ^‒2) and three nitrogen application levels of 225 kg hm ^‒2 (N₃), 180 kg hm ^‒2 (N₂) and 135 kg hm ^‒2 (N₁). The results showed that farming measures and nitrogen application level had significant effects on wheat leaf area index, photosynthetic potential, SPAD value, and photosynthetic rate; irrigation level had significant effects on photosynthetic rate. During the whole growth periods, compared with CT, NT increased wheat leaf area index, photosynthetic potential, SPAD value, and photosynthetic rate by 14.5%-44.1%, 13.2%-16.3%, 7.4%-9.0%, and 14.5%-24.2%, respectively; Compared with I₂, the photosynthetic rate of wheat I₁ decreased by 6.5%-13.6%. Compared with N₃, the leaf area index, photosynthetic potential, SPAD value, and photosynthetic rate of N₁ decreased by 6.4%-13.6%, 7.5%-12.7%, 6.0%-10.2%, and 7.5%-17.5%, respectively. There was no significant difference between N₂ and N₃. Cultivation measures, nitrogen application level, and irrigation level all had significant effects on dry matter accumulation and grain yield in wheat. Compared with CT, NT increased by 13.4%-16.5% and 9.0%-13.4%; Compared with I₂, I₁ decreased by 6.5%-6.7% and 4.3%-7.4%; Compared with N₃, the dry matter accumulation and grain yield of N₁ decreased by 10.0%-11.9% and 12.6%-19.4%, respectively, and there was no significant difference between N₂ and N₃. Correlation matrix analysis showed that the combined water and nitrogen reduction of no-tillage maize mulching could delay the decrease of wheat SPAD value, prolonged the photosynthetic time, and increased the photosynthetic potential and photosynthetic rate of wheat to increase yield.

Agricultural Greenhouse Gas Fluxes Under Different Cover Crop Systems

Cultivated lands that support high productivity have the potential to produce a large amount of GHG emissions, including carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). Intensive land management practices can stimulate CO2, N2O, and CH4 emissions from the soil. Cover crop establishment is considered as one of the sustainable land management strategies under warm and humid environmental conditions. To better understand how the incorporation of cover crops affect three major GHGs, we compared trace gas fluxes in a no-till maize field over the whole growing season in 2018 in a no cover crop (Tr) system and three cover crop systems: crimson clover (CC), cereal rye (CR), and living mulch (LM) using white clover. In 2019, we further explored potential differences in the three GHGs between in-row (IR) and between-row (BWR) of maize for LM and Tr systems during the early growing season. Measurements were taken using a cavity ring-down spectroscopy gas analyzer in Watkinsville, GA. In 2018, the highest CO2 flux (7.00 μmol m−2 s−1) was observed from BWR of maize for LM. The maximum N2O flux observed in LM on June 20th in 2018 was when soil N increase rate was the largest. Soils served as sinks for CH4 and Tr system served as the smallest CH4 sink compared to the other three cover crop systems. For N2O, the highest fluxes were observed from the TrIR plot (4.13 μmol m−2 hr−1) in 2019 with the greatest N inputs. In 2019, we observed a smaller CH4 sink in TrIR (−0.13 μmol m−2 hr−1) compared to TrBWR (−0.67 μmol m−2 hr−1) due potentially to greater NH4+ inhibition effects on CH4 consumption from greater N fertilizer inputs. The net carbon equivalent (CE) from May 23rd to Aug 16th in 2018, taking into account the three GHG fluxes, soil carbon content, and fertilizer, irrigation, and herbicide application, were 32–97, 35–101, 63–139, and 40–106 kg ha−1 yr−1 for CC, CR, LM, and Tr, respectively. LM had the lowest net CE after removing white clover respiration (−16–60 kg ha−1 yr−1). Our results show that implementing different types of cover crop systems and especially the LM system have some potential to mitigate climate change.

Design and experiment of seed furrow cleaning device based on throwing and sliding for no-till maize seeding

In order to solve the serious problems of seeds are covered by residual film and overhead by straw during no-till seeding, a seed furrow cleaning device for no-till maize seeding was developed, which adopted a collaborative cleaning method of rotating spring teeth and curved sliding shovel. The movement process and motion trajectory of throwing residual film and straw were constructed. The maximum distance of throwing to one side in horizontal and maximum height in vertical were obtained. The motion trajectory of adjacent spring teeth was analyzed by Matlab, the motion trajectories of adjacent spring teeth at different speeds of 120 r/min, 150 r/min and 180 r/min were achieved, the theoretical analysis results showed that the area of omitted area decreased with the increase of rotation speed. Based on theoretical and simulation analysis of critical parameters, the forward speed of machine, rotation speed of spring teeth, and dip angle between spring teeth and rotary disc were selected as the influencing factor. Straw cleaning rate (SCR) and residual film cleaning rate (RFCR) were selected as the response values for three factors and three levels of orthogonal experiment design. The optimal combination of the selected parameters was obtained, and the field test verification was also conducted. The results showed that the rotation speed of spring teeth, forward speed and dip angle of spring teeth significantly affect SCR and RFCR were in decreasing order. The field test results indicated that when forward speed was 6 km/h, rotation speed of spring teeth was 180 r/min and dip angle of spring teeth was 40°, SCR and RFCR were 88.27% and 84.31%, respectively. This study provides a reference for the development of no-till seeder in Xinjiang and the northwestern regions of China. Keywords: maize, conservation tillage, no-till seeding, seed furrow cleaning, straw, residual film DOI: 10.25165/j.ijabe.20221504.7097 Citation: Yuan P P, Li H W, Lu C Y, Wang Q J, He J, Huang S H, et al. Design and experiment of seed furrow cleaning device based on throwing and sliding for no-till maize seeding. Int J Agric & Biol Eng, 2022; 15(4): 95–102.

Weed Dynamics In No-Till Maize System And Its Management: A Review

Among different factors, tillage and weed management are two important factors that influence remarkably the growth and yield of maize. The present review reveals that Echinochloa colona L. is the most dominant weed species with an importance value index (IVI) of 41 followed by Papaver rhoeas L. (32.6), Descurainia Sophia L. (22.27) and Polygonum aviculare L (16.16) in no-till maize. Wider spacing and initial slow growth of maize during the first 3-4 weeks provides enough opportunity for weeds to invade and offer severe competition, resulting in 60-81% in maize yield losses. The shift of the weed population towards perennial was observed under NT. Species like Xanthium strumarium, Solanum nigrum, Euphorbia helioscopia, Convolvulus arvensis, Sorghum halepense, Digitaria sanguinalis, Sonchus oleraceus and Euphorbia vermiculata were associated with no-till Zea mays. The highest weed seed density was found in conservation agriculture practices (no-tillage, no-fertilizer and no-herbicide use) with the highest seed distributed in 0-1 cm depth followed by 1-3 cm depth. Weed control efficiency of Nicosulfuron @0.90 kg/ha was found the highest (98.8%) followed by Atrazine + Tembotrione + Atrazine (@1 kg/ha + 120 g/ha + 0.5 kg/ha) (98.7%) and Tembotrione + atrazine (@ 120 g/ha + 0.5 kg/ha) (96.5%), therefore were very effective in controlling weed in no-till Zea mays.